阅读说明：本技术 用于优化双连接技术中的urllc服务的无线电资源的方法和用户设备装置 (Method and user equipment device for optimizing radio resources for URLLC services in dual connectivity technology ) 是由 苏尼尔·库马尔 纳韦恩·库马尔 卡蒂克扬·苏布拉马尼亚姆 于 2020-05-29 设计创作，主要内容包括：提供了一种用于在双连接性技术中优化用于超可靠低延迟通信服务的无线电资源的方法,该方法包括：用户设备(UE)使用第一无线电接入技术(RAT)从基站接收下行链路(DL)数据；基于成功接收到DL数据,使用第一RAT向基站发送第一确认(ACK)信号；UE基于UE使用第一RAT成功接收到DL数据,更新映射表中的DL数据的映射表序列号；UE在检测到使用第二RAT接收到的DL数据中的错误时,检查映射表；以及基于在映射表中发现DL数据的映射表序列号,使用UE的第二RAT向基站发送第二ACK信号。(There is provided a method for optimizing radio resources for an ultra-reliable low-delay communication service in a dual connectivity technology, the method comprising: a User Equipment (UE) receiving Downlink (DL) data from a base station using a first Radio Access Technology (RAT); transmitting a first Acknowledgement (ACK) signal to a base station using a first RAT based on successful receipt of DL data; the UE successfully receives the DL data by using the first RAT based on the UE, and updates the mapping table sequence number of the DL data in the mapping table; the UE checks the mapping table when detecting an error in the DL data received using the second RAT; and transmitting a second ACK signal to the base station using a second RAT of the UE based on a mapping table sequence number of the DL data found in the mapping table.)

1. A method for optimizing radio resources for an ultra-reliable low-latency communication service in dual connectivity technology, the method comprising:

a User Equipment (UE) device receiving Downlink (DL) data from a base station using a first Radio Access Technology (RAT);

based on successful receipt of the DL data, transmitting a first Acknowledgement (ACK) signal to the base station using the first RAT;

the UE device updates a mapping table sequence number of DL data in a mapping table based on the UE device successfully receiving the DL data using the first RAT;

the UE device checking the mapping table upon detecting an error in DL data received using a second RAT; and

transmitting a second ACK signal to the base station using the second RAT of the UE device based on a mapping table sequence number of the DL data found in the mapping table.

2. The method of claim 1, wherein a Packet Data Convergence Protocol (PDCP) copy and split bearer copy function is enabled for the UE device to receive the DL data in one of a coding block group format and a transport block format.

3. The method of claim 1, wherein,

the first RAT is a network including at least one of 2G, 3G, 4G, 5G, 6G, and non-3 GPP,

the second RAT is a network including at least one of 2G, 3G, 4G, 5G, 6G, and non-3 GPP, and

the first RAT and the second RAT are the same or different.

4. The method of claim 1, further comprising:

the UE device sends a Negative ACK (NACK) signal to the base station using the second RAT based on a mapping table sequence number for which the DL data is not found in the mapping table.

5. The method of claim 4, further comprising:

based on the base station receiving the NACK signal, the UE device receives complete DL data from the base station using the second RAT.

6. The method of claim 4, further comprising:

based on the base station receiving the NACK signal, the UE device receives partial DL data from the base station using the second RAT.

7. The method of claim 1, wherein each of the first RAT and the second RAT comprises:

a first Medium Access Control (MAC) layer and a first Radio Link Control (RLC) layer designated to operate using a long term evolution communication standard,

a second MAC layer and a second RLC layer designated to operate using the 5G new radio communication standard, and

the first RAT and the second RAT are the same or different.

8. The method of claim 1, wherein the mapping table comprises a mapping between Coding Block Groups (CBGs) and Packet Data Convergence Protocol (PDCP) sequence numbers, a mapping between Transport Blocks (TBs) and the PDCP sequence numbers, a mapping between PDCP and the PDCP sequence numbers, a mapping between CBGs and CBG sequence numbers, or a mapping between TB and TB sequence numbers.

9. The method of claim 1, wherein the mapping table resides at a media access control layer, a radio link control layer, or a packet data convergence protocol layer of the UE device.

10. A User Equipment (UE) apparatus for optimizing radio resources for an ultra-reliable low-delay communication service in dual connectivity technology, the UE apparatus comprising:

a processor; and

a memory communicatively coupled to the processor and configured to store one or more processor-executable instructions that, when executed by the processor, cause the processor to:

receiving Downlink (DL) data from a base station using a first Radio Access Technology (RAT),

transmitting a first Acknowledgement (ACK) signal to the base station using the first RAT based on successful receipt of the DL data,

updating a mapping table sequence number for DL data in a mapping table based on successful receipt of the DL data using the first RAT,

checking the mapping table upon detecting an error in the DL data received using the second RAT, and

transmitting a second ACK signal to the base station using the second RAT based on a mapping table sequence number of the DL data found in the mapping table.

11. The UE device of claim 10, wherein a Packet Data Convergence Protocol (PDCP) copy and split bearer copy function is enabled for the UE device to receive the DL data in one of a coding block group format and a transport block format.

12. The UE apparatus of claim 10,

the first RAT is a network including at least one of 2G, 3G, 4G, 5G, 6G, and non-3 GPP,

the second RAT is a network including at least one of 2G, 3G, 4G, 5G, 6G, and non-3 GPP, and

the first RAT and the second RAT are the same or different.

13. The UE device of claim 10, wherein the one or more processor-executable instructions executed by the processor further cause the processor to:

transmitting a Negative ACK (NACK) signal to the base station using the second RAT based on a mapping table sequence number for which the DL data is not found in the mapping table.

14. The UE device of claim 13, wherein the one or more processor-executable instructions executed by the processor further cause the processor to:

receiving, based on the base station receiving the NACK signal, complete DL data from the base station using the second RAT.

15. The UE device of claim 13, wherein the one or more processor-executable instructions executed by the processor further cause the processor to:

receiving partial DL data from the base station using the second RAT based on the base station receiving the NACK signal.

Technical Field

The present disclosure relates to the field of telecommunications, in particular, but not exclusively, to a method and User Equipment (UE) for optimizing radio resources when a data packet convergence protocol (PDCP) copy function is enabled for an ultra-reliable low delay communication (URLLC) service in Dual Connectivity (DC) technology.

Background

The 5G New Radio (NR) introduces a concept of replication and splitting bearers at the PDCP. Replication is as if one packet is sent multiple times on different carriers to improve reliability. If the data packets are transmitted on multiple carriers, at least one copy of the data packet is likely to be successfully received by the UE. However, it also has some disadvantages. For example, overhead is doubled since each duplicate packet increases overhead, reducing spectral efficiency. Furthermore, if the packet is sent on two carriers, each carrier will consider it to be a separate packet of its own. For example, consider that the UE successfully received a packet on carrier 2, but failed to receive a packet on carrier 1. This will initiate a hybrid automatic repeat request (HARQ) retransmission on carrier 1 even if the UE has received the packet. This is because the UE cannot decode the packet on carrier 1. Therefore, the next generation node b (gnb), also referred to as the base station, will continue to retransmit the packet and continue to consume more resources.

The PDCP replication procedure is performed as follows. When submitting a PDCP Packet Data Unit (PDU) to a lower layer, if a transmitting PDCP entity is associated with one Radio Link Control (RLC) entity, the transmitting PDCP entity should submit the PDCP PDU to the associated RLC entity. Similarly, if the transmitting PDCP entity is associated with two RLC entities and a PDCP duplication procedure is activated and the PDCP PDUs are also PDCP data PDUs, the PDCP data PDUs are duplicated and transmitted to the two RLC entities. Similarly, if the PDCP PDU is a PDCP control PDU, the PDCP control PDU is submitted to the primary RLC entity. In addition, activation or deactivation of PDCP copying of the PDCP entity is configured with PDCP copying.

To discard duplicate PDUs of an entity configured with PDCP duplication, a sending PDCP entity may instruct the other AM RLC entity to discard the duplicate PDCP data PDUs if one of two associated acknowledged successful transmission of PDCP data PDUs. Similarly, if the deactivation of PDCP duplication is indicated, all duplicated PDCP data PDUs in the secondary RLC entity are discarded. By using a Downlink (DL) user data frame, the RLC entity can know which PDCP Sequence Number (SN) the RLC needs to discard. The frame format of NR has been introduced in the user plane protocol (NR-UP) specification. The frame format is defined to allow the respective node to detect lost NR-U packets and is associated with the transmission of downlink NR PDCP PDUs. Therefore, when the PDCP copy function is enabled for URLLC service, radio resources need to be optimized.

The information disclosed in the background section of this disclosure is for the purpose of enhancing an understanding of the general background of the invention and is not to be taken as an admission or any form of suggestion that such information forms part of the prior art already known to a person skilled in the art.

Disclosure of Invention

Technical problem

Various aspects of the present disclosure are to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide a method for optimizing radio resources of URLLC service in DC technology.

Solution to the problem

According to an aspect of the present disclosure, a method for optimizing radio resources of URLLC services in DC technology is provided. The method comprises the following steps: the UE receiving DL data from a base station using a first Radio Access Technology (RAT); transmitting a first Acknowledgement (ACK) signal to a base station using a first RAT when the DL data is successfully received; when the UE successfully receives the DL data by using the first RAT, the UE updates the mapping table sequence number of the DL data in the mapping table; the UE checking the mapping table when detecting an error in receiving DL data using the second RAT; and transmitting a second ACK signal to the base station using a second RAT of the UE when a mapping table sequence number of the DL data is found in the mapping table.

According to an aspect of the present disclosure, there is provided a UE for optimizing radio resources for URLLC services in DC technology. The UE may include a processor and a memory communicatively coupled to the processor, wherein the memory stores processor-executable instructions that, when executed, cause the processor to: the UE receiving DL data from a base station using a first RAT; transmitting a first ACK signal to a base station using a first RAT when DL data is successfully received; when the UE successfully receives the DL data by using the first RAT, the UE updates the mapping table sequence number of the DL data in the mapping table; the UE checking the mapping table when detecting an error in receiving DL data using the second RAT; and transmitting a second ACK signal to the base station using a second RAT of the UE when the mapping table sequence number of the DL data is found in the mapping table.

According to an aspect of the present disclosure, a method of optimizing PDCP replication in a multi-RAT UE is provided. The method comprises the following steps: receiving, by a UE, a plurality of data packets on a first RAT; the UE detecting an error in receiving a data packet on a first RAT; the UE checks whether at least one data packet has been received to the second RAT; and if at least one data packet has been received on the second RAT, the UE sends a message on the first RAT indicating that a plurality of data packets have been received.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

Advantageous effects of the invention

The present disclosure reduces resource consumption by reducing the number of HARQ retransmissions of received data or packets, making it advantageous for delay sensitive applications of fifth generation wireless networks when applying PDCP and splitting bearers.

The present disclosure reduces resource consumption, thereby saving radio resources that other UEs may use.

The present disclosure improves the spectral efficiency and spectral reuse of cellular networks due to the reduction of HARQ retransmission times.

By virtue of the above advantages, URLLC applications such as factory automation, remote motion control, smart grid and autonomous vehicles will certainly benefit from this.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the principles disclosed. In the figures, the left-most digit or digits of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components. Some embodiments of systems and/or methods consistent with embodiments of the present subject matter are described below, by way of example only, and with reference to the accompanying drawings.

Fig. 1 illustrates a Coded Block Group (CBG) based transmission according to an embodiment.

Figure 2 illustrates a mapping table of PDCP sequence numbers to CBGs, according to an embodiment.

Fig. 3A illustrates a timing diagram of an RLC and Medium Access Control (MAC) layer in which a UE internally notifies a NR of received packet information according to an embodiment.

Fig. 3B illustrates a timing diagram of the RLC and Medium Access Control (MAC) layers of the UE internally notifying the NR of the received packet information according to an embodiment.

Fig. 4A illustrates a timing diagram of a UE internally notifying the RLC and MAC layers of Long Term Evolution (LTE) of received packet information according to an embodiment.

Fig. 4B illustrates a timing diagram of the UE internally notifying the RLC and MAC layers of Long Term Evolution (LTE) of received packet information according to an embodiment.

Fig. 5A shows a flow diagram of a method for optimizing radio resources of URLLC services in DC technology according to an embodiment.

Fig. 5B shows a flow diagram of a method for optimizing radio resources of URLLC services in DC technology according to an embodiment.

It will be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

Detailed Description

In this document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment or implementation of the subject matter described herein is "exemplary" and is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intention to limit the disclosure to the specific forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a device, apparatus, or method that comprises a list of elements or steps does not include only those elements or steps, but may include other elements or steps not expressly listed or inherent to such device, apparatus, or method. That is, one or more elements of a system or apparatus that is performed by "a" or "an" does not preclude the presence of other or additional elements of the system or method, without further limitation.

In the following detailed description of the embodiments of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

Fig. 1 illustrates CBG-based transmission according to an embodiment.

Referring to fig. 1, when a base station enables PDCP copy and split bearer copy functions, the base station may perform PDU transmission based on CBG. The base station may maintain a PDCP sequence number to CBG mapping table during the fabrication of a Transport Block (TB), which may be sent to a UE (e.g., UE device) along with DL data. The mapping table of PDCP sequence numbers to CBGs may be referred to as a mapping table. The base station may form 1 to n CBGs 105 from 1 to n RLC PDUs 103, may form 1 to n PDCP PDUs 101, and transmit the CBGs in the TB to the UE.

Figure 2 illustrates a mapping table of PDCP sequence numbers to CBGs, according to an embodiment.

The UE internally maintains a mapping table of PDCP sequence numbers to CBGs. The mapping table of PDCP sequence numbers to CBGs may be referred to as a mapping table. The table includes a user identifier (user id), a PDCP Sequence Number (SN), an RLC SN, a HARQ process id, a CBG number, and an ACK received flag. The mapping table may include a mapping between CBG and PDCP sequence numbers, or TB and PDCP sequence numbers, or PDCP and PDCP sequence numbers, or CBG and CBG sequence numbers, or TB and TB sequence numbers. As shown in fig. 2, this table is maintained and updated by the UE when the UE receives DL data from the base station. The mapping table may reside in the MAC layer or RLC layer or PDCP layer in the UE. In an embodiment, the mapping table may reside in a Service Data Adaptation Protocol (SDAP) layer by creating a shared memory space for use by stacks associated with multiple RATs. In an embodiment, the mapping table may reside in the network, i.e. in the base station. In an embodiment, the mapping table may be maintained by the network at one of a functional portion of the network function and the service-based architecture virtualized by the cloud platform. For example, when the LTE RAT of the UE receives DL data from the base station and successfully processes the DL data, the LTE RAT of the UE may transmit an ACK signal to the base station. Meanwhile, the LTE RAT may update the PDCP sequence number to a CBG mapping table for the received DL data. The PDCP sequence number may be referred to as a mapping table sequence number. In the next operation, the LTE RAT of the UE may internally notify the NR RAT of the UE of the received DL data. More specifically, the NR RLC of the UE may inform the NR MAC of the UE of the received DL data. The NR MAC may then update the "ACK received flag from other RAT" in the table to TRUE. When the NR MAC of the UE fails to successfully decode the received DL data or finds that the received DL data is erroneous, the NR MAC may perform the following actions:

if the "ACK received flag from other RAT" in the table is TRUE, i.e., DL data has been successfully received by other RAT, the NR MAC of the UE may send ACK to the base station instead of sending negative ACK (nack) to the base station. In this case, there is no need to retransmit the DL data, since the other RATs have successfully received and processed the DL data.

If the "ACK received from other RAT" in the table is FALSE, i.e. DL data has not been successfully received by other RAT, the NR MAC of the UE may send NACK to the base station according to the normal procedure. In this case, since the other RAT does not successfully receive and process the DL data, the DL data needs to be retransmitted.

In an embodiment, the mapping table has a list of CBG numbers when the PDCP copy and split bearer copy functions are enabled to receive DL data in CBG format. In an embodiment, the mapping table has one list of TB numbers when the PDCP copy and split bearer copy functions are enabled to receive DL data in TB format.

Fig. 3A and 3B illustrate timing diagrams of RLC and MAC layers in which a UE internally notifies a NR of received packet information according to an embodiment.

Fig. 3A and 3B show a PDCP 301, a radio link control _ near radio (RLC _ NR)303, a medium access control _ near radio (MAC _ NR)304, a radio link control _ long term evolution (RLC _ LTE)305, and a medium access control _ long term evolution (MAC _ LTE)312 of a base station 300. Similarly, the UE 306 includes PDCP 311, RLC _ NR 307, MAC _ NR 308, RLC _ LTE 309, and MAC _ LTE 310. RLC _ NR 303, MAC _ NR 304, RLC _ NR 307, and MAC _ NR 308 may be included in a RAT (e.g., a first RAT) using a communication standard of 5G NR. RLC _ LTE 305, MAC _ LTE 312, RLC _ LTE 309, and MAC _ LTE 310 may be included in a RAT (e.g., a second RAT) that uses the LTE communication standard.

In an embodiment, at the PDCP 301 of the base station, a PDCP copy and split bearer copy function may be activated at operation 313. DL data may be transmitted from the PDCP 301 to the RLC _ NR 303 in operation 315, and transmitted to the RLC _ LTE 305 of the base station in operation 321. Operations 315 and 321 may occur in parallel or sequentially. DL data may also be referred to as DL packets. In operation 317, DL data from the RLC _ NR 303 may be transmitted to the MAC _ NR 304 of the base station.

Similarly, DL data from the RLC _ LTE 305 may be transmitted to the MAC _ LTE 312 of the base station in operation 323. DL data may be transmitted from the base station to the UE, i.e., to the MAC _ NR 308 in operation 319, and to the MAC _ LTE 310 of the UE in operation 325. In an embodiment, the DL data may be a plurality of data packets. At this time, upon receiving the DL data, the MAC _ LTE 310 may transmit a first ACK signal (i.e., HARQ ACK) to the MAC _ LTE 312 in operation 327. The first ACK signal may indicate that the MAC _ LTE 310 of the UE successfully received the DL data. In operation 329, the MAC _ LTE 310 may transmit DL data to the RLC _ LