Beam fault recovery technique

文档序号：441122 发布日期：2021-12-24 浏览：15次中文

阅读说明：本技术 波束故障恢复技术 (Beam fault recovery technique ) 是由周彦 T.罗 S.阿卡拉卡兰张晓霞于 2020-04-28 设计创作，主要内容包括：描述了用于无线通信的方法、系统和设备。无线设备可以标识用于无线通信的资源,该资源处于第一状态,在该第一状态中,该资源对于无线通信是活动的而对于通信故障恢复过程是不活动的。无线设备可以确定在第一通信周期期间已经发生了通信故障。在一些情况下,可以使用用于确认通信故障的一种或多种技术来验证故障。无线设备可以在第二通信周期期间并且至少部分地基于通信故障将资源转变到第二状态,在该第二状态中,该资源对于无线通信是不活动的而对于通信故障恢复过程是活动的。无线设备可以使用转变为第二状态的资源来执行通信故障恢复过程。(Methods, systems, and devices for wireless communication are described. The wireless device may identify a resource for wireless communication, the resource being in a first state in which the resource is active for wireless communication and inactive for a communication failure recovery procedure. The wireless device may determine that a communication failure has occurred during the first communication period. In some cases, the failure may be verified using one or more techniques for confirming a communication failure. The wireless device may transition the resource to a second state during a second communication period and based at least in part on the communication failure, in which the resource is inactive for wireless communication and active for a communication failure recovery procedure. The wireless device may perform a communication failure recovery procedure using the resources that transitioned to the second state.)

1. A method for wireless communications at a first wireless device, comprising:

Establishing a wireless connection with a second wireless device via a first beam pair link;

initiating a beam failure recovery procedure during a second communication period based at least in part on a communication failure with the second wireless device during a first communication period;

communicating with the second wireless device using a second beam pair link during the second communication period;

establishing an updated first beam pair link based at least in part on the beam failure recovery procedure; and

resuming communication with the link using the updated first beam after the second communication period.

2. The method of claim 1, wherein the second beam pair link uses a different Transmit Receive Point (TRP) than the first beam pair link, and wherein the different TRP and the second beam pair link are preconfigured prior to the first communication period.

3. The method of claim 1, further comprising:

transmitting a redundant communication to the second wireless device using the first beam-pair link during the second communication period.

4. The method of claim 1, further comprising:

releasing resources associated with the second beam pair link in response to establishing the updated first beam pair link.

5. A method for wireless communications at a wireless device, comprising:

identifying a first wireless resource for an on-demand beam failure recovery process and a periodic wireless resource configured for other beam failure recovery processes;

determining that a communication failure has occurred during a first communication period;

determining that a second communication period includes the periodic wireless resource;

selecting one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based at least in part on the communication failure and the second communication period comprising the periodic radio resource; and

performing the on-demand beam failure recovery procedure using the selected radio resource.

6. The method of claim 5, wherein the selecting comprises:

identifying that the periodic radio resource is prioritized over the first radio resource in the second communication period; and

selecting the periodic wireless resource for performing the on-demand beam failure recovery procedure.

7. The method of claim 6, wherein the priority of the first radio resource and the periodic radio resource is based at least in part on a latency target of communications during the first communication period.

8. The method of claim 5, wherein the selecting comprises:

determining that communications during the first communication period are low latency communications; and

selecting the first radio resource for performing the on-demand beam failure recovery procedure based at least in part on the communication during the first communication period being a low latency communication.

9. The method of claim 5, wherein the selecting comprises:

selecting the periodic wireless resource for performing the on-demand beam failure recovery procedure based at least in part on a timing of the periodic wireless resource being within a time threshold of the first wireless resource.

10. A method for wireless communications at a wireless device, comprising:

configuring a radio resource for a beam failure recovery procedure;

determining an initial fault state for a first communication cycle based at least in part on a failure to receive acknowledgement feedback for communication in the first communication cycle;

confirming a communication failure for the first communication cycle based at least in part on the redundant indication of confirmation feedback; and

performing the beam failure recovery procedure using the radio resource.

11. The method of claim 10, wherein the method is performed at a User Equipment (UE), and wherein confirming the communication failure comprises:

monitoring a downlink portion of the radio resource for one or more reference signal transmissions via one or more candidate beams to be selected by the UE;

determining that the one or more reference signal transmissions are present on the downlink portion of the wireless resource;

selecting a first candidate beam based at least in part on the measurements of the one or more reference signal transmissions; and

transmitting a beam failure request indicating the first candidate beam on an uplink portion of the radio resource.

12. The method of claim 11, wherein the one or more reference signal transmissions are identified based at least in part on a scrambling sequence used to scramble the one or more reference signal transmissions.

13. The method of claim 11, further comprising:

for a subsequent communication cycle, determining the initial fault state for the subsequent communication cycle;

monitoring the downlink portion of the wireless resources associated with the subsequent communication period for the one or more reference signal transmissions;

Determining that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication period; and

interrupting the beam failure recovery process based at least in part on determining that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication cycle.

14. The method of claim 10, wherein the method is performed by a base station, and wherein confirming the communication failure comprises:

transmitting an indication to a User Equipment (UE) in a downlink transmission that the beam failure recovery procedure is activated; and

receiving a response from the UE to the indication that the beam failure recovery procedure is activated.

15. The method of claim 14, wherein the response from the UE indicates acceptance to activate the beam failure recovery procedure, and wherein the base station performs the beam failure recovery procedure based at least in part on the acceptance.

16. The method of claim 14, wherein the response from the UE indicates that the UE rejects activation of the beam failure recovery procedure and indicates successful communication during the first communication period, and wherein the base station interrupts the beam failure recovery procedure based at least in part on the response from the UE.

17. The method of claim 10, wherein the method is performed by a User Equipment (UE), and wherein confirming the communication failure comprises:

receiving an indication that the beam failure recovery procedure is activated in a downlink transmission from a base station; and

sending a response to the indication that the beam failure recovery procedure is activated to the base station.

18. The method of claim 17, wherein the response to the base station indicates acceptance of activation of the beam failure recovery procedure, and wherein the UE performs the beam failure recovery procedure based at least in part on the acceptance.

19. The method of claim 10, wherein the method is performed by a User Equipment (UE), and wherein confirming the communication failure comprises:

transmitting a request to a base station for activation of the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

20. The method of claim 10, wherein the method is performed by a base station, and wherein confirming the communication failure comprises:

receiving a request from a User Equipment (UE) to activate the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

21. The method of claim 10, wherein the method is performed by a User Equipment (UE), and wherein confirming the communication failure comprises:

polling a base station that is to receive uplink communications from the UE during a preceding communication period to determine whether the acknowledgement feedback is sent by the base station;

receiving a response from the base station indicating whether the acknowledgement feedback was sent by the base station; and

continuing or interrupting the beam failure recovery process based at least in part on the response from the base station.

22. The method of claim 21, wherein the uplink communication from the UE during the preceding communication period is identified based at least in part on a sequence number of the uplink communication, an index of a resource allocation of the uplink communication, or any combination thereof.

23. The method of claim 10, wherein the method is performed by a base station, and wherein confirming the communication failure comprises:

polling a User Equipment (UE) to receive downlink communications from the base station during a preceding communication period to determine whether the acknowledgement feedback is sent by the UE;

receiving, from the UE, a response indicating whether the acknowledgement feedback was sent by the UE; and

Continuing or interrupting the beam failure recovery procedure based at least in part on the response from the UE.

24. The method of claim 23, wherein the downlink communication from the base station during the preceding communication period is identified based at least in part on a sequence number of the downlink communication, an index of a resource allocation of the downlink communication, or any combination thereof.

25. The method of claim 10, wherein confirming the communication failure comprises:

determining that a packet transmitted during the first communication period is a retransmission of a previous transmission of the packet and that the previous acknowledgement feedback was previously transmitted for the packet; and

sending an indication of the prior acknowledgement feedback.

26. The method of claim 25, wherein the prior transmission of the packet comprises an activation indication, and wherein an activation time is determined based on a transmission time of the prior acknowledgement feedback.

27. A method for wireless communications at a wireless device, comprising:

configuring a radio resource for a beam failure recovery procedure, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery procedure and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery procedure;

Determining that a communication failure has occurred during a first communication period;

transitioning the wireless resource from the first state to the second state during a second communication period and based at least in part on the communication failure; and

performing the beam failure recovery procedure using the wireless resource transitioned to the second state.

28. The method of claim 27, wherein the configuring comprises:

exchanging Radio Resource Control (RRC) messages indicating the radio resources configured for the beam failure recovery procedure.

29. The method of claim 27, wherein the radio resources comprise a first downlink resource for transmitting one or more reference signals using one or more beams by a first transmit-receive point and a first uplink resource for transmitting a beam failure request by a User Equipment (UE).

30. The method of claim 29, wherein the first downlink resource is a common resource for transmitting the one or more reference signals to a plurality of UEs, and the first uplink resource is a UE-specific resource separately configured for each of the plurality of UEs.

Background

The following relates to wireless communications, and more particularly to management of communication failures in beamformed wireless transmissions.

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be able to support communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems, such as Long Term Evolution (LTE) systems, LTE-advanced (LTE-a) systems, or LTE-a Pro systems, and fifth generation (5G) systems that may be referred to as New Radio (NR) systems. These systems may employ techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communication system may include multiple base stations or network access nodes, each supporting communication for multiple communication devices, which may alternatively be referred to as User Equipment (UE), simultaneously.

Disclosure of Invention

A method of wireless communication at a wireless device is described. The method may include configuring radio resources for a beam failure recovery process. The radio resource may be configured to have a first state. The first state of the radio resource may be active for data communications and inactive for a beam failure recovery procedure. The radio resource may also be configured to have a second state. The second state radio resource may be inactive for data communications and active for beam failure recovery procedures. The method may determine that a communication failure has occurred within a first communication period. The method may also include transitioning the wireless resource from the first state to the second state during the second communication period and based on the communication failure. In addition, the method may include performing the beam failure recovery procedure using the radio resource transitioned to the second state.

An apparatus for wireless communication at a wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor and memory may be configured to configure radio resources for a beam failure recovery process. The radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for a beam failure recovery procedure. The radio resource is further configured to have a second state in which the radio resource is inactive for data communications and active for a beam failure recovery procedure. The processor and the memory may be configured to determine that a communication failure has occurred within a first communication cycle. The processor and the memory may be further configured to transition the wireless resource from the first state to the second state during the second communication period and based on the communication failure. The processor and memory may be configured to perform the beam failure recovery procedure using the radio resource transitioned to the second state.

Another apparatus for wireless communication at a wireless device is described. The apparatus may include means for: configuring a radio resource for a beam failure recovery process, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery process and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery process; determining that a communication failure has occurred within a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based on the communication failure; and performing the beam failure recovery procedure using the radio resource transitioned to the second state.

A non-transitory computer-readable medium storing code for wireless communication at a wireless device is described. The code may include instructions executable by a processor to: configuring a radio resource for a beam failure recovery process, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery process and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery process; determining that a communication failure has occurred within a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based on the communication failure; and performing the beam failure recovery procedure using the radio resource transitioned to the second state.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration may include operations, features, components, or instructions to: exchanging an RRC message indicating radio resources configurable for the beam failure recovery procedure.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the wireless resources include a first downlink resource for transmitting, by the first transmit-receive point, one or more reference signals using one or more beams, and a first uplink resource for transmitting, by the UE, a beam failure request.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first downlink resource may be a common resource for transmitting the one or more reference signals to a group of UEs, and the first uplink resource may be a UE-specific resource separately configured for each of the group of UEs.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first uplink resources comprise one or more of physical uplink control channel resources, physical random access channel resources, or a combination thereof.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first uplink resources comprise one or more of UE-specific time resources, frequency resources, spatial resources, code domain resources, or a combination thereof.

A method of wireless communication at a wireless device is described. The method may include identifying a first radio resource for an on-demand beam failure recovery procedure and a periodic radio resource configured for other beam failure recovery procedures. The method may also determine that a communication failure has occurred within the first communication period, and determine that the second communication period includes the periodic wireless resource. The method may also include selecting one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based on the communication failure and the second communication cycle including the periodic radio resource. Additionally, the method may include performing the on-demand beam failure recovery procedure using the selected radio resource.

An apparatus for wireless communication at a wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor and memory may be configured to identify a first radio resource for an on-demand beam failure recovery procedure and a periodic radio resource configured for other beam failure recovery procedures. The processor and the memory may be configured to determine that a communication failure has occurred within a first communication cycle. Additionally, the processor and memory may be configured to determine that the second communication period includes the periodic radio resource. The processor and memory may be further configured to select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based on the communication failure and the second communication period including the periodic radio resource. The processor and memory may also be configured to perform the on-demand beam failure recovery procedure using the selected radio resource.

Another apparatus for wireless communication at a wireless device is described. The apparatus may include means for: identifying a first wireless resource for an on-demand beam failure recovery process and a periodic wireless resource configured for other beam failure recovery processes; determining that a communication failure has occurred within a first communication period; determining that the second communication period includes the periodic radio resource; based on the communication failure and the second communication cycle including the periodic radio resource, selecting one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure; and performing the on-demand beam failure recovery procedure using the selected radio resource.

A non-transitory computer-readable medium storing code for wireless communication at a wireless device is described. The code may include instructions executable by the processor to: identifying a first wireless resource for an on-demand beam failure recovery process and a periodic wireless resource configured for other beam failure recovery processes; determining that a communication failure has occurred within a first communication period; determining that the second communication period includes the periodic radio resource; based on the communication failure and the second communication cycle including the periodic radio resource, selecting one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure; and performing the on-demand beam failure recovery procedure using the selected radio resource.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the selection may include operations, features, components, or instructions to: identifying that the periodic radio resource may be prioritized over the first radio resource in the second communication period; and selecting the periodic radio resource for performing the on-demand beam failure recovery procedure.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the priority of the first wireless resource and the periodic wireless resource may be based on a communication latency target during the first communication period.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the selection may include operations, features, components, or instructions to: determining that the communication within the first communication period may be a low latency communication; and selecting the first radio resource for performing the on-demand beam failure recovery procedure based on the communication during the first communication period being a low latency communication.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the selection may include operations, features, components, or instructions to: selecting the periodic wireless resource for performing the on-demand beam failure recovery procedure based on the timing of the periodic wireless resource being within a time threshold of the first wireless resource.

A method of wireless communication at a wireless device is described. The method may include determining that the uplink communication has an uplink payload at or below a threshold payload size. Uplink communications with payload sizes above the threshold payload size may have a Cyclic Redundancy Check (CRC) appended to the uplink payload. Uplink communications having payload sizes at or below the threshold payload size may be sent without the CRC appended to the uplink payload. The method may also include configuring the uplink communication to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size. Additionally, the method may include processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

An apparatus for wireless communication at a wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor and memory are configured to determine that the uplink communication has an uplink payload at or below a threshold payload size. Uplink communications having a payload size above the threshold payload size will have a CRC appended to the uplink payload, while uplink communications having a payload size at or below the threshold payload size will be sent without a CRC appended to the uplink payload. The processor and memory are configured to configure uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size. The processor and memory are further configured to process the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

Another apparatus for wireless communication at a wireless device is described. The apparatus may include means for: determining that an uplink communication has an uplink payload at or below a threshold payload size, wherein the uplink communication having a payload size above the threshold payload size will have a CRC appended to the uplink payload and the uplink communication having a payload size at or below the threshold payload size will be transmitted without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

A non-transitory computer-readable medium storing code for wireless communication at a wireless device is described. The code may include instructions executable by a processor to: determining that an uplink communication has an uplink payload at or below a threshold payload size, wherein the uplink communication having a payload size above the threshold payload size will have a CRC appended to the uplink payload and the uplink communication having a payload size at or below the threshold payload size will be transmitted without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration may include operations, features, components, or instructions to: the acknowledgement feedback is formatted for transmission using uplink shared channel data, and/or wherein the acknowledgement feedback and the uplink shared channel data share the same CRC.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the acknowledgement feedback is sent with the uplink shared channel data in a Medium Access Control (MAC) control element.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the acknowledgement feedback may be a one-bit indication of receipt of motion control data and may be transmitted with the uplink shared channel data.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration may include operations, features, components, or instructions to: the acknowledgement feedback is configured to exceed the threshold payload size.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the acknowledgement feedback may be padded with one or more bits so as to have a payload size that exceeds the threshold payload size.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the acknowledgement feedback may be encoded to have a payload size that is greater than the threshold payload size.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the acknowledgement feedback may be repeated one or more times to provide a payload size that exceeds the threshold payload size.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the configuration may include operations, features, components, or instructions to: providing feedback on the acknowledgement may include the CRC regardless of a dynamic indication of the uplink payload size.

A method of wireless communication at a wireless device is described. The method may include configuring radio resources for a beam failure recovery procedure. The method may also include determining an initial fault state for the first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle. The method may also include acknowledging a communication failure of the first communication cycle based on the redundant indication of the acknowledgment feedback. In addition, the method may include performing the beam failure recovery procedure using the radio resource.

Another apparatus for wireless communication at a wireless device is described. The apparatus may include means for: configuring a radio resource for a beam failure recovery procedure; determining an initial fault state for a first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle; confirming a communication failure of the first communication cycle based on the redundant indication fed back for the confirmation; and performing the beam failure recovery procedure using the radio resource.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed at a UE, and wherein the confirming the communication failure may comprise operations, features, means, or instructions for: monitoring a downlink portion of the radio resource for one or more reference signal transmissions via one or more candidate beams to be selected by the UE; determining that the one or more reference signal transmissions may be present on a downlink portion of the radio resource; selecting a first candidate beam based on measurements of the one or more reference signal transmissions; and transmitting a beam failure request indicating the first candidate beam on an uplink portion of the radio resource.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the one or more reference signal transmissions may be identified based on a scrambling sequence used to scramble the one or more reference signal transmissions.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions to: for a subsequent communication cycle, determining an initial fault state for the subsequent communication cycle; monitoring a downlink portion of radio resources associated with a subsequent communication period for the one or more reference signal transmissions; determining that the one or more reference signal transmissions may not be present on a downlink portion of the radio resource associated with the subsequent communication period; and interrupting the beam failure recovery process based on the determination that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication period.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a base station, and wherein the confirming the communication failure may comprise operations, features, components, or instructions to: transmitting an indication to the UE in a downlink transmission that the beam failure recovery procedure may be activated; and receiving a response from the UE to the indication that the beam failure recovery procedure may be activated.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the response from the UE indicates that the beam failure recovery process is activated for the access, and wherein the base station performs the beam failure recovery process based at least in part on the acceptance.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the response from the UE indicates that the UE refuses to activate the beam failure recovery procedure and indicates successful communication during the first communication period, and wherein the base station discontinues the beam failure recovery procedure based on the response from the UE.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a UE, and wherein the confirming the communication failure may comprise operations, features, means, or instructions for: receiving an indication that the beam failure recovery procedure may be activated in a downlink transmission from a base station, and transmitting a response to the base station indicating that the beam failure recovery procedure may be activated.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the response to the base station indicates that the beam failure recovery process is activated, and wherein the UE performs the beam failure recovery process based on the acceptance.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the response to the base station indicates that the UE refuses to activate the beam failure recovery procedure and indicates successful communication during the first communication period, and wherein the UE discontinues the beam failure recovery procedure based on the response to the base station.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a UE, and wherein the confirming the communication failure may comprise operations, features, means, or instructions for: transmitting a request to a base station to activate the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a base station, and wherein the confirming the communication failure may comprise operations, features, components, or instructions to: receiving a request from a UE to activate the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a UE, and wherein the confirming the communication failure may comprise operations, features, means, or instructions for: polling a base station that receives uplink communications from the UE during a previous communication period to determine whether the acknowledgement feedback was sent by the base station; receiving a response from the base station indicating whether the acknowledgment feedback was sent by the base station; and continuing or interrupting the beam failure recovery process based on the response from the base station.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the uplink communication from the UE during the preceding communication period may be identified based on a sequence number of the uplink communication, an index of a resource allocation of the uplink communication, or any combination thereof.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the polling may be sent in an uplink communication carrying uplink control information or data traffic.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the poll is transmitted using a different beam or a different transmit-receive point (TRP) than the original transmission used for the uplink communication.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the response from the base station indicates that the acknowledgement feedback was previously sent and indicates a time of initial transmission of the acknowledgement feedback.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the uplink communication includes an activation indication, and wherein the activation time may be determined based on a time of an initial transmission of the acknowledgement feedback.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the method may be performed by a base station, and wherein the confirming the communication failure may comprise operations, features, components, or instructions to: polling a UE that receives downlink communications from the base station during a previous communication period to determine whether the acknowledgement feedback is sent by the UE; receiving a response from the UE indicating whether the acknowledgement feedback was sent by the UE; and continuing or interrupting the beam failure recovery procedure based on the response from the UE.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the downlink communication from the base station during the preceding communication period may be identified based on a sequence number of the downlink communication, an index of a resource allocation of the downlink communication, or any combination thereof.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the poll may be sent in a downlink communication carrying downlink control information or data traffic.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the poll is transmitted using a different beam or a different TRP than the original transmission used for the downlink communication.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the response from the UE indicates that the acknowledgement feedback was previously sent and indicates a time of initial transmission of the acknowledgement feedback;

in some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the downlink communication includes an activation indication, and wherein the activation time may be determined based on a time of an initial transmission of the acknowledgement feedback.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, confirming the communication failure may include operations, features, components, or instructions for: determining that a packet transmitted during the first communication period may be a retransmission of a previous transmission of the packet and that the previous acknowledgement feedback was previously transmitted for the packet; and sending an indication of the prior acknowledgement feedback.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the prior transmission of the packet includes an activation indication, and wherein the activation time may be determined based on a transmission time of the prior acknowledgement feedback.

A method of wireless communication at a wireless device is described. The method may include identifying a radio resource for a beam failure recovery procedure. The determination to initiate the beam failure recovery procedure may be based on acknowledgement feedback of communications in the first communication period. The method may also include determining that the first communication period has no data to transmit. The method may also include transmitting an indication that no data is to be transmitted for the first communication period. Additionally, the method may include inferring that acknowledgement feedback associated with the first communication period indicates successful communication for the purpose of initiating the beam failure recovery procedure.

An apparatus for wireless communication at a wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor and memory may be configured to identify a wireless resource for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period. The processor and memory may be configured to determine that the first communication cycle has no data to transmit. The processor and memory may also be configured to transmit an indication that no data is to be transmitted for the first communication cycle. The processor and memory may be configured to infer that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

Another apparatus for wireless communication at a wireless device is described. The apparatus may include means for: identifying wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period; determining that the first communication period has no data to transmit; transmitting an indication that no data is to be transmitted for the first communication period; and speculating that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

A non-transitory computer-readable medium storing code for wireless communication at a wireless device is described. The code may include instructions executable by a processor to: identifying wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period; determining that the first communication period has no data to transmit; transmitting an indication that no data is to be transmitted for the first communication period; and speculating that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the indication that the first communication period may have no data to send may be a physical or bit sequence.

A method of wireless communication at a first wireless device is described. The method may include establishing a wireless connection with a second wireless device via a first beam pair link. The method may also include receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam sweep pattern that uses one or more beams. The method may also include receiving the first transmission from the second wireless device in the first communication period according to the first beam sweep pattern. Additionally, the method may include transmitting a response transmission to the second wireless device based on the first transmission. The response transmission may be transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

An apparatus for wireless communication at a first wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor memory may be configured to establish a wireless connection with a second wireless device via a first beam pair link. The processor and memory may be configured to receive, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam sweep pattern that uses one or more beams. The processor and memory may be further configured to receive the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern, and to transmit a response transmission to the second wireless device based on the first transmission. The response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

Another apparatus for wireless communication at a first wireless device is described. The apparatus may include means for: establishing a wireless connection with a second wireless device via a first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

A non-transitory computer-readable medium storing code for wireless communication at a first wireless device is described. The code may include instructions executable by a processor to: establishing a wireless connection with a second wireless device via a first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first transmission may be a downlink transmission including downlink shared channel information, downlink control channel information, or a combination thereof, and the response transmission may be an uplink transmission including uplink shared channel information, uplink control channel information, or a combination thereof.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first beam scanning pattern comprises a set of downlink beams and the second beam scanning pattern comprises a set of uplink beams having beams reciprocal to the set of downlink beams.

A method of wireless communication at a first wireless device is described. The method may include establishing a wireless connection with a second wireless device via a first beam pair link. The method may also include initiating a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period. The method may also include communicating with the second wireless device using a second beam pair link during the second communication period. The method may also include establishing an updated first beam pair link based on the beam failure recovery procedure. Additionally, the method may include resuming communication with the link using the updated first beam after the second communication period.

An apparatus for wireless communication at a first wireless device is described. The apparatus may include a processor and a memory coupled to the processor. The processor and memory may be configured to establish a wireless connection with a second wireless device via a first beam pair link. The processor and memory may be configured to initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period. The processor and memory may be configured to communicate with the second wireless device using a second beam pair link during the second communication period. The processor memory may be configured to establish an updated first beam pair link based on the beam failure recovery procedure. The processor and memory may be further configured to resume communication with the link using the updated first beam after the second communication period.

Another apparatus for wireless communication at a first wireless device is described. The apparatus may include means for: establishing a wireless connection with a second wireless device via a first beam pair link; initiating a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period; communicating with the second wireless device using a second beam pair link during the second communication period; establishing an updated first beam pair link based on the beam failure recovery process; and resuming communication to the link using the updated first beam after the second communication period.

A non-transitory computer-readable medium storing code for wireless communication at a first wireless device is described. The code may include instructions executable by a processor to: establishing a wireless connection with a second wireless device via a first beam pair link; initiating a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period; communicating with the second wireless device using a second beam pair link during the second communication period; establishing an updated first beam pair link based on the beam failure recovery process; and resuming communication to the link using the updated first beam after the second communication period.

In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the second beam pair link uses a different TRP than the first beam pair link, and wherein the different TRP and the second beam pair link may be preconfigured prior to the first communication period.

Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions to: transmitting a redundant communication to the second wireless device using the first beam-pair link during the second communication period.

Drawings

Fig. 1 illustrates an example of a wireless communication system that supports beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 2A-2C illustrate examples of wireless communication systems that support beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 3 illustrates an example of a beam failure recovery configuration supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 4 illustrates an example of a beam failure recovery configuration supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 5 illustrates an example of a process flow to support a beam failure recovery technique in accordance with one or more aspects of the present disclosure.

Fig. 6 illustrates an example of a process flow to support a beam failure recovery technique in accordance with one or more aspects of the present disclosure.

Fig. 7 and 8 illustrate block diagrams of devices that support beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 9 illustrates a block diagram of a communication manager supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Fig. 10 illustrates a diagram of a system including a user equipment supporting beam failure recovery techniques in accordance with one or more aspects of the disclosure.

Fig. 11 illustrates a diagram of a system including a base station supporting beam failure recovery techniques in accordance with one or more aspects of the disclosure.

Fig. 12-18 show flow diagrams illustrating methods of supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure.

Detailed Description

Wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28GHz, 40GHz, 60GHz, etc.). Wireless communications at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors such as temperature, atmospheric pressure, diffraction, and the like. As a result, signal processing techniques such as beamforming can be used to coherently combine the energy and overcome the path loss at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from base stations and/or UEs may be beamformed. Further, the receiving device may use beamforming techniques to configure the antennas and/or antenna arrays such that transmissions are received in a directional manner. In some cases, the device may select an active beam for communicating with the network by selecting a strongest beam from a plurality of candidate beams.

In some aspects, wireless communication systems (such as those operating in mmW frequency ranges) may experience communication loss due to beam failure events and/or radio link failure events. For example, a current transmit/receive Beam Pair Link (BPL) for a UE and/or base station may become unavailable or useless due to UE mobility, congestion, etc. When this occurs, a communication failure recovery procedure may be implemented to identify and activate a new beam for communication. Some techniques may include resources that are used for pre-configured communication failure recovery procedures for a UE and/or a base station and that are available. For example, a particular set of resources may be configured according to a periodic schedule (e.g., for each time slot, every other time slot, etc.). In some cases, on-demand resources may be activated during communication failures, but otherwise usable during normal wireless communications. For example, a wireless device (which may be an example of a UE and/or a base station) may identify resources configured in a first state. In some aspects, the resources configured in the first state may be active or otherwise available for wireless communication between the base station and the UE, between base stations, and/or between UEs. However, the resources configured in the first state may be inactive to be used for the communication failure recovery process. A wireless device (e.g., a base station and/or UE) may determine that a communication failure, e.g., a beam failure, a radio link failure, etc., occurred during a first communication period. Thus, the wireless device may transition the resource to a second state in which the resource is inactive for wireless communication and active for a communication failure recovery procedure. The wireless device may perform a communication failure recovery procedure using the resources that have transitioned to the second state.

In some cases, the base station may determine that on-demand resources will be used for at least some communication failures (e.g., communication failures of certain UEs, communication failures of UEs that have low latency or high priority services enabled, etc.), and may configure one or more UEs with on-demand failure recovery resources (which may be referred to herein as Beam Failure Recovery (BFR) resources) that are preconfigured with resources that may be activated by the UEs and the base station in the event of a communication failure. Such on-demand BFR resources may be activated upon determining a communication failure and may be used to establish an updated BPL for subsequent communications. In some cases, one or more UEs may be configured with on-demand BFR resources and periodic BFR resources. In such a case, priority rules may be utilized to select which of the on-demand BFR resources or the periodic BFR resources to use to establish the updated BPL.

In some cases, activation of on-demand BFR resources for BFR procedures may be based on one or both of the UE or the base station not receiving expected communications or receiving a feedback indication indicating that a particular communication was not successfully received. For example, the base station may send downlink communications to the UE based on the downlink resource allocation. In the event that the UE receives the downlink resource allocation and fails to successfully decode the downlink communication, the UE may send a Negative Acknowledgement (NACK) to the base station to indicate the downlink communication failure. Furthermore, in the event that the UE does not successfully receive the downlink resource allocation, the UE may not monitor the downlink communications and may not send any feedback, which the base station may then consider to be a communication failure. Further, in some cases, the UE may successfully receive the downlink communication and send an Acknowledgement (ACK) of the successful reception to the base station, but the base station may not receive the ACK feedback or there may be a decoding error that causes the base station to decode the ACK when the UE sends a NACK. A similar situation may occur when a UE transmits an uplink transmission to a base station.

Various aspects of the present disclosure further provide techniques for enhancing the robustness of beam failure recovery activation to reduce situations where one wireless device (e.g., a UE or a base station) may be tasked with a communication failure while another wireless device does not infer that a communication failure has occurred. In some cases, reliability of acknowledgment feedback transmission may be enhanced by specifying that such acknowledgment feedback is transmitted with a CRC regardless of the payload size of the acknowledgment feedback, which may reduce instances in which a receiving device erroneously decodes an ACK as a NACK. In some cases, the reliability of BFR resource activation may be enhanced by one or more redundant indications that BFR resources are to be activated. Additionally or alternatively, in some cases, a no-traffic indication may be provided by the transmitting device, which may be used by the receiving device to determine that lack of transmission is intentional and not to speculate that a communication failure has occurred. As the number of occasions for one wireless device of BPL to activate BFR resources to initiate a BFR procedure decreases, the various techniques provided herein, or a combination thereof, may allow for more reliable and efficient communication.

Further, in some cases, communication reliability may be enhanced by transmitting using multiple beams. In such a case, the base station may transmit downlink transmissions (e.g., all or portions of downlink transmissions transmitted using multiple different beams), for example, using a beam scanning pattern, which may improve the likelihood of successful reception at the UE. Further, in some cases, the UE may transmit responsive uplink communications using an uplink beam quasi co-located with a beam of a beam scanning pattern (QCLed) used for downlink transmissions. In some cases, such techniques may be used based on one or more measurements indicating that an established BPL may become unreliable, and beam scanning using multiple beams in relatively close proximity to the established BPL may improve the likelihood of successful communication.

In addition, in some cases, to reduce communication gaps in the event of a communication failure on the first BPL and the first TRP, the UE may communicate using different TRPs and/or BPLs while the BFR procedure is being performed for the first BPL/TRP. In some cases, the UE and the second TRP may transmit communications to maintain connectivity of the UE when the BFR resource is activated. Once the BFR procedure is completed and an updated BPL is established between the UE and the first TRP, resources associated with the second BPL/TRP may be released. In some cases, in the event of a communication failure of the first BPL/TRP, the UE and the second TRP/BPL may be preconfigured for such communication. In some cases, the second TRP/BPL may be preconfigured based on a signal quality measurement of the first TRP/BPL being below a threshold or based on periodic time intervals when communication failures historically occur (e.g., due to periodic equipment movement in an industrial internet of things (IIoT) deployment).

Aspects of the present disclosure are first described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to beam failure recovery techniques.

Fig. 1 illustrates an example of a wireless communication system 100 that supports beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The wireless communication system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an LTE-advanced (LTE-a) network, an LTE-a Pro network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low cost and low complexity devices.

The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may comprise or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga-NodeB (any of which may be referred to as a gNB), a home NodeB, a home eNodeB, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UEs 115 described herein may be capable of communicating with various types of base stations 105 and network devices, including macro enbs, small cell enbs, gnbs, relay base stations, and the like.

Each base station 105 may be associated with a particular geographic coverage area 110 in which communications with various UEs 115 are supported. Each base station 105 may provide communication coverage for a respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication links 125 shown in the wireless communication system 100 may include uplink transmissions from the UEs 115 to the base stations 105 or downlink transmissions from the base stations 105 to the UEs 115. The downlink transmission may also be referred to as a forward link transmission, and the uplink transmission may also be referred to as a reverse link transmission.

The geographic coverage area 110 of a base station 105 can be divided into sectors that form a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hotspot, or other type of cell, or various combinations thereof. In some examples, the base stations 105 may be mobile and thus provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the same base station 105 or different base stations 105 may support the overlapping geographic coverage areas 110 associated with different technologies. The wireless communication system 100 can include, for example, a heterogeneous LTE/LTE-A/LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

The term "cell" refers to a logical communication entity for communication with a base station 105 (e.g., over a carrier) and may be associated with an identifier (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)) for distinguishing neighboring cells operating via the same or different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine Type Communication (MTC), narrowband internet of things (NB-IoT), enhanced mobile broadband (eMBB), or other protocol types) that may provide access for different types of devices. In some cases, the term "cell" may refer to a portion (e.g., a sector) of the geographic coverage area 110 acted on by a logical entity.

The UEs 115 may be dispersed throughout the wireless communication system 100, and each UE 115 may be fixed or mobile. UE 115 may also be referred to as a mobile device, a wireless device, a remote device, a handset, or a subscriber device, or some other suitable terminology, where a "device" may also be referred to as a unit, station, terminal, or client. The UE 115 may also be a personal electronic device, such as a cellular telephone, a Personal Digital Assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, the UE 115 may also refer to a Wireless Local Loop (WLL) station, an internet of things (IoT) device, an internet of everything (IoE) device, or an MTC device, among others, which may be implemented in various articles of manufacture such as appliances, vehicles, meters, and so on.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication techniques that allow devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communications or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay the information to a central server or application that may utilize the information or present the information to a human interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, device monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business billing.

Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communications (e.g., a mode that supports unidirectional communications via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for the UE 115 include entering a power saving "deep sleep" mode when not engaged in active communication, or operating on a limited bandwidth (e.g., according to narrowband communication). In some cases, the UE 115 may be designed to support critical functions (e.g., mission critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communication for these functions.

In some cases, the UE 115 may also be able to communicate directly with other UEs 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more of a group of UEs 115 communicating with D2D may be within the geographic coverage area 110 of the base station 105. The other UEs 115 in the group may be outside the geographic coverage area 110 of the base station 105 or may not be able to receive transmissions from the base station 105. In some cases, multiple groups of UEs 115 communicating via D2D may utilize a one-to-many (1: M) system, where each UE 115 transmits to every other UE 115 in the group. In some cases, the base station 105 facilitates scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without base station 105 involvement.

The base stations 105 may communicate with the core network 130 and each other. For example, the base stations 105 may interface with the core network 130 over backhaul links 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via the core network 130) over a backhaul link 134 (e.g., via an X2, Xn, or other interface).

Core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an Evolved Packet Core (EPC) that may include at least one Mobility Management Entity (MME), at least one serving gateway (S-GW), and at least one Packet Data Network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be communicated through the S-GW, which may itself be connected to the P-GW. The P-GW may provide IP address assignment as well as other functions. The P-GW may be connected to a network operator IP service. The operator IP services may include access to the internet, intranets, IP Multimedia Subsystem (IMS) or Packet Switched (PS) streaming services.

At least some network devices, such as base station 105-a, may include a subcomponent, such as access network entity 105-b, which may be an example of an Access Node Controller (ANC). Each access network entity 105-b may communicate with the UE 115 through a plurality of other access network transmitting entities, which may be referred to as radio heads 105-c, smart radio heads, or TRPs. In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or incorporated into a single network device (e.g., base station 105).

The wireless communication system 100 may operate using one or more frequency bands, such as in the range of 300 megahertz (MHz) to 300 GHz. Because the length of the wavelength ranges from about one decimeter to one meter, the 300MHz to 3GHz region is sometimes referred to as the Ultra High Frequency (UHF) region or decimeter band. Building and environmental features may block or redirect UHF waves. However, the waves may penetrate the structure sufficiently for the macro cell to provide service to the UE 115 located indoors. UHF-wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100km) compared to transmission of smaller and longer waves using the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz.

The wireless communication system 100 may also operate in the ultra-high frequency (SHF) region using a frequency band from 3GHz to 30GHz, also referred to as a centimeter band. The SHF region contains bands such as the 5 gigahertz industrial, scientific, and medical (ISM) band that may be opportunistically used by equipment that may be tolerant of interference from other users.

The wireless communication system 100 may also operate in the Extremely High Frequency (EHF) region of the spectrum, also referred to as the millimeter-band (mm-band), e.g., from 30GHz to 300 GHz. In some examples, the wireless communication system 100 may support mmW communication between the UE115 and the base station 105, and EHF antennas of respective devices may be smaller and more closely spaced than UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may be affected by greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the designated use of bands across these frequency regions may vary from country to country or regulatory agency.

In some cases, the wireless communication system 100 may utilize both the licensed radio frequency spectrum band and the unlicensed radio frequency spectrum band. For example, the wireless communication system 100 may employ Licensed Assisted Access (LAA), unlicensed LTE (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 gigahertz ISM band. When operating in the unlicensed radio frequency spectrum band, wireless devices such as base stations 105 and UEs 115 may employ a Listen Before Talk (LBT) procedure to ensure that a frequency channel is cleared before data is transmitted. In some cases, operation in the unlicensed band may be based on a carrier aggregation configuration in combination with component carriers operating in the licensed band (e.g., LAA). Operations in the unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in the unlicensed spectrum may be based on Frequency Division Duplexing (FDD), Time Division Duplexing (TDD), or a combination of both.

In some examples, a base station 105 or UE 115 may be equipped with multiple antennas that may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication can improve spectral efficiency by employing multipath signal propagation by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may be transmitted, for example, by the transmitting device via different antennas or different combinations of antennas. Also, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO) in which a plurality of spatial layers are transmitted to the same receiving device and multi-user MIMO (MU-MIMO) in which a plurality of spatial layers are transmitted to a plurality of devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used in a transmitting device or a receiving device (e.g., base station 105 or UE 115) to shape or steer an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array such that signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals communicated via the antenna elements may include the transmitting device or the receiving device applying certain amplitude and phase offsets to the signals carried via each of the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to an antenna array of a transmitting device or a receiving device, or relative to some other orientation).

In one example, the base station 105 may use multiple antennas or antenna arrays for beamforming operations for directional communication with the UEs 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times in different directions by the base station 105, which may include signals transmitted according to different sets of beamforming weights associated with different transmission directions. The beam directions may be identified (e.g., by the base station 105 or a receiving device such as the UE 115) using the transmissions in the different beam directions for subsequent transmission and/or reception by the base station 105.

The base station 105 may transmit some signals, such as data signals associated with a particular receiving device, in a single beam direction (e.g., a direction associated with a receiving device, such as UE 115). In some examples, a beam direction associated with transmission along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, the UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report an indication of its received signal to the base station 105 at the highest signal quality or otherwise acceptable signal quality. Although the techniques are described with reference to signals transmitted by the base station 105 in one or more directions, the UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by the UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmW receiving device) may attempt multiple receive beams when receiving various signals such as synchronization signals, reference signals, beam selection signals, or other control signals from the base station 105. For example, a receiving device may attempt multiple receive directions by: receiving via different antenna sub-arrays, processing received signals according to the different antenna sub-arrays, receiving according to different sets of receive beamforming weights applied to signals received in multiple antenna elements of the antenna array, or processing received signals according to different sets of receive beamforming weights applied to signals received in multiple antenna elements of the antenna array, either of which steps may be referred to as "listening" according to different receive beams or receive directions. In some examples, a receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving data signals). The single receive beam may be aligned in a beam direction determined based at least in part on sensing according to a different receive beam direction (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio, or an otherwise acceptable signal quality based at least in part on sensing according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may be located within one or more antenna arrays that support MIMO operation, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located in an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with the base station 105 may be located at different geographic locations. The base station 105 may have an antenna array with rows and columns of multiple antenna ports that the base station 105 may use to support beamforming for communications with the UEs 115. Likewise, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

In some cases, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communications over the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. The Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. The MAC layer may perform priority processing and multiplex logical channels into transport channels. The MAC layer may also provide retransmissions in the MAC layer using hybrid automatic repeat request (HARQ) to improve link efficiency. In the control plane, a Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of RRC connections between the UE 115 and the base station 105 or core network 130 that support radio bearers for user plane data. In the physical layer, transport channels may be mapped to physical channels.

In some cases, the UE 115 and the base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique that increases the likelihood of correctly receiving data over the communication link 125. HARQ may include a combination of error detection (e.g., using CRC), Forward Error Correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). Under poor radio conditions (e.g., signal-to-noise ratio conditions), HARQ may improve throughput in the MAC layer. In some cases, a wireless device may support HARQ feedback for the same slot, where the device may provide HARQ feedback in a particular slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

The time interval in LTE or NR can be expressed as a multiple of the basic time unit, which may for example be referred to as T_sA sample period of 1/30,720,000 seconds. The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as T_f＝307,200T_s. The radio frame may be identified by a System Frame Number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered 0 to 9, and each subframe may have a duration of 1 ms. The subframe may be further divided into 2 slots, each slot having a duration of 0.5ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). Each symbol period may contain 2048 sample periods in addition to a cyclic prefix. In some cases, a subframe may be the smallest scheduling unit of the wireless communication system 100 and may be referred to as a Transmission Time Interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in bursts of a shortened tti (sTTI) or in selected component carriers using sTTI).

In some wireless communication systems, a slot may be further divided into a plurality of minislots containing one or more symbols. In some examples, the symbol of the micro-slot or the micro-slot may be the minimum scheduling unit. For example, the duration of each symbol may vary depending on the subcarrier spacing or operating frequency band. Further, some wireless communication systems may implement time slot aggregation, where multiple time slots or minislots are aggregated together and used for communication between the UE 115 and the base station 105.

The term "carrier" refers to a set of radio spectrum resources having a defined physical layer structure for supporting communications over the communication link 125. For example, the carrier of the communication link 125 may comprise a portion of a radio frequency spectrum operating according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. The carriers may be associated with predefined frequency channels (e.g., evolved universal mobile telecommunications system terrestrial radio access (E-UTRA) absolute radio frequency channel numbers (EARFCNs)) and may be located according to a channel grid for discovery by UEs 115. The carriers may be downlink or uplink (e.g., in FDD mode), or configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted over the carrier may be composed of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as Orthogonal Frequency Division Multiplexing (OFDM) or discrete fourier transform spread OFDM (DFT-S-OFDM)).

The organization of the carriers may be different for different radio access technologies (e.g., LTE-A, LTE-A Pro, NR). For example, communication over carriers may be organized according to TTIs or slots, each of which may include user data as well as control information or signaling to support decoding of the user data. The carriers may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling that coordinates the operation for the carriers. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers.

The physical channels may be multiplexed on the carriers according to various techniques. The physical control channels and physical data channels may be multiplexed on the downlink carrier using, for example, Time Division Multiplexing (TDM) techniques, Frequency Division Multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, the control information sent in the physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

The carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as a carrier or "system bandwidth" of the wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80MHz) of the carrier for a particular radio access technology. In some examples, each serving UE 115 may be configured to operate over part or all of the carrier bandwidth. In other examples, some UEs 115 may be configured for operation using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within a carrier (e.g., an "in-band" deployment of narrowband protocol types).

One or more of the base stations 105, when configured as a wireless device, can include a Base Station (BS) communication manager 101 that can identify resources for wireless communication that are in a first state in which the resources are active for wireless communication and inactive for a communication failure recovery procedure. The BS communication manager 101 may determine that a communication failure has occurred within the first communication period. The BS communication manager 101 may transition the resource to a second state during a second communication period and based at least in part on the communication failure, in which the resource is inactive for wireless communication and active for a communication recovery procedure. The BS communication manager 101 may perform a communication failure recovery procedure using the resource transitioned to the second state. In some cases, the resources may be pre-configured (e.g., via RRC signaling) as on-demand BFR resources. In some cases, the determination of a communication failure may be based on one or more enhanced feedback communications or redundant indications of the failure.

The base station 115, when configured as a wireless device, can include the UE communication manager 102, which can identify resources for wireless communication that are in a first state in which the resources are active for wireless communication and inactive for a communication failure recovery procedure. The UE communication manager 102 may determine that a communication failure has occurred within the first communication period. The UE communication manager 102 may transition the resource to a second state during a second communication period and based at least in part on the communication failure, in which the resource is inactive for wireless communication and active for a communication recovery procedure. The UE communication manager 102 may perform a communication failure recovery procedure using the resource transitioned to the second state. In some cases, the determination of a communication failure may be based on one or more enhanced feedback communications or redundant indications of the failure.

Fig. 2A-2C illustrate an example of a wireless communication system 200 that supports beam failure recovery techniques in accordance with one or more aspects of the present disclosure. In some examples, wireless communication system 00 may implement aspects of wireless communication system 100. Aspects of the wireless communication system 200 may be implemented by a base station 205 and/or a UE 215, which may be examples of corresponding devices described herein.

The base station 205 may communicate with the UE 215 using a first BPL, which may include a first beam 210 used by the base station 205 and a second beam 220 used by the UE 215. In some aspects, beams 210 and/or 220 may be considered active beams or BPLs. That is, the beam 210 may be an active transmit beam and/or an active receive beam used by the base station 205 to perform wireless communications with the UE 215. Similarly, the beam 220 may be an active transmit beam and/or an active receive beam used by the UE 215 to perform wireless communications with the base station 205.

In some aspects, techniques may include pre-configured periodic BFR resources for the base station 205 and the UE 215, as well as pre-configured and activated on-demand BFR resources in the event of communication failure. In some cases, to reduce overhead, on-demand BFR resources may be configured. For example, in the case of configuring periodic BFR resources, the period of Beam Failure Indication (BFI) reporting and/or contention-free random access (CFRA) Random Access Channel (RACH) resources may be relatively long in order to reduce the overhead associated with such periodic resources, as both parties may not know when a communication failure may occur. For example, the BFI reporting periodicity may be at least 2ms, the RACH resource periodicity may be at least 10ms, there may be 4 slots between the RACH transmission slot and the response window start slot, etc. In some aspects, the average BFR completion duration may be long, e.g., at least (BFI reporting period)/2 + (RACH resource period)/2 +4 time slots ═ 6.5 ms. This may be surmised that the Beam Fault Discovery (BFD) reference signal period is at most 2ms, the maximum count of BFIs is 1, the BFI reports negligible delay to the following candidate beam reference signal, the response window duration is one slot, and there are no errors from the pre-pilot transmission to the response reception. Where retransmissions are involved, the delay may be further increased. However, this approach may have relatively large latency, which may be undesirable for high priority or low latency communications.

Thus, in some cases, on-demand BFR resources may be configured, which are activated in case of communication failure. For example, the on-demand BFR resources may be pre-configured (e.g., via RRC signaling) and used for BFR procedures in the event of a communication failure or for uplink and downlink communications in the absence of a communication failure. A communication cycle/cycle may be considered to have failed if a packet transmitted in at least one direction (e.g., uplink and/or downlink) is not successfully received and decoded. In some examples, this may include any retransmission of the failed packet. In some aspects, a communication failure of a communication cycle/cycle may indicate that a beam failure (e.g., which may include loss of all active control beams within a cell) and/or a radio link failure (e.g., which may include an entire cell failure, such as a complete loss of communication between the cell and the UE 215) has occurred. In some aspects, a communication period/cycle may refer to any time frame in which communication is performed between the base station 205 and the UE 215. For example, based on periodic traffic, the base station 205 and/or the UE 215 may be synchronized with respect to the expected communications (e.g., for initial transmissions and/or retransmissions) such that communication failures within a communication cycle/cycle are known or may be detected by each device.

In some aspects, the configured on-demand BFR resources may include resources (e.g., time resources, frequency resources, spatial resources, code resources, or the like, alone or in any combination) configured for the base station 205 and the UE 215. For example, the base station 205 may transmit a signal (e.g., an RRC signal, a MAC control element, etc.) to the UE 215 to configure the resources. In some cases, the resource may be configured in a first state in which the resource is active for wireless communication between the base station 205 and the UE 215 and inactive for a communication failure recovery procedure. That is, the resources may be used for communication between the base station 205 and the UE 215 over the beams 210 and 220, respectively, but may be dynamically activated (e.g., transitioned to the second state) upon detecting or otherwise determining that a communication failure occurred within the first communication period/cycle. In the second state, the resources may be inactive for wireless communications and active for communications failure recovery procedures. Accordingly, the base station 205 and the UE 215 may transition the resource to the second state in response to the communication failure and use the resource to identify a new candidate beam for future communication during a communication failure recovery procedure. That is, the new beam identified in the communication cycle/cycle in which the communication failure recovery process occurs may be applied to the subsequent communication cycle/cycle.

Accordingly and referring to fig. 2A, the base station 205 and the UE 215 may identify resources for wireless communication, the resources being in a first state. The wireless communication may include the base station 205 communicating with the UE 215 using a first BPL including a beam 210 (e.g., a currently active transmit and/or receive beam of the base station 205) and a beam 220 (e.g., a currently active transmit and/or receive beam of the UE 215). In some cases, the base station 205 and/or the UE 215 may determine that a communication failure occurred during the first communication period. As discussed, a communication failure may refer to a beam failure (e.g., a loss of a control beam of the base station 205), a radio link failure (e.g., a complete loss of communication between the base station 205 and the UE 215), and so on. The first communication period (or cycle) may refer to any time period during which the intended communication of information (uplink, downlink, or both) occurs between the base station 205 and the UE 215. In one non-limiting example, this can include no transmission from the UE 215 or no initial transmission and/or retransmission received by the base station 205. For example, the UE 215 may not transmit or the base station 205 may not receive a downlink acknowledgement transmission and/or an uplink packet transmission.

Thus, in some examples, both the base station 205 and the UE 215 may detect or otherwise determine that a communication failure has occurred. In response, both the base station 205 and the UE 215 may transition the on-demand BFR resource to a second state in which the resource is inactive for wireless communication and active for communication failure recovery procedures. That is, upon detecting a communication failure, the base station 205 and the UE 215 may identify preconfigured BFR resources associated with the BFR procedure (but available for wireless communication when in the first state) and transition those resources to the second state in which they are available or in activity for the BFR procedure. The base station 205 and the UE 215 may perform a BFR procedure using the resources transitioned to the second state.

For example, and referring to fig. 2B, this may include the base station 205 transmitting one or more BFR candidate beam Reference Signals (RSs) 225 using the BFR resources transitioned to the second state. In some aspects, this may include the base station 205 transmitting the BFR candidate beams RS225 in a scanning manner (e.g., in multiple directions). For example, the base station 205 may transmit a BFR candidate beam Reference Signal (RS)225-a in a first direction, a BFR candidate beam RS 225-b in a second direction, a BFR candidate beam RS 225-c in a third direction, and a candidate beam RS 225-d in a fourth direction. In one non-limiting example, this may include the base station 205 using a set of candidate beams maintained for the UE 215, such as the first four, six candidate beams 215 associated with the UE. It should be understood that more or fewer BFR candidate beams RS225 may be transmitted.

In some aspects, the UE 215 may monitor the BFR resources transitioning to the second state for receiving one or more of the BFR candidate beams RS225 based on determining that a communication failure has occurred. For example, the UE 215 may measure the quality (e.g., received signal strength) of the BFR candidate beams RS225 using one or more received beams to identify preferred candidate beams from the BFR candidate beams RS 225. For example, the UE 215 may identify the best candidate beam and/or the first N candidate beams from the BFR candidate beams RS225, where N is a positive integer of 2 or greater.

Referring to fig. 2C, the base station 205 may transmit a BFR request signal (BFRQ) to the base station 205 that carries or otherwise communicates an indication identifying a preferred candidate beam (e.g., the best candidate beam or the first N candidate beams) from the BFR candidate beam RS 225. In some aspects, the BFRQ may be transmitted using beam 230, which may correspond to a preferred candidate beam in some examples.

Accordingly, the base station 205 may receive the BFRQ and identify the preferred candidate beam indicated by the UE 215. The base station 205 may use the beam as its new active BPL in wireless communications with the UE 215. That is, the base station 205 may receive the BFRQ and identify the best candidate beam (or the first N candidate beams) that the UE 215 receives from the base station 205. The base station 205 may employ or otherwise select the preferred candidate beam identified in the BFRQ and select it as the new active beam to use in the updated BPL for communication with the UE 215. Similarly, the UE 215 may select a preferred candidate beam (e.g., beam 230) for communicating with the base station 205. Upon successful completion of the BFR procedure, the base station 205 and the UE 215 may transition the preconfigured BFR resources back to the first state in which the BFR resources are active for wireless communication between the base station 205 and the UE 215. That is, upon the base station 205 receiving the BFRQ and identifying the updated BPL, the base station 205 and the UE 215 may know that the BFR resources are no longer needed for the communication failure recovery process and may therefore transition the BFR resources back to the first state in which the BFR resources are available for wireless communication between the base station 205 and the UE 215 and are inactive for the communication failure recovery process.

In some aspects, one or more BFR candidate beams RS225 may be common to all UEs (because it was beam scanned), while uplink resources (e.g., BFRQ for using beams 230) may be configured individually on a per-UE basis or implicitly derived based on downlink and/or uplink allocations of UEs. In some cases, the uplink resources for BFRQ may be per-UE resources (e.g., indicated in RRC or in MAC-CE), including Physical Uplink Control Channel (PUCCH) resources, Physical Random Access Channel (PRACH) resources, or a combination thereof. Such per-UE resources may be separated, for example, in the time, frequency, spatial, or code domain, or a combination thereof.

In some cases, the base station 205 and the UE 215 may configure on-demand BFR resources and periodic BFR resources. For example, periodic BFR resources may be configured, wherein the base station 205 may transmit the candidate beam RS225 regardless of whether a communication failure occurs, and the UE 215 may have associated uplink resources (e.g., individual time resources, frequency resources, spatial resources, code resources, etc., or any combination thereof) for transmission of BFRQ. In some cases, it may happen that the UE 215, the base station 205, or both determine that a communication failure has occurred, which will trigger activation of the on-demand BFR resources within a time period (e.g., within one communication period or cycle) in which periodic BFR resources are also configured. In such a case, a priority rule may be established that indicates which BFR resources are to be used for the BFR procedure. For example, the priority rule may indicate that periodic BFR resources are to be used in this case. In other cases, the priority rule may indicate that the periodic BFR resources are to be used for communication with a predetermined latency target when a failure is determined within a window before the periodic BFR resources (e.g., if a failure is detected within a certain number of communication cycles of the periodic BFR resources, the eMBB communication may use the periodic BFR resources) and use on-demand BFR resources for lower latency or higher priority transmission (e.g., on-demand BFR resources for ultra-reliable low latency communication (URLLC)). In such a case, priority rules may be utilized to select which of the on-demand BFR resources or the periodic BFR resources to use to establish the updated BPL. In some cases, the priority rules may be preconfigured, statically configured, or semi-statically configured.

In some cases, the activation of the on-demand BFR resources for the BFR procedure may be based on one or both of the UE 215 or the base station 205 not receiving the expected communications or receiving a feedback indication indicating that a particular communication was not successfully received. For example, the base station 205 may send downlink communications to the UE 215 based on the downlink resource allocation. In the event that the UE 215 receives the downlink resource allocation and fails to successfully decode the downlink communication, the UE 215 may send a NACK to the base station 205 to indicate the downlink communication failure. Further, in the event that the UE 215 does not successfully receive the downlink resource allocation, the UE 215 may not monitor the downlink communications and may not send any feedback, which the base station 205 may then consider to be a communication failure. Further, in some cases, the UE 215 may successfully receive the downlink communication and send an ACK to the base station 205, but the base station 205 may not receive the ACK feedback or there may be a decoding error that causes the base station 205 to decode the ACK when the UE 215 sends a NACK. A similar situation may occur when the UE 215 transmits an uplink transmission to the base station 205.

In some cases, the robustness of beam failure recovery activation may be enhanced in accordance with the techniques discussed herein to reduce the instances in which one wireless device (e.g., UE 215 or base station 205) may infer that a communication failure has occurred while another wireless device does not consider that a communication failure has occurred. In some cases, reliability of acknowledgment feedback transmission may be enhanced by specifying that such acknowledgment feedback is transmitted with a CRC regardless of the payload size of the acknowledgment feedback, which may reduce instances in which a receiving device erroneously decodes an ACK as a NACK. In some cases, the reliability of BFR resource activation may be enhanced by one or more redundant indications that BFR resources are to be activated. Additionally or alternatively, in some cases, a no-traffic indication may be provided by the transmitting device, which may be used by the receiving device to determine that lack of transmission is intentional and not to speculate that a communication failure has occurred. As the number of occasions for one wireless device of BPL to activate BFR resources to initiate a BFR procedure decreases, the various techniques provided herein, or a combination thereof, may allow for more reliable and efficient communication. For example, one or more integrated circuits (e.g., transceivers, processors, etc.) of a wireless device (e.g., UE 215 or base station 205) may implement the beam failure recovery techniques discussed herein to reduce the overall power consumption of the wireless device.

Further, in some cases, communication reliability may be enhanced by transmitting using multiple beams. In such a case, the base station 205 may transmit a downlink transmission (e.g., all or a portion of a downlink transmission transmitted using multiple different beams), for example, using a beam sweep pattern, which may increase the likelihood of successful reception at the UE 215. Further, in some cases, the UE 215 may transmit responsive uplink communications using the uplink beam with the beam QCLed of the beam scanning pattern used for downlink transmissions. In some cases, such techniques may be used based on one or more measurements indicating that an established BPL may become unreliable, and beam scanning using multiple beams in relatively close proximity to the established BPL may improve the likelihood of successful communication. Additionally, in some cases, to reduce communication gaps in the event of a communication failure on the first BPL and the first TRP, the UE 215 may communicate using a different TRP and/or BPL while the BFR procedure is being performed for the first BPL/TRP. Once the BFR procedure is completed and the updated BPL is established between the UE 215 and the first TRP, resources associated with the second BPL/TRP may be released. In some cases, both the first TRP and the second TRP may be associated with the same base station 205. In some cases, the UE 215 may transmit to two or more different TRPs during a BFR procedure that may include a first TRP to increase the likelihood of successful communication.

Fig. 3 illustrates an example of a BFR configuration 300 supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. In some examples, BFR configuration 300 may implement aspects of wireless communication system 100 or 200. Aspects of the BFR configuration 300 may be implemented by a base station and/or a UE, which may be examples of corresponding devices described herein. In some aspects, a base station and/or UE may be an example of a wireless device implementing aspects of the described technology.

In some aspects, a base station may perform wireless communication with one or more UEs, where N UEs are shown as an example and N corresponds to a positive integer of 1 or greater. In the example shown in the BFR configuration 300, this may include the base station performing downlink transmission 305 to UE 1, downlink transmission 310 to UE 2, and continuing downlink transmission up to downlink transmission 315 to UE N. Although BFR configuration 300 shows such downlink transmissions as data transmissions (e.g., PDSCH), it should be understood that downlink transmissions may be any combination of control, system, and/or data transmitted to the respective UEs.

In some aspects, the wireless communication may include one or more uplink transmissions from the N UEs to the base station. For example, this may include a first uplink transmission 320 from UE 1, a second uplink transmission 325 from UE 2, and continuing the uplink transmission up to the uplink transmission 330 from UE N. Also, while BFR configuration 300 shows such uplink transmission to be data transmission (e.g., PUSCH), it should be understood that uplink transmission may be any combination of control, system, and/or data communicated to the respective base station.

Although not shown in the BFR configuration 300, it should be understood that uplink and/or downlink transmissions may include one or more of initial transmissions and/or retransmissions of information between the base station and the respective UE.

Uplink and/or downlink transmissions (e.g., initial transmissions) may occur during a first communication period (or communication cycle). A communication period may refer to any time period in which communication is expected to occur, including uplink transmissions and/or downlink transmissions.

In some aspects, one or more of the wireless communications between base stations, UEs, may occur over resources configured or otherwise operating in the first state. A resource may refer to any combination of time resources, frequency resources, spatial resources, code resources, and the like. The resource configured in the first state may indicate that the resource is available for wireless communication between the base station and the UE. For example, one or more of downlink transmissions 305, 310, and/or 315 may be performed using some or all of the resources in the first state. Similarly, one or more of uplink transmissions 320, 325, and/or 330 may be performed using some or all of the resources in the first state. Thus, the resources in the first state may be available to the base station and/or UE to perform wireless communications (e.g., PUCCH/PUSCH/PDCCH/PDSCH communications). In some aspects, the resource in the first state may be inactive or unavailable for BFR procedures. That is, resources for the BFR procedure may be allocated or otherwise identified, but are inactive for such communication failure recovery procedures until a communication failure occurs.

In some aspects, resources may be preconfigured before a communication failure occurs. For example, the base station may signal to the UE to configure resources in the first state. Examples of signals may include, but are not limited to, RRC signals, MAC control elements, initial configuration signals, and the like. Accordingly, the base station and the UE may identify resources for wireless communication, the resources being in a first state. However, the base station and/or the UE may determine that a communication failure occurred during the first communication period (e.g., during one or more initial transmissions/retransmissions). A communication failure may refer to a beam failure and/or a radio link failure.

Accordingly, the base station and the UE may transition the resource from the first state to the second state in response to the communication failure. In the second state, the resource may be inactive for wireless communication and active for BFR procedures. That is, upon detection of a communication failure between the base station and the UE, the resources in the first state for wireless communication between the base station and the UE may be dynamically transitioned or otherwise adapted for the BFR procedure. In some aspects, this may minimize waste by allowing fewer or no periodic BFR resources to be configured and available for periodic BFR procedures.

In some aspects, the base station and the UE may perform the communication failure recovery procedure using resources that have transitioned to the second state (e.g., using resources that are activated for a BFR procedure in response to detecting the communication failure). In some aspects, this may include the base station transmitting (and the UE receiving) the one or more BFR candidate beams RS using the resources transitioned to the second state. For example, the base station may transmit one or more BFR candidate beams RS across at least a portion of its coverage area in a scanning manner using different transmit beams. For example, the base station may transmit a first BFR candidate beam RS 335 on beam 1, a second BFR candidate beam RS 340 on beam 2, and continue until an nth BFR candidate beam RS 345 is transmitted on beam N, where N is a positive integer of 1 or greater. In some aspects, each beam used to transmit the BFR candidate beam RS may be unique (e.g., may have an assigned unique identifier) and/or may be transmitted in a different direction (e.g., in a scanning manner). In some aspects, each BFR candidate beam RS may be transmitted in one symbol (e.g., CSI-RS) and may have a corresponding uplink resource with the same base station beam for transmission and reception. For example, each uplink resource may be one symbol PUCCH (e.g., format 0 or 2).

In some aspects, based on detecting or otherwise determining that a communication failure has occurred, the UE may monitor the BFR candidate beam RS to determine or otherwise identify a preferred candidate beam for future communication with the base station. For example, the UE may identify the best candidate beam from the BFR candidate beams RS and/or may identify the first N candidate beams from the BFR candidate beams RS, where N is a positive integer of 2 or more.

In some aspects, the UE may send a BFRQ to the base station using one or more of the resources transitioning to the second state. In the example shown in BFR configuration 300, this may include one or more PUCCH resources in one slot. In some aspects, the BFRQ may carry or otherwise communicate an indication identifying a preferred candidate beam (e.g., the best candidate beam and/or the first N candidate beams).

As discussed, in some examples, each beam used to transmit the BFR candidate beam RS may have corresponding uplink resources for transmitting BFRQ to the base station. For example, the first BFRQ 350 may correspond to the first BFR candidate beam RS 335 using beam 1, the second BFRQ 355 may correspond to the second BFR candidate beam RS 340 using beam 2, and the nth BFRQ 360 may correspond to the nth BFR candidate beam RS 345 using beam N. Thus, in some aspects, the UE may select an uplink resource from the resources transitioning to the second state based on its preferred candidate beam. That is, when the first BFR candidate beam RS 335 is the preferred candidate beam, the UE may transmit the first BFRQ 350 to the base station using beam 1. Thus, the base station may know or otherwise identify a preferred candidate beam among the BFRQs received from the UE based on which beam the BFRQ is transmitted on.

Further, in some examples, a base station may receive multiple BFRQs from different UEs. In this context, a unique initial cyclic shift, frequency allocation, etc., associated with each UE may be used to distinguish between different UEs. Thus, the base station may receive the BFRQ, identify a preferred candidate beam for the UE, and select that beam to use in the updated BPL to continue communicating with the UE.

As discussed, aspects of the described techniques may include a UE and a base station determining that a communication failure has occurred. Examples of a communication failure may include, but are not limited to, the UE speculating that an on-demand BFR is configured (e.g., a communication failure has occurred, thus transitioning resources to a second state) if at least one of a downlink ACK and/or an uplink packet has never been issued (e.g., the UE has never sent) in a previous cycle (e.g., during the first communication period). Another example of a communication failure may include, but is not limited to, the base station speculatively configuring an on-demand BFR (e.g., a communication failure has occurred, thus transitioning resources to the second state) if at least one of the downlink ACKs and/or uplink packets is never received in a previous cycle (e.g., during the first communication period).

In some cases, there may be a mismatch between the UE and the base station, e.g., one wireless device may detect a communication failure while another wireless device may not. That is, table 1 below shows an exemplary matching scenario (in terms of whether each wireless device determines or otherwise identifies a communication failure):

TABLE 1

As shown in table 1, when both downlink ACK and Uplink (UL) packets are transmitted by the UE and received by the base station, both devices may determine that there is no communication failure (e.g., BFRs are not configured such that the resources remain in the first state). In the event that at least one of the DL ACK and UL packets is not transmitted by the UE but received by the base station, both devices may determine that a communication failure has occurred (e.g., BFR is configured such that the resources transition to the second state).

A possible NACK-to-ACK match may include an ACK configured for PUCCH format 0 or format 2, especially for small packet transmissions (e.g., Reed-Muller, no CRC), if PUSCH is sent but ACK is not sent/received. Such small packet transmissions may specify that CRC is not to be used if the packet has a threshold number of bits or less (e.g., ≦ 11 bits). A transmission without a CRC may result in more frequent NACK-to-ACK errors than a transmission including a CRC. In this case, the UE may transmit on the BFR resources it considers to have reserved for it (e.g., the resources to transition to the second state), but in fact the resources may not have been activated by the base station. Various aspects of the present disclosure provide enhanced robustness for unmatched on-demand BFR activation.

In some cases, errors in ACK/NACK decoding may be reduced by techniques that apply a CRC to a feedback transmission (e.g., ACK/NACK feedback) regardless of the payload size of the uplink communication used to transmit the feedback. In some cases, the UE may determine that the uplink ACK/NACK feedback is less than or equal to a threshold indicating no CRC, and the UE may transmit the ACK/NACK feedback using an uplink transmission that shares a CRC with another uplink (such as a PUSCH transmission). In some cases, the UE may format the ACK/NACK feedback as a MAC-CE that is transmitted with the uplink shared channel transmission, thus calculating a CRC for the entire uplink transmission including the feedback information. In some cases, a MAC-CE may be defined to carry such feedback data, and the base station may identify the MAC-CE in the uplink transmission and decode the feedback accordingly. In some cases, the UE may be deployed in an IIoT or factory automation setting, and the acknowledged downlink transmission may be a motion control command, where the ACK/NACK feedback is a single bit indicating that the downlink command has been received. In such a case, a single bit may be defined for transmission with the uplink shared channel transmission (e.g., in a special MAC-CE), which provides such feedback and shares the CRC with the uplink shared channel transmission, thus having a higher likelihood of successful and correct decoding.

In other cases, the UE and the base station may configure the feedback transmission to have their own CRC even when the payload size is equal to or less than the payload size threshold. In some cases, the UE may add one or more padding bits (e.g., leading or trailing 1 or 0) to the feedback payload such that the padded payload exceeds a CRC-appended threshold (e.g., >11 bits). In other cases, the feedback payload may be encoded according to an encoding technique that provides an encoded output that exceeds a threshold for CRC attachment (e.g., bit patterns that are less than the threshold may be mapped to corresponding bit patterns that exceed a payload threshold size for CRC attachment). In other cases, the feedback payload may be repeated one or more times, so that the repeated payload exceeds the CRC-appended threshold. In still further cases, one or more combinations of padding, coding, or repetition may be used so that the payload exceeds the CRC attachment threshold. In some cases, the base station and the UE may dynamically indicate to the other party that a particular CRC attachment option applies to uplink transmissions with small payloads (e.g., ≦ 11 bits).

In some aspects of the present disclosure, the robustness of the activation of a BFR may be enhanced by providing confirmation of BFR activation or redundant indication of BFR activation. In some cases, such confirmation may be based on the base station transmitting the candidate beam RS if the base station determines a communication failure and the UE transmitting the BFRQ after detecting the candidate beam RS. In this case, if the UE does not detect any expected candidate beam RS (e.g., CSI-RS identified by a special scrambling sequence), the UE will not issue a BFRQ. In such a case, if the UE erroneously determines that the BFR procedure is activated, it does not receive the candidate beam RS, and then determines that the BFR procedure is not activated and communicates using the existing BPL in the subsequent communication cycle.

In other cases, the base station may send an explicit indication of whether the BFR procedure is activated in the current cycle. For example, in the initial downlink transmission of the current cycle, the base station may indicate BFR activation and a cause (e.g., one or more bits indicating that no uplink traffic was received or a NACK was received). The UE may accept activation in the initial uplink transmission upon receiving the explicit indication and the BFR procedure may proceed. For example, the base station may indicate BFR activation as due to not receiving an acknowledgement in the last cycle, even if the UE sent an acknowledgement in the last cycle, so the base station erroneously determines to configure a BFR because the UE did not receive a downlink transmission. In such a case, the UE may reject activation for a corresponding reason (e.g., if the base station reason indicates that no downlink ACK was received in the last cycle, the UE may reject for a reason that the downlink transmission was successfully sent in the last cycle). If activation is denied, both parties will assume that the BFR is not active in the current loop and use the existing BPL.

In a further case, the UE may indicate the communication result of the previous cycle. For example, in an initial uplink transmission, the UE may indicate the previous communication result and potentially request on-demand BFR activation. In such a case, the UE may provide a cause indication (e.g., a downlink ACK was not sent in the last cycle, but the base station may have received both DL ACK and UL traffic in error in the last cycle). Based on the initial uplink transmission of the NACK indicating the last cycle, the base station may activate the BFR procedure and both the UE and the base station may perform the BFR procedure.

In still further cases, if there is no communication for transmission, the UE, the base station, or both may transmit a 'no traffic' indication in the transmission opportunity. In such a case, an explicit indication of no traffic may be provided so that the receiving device may recognize that no traffic is present and may not erroneously determine that the transmission was not received due to a communication failure. In some cases, the no traffic indication may be a low rate physical or bit sequence indicating that there is no data to send. In other cases, the no traffic indicator may be implicitly determined when there is no transmission at all. The no traffic indicator may be issued during, before, or after the corresponding transmission opportunity (e.g., in the desired uplink/downlink initial transmission opportunity). When transmitting the no traffic indication, the transmitting and receiving device may speculate that an ACK for the corresponding "no traffic" transmission was received/issued when the BFR was determined to be active.

In other cases, the base station or UE may poll another device without successfully receiving the transmitted feedback. In such a case, after issuing a packet but not detecting the corresponding ACK/NACK, the base station or UE may poll another device to see if an ACK/NACK has been issued for the corresponding packet. In some cases, a packet may be identified by a dedicated sequence number (e.g., PDCP sequence number) or a corresponding time/frequency resource allocation (e.g., in an indication of a frame/slot index used for transmission). The packet may carry traffic or control information (e.g., MAC-CE). In some cases, the poll may be sent using a different BPL or TRP. The report in response to the poll may indicate whether and when the earliest ACK/NACK indication and result was issued. In some cases, if the transmitted packet contains control information (e.g., MAC-CE) and the polled report indicates that an ACK was issued, the corresponding MAC-CE activation time may be based on the timing of the earliest ACK issued.

In some cases, the base station or UE may determine that the received transmission is a retransmission of a previous transmission. Further, where an ACK is sent in response to a prior transmission, the receiving device may indicate in the response communication that ACK/NACK feedback has been sent, and may provide a corresponding transmission index. In some cases, the MAC-CE activation time may be based on the time the earliest ACK was issued, in the case where the previous transmission included a MAC-CE and the response indicated that an ACK was issued.

In some other cases, the reliability of the communication may be enhanced by transmitting multiple times on two or more beams. In such a case, the base station may transmit the downlink packet under a specific beam scanning pattern. For example, the base station may provide an indication that the downlink transmission will use a beam scanning pattern and then transmit all or a portion of the downlink transmission using each of the two or more beams indicated in the beam scanning pattern. In such a case, the UE may transmit a responsive uplink transmission using the same beam scanning pattern (e.g., using transmit beams of two or more beams QCLs as used in the downlink transmission). Further, uplink transmission using the beam scanning pattern may not be explicitly indicated separately for uplink transmission. In such a case, the downlink transmission may include a PDCCH or PDSCH transmission, or both, while the uplink transmission may include a PUCCH or PUSCH transmission, or both.

Fig. 4 illustrates an example of a BFR configuration 400 supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. In some examples, BFR configuration 400 may implement aspects of wireless communication systems 100, 200, and/or BFR configuration 300. Aspects of the BFR configuration 400 may be implemented by a first TRP, a second TRP, and/or a UE, which may be examples of corresponding devices described herein. BFR configuration 400 may include a previous communication period/cycle 405, a current communication period/cycle 410, and a subsequent communication period/cycle 415. The BFR configuration 400 illustrates an exemplary case where the communication failure recovery procedure is successful, and optionally includes acknowledging the TRP receiving the BFRQ. In this example, communication may be performed using a first TRP/BPL that has undergone a BFR procedure, and communication may be performed using a second TRP/BPL while the BFR procedure is being performed at the first TRP/BPL.

For example, the base station and the first TRP may perform wireless communication via the first BPL during the previous communication period/cycle 405. In some cases, the second TRP and the second BPL may be preconfigured in a previous cycle for use with the BFR process of the first BPL. In some aspects, wireless communication may be interrupted due to a communication failure detected or otherwise determined by the first TRP and the UE. Accordingly, the first TRP and the UE may transition the resource from the first state to the second state such that the resource is active for the communication failure recovery procedure. The communication failure recovery procedure may be implemented or otherwise performed during the current communication cycle/loop 410.

That is, the communication failure recovery procedure may include the first TRP transmitting the one or more BFR candidate beams RS in the downlink transmission 420 using the resource transitioned to the second state. The UE may monitor the BFR candidate beams RS to identify preferred candidate beams (e.g., the best candidate beam or the first N candidate beams, where N is a positive integer value of 2 or greater). The UE may transmit a BFRQ in the uplink transmission 425 using the resources transitioned to the second state. In some aspects, the BFRQ may carry or convey an indication identifying the best candidate beam for the UE.

The first TRP may receive a BFRQ from the UE and identify the best candidate beam. In some examples, the first TRP may optionally respond to the BFRQ by sending an ACK 430 to the UE acknowledging receipt of the BFRQ. In some aspects, the ACK 430 may carry or convey an indication confirming the identity of the best candidate beam, may explicitly identify the best candidate beam from the BFRQ, and/or may be transmitted using the beam corresponding to the best candidate beam. In some aspects, ACK 430 may be sent using the resources that transitioned to the second state. Thus, the first TRP and the UE may select the best candidate beam as a new beam to use for wireless communication during the post-communication period/cycle 415.

In this example, the UE and the second TRP may exchange communications during the BFR procedure in the current communication period/cycle 410. In this example, the second TRP may transmit downlink transmission 435 (e.g., a PUCCH or PUSCH transmission). The UE may send a response uplink transmission 440 to the second TRP using the second BPL, which may be acknowledged in this example by an ACK transmission 445 of the second TRP. After the BFR procedure, the UE and the second TRP may release resources of the second BPL and the second TRP. In some cases, the first TRP and the second TRP may be associated with the same base station. In some cases, during the BFR procedure, the UE and the first TRP may also communicate traffic on the previous first BPL to provide diversity.

Fig. 5 illustrates an example of a process flow 500 supporting a beam failure recovery technique in accordance with one or more aspects of the present disclosure. In some examples, the process flow 500 may implement aspects of the wireless communication system 100, 200 and/or the BFR configuration 300 or 400. Aspects of the process flow 500 may be implemented by the UE 505 and/or the base station 510, which may be examples of corresponding devices described herein. In some aspects, a UE 505, a base station 510, and/or a TRP may be considered a wireless device in the context of the present disclosure.

At 515, the base station 510 may configure periodic and on-demand BFR resources. In some cases, periodic and on-demand BFR resources may be configured and priority rules used where periodic and on-demand BFRs occur in the same communication cycle. At 520, base station 510 may send configuration information to UE 505. In some cases, the configuration information may be sent in RRC signaling indicating common downlink reference signal resources and UE-specific uplink resources for BFRQ.

At 525, UE 505 may configure BFR resources. In some cases, UE 505 may configure periodic and on-demand BFR resources. In some cases, the on-demand BFR resource may be in a first state in which the resource is active for wireless communication and inactive for a communication failure recovery procedure. At 530, UE 505 and base station 510 may transmit uplink and downlink communications. For example, such communication may occur via the first BPL.

At 535, UE 505 may determine that a communication failure has occurred during the first communication period. In some aspects, this may include determining that an initial transmission and/or retransmission was not sent to base station 510 during the first communication period. In some aspects, the initial transmission and/or retransmission may include a downlink ACK transmission and/or an uplink packet transmission.

At 540, the base station 510 may determine that a communication failure occurred within the first communication period. In some aspects, this may include determining that an initial transmission and/or retransmission was not received from UE 505 during the first communication period. In some aspects, the initial transmission and/or retransmission may include a downlink ACK transmission and/or an uplink packet transmission.

At 545, the UE 505 and the base station 510 may confirm the failure. In some cases, the failure may be confirmed by a redundant initiation of an ACK/NACK transmission. In some cases, the acknowledgement may be transmitted based on a reference signal transmitted by the base station as part of the BFR procedure. In some cases, an explicit indication of the failure may be provided and confirmed.

At 550, UE 505 may identify BFR resources for the BFR procedure. In some cases, the BFR resources may be determined based on priority rules for on-demand BFRs and periodic BFRs. At 555, the base station may identify BFR resources for the BFR procedure. In some cases, the BFR resources may be determined based on priority rules for on-demand BFRs and periodic BFRs.

At 560, UE 505 and base station 510 may perform a BFR procedure to identify an updated BPL for continued communication. In some aspects, this may include the base station 510 transmitting (and the UE 505 receiving) one or more BFR candidate beams RS using the resources transitioned to the second state. In some aspects, this may include the UE 505 transmitting (and the base station 510 receiving) a beam failure recovery request signal (e.g., BFRQ) identifying a preferred candidate beam associated with at least one of the one or more BFR candidate beams RS. In some aspects, the UE 505 and the base station 510 may perform wireless communication during the third communication period using the best candidate beam identified in the beam failure recovery request signal. In some aspects, this may include the base station 510 determining that no beam failure recovery request signal was received from the UE 505 during the second communication period. Accordingly, the base station 510 may perform wireless communication with the UE 505 during the third communication period using the same beam as that used during the first communication period. At 565, UE 505 and base station 510 may communicate using the updated BPL.

Fig. 6 illustrates an example of a process flow 600 to support beam failure recovery techniques in accordance with one or more aspects of the present disclosure. In some examples, processing flow 600 may implement aspects of wireless communication systems 100, 200 and/or BFR configurations 300 or 400. Aspects of processing flow 600 may be implemented by UE 610, first TRP 605, and second TRP 615, which may be examples of corresponding devices described herein. In some aspects, a UE and/or a TRP may be considered a wireless device in the context of the present disclosure.

At 620, the first TRP 605 may configure periodic and on-demand BFR resources. In some cases, periodic and on-demand BFR resources may be configured and priority rules used where periodic and on-demand BFRs occur in the same communication cycle. At 625, the first TRP 605 may send configuration information to UE 610. In some cases, the configuration information may be sent in RRC signaling indicating common downlink reference signal resources and UE-specific uplink resources for BFRQ.

At 630, UE 610 may configure BFR resources. In some cases, the UE 610 may configure periodic and on-demand BFR resources. In some cases, the on-demand BFR resource may be in a first state in which the resource is active for wireless communication and inactive for a communication failure recovery procedure.

At 635, the first TRP 605, UE 610, and second TRP 615 may be preconfigured with a second BPL at the second TRP 615. In some cases, the configuration of the second BPL may be a pre-configuration of the secondary BPL for use in the event of a communication failure. In some cases, the configuration of the second BPL may be a periodic configuration. In some cases, the configuration of the second BPL may be triggered by a measurement report associated with the first BPL, or based on periodic historical communication failures (e.g., based on equipment movement in IIoT deployments).

At 640, the first TRP 605 may determine that a communication failure occurred within the first communication period. In some aspects, this may include determining that an initial transmission and/or retransmission was not sent to the UE 610 during the first communication period. In some aspects, the initial transmission and/or retransmission may include a downlink ACK transmission and/or an uplink packet transmission.

At 645, the UE 610 may determine that a communication failure occurred within the first communication period. In some aspects, this may include determining that an initial transmission and/or retransmission was not received from the first TRP 605 during the first communication period. In some aspects, the initial transmission and/or retransmission may include a downlink ACK transmission and/or an uplink packet transmission. In some cases, the confirmation of the communication failure may be performed in accordance with various techniques discussed herein.

At 650, the UE 610 and the second TRP 615 may communicate using a preconfigured second BPL. In such a case, uninterrupted communication or relatively small communication interruptions may be provided to the UE 610.

At 655, first TRP 605 and UE 610 may perform a BFR procedure to identify an updated first BPL for continued communication. In some aspects, this may include the first TRP 605 transmitting (and the UE 610 receiving) the one or more BFR candidate beams RS using the resource transitioning to the second state. In some aspects, this may include the UE 610 transmitting (and the first TRP 605 receiving) a beam failure recovery request signal (e.g., BFRQ) identifying a preferred candidate beam associated with at least one of the one or more BFR candidate beams RS. At 660, the UE 610 and the first TRP 605 may communicate using the updated BPL. At 665, the first TRP 605, UE 610, and second TRP 615 may release resources of a second TRP associated with the second BPL.

Fig. 7 illustrates a block diagram 700 of an apparatus 705 that supports beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The device 705 may be an example of aspects of a UE 115 or a base station 105 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 720. The device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to beam failure recovery techniques, etc.). Information may be passed to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 1020 or 1120 as described with reference to fig. 10 and 11. Receiver 710 may utilize a single antenna or a group of antennas.

The communication manager 715 may configure a radio resource for a beam failure recovery process, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery process, and a second state in which the radio resource is inactive for data communications and active for the beam failure recovery process; determining that a communication failure has occurred within a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based on the communication failure; and performing the beam failure recovery procedure using the radio resource transitioned to the second state.

The communication manager 715 may also identify a first wireless resource for the on-demand beam failure recovery process and a periodic wireless resource configured for other beam failure recovery processes, determine that a second communication cycle includes the periodic wireless resource, determine that a communication failure has occurred within the first communication cycle, select one of the first wireless resource or the periodic wireless resource for performing the on-demand beam failure recovery process based on the communication failure and the second communication cycle includes the periodic wireless resource, and perform the on-demand beam failure recovery process using the selected wireless resource.

The communication manager 715 may also determine that the uplink communication has an uplink payload at or below a threshold payload size, wherein uplink communications with payload sizes above the threshold payload size will have a CRC appended to the uplink payload and uplink communications with payload sizes at or below the threshold payload size will be transmitted without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

The communication manager 715 may also configure radio resources for the beam failure recovery process; determining an initial fault state for a first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle; confirming a communication failure of the first communication cycle based on the redundant indication fed back for the confirmation; and performing the beam failure recovery procedure using the radio resource.

The communication manager 715 may also identify wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period; determining that the first communication period has no data to transmit; transmitting an indication that no data is to be transmitted for the first communication period; and speculating that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

The communication manager 715 may also establish a wireless connection with the second wireless device via the first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

The communication manager 715 may also establish a wireless connection with a second wireless device via a first beam pair link, initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period, establish an updated first beam pair link based on the beam failure recovery procedure, resume communication using the updated first beam pair link after the second communication period, and communicate with the second wireless device using a second beam pair link during the second communication period. The communication manager 715 may be an example of aspects of the communication manager 1010 or 1110 as described herein.

The communication manager 715 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or in any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 715 or subcomponents thereof may be controlled by a general purpose processor, a DSP, an Application Specific Integrated Circuit (ASIC), an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, which is intended to perform the functions described in this disclosure.

The communication manager 715 or subcomponents thereof may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, the communication manager 715 or subcomponents thereof may be separate and distinct components, in accordance with various aspects of the present disclosure. In some examples, the communication manager 715 or subcomponents thereof may be combined with one or more other hardware components including, but not limited to, an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in accordance with the present disclosure, or combinations thereof, in accordance with various aspects of the present disclosure.

Transmitter 720 may transmit signals generated by other components of device 705. In some examples, the transmitter 720 may be collocated with the receiver 710 in a transceiver module. For example, the transmitter 720 may be an example of aspects of the transceiver 1020 or 1120 as described with reference to fig. 10 and 11. The transmitter 720 may utilize a single antenna or a group of antennas.

Fig. 8 illustrates a block diagram 800 of an apparatus 805 that supports beam failure recovery techniques in accordance with one or more aspects of the disclosure. The device 805 may be an example of aspects of the device 705, the UE 115, or the base station 105 as described herein. The device 805 may include a receiver 810, a communication manager 815, and a transmitter 850. The device 805 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

Receiver 810 can receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to beam failure recovery techniques, etc.). Information may be passed to other components of device 805. The receiver 810 may be an example of aspects of the transceiver 1020 or 1120 as described with reference to fig. 10 and 11. Receiver 810 may utilize a single antenna or a group of antennas.

The communication manager 815 may be an example of aspects of the communication manager 715 as described herein. The communication manager 815 may include a resource manager 820, a communication failure manager 825, a resource transition manager 830, a communication failure recovery manager 835, a resource selection manager 840, and a CRC manager 845. The communication manager 815 may be an example of aspects of the communication manager 1010 or 1110 as described herein.

In some cases, the resource manager 820 may configure a radio resource for a beam failure recovery process, where the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery process, and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery process. The communication failure manager 825 may determine that a communication failure has occurred within the first communication period. The resource transition manager 830 may transition the wireless resource from the first state to the second state during the second communication period and based on the communication failure. The communication failure recovery manager 835 may perform the beam failure recovery procedure using the radio resource transitioned to the second state.

In some cases, the communication manager 820 may identify a first radio resource for an on-demand beam failure recovery procedure and a periodic radio resource configured for other beam failure recovery procedures, and determine that a second communication period includes the periodic radio resource. The communication failure manager 825 may determine that a communication failure has occurred within the first communication period. The resource selection manager 840 may select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based on the communication failure and the second communication cycle including the periodic radio resource. The communication failure recovery manager 835 may perform the on-demand beam failure recovery procedure using the selected radio resource.

In some cases, resource manager 820 may determine that the uplink communication has an uplink payload at or below a threshold payload size, where uplink communications with a payload size above the threshold payload size will have a CRC appended to the uplink payload, and uplink communications with a payload size at or below the threshold payload size will be sent without a CRC appended to the uplink payload. CRC manager 845 may configure the uplink communication to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size, and process the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

In some cases, resource manager 820 may configure radio resources for a beam failure recovery process. The communication failure manager 825 may determine an initial failure state of the first communication cycle based on failing to receive acknowledgement feedback for communication in the first communication cycle, and acknowledge the communication failure of the first communication cycle based on the redundant indication of the acknowledgement feedback. The communication failure recovery manager 835 may perform a beam failure recovery procedure using the radio resources.

In some cases, the resource manager 820 may identify wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period. The resource selection manager 840 may determine that the first communication period has no data to transmit and transmit an indication that the first communication period has no data to transmit. The communication failure manager 825 may infer that the acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

In some cases, resource manager 820 may establish a wireless connection with a second wireless device via a first beam pair link. The resource selection manager 840 may receive an indication from the second wireless device to transmit a first transmission in a first communication period according to a first beam sweep pattern using one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

In some cases, resource manager 820 may establish a wireless connection with a second wireless device via a first beam pair link. The communication failure recovery manager 835 may initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period, establish an updated first beam pair link based on the beam failure recovery procedure, and recover communication using the updated first beam pair link after the second communication period. The resource selection manager 840 may communicate with the second wireless device using a second beam pair link during the second communication period.

The transmitter 850 may transmit signals generated by other components of the device 805. In some examples, transmitter 850 may be collocated with receiver 810 in a transceiver module. For example, the transmitter 850 may be an example of aspects of the transceiver 1020 or 1120 as described with reference to fig. 10 and 11. Transmitter 850 may utilize a single antenna or a group of antennas.

Fig. 9 illustrates a block diagram 900 of a communication manager 905 supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The communication manager 905 may be an example of aspects of the communication manager 715, the communication manager 815, or the communication manager 1010 described herein. The communication manager 905 may include a resource manager 910, a communication failure manager 915, a resource transition manager 920, a communication failure recovery manager 925, an RRC manager 930, a resource selection manager 935, and a CRC manager 940. Each of these modules may communicate with each other, directly or indirectly (e.g., via one or more buses).

The resource manager 910 may configure a radio resource for a beam failure recovery process, where the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery process, and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery process.

In some examples, the communication manager 910 may identify a first radio resource for an on-demand beam failure recovery procedure and a periodic radio resource configured for other beam failure recovery procedures. In some examples, resource manager 910 may determine that the second communication period includes the periodic wireless resource. In some examples, the resource manager 910 may identify that the periodic wireless resource is prioritized over the first wireless resource in the second communication period.

In some examples, resource manager 910 may determine that the uplink communication has an uplink payload at or below a threshold payload size, where uplink communications with a payload size above the threshold payload size will have a CRC appended to the uplink payload and uplink communications with a payload size at or below the threshold payload size will be sent without a CRC appended to the uplink payload.

In some examples, resource manager 910 may configure radio resources for a beam failure recovery process. In some examples, resource manager 910 may identify a wireless resource for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period. In some examples, resource manager 910 may establish a wireless connection with a second wireless device via a first beam pair link.

In some cases, the wireless resources include a first downlink resource for transmitting, by the first transmit-receive point, one or more reference signals using one or more beams, and a first uplink resource for transmitting, by the UE, a beam failure request. In some cases, the first downlink resource is a common resource for transmitting the one or more reference signals to a group of UEs, and the first uplink resource is a UE-specific resource separately configured for each of the group of UEs. In some cases, the first uplink resources include one or more of physical uplink control channel resources, physical random access channel resources, or a combination thereof. In some cases, the first uplink resources include one or more of UE-specific time resources, frequency resources, spatial resources, code domain resources, or a combination thereof.

The communication failure manager 915 may determine that a communication failure has occurred within the first communication period. In some examples, the communication failure manager 915 may determine an initial failure state for a first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle. In some examples, the communication failure manager 915 may acknowledge the communication failure of the first communication cycle based on the redundant indication of the acknowledgement feedback.

In some examples, the communication failure manager 915 may infer that the acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

In some examples, the communication failure manager 915 may monitor the downlink portion of the radio resource for one or more reference signal transmissions via one or more candidate beams to be selected by the UE. In some examples, the communication failure manager 915 may determine that the one or more reference signal transmissions are present on the downlink portion of the wireless resource. In some examples, the communication failure manager 915 may select the first candidate beam based on measurements of one or more reference signal transmissions.

In some examples, the communication failure manager 915 may transmit a beam failure request indicating the first candidate beam on an uplink portion of the wireless resource. In some examples, the communication failure manager 915 may determine an initial failure state for a subsequent communication cycle based on the subsequent communication cycle.

In some examples, the communication failure manager 915 may monitor a downlink portion of the radio resource associated with the subsequent communication cycle for the one or more reference signal transmissions. In some examples, the communication failure manager 915 may determine that the one or more reference signals do not exist for transmission on the downlink portion of the radio resource associated with the subsequent communication period. In some examples, the communication failure manager 915 may discontinue the beam failure recovery process based on determining that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication period.

In some examples, the communication failure manager 915 may send an indication to the UE in a downlink transmission that the beam failure recovery procedure is activated. In some examples, the communication failure manager 915 may receive a response from the UE to the indication that the beam failure recovery procedure is activated.

In some examples, the communication failure manager 915 may receive an indication that the beam failure recovery procedure is activated in a downlink transmission from a base station. In some examples, the communication failure manager 915 may send a response to the base station indicating that the beam failure recovery procedure is activated. In some examples, the communication failure manager 915 may transmit a request to a base station to activate the beam failure recovery procedure, where the request indicates that a previous downlink transmission from the base station was not successfully received at the UE. In some examples, the communication failure manager 915 may receive a request from a UE to activate the beam failure recovery procedure, where the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

In some examples, the communication failure manager 915 may poll a base station that received uplink communications from the UE during a previous communication period to determine whether the acknowledgement feedback was sent by the base station.

In some examples, the communication failure manager 915 may receive a response from the base station indicating whether the acknowledgement feedback was sent by the base station. In some examples, the communication failure manager 915 may continue or discontinue the beam failure recovery process based on the response from the base station.

In some examples, the communication failure manager 915 may poll a UE that received downlink communications from the base station during a previous communication period to determine whether the acknowledgement feedback was sent by the UE. In some examples, the communication failure manager 915 may receive a response from the UE indicating whether the acknowledgement feedback was sent by the UE. In some examples, the communication failure manager 915 may continue or discontinue the beam failure recovery process based on the response from the UE.

In some examples, the communication failure manager 915 may determine that the packet transmitted during the first communication period is a retransmission of a previous transmission of the packet and that the previous acknowledgement feedback was previously transmitted for the packet. In some examples, the communication fault manager 915 may send an indication of prior acknowledgement feedback. In some cases, the one or more reference signal transmissions are identified based on a scrambling sequence used to scramble the one or more reference signal transmissions.

In some cases, the response from the UE indicates that the beam failure recovery procedure is activated, and wherein the base station performs the beam failure recovery procedure based at least in part on the acceptance.

In some cases, the response from the UE indicates that the UE refuses to activate the beam failure recovery procedure and indicates successful communication during the first communication period, and wherein the base station discontinues the beam failure recovery procedure based on the response from the UE. In some cases, the response to the base station indicates that the beam failure recovery procedure is activated, and wherein the UE performs the beam failure recovery procedure based on the acceptance. In some cases, the response to the base station indicates that the UE refuses to activate the beam failure recovery procedure and indicates successful communication during the first communication period, and wherein the UE discontinues the beam failure recovery procedure based on the response to the base station. In some cases, the uplink communication from the UE during the preceding communication period is identified based on a sequence number of the uplink communication, an index of a resource allocation of the uplink communication, or any combination thereof.

In some cases, the poll is sent in an uplink communication carrying uplink control information or data traffic. In some cases, the poll is transmitted using a different beam or a different TRP than the original transmission used for the uplink communication.

In some cases, the response from the base station indicates that the acknowledgement feedback was previously sent and indicates the time of the initial transmission of the acknowledgement feedback. In some cases, the uplink communication includes an activation indication, and wherein the activation time is determined based on a time of an initial transmission of the acknowledgement feedback.

In some cases, the downlink communication from the base station during the preceding communication period is identified based on a sequence number of the downlink communication, an index of a resource allocation of the downlink communication, or any combination thereof. In some cases, the poll is sent in a downlink communication carrying downlink control information or data traffic.

In some cases, the poll is transmitted using a different beam or a different TRP than the original transmission used for the downlink communication. In some cases, the response from the UE indicates that the acknowledgement feedback was previously sent and indicates the time of the initial transmission of the acknowledgement feedback. In some cases, the downlink communication includes an activation indication, and wherein the activation time is determined based on a time of an initial transmission of the acknowledgement feedback. In some cases, the prior transmission of the packet includes an activation indication, and wherein the activation time is determined based on a transmission time of the prior acknowledgement feedback.

The resource transition manager 920 may transition the wireless resource from the first state to the second state during the second communication period and based on the communication failure.

The communication failure recovery manager 925 may perform the beam failure recovery procedure using the radio resource transitioned to the second state. In some examples, the communication failure recovery manager 925 may perform the on-demand beam failure recovery procedure using the selected radio resource. In some examples, the communication failure recovery manager 925 may initiate a beam failure recovery procedure during the second communication period based on a communication failure with the second wireless device during the first communication period.

In some examples, the communication failure recovery manager 925 may establish an updated first beam pair link based on the beam failure recovery procedure. In some examples, the communication failure recovery manager 925 may resume communication with the updated first beam pair link after the second communication period.

The resource selection manager 935 may select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based on the communication failure and the second communication period including the periodic radio resource.

In some examples, the resource selection manager 935 may determine that the first communication period has no data to send. In some examples, the resource selection manager 935 may send an indication that there is no data to send for the first communication period.

In some examples, the resource selection manager 935 may receive an indication from the second wireless device to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams. In some examples, the resource selection manager 935 may receive the first transmission from the second wireless device in the first communication period according to the first beam scanning pattern. In some examples, the resource selection manager 935 may transmit a response transmission to the second wireless device based on the first transmission, where the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

In some examples, the resource selection manager 935 may communicate with the second wireless device using a second beam pair link during the second communication period.

In some examples, the resource selection manager 935 may select periodic wireless resources for performing an on-demand beam failure recovery procedure.

In some examples, the resource selection manager 935 may determine that the communication during the first communication period is a low latency communication. In some examples, the resource selection manager 935 may select the first wireless resource for performing the on-demand beam failure recovery procedure based on the communication during the first communication period being a low-latency communication. In some examples, the resource selection manager 935 may select the periodic wireless resource for performing the on-demand beam failure recovery procedure based on a timing of the periodic wireless resource being within a time threshold of the first wireless resource.

In some examples, the resource selection manager 935 may send a redundant communication to the second wireless device using the first beam-pair link during the second communication period.

In some examples, the resource selection manager 935 may release resources associated with the second beam pair link in response to establishing the updated first beam pair link.

In some cases, the priority of the first radio resource and the periodic radio resource is based on a communication latency target during the first communication period.

In some cases, the indication that no data is to be sent for the first communication period is a physical or bit sequence. In some cases, the indication that there is no data to transmit for the first communication period is a lack of any transmission in the first communication period. In some cases, the indication that no data is to be sent for the first communication period is provided before, during, or after the first communication period. In some cases, the first transmission is a downlink transmission that includes downlink shared channel information, downlink control channel information, or a combination thereof.

In some cases, the response transmission is an uplink transmission that includes uplink shared channel information, uplink control channel information, or a combination thereof. In some cases, the first beam scanning pattern includes a set of downlink beams and the second beam scanning pattern includes a set of uplink beams having beams reciprocal to the set of downlink beams. In some cases, the second beam pair link uses a different TRP than the first beam pair link, and wherein the different TRP and the second beam pair link are preconfigured prior to the first communication period.

CRC manager 940 may configure uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size. In some examples, CRC manager 940 may process the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC. In some examples, CRC manager 940 may format the acknowledgement feedback for transmission using uplink shared channel data, and/or wherein the acknowledgement feedback and the uplink shared channel data share the same CRC.

In some examples, CRC manager 940 may configure the acknowledgement feedback to exceed the threshold payload size. In some examples, CRC manager 940 may provide a dynamic indication that the acknowledgement feedback will include the CRC regardless of the uplink payload size.

In some cases, the acknowledgement feedback is sent with the uplink shared channel data in a MAC control element. In some cases, the acknowledgement feedback is a one-bit indication of the receipt of motion control data and is sent with the uplink shared channel data. In some cases, the acknowledgement feedback is padded with one or more bits to have a payload size that exceeds the threshold payload size. In some cases, the acknowledgement feedback is encoded to have a payload size greater than the threshold payload size. In some cases, the acknowledgement feedback is repeated one or more times to provide a payload size that exceeds the threshold payload size.

RRC manager 930 may exchange RRC messages indicating radio resources configured for the beam failure recovery procedure.

Fig. 10 illustrates a diagram of a system 1000 that includes an apparatus 1005 that supports beam failure recovery techniques in accordance with one or more aspects of the present disclosure. Device 1005 may be an example of, or include a component of, device 705, device 805, or UE 115 described herein. Device 1005 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1010, a transceiver 1020, an antenna 1025, a memory 1030, a processor 1040, and an I/O controller 1050. These components may be in electronic communication via one or more buses, such as bus 1055.

The communication manager 1010 can configure a radio resource for a beam failure recovery procedure, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery procedure and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery procedure; determining that a communication failure has occurred within a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based on the communication failure; and performing the beam failure recovery procedure using the radio resource transitioned to the second state.

The communication manager 1010 may also identify a first radio resource for an on-demand beam failure recovery process and a periodic radio resource configured for other beam failure recovery processes, determine that a second communication cycle includes the periodic radio resource, determine that a communication failure has occurred within the first communication cycle, select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery process based on the communication failure and the second communication cycle including the periodic radio resource, and perform the on-demand beam failure recovery process using the selected radio resource.

The communication manager 1010 can also determine that the uplink communication has an uplink payload at or below a threshold payload size, wherein uplink communications with payload sizes above the threshold payload size will have a CRC appended to the uplink payload and uplink communications with payload sizes at or below the threshold payload size will be transmitted without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

The communication manager 1010 may also configure radio resources for the beam failure recovery process; determining an initial fault state for a first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle; confirming a communication failure of the first communication cycle based on the redundant indication fed back for the confirmation; and performing the beam failure recovery procedure using the radio resource.

The communication manager 1010 can also identify wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period; determining that the first communication period has no data to transmit; transmitting an indication that no data is to be transmitted for the first communication period; and speculating that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

The communication manager 1010 may also establish a wireless connection with a second wireless device via a first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

The communication manager 1010 may also establish a wireless connection with a second wireless device via a first beam pair link, initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period, establish an updated first beam pair link based on the beam failure recovery procedure, resume communication using the updated first beam pair link after the second communication period, and communicate with the second wireless device using a second beam pair link during the second communication period.

As described herein, the transceiver 1020 may communicate bi-directionally via one or more antennas, wired or wireless links. For example, transceiver 1020 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate packets and provide the modulated packets to the antennas for transmission, as well as to demodulate packets received from the antennas.

In some cases, a wireless device may include a single antenna 1025. However, in some cases, the device may have more than one antenna 1025, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously.

Memory 1030 may include RAM, ROM, or a combination thereof. The memory 1030 may store computer readable code 1035 comprising instructions that, when executed by a processor (e.g., the processor 1040), cause the device to perform various functions described herein. In some cases, memory 1030 may contain, among other things, a BIOS that may control basic hardware or software operations, such as interacting with peripheral components or devices.

Processor 1040 may include intelligent hardware devices (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1040 may be configured to operate the memory array using a memory controller. In other cases, a memory controller may be integrated into processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks to support beam failure recovery techniques).

I/O controller 1050 may manage input and output signals for device 1005. I/O controller 1050 may also manage not integrating intoPeripheral devices in device 1005. In some cases, I/O controller 1050 may represent a physical connection or port to an external peripheral device. In some cases, I/O controller 1050 may utilize a processor such as Such as an operating system or another known operating system. In other cases, I/O controller 1050 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I/O controller 1050 can be implemented as part of a processor. In some cases, a user may interact with device 1005 via I/O controller 1050 or via hardware components controlled through I/O controller 1050.

Code 1035 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. Code 1035 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, code 1035 may not be directly executable by processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

Fig. 11 illustrates a diagram of a system 1100 that includes a device 1105 that supports beam failure recovery techniques in accordance with one or more aspects of the disclosure. Device 1105 may be an example of or include a component of device 705, device 805, or base station 105 described herein. The device 1105 may include components for two-way voice and data communications including components for sending and receiving communications including a communications manager 1110, a network communications manager 1115, a transceiver 1120, an antenna 1125, a memory 1130, a processor 1140 and an inter-station communications manager 1145. These components may be in electronic communication via one or more buses, such as bus 1155.

The communication manager 1110 may configure a radio resource for a beam failure recovery procedure, wherein the radio resource is configured to have a first state in which the radio resource is active for data communication and inactive for the beam failure recovery procedure and to have a second state in which the radio resource is inactive for data communication and active for the beam failure recovery procedure; determining that a communication failure has occurred within a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based on the communication failure; and performing the beam failure recovery procedure using the radio resource transitioned to the second state.

The communication manager 1110 may also identify a first radio resource for the on-demand beam failure recovery process and a periodic radio resource configured for other beam failure recovery processes, determine that a second communication cycle includes the periodic radio resource, determine that a communication failure occurred within the first communication cycle, select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery process based on the communication failure and the second communication cycle including the periodic radio resource, and perform the on-demand beam failure recovery process using the selected radio resource.

Communication manager 1110 may also determine that the uplink communication has an uplink payload at or below a threshold payload size, wherein uplink communications with a payload size above the threshold payload size will have a CRC appended to the uplink payload and uplink communications with a payload size at or below the threshold payload size will be transmitted without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC.

Communication manager 1110 may also configure radio resources for the beam failure recovery process; determining an initial fault state for a first communication cycle based on a failure to receive acknowledgement feedback for communication in the first communication cycle; confirming a communication failure of the first communication cycle based on the redundant indication fed back for the confirmation; and performing the beam failure recovery procedure using the radio resource.

Communication manager 1110 may also identify wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback of communications in the first communication period; determining that the first communication period has no data to transmit; transmitting an indication that no data is to be transmitted for the first communication period; and speculating that acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

Communication manager 1110 may also establish a wireless connection with a second wireless device via a first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

The communication manager 1110 may also establish a wireless connection with a second wireless device via a first beam pair link, initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period, establish an updated first beam pair link based on the beam failure recovery procedure, resume communication using the updated first beam pair link after the second communication period, and communicate with the second wireless device using a second beam pair link during the second communication period.

The network communication manager 1115 may manage (e.g., via one or more wired backhaul links) communication with a core network. For example, the network communication manager 1115 may manage transmissions of data communications for client devices (such as one or more UEs 115).

The transceiver 1120 may communicate bi-directionally via one or more antennas, wired, or wireless links, as described herein. For example, transceiver 1120 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1120 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission and to demodulate packets received from the antenna.

In some cases, the wireless device may include a single antenna 1125. However, in some cases, the device may have more than one antenna 1125 that may be capable of transmitting or receiving multiple wireless transmissions simultaneously.

The memory 1130 may include RAM, ROM, or a combination thereof. The memory 1130 may store computer readable code 1135 comprising instructions that, when executed by a processor (e.g., processor 1140), cause the device to perform various functions described herein. In some cases, memory 1130 may contain, among other things, a BIOS, which may control basic hardware or software operations, such as interacting with peripheral components or devices.

Processor 1140 may include intelligent hardware devices (e.g., general purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combinations thereof). In some cases, processor 1140 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 1140. Processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1130) to cause device 1105 to perform various functions (e.g., functions or tasks to support beam failure recovery techniques).

The inter-station communication manager 1145 may manage communications with other base stations 105 and may include a controller or scheduler to control communications with the UEs 115 in cooperation with the other base stations 105. For example, the inter-station communication manager 1145 may coordinate scheduling of transmissions to the UEs 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-station communication manager 1145 may provide an X2 interface within LTE/LTE-a wireless communication network technology to provide communications between base stations 105.

Code 1135 may include instructions for implementing aspects of the present disclosure, including instructions for supporting wireless communications. Code 1135 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, code 1135 may not be directly executable by processor 1140, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

Fig. 12 illustrates a flow diagram showing a method 1200 of supporting a beam failure recovery technique in accordance with one or more aspects of the present disclosure. The operations of method 1200 may be performed by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1200 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1205, the UE or base station can configure a radio resource for a beam failure recovery procedure, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery procedure and a second state in which the radio resource is inactive for data communications and active for the beam failure recovery procedure. Operation 1205 may be performed according to the methods described herein. In some examples, aspects of operation 1205 may be performed by a resource manager as described with reference to fig. 7-11.

At 1210, the UE or the base station may determine that a communication failure has occurred during a first communication period. Operation 1210 may be performed according to the methods described herein. In some examples, aspects of operation 1210 may be performed by a communication fault manager as described with reference to fig. 7-11.

At 1215, the UE or base station may transition the radio resource from the first state to the second state during a second communication period and based on the communication failure. Operation 1215 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1215 may be performed by a resource transition manager as described with reference to fig. 7-11.

At 1220, the UE or the base station performs the beam failure recovery procedure using the radio resource transitioned to the second state. Operation 1220 may be performed according to the methods described herein. In some examples, aspects of operation 1220 may be performed by a communication failover manager as described with reference to fig. 7-11.

Fig. 13 illustrates a flow diagram showing a method 1300 of supporting a beam failure recovery technique in accordance with one or more aspects of the present disclosure. The operations of method 1300 may be performed by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1300 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1305, the UE or base station may identify a first radio resource for an on-demand beam failure recovery procedure and a periodic radio resource configured for other beam failure recovery procedures. Operation 1305 may be performed according to the methods described herein. In some examples, aspects of operation 1305 may be performed by a resource manager as described with reference to fig. 7-11.

At 1310, the UE or base station may determine that a communication failure has occurred during the first communication period. Operation 1310 may be performed according to the methods described herein. In some examples, aspects of operation 1310 may be performed by a communication fault manager as described with reference to fig. 7-11.

At 1315, the UE or the base station may determine that the second communication period includes the periodic radio resource. Operation 1315 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1315 may be performed by a resource manager as described with reference to fig. 7-11.

At 1320, the UE or base station may select one of the first radio resource or the periodic radio resource for performing the on-demand beam failure recovery procedure based on the communication failure and the second communication cycle including the periodic radio resource. Operation 1320 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1320 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1325, the UE or base station may perform the on-demand beam failure recovery procedure using the selected wireless resource. Operation 1325 may be performed according to methods described herein. In some examples, aspects of operation 1325 may be performed by a communication failover manager as described with reference to fig. 7-11.

Fig. 14 illustrates a flow diagram showing a method 1400 of supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The operations of the method 1400 may be performed by the UE 115 or the base station 105, or components thereof, as described herein. For example, the operations of method 1400 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1405, the UE or the base station may determine that the uplink communication has an uplink payload at or below a threshold payload size, wherein the uplink communication having a payload size above the threshold payload size will have a CRC appended to the uplink payload and the uplink communication having a payload size at or below the threshold payload size will be sent without a CRC appended to the uplink payload. Operation 1405 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1405 may be performed by a resource manager as described with reference to fig. 7-11.

At 1410, the UE or base station may configure uplink communications to include acknowledgement feedback to include a CRC appended to the uplink payload regardless of the uplink payload size. Operation 1410 may be performed according to the methods described herein. In some examples, aspects of operation 1410 may be performed by a CRC manager as described with reference to fig. 7-11.

At 1415, the UE or the base station may process the uplink communication based on the uplink communication including the acknowledgement feedback and the CRC. Operation 1415 may be performed according to the methods described herein. In some examples, aspects of operation 1415 may be performed by a CRC manager as described with reference to fig. 7-11.

Fig. 15 shows a flow diagram illustrating a method 1500 of supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The operations of method 1500 may be performed by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1500 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1505, the UE or base station may configure radio resources for a beam failure recovery procedure. Operation 1505 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1505 may be performed by a resource manager as described with reference to fig. 7-11.

At 1510, the UE or base station may determine an initial failure state for a first communication cycle based on failing to receive acknowledgement feedback for communication in the first communication cycle. Operation 1510 may be performed according to the methods described herein. In some examples, aspects of operation 1510 may be performed by a communication fault manager as described with reference to fig. 7-11.

At 1515, the UE or the base station may acknowledge the communication failure for the first communication cycle based on the redundant indication of the acknowledgement feedback. Operation 1515 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1515 may be performed by the communication fault manager as described with reference to fig. 7-11.

At 1520, the UE or base station may perform the beam failure recovery procedure using the radio resources. Operation 1520 may be performed according to methods described herein. In some examples, aspects of operation 1520 may be performed by a communication failover manager as described with reference to fig. 7-11.

Fig. 16 illustrates a flow diagram showing a method 1600 of supporting a beam failure recovery technique in accordance with one or more aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1600 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1605, the UE or base station may identify wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based on acknowledgement feedback for communication in the first communication period. Operation 1605 may be performed in accordance with the methodologies described herein. In some examples, aspects of operation 1605 may be performed by a resource manager as described with reference to fig. 7-11.

At 1610, the UE or base station may determine that the first communication period has no data to transmit. Operation 1610 may be performed according to methods described herein. In some examples, aspects of operation 1610 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1615, the UE or base station may transmit an indication that there is no data to transmit for the first communication period. Operation 1615 may be performed according to methods described herein. In some examples, aspects of operation 1615 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1620, the UE or base station may infer that acknowledgement feedback associated with the first communication period indicates successful communication for the purpose of initiating the beam failure recovery procedure. Operation 1620 may be performed according to methods described herein. In some examples, aspects of operation 1620 may be performed by a communication fault manager as described with reference to fig. 7-11.

Fig. 17 illustrates a flow diagram showing a method 1700 of supporting a beam failure recovery technique in accordance with one or more aspects of the present disclosure. The operations of method 1700 may be implemented by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1700 may be performed by a communication manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1705, the UE or base station may establish a wireless connection with a second wireless device via a first beam pair link. Operation 1705 may be performed according to methods described herein. In some examples, aspects of operation 1705 may be performed by a resource manager as described with reference to fig. 7-11.

At 1710, the UE or base station may receive an indication from the second wireless device to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams. Operation 1710 may be performed according to the methods described herein. In some examples, aspects of operation 1710 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1715, the UE or base station may receive the first transmission from the second wireless device in the first communication period according to the first beam scanning pattern. Operation 1715 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1715 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1720, the UE or the base station may transmit a response transmission to the second wireless device based on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period. Operation 1720 may be performed according to methods described herein. In some examples, aspects of operation 1720 may be performed by a resource selection manager as described with reference to fig. 7-11.

Fig. 18 illustrates a flow diagram showing a method 1800 of supporting beam failure recovery techniques in accordance with one or more aspects of the present disclosure. The operations of method 1800 may be implemented by a UE 115 or a base station 105, or components thereof, as described herein. For example, the operations of method 1800 may be performed by a communications manager as described with reference to fig. 7-11. In some examples, the UE or base station may execute the set of instructions to control the functional elements of the UE or base station to perform the functions described below. Additionally or alternatively, the UE or base station may use dedicated hardware to perform aspects of the functions described below.

At 1805, the UE or base station may establish a wireless connection with a second wireless device via a first beam pair link. Operation 1805 may be performed in accordance with the methods described herein. In some examples, aspects of operation 1805 may be performed by a resource manager as described with reference to fig. 7-11.

At 1810, the UE or the base station may initiate a beam failure recovery procedure during a second communication period based on a communication failure with the second wireless device during the first communication period. Operation 1810 may be performed according to the methods described herein. In some examples, aspects of operation 1810 may be performed by a communication failover manager as described with reference to fig. 7-11.

At 1815, the UE or base station may communicate with the second wireless device using a second beam pair link during the second communication period. Operation 1815 may be performed according to the methods described herein. In some examples, aspects of operation 1815 may be performed by a resource selection manager as described with reference to fig. 7-11.

At 1820, the UE or the base station may establish an updated first beam pair link based on the beam failure recovery procedure. Operation 1820 may be performed according to methods described herein. In some examples, aspects of operation 1820 may be performed by a communication failover manager as described with reference to fig. 7-11.

At 1825, the UE or the base station may resume communication with the link using the updated first beam after the second communication period. Operation 1825 may be performed according to methods described herein. In some examples, aspects of operation 1825 may be performed by a communication failover manager as described with reference to fig. 7-11.

It should be noted that the methods described herein describe possible embodiments, and that the operations may be rearranged or otherwise modified, and that other embodiments are possible. Further, aspects from two or more methods may be combined.

The following provides an overview of examples of the present disclosure:

example 1: a method for wireless communications at a first wireless device, comprising: establishing a wireless connection with a second wireless device via a first beam pair link; initiating a beam failure recovery procedure during a second communication period based at least in part on a communication failure with the second wireless device during a first communication period; communicating with the second wireless device using a second beam pair link during the second communication period; establishing an updated first beam pair link based at least in part on the beam failure recovery procedure; and resuming communication to the link using the updated first beam after the second communication period.

Example 2: the method of example 1, wherein the second beam pair link uses a different TRP than the first beam pair link, and/or wherein the different TRP and the second beam pair link are preconfigured prior to the first communication period.

Example 3: the method of example 1 or 2, further comprising: transmitting a redundant communication to the second wireless device using the first beam-pair link during the second communication period.

Example 4: the method of any of examples 1-3, further comprising: releasing resources associated with the second beam pair link in response to establishing the updated first beam pair link.

Example 5: a method for wireless communications at a wireless device, comprising: identifying a first wireless resource for an on-demand beam failure recovery process and a periodic wireless resource configured for other beam failure recovery processes; determining that a communication failure has occurred during a first communication period; determining that a second communication period includes the periodic wireless resource; selecting one of the first wireless resource or the periodic wireless resource for performing the on-demand beam failure recovery procedure based at least in part on the communication failure and the second communication period comprising the periodic wireless resource; and performing the on-demand beam failure recovery procedure using the selected radio resource.

Example 6: the method of example 5, wherein the selecting comprises: identifying that the periodic radio resource is prioritized over the first radio resource in the second communication period; and selecting the periodic radio resource for performing the on-demand beam failure recovery procedure.

Example 7: the method of example 5 or 6, wherein the priority of the first radio resource and the periodic radio resource is based at least in part on a communication latency target during the first communication period.

Example 8: the method of examples 5 or 7, wherein the selecting comprises: determining that communications during the first communication period are low latency communications; and selecting the first radio resource for performing the on-demand beam failure recovery procedure based at least in part on the communication during the first communication period being a low latency communication.

Example 9: the method of any of examples 5 to 7, wherein the selecting comprises: selecting the periodic wireless resource for performing the on-demand beam failure recovery procedure based at least in part on a timing of the periodic wireless resource being within a time threshold of the first wireless resource.

Example 10: a method for wireless communications at a wireless device, comprising: configuring a radio resource for a beam failure recovery procedure; determining an initial fault state for a first communication cycle based at least in part on a failure to receive acknowledgement feedback for communication in the first communication cycle; confirming a communication failure for the first communication cycle based at least in part on the redundant indication of confirmation feedback; and performing the beam failure recovery procedure using the radio resource.

Example 11: the method of example 10, wherein the method is performed at a UE, and/or wherein the confirming the communication failure comprises: monitoring a downlink portion of the radio resource for one or more reference signal transmissions via one or more candidate beams to be selected by the UE; determining that the one or more reference signal transmissions are present on the downlink portion of the wireless resource; selecting a first candidate beam based at least in part on the measurements of the one or more reference signal transmissions; and transmitting a beam failure request indicating the first candidate beam on an uplink portion of the radio resource.

Example 12: the method of example 10 or 11, wherein the one or more reference signal transmissions are identified based at least in part on a scrambling sequence used to scramble the one or more reference signal transmissions.

Example 13: the method of any of examples 10-12, further comprising: for a subsequent communication cycle, determining the initial fault state for the subsequent communication cycle; monitoring the downlink portion of the wireless resources associated with the subsequent communication period for the one or more reference signal transmissions; determining that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication period; and interrupting the beam failure recovery process based at least in part on determining that the one or more reference signal transmissions are not present on the downlink portion of the wireless resource associated with the subsequent communication cycle.

Example 14: the method of example 10, wherein the method is performed by a base station, and/or wherein the confirming the communication failure comprises: transmitting an indication to the UE that the beam failure recovery procedure is activated in a downlink transmission; and receiving a response from the UE to the indication that the beam failure recovery procedure is activated.

Example 15: the method of example 10 or 14, wherein the response from the UE indicates acceptance of activation of the beam failure recovery procedure, and/or wherein the base station performs the beam failure recovery procedure based at least in part on the acceptance.

Example 16: the method of example 10, 14, or 15, wherein the response from the UE indicates that the UE refuses activation of the beam failure recovery procedure and indicates successful communication during the first communication period, and/or wherein the base station discontinues the beam failure recovery procedure based at least in part on the response from the UE.

Example 17: the method according to any of examples 10 to 13, wherein the method is performed by a UE, and/or wherein the confirming the communication failure comprises: receiving an indication that the beam failure recovery procedure is activated in a downlink transmission from a base station; and sending a response to the indication that the beam failure recovery procedure is activated to the base station.

Example 18: the method of any of examples 10 to 13 or 17, wherein the response to the base station indicates acceptance of activation of the beam failure recovery procedure, and/or wherein the UE performs the beam failure recovery procedure based at least in part on the acceptance.

Example 19: the method of any of examples 10 to 13, 17 or 18, wherein the method is performed by a UE, and/or wherein the confirming the communication failure comprises: transmitting a request to a base station for activation of the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

Example 20: the method of any of examples 10 or 14 to 16, wherein the method is performed by a base station, and/or wherein the confirming the communication failure comprises: receiving a request from a UE to activate the beam failure recovery procedure, wherein the request indicates that a previous downlink transmission from the base station was not successfully received at the UE.

Example 21: the method of any of examples 10 to 13 or 17 to 19, wherein the method is performed by a UE, and/or wherein the confirming the communication failure comprises: polling a base station that is to receive uplink communications from the UE during a preceding communication period to determine whether the acknowledgement feedback is sent by the base station; receiving a response from the base station indicating whether the acknowledgement feedback was sent by the base station; and continuing or interrupting the beam failure recovery process based at least in part on the response from the base station.

Example 22: the method of any of examples 10-13, 17-19, and 21, wherein the uplink communication from the UE during the preceding communication period is identified based at least in part on a sequence number of the uplink communication, an index of a resource allocation of the uplink communication, or any combination thereof; wherein the poll is sent in an uplink communication carrying uplink control information or data traffic; wherein the poll is transmitted using a different beam or a different TRP than the original transmission used for the uplink communication; wherein the response from the base station indicates that the acknowledgement feedback was previously sent and indicates a time of initial transmission of the acknowledgement feedback; or wherein the uplink communication comprises an activation indication, and/or wherein an activation time is determined based on the time of the initial transmission of the acknowledgement feedback.

Example 23: the method of any of examples 10, 14 to 16 or 20, wherein the method is performed by a base station, and/or wherein the confirming the communication failure comprises: polling a UE that is to receive downlink communications from the base station during a preceding communication period to determine whether the acknowledgement feedback is sent by the UE; receiving, from the UE, a response indicating whether the acknowledgement feedback was sent by the UE; and continuing or interrupting the beam failure recovery procedure based at least in part on the response from the UE.

Example 24: the method of any of examples 10, 14 to 16, 20 or 23, wherein the downlink communication from the base station during the preceding communication period is identified based at least in part on a sequence number of the downlink communication, an index of a resource allocation of the downlink communication, or any combination thereof; wherein the poll is sent in a downlink communication carrying downlink control information or data traffic; wherein the poll is transmitted using a different beam or a different TRP than the original transmission used for the downlink communication; wherein the response from the UE indicates that the acknowledgement feedback was previously sent and indicates a time of initial transmission of the acknowledgement feedback; wherein the downlink communication comprises an activation indication; or wherein an activation time is determined based on the time of the initial transmission of the acknowledgement feedback.

Example 25: the method of any of examples 10 to 24, wherein the confirming of the communication failure comprises: determining that a packet transmitted during the first communication period is a retransmission of a previous transmission of the packet and that the previous acknowledgement feedback was previously transmitted for the packet; and sending an indication of the prior acknowledgement feedback.

Example 26: the method according to any of examples 10 to 25, wherein the previous transmission of the packet comprises an activation indication, and/or wherein an activation time is determined based on a transmission time of the previous acknowledgement feedback.

Example 27: a method for wireless communications at a wireless device, comprising: configuring a radio resource for a beam failure recovery procedure, wherein the radio resource is configured to have a first state in which the radio resource is active for data communications and inactive for the beam failure recovery procedure and to have a second state in which the radio resource is inactive for data communications and active for the beam failure recovery procedure; determining that a communication failure has occurred during a first communication period; transitioning the wireless resource from the first state to the second state during a second communication period and based at least in part on the communication failure; and performing the beam failure recovery procedure using the wireless resource transitioned to the second state.

Example 28: the method of example 27, wherein the configuring comprises: exchanging RRC messages indicating the radio resources configured for the beam failure recovery procedure.

Example 29: the method of example 27 or 28, wherein the wireless resources comprise a first downlink resource for transmitting one or more reference signals by a first TRP using one or more beams and a first uplink resource for transmitting a beam failure request by a UE.

Example 30: the method of any of examples 27 to 29, wherein the first downlink resource is a common resource for transmitting the one or more reference signals to a plurality of UEs, and the first uplink resource is a UE-specific resource separately configured for each of the plurality of UEs; or wherein the first uplink resources comprise one or more of physical uplink control channel resources, physical random access channel resources, UE-specific time resources, frequency resources, spatial resources, code domain resources, or a combination thereof.

Example 31: a method for wireless communications at a wireless device, comprising: determining that an uplink communication has an uplink payload at or below a threshold payload size, wherein the uplink communication having a payload size above the threshold payload size will have a CRC appended to the uplink payload and the uplink communication having a payload size at or below the threshold payload size will be sent without a CRC appended to the uplink payload; configuring uplink communications to include acknowledgement feedback to include the CRC appended to the uplink payload regardless of the uplink payload size; and processing the uplink communication based at least in part on the uplink communication including the acknowledgement feedback and the CRC.

Example 32: the method of example 31, wherein the configuring comprises: formatting the acknowledgement feedback for transmission using uplink shared channel data, and/or wherein the acknowledgement feedback and the uplink shared channel data share the same CRC.

Example 33: the method of example 31 or 32: wherein the acknowledgement feedback is sent with the uplink shared channel data in a MAC control element.

Example 34: the method of any of examples 31-33: wherein the acknowledgement feedback is a one bit indication of receipt of motion control data and is transmitted with the uplink shared channel data.

Example 35: the method of any of examples 31-34: wherein the configuring comprises: configuring the acknowledgement feedback to exceed the threshold payload size.

Example 36: the method of any one of examples 31-35: wherein the acknowledgement feedback is padded with one or more bits to have a payload size that exceeds the threshold payload size.

Example 37: the method of any of examples 31-36: wherein the acknowledgement feedback is encoded to have a payload size greater than the threshold payload size.

Example 38: the method of any one of examples 31 to 37: wherein the acknowledgement feedback is repeated one or more times to provide a payload size that exceeds the threshold payload size.

Example 39: the method of any of examples 31-38: wherein the configuring comprises: providing a dynamic indication that the acknowledgement feedback is to include the CRC regardless of the uplink payload size.

Example 40: a method for wireless communications at a wireless device, comprising: identifying wireless resources for a beam failure recovery procedure, wherein the determination to initiate the beam failure recovery procedure is based at least in part on acknowledgement feedback of communications in the first communication cycle; determining that the first communication period has no data to transmit; transmitting an indication that there is no data to transmit for the first communication period; and speculating that the acknowledgement feedback associated with the first communication cycle indicates successful communication for the purpose of initiating the beam failure recovery procedure.

Example 41: the method of example 40, wherein the indication that there is no data to send for the first communication period is a physical or bit sequence.

Example 42: the method of example 40, wherein the indication that there is no data to send for the first communication period is a lack of any sending in the first communication period.

Example 43: the method of example 40 or 41, wherein the indication that there is no data to send for the first communication period is provided before, during, or after the first communication period.

Example 44: the method of any of examples 40-43, wherein the acknowledgement feedback is a sequence of bits representing a positive acknowledgement.

Example 45: the method of any of examples 40-43, wherein the acknowledgement feedback is a sequence of bits representing a negative acknowledgement.

Example 46: the method of any of examples 40 to 43, wherein the acknowledgement feedback is no transmission.

Example 47: a method for wireless communications at a first wireless device, comprising: establishing a wireless connection with a second wireless device via a first beam pair link; receiving, from the second wireless device, an indication to transmit a first transmission in a first communication period according to a first beam scanning pattern that uses one or more beams; receiving the first transmission from the second wireless device in the first communication period according to the first beam sweeping pattern; and transmitting a response transmission to the second wireless device based at least in part on the first transmission, wherein the response transmission is transmitted using a second beam sweep pattern corresponding to the first beam sweep pattern in the first communication period.

Example 48: the method of example 47: wherein the first transmission is a downlink transmission comprising downlink shared channel information, downlink control channel information, or a combination thereof; and/or wherein the response transmission is an uplink transmission comprising uplink shared channel information, uplink control channel information, or a combination thereof.

Example 49: the method of example 47 or 48: wherein the second beam scanning pattern is not explicitly indicated by the second wireless device.

Example 50: the method of any one of examples 47-49: wherein the first beam scanning pattern comprises a set of downlink beams and the second beam scanning pattern comprises a set of uplink beams having beams reciprocal to the set of downlink beams.

Example 51: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 1-4.

Example 52: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 5-9.

Example 53: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 10-26.

Example 54: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 27-30.

Example 55: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 31-39.

Example 56: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform the method of any of examples 40-46.

Example 57: a device for wireless communication, comprising: a processor; a memory coupled with the processor, the processor and memory configured to perform a method according to any one of examples 47-49.

Example 58: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 1-4.

Example 59: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 5-9.

Example 60: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 10-26.

Example 61: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 27-30.

Example 62: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 31-39.

Example 63: an apparatus for wireless communication, comprising at least one means for performing the method of any of examples 40-46.

Example 64: an apparatus for wireless communication, comprising at least one means for performing the method of any one of examples 47-49.

Example 65: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 1-4.

Example 66: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 5-9.

Example 67: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 10-26.

Example 68: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 27-30.

Example 69: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 31-39.

Example 70: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any of examples 40-46.

Example 71: a non-transitory computer-readable medium storing code for wireless communication, comprising: a processor; a memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of examples 47 to 49.

The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, single-carrier frequency division multiple access (SC-FDMA), and other systems. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. The IS-2000 version IS commonly referred to as CDMA 20001X, 1X, etc. IS-856(TIA-856) IS commonly referred to as CDMA 20001 xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (wcdma) and other variants of CDMA. A TDMA system may implement a radio technology such as global system for mobile communications (GSM).

The OFDMA system may implement radio technologies such as Ultra Mobile Broadband (UMB), E-UTRA, Institute of Electrical and Electronics Engineers (IEEE)802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE, LTE-A and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, LTE-A Pro, NR, and GSM are described in documents entitled "3 rd Generation partnership project" (3GPP) organization. CDMA2000 and UMB are described in documents from an organization named "3 rd generation partnership project 2" (3GPP 2). The techniques described herein may be used for the systems and radio techniques mentioned herein as well as other systems and radio techniques. Although aspects of the LTE, LTE-A, LTE-A Pro or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro or NR terminology may be used in many of the descriptions, the techniques described herein may be applied beyond LTE, LTE-A, LTE-A Pro or NR applications.

A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs subscribing to a network provider for services. Small cells may be associated with lower power base stations than macro cells, and may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency bands as macro cells. According to various examples, small cells may include pico cells, femto cells, and micro cells. A pico cell may, for example, cover a small geographic area and may allow unrestricted access by UEs subscribing to a network provider for services. A femto cell may also cover a small geographic area (e.g., a home) and may provide unrestricted access by UEs associated with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs of home users, etc.). The eNB for the macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communication using one or more component carriers.

The wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations are approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operations.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with the following: a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and embodiments are within the scope of the disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination of these. Features implementing functions may also be physically located at various locations, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media (including any medium that facilitates transfer of a computer program from one place to another). A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, a non-transitory computer-readable medium may comprise Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory, Compact Disc (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes CD, laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

Also, as used herein (including in the claims), "or" as used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of … …" or "one or more" indicates an inclusive list such that, for example, at least one of A, B or C represents a or B or C or AB or AC or BC or ABC (i.e., a and B and C). Also, as used herein, the phrase "based on" should not be construed as a reference to a closed condition set. For example, an exemplary operation described as "based on condition a" may be based on both condition a and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on".

In the drawings, similar components or features may have the same reference label. In addition, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first numerical reference label is used in the specification, that description applies to any one of the similar components having the same first reference label, regardless of the second or other subsequent reference labels.

The description set forth herein in connection with the drawings describes example configurations and is not intended to represent all examples that may be practiced or within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "superior to other examples. The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

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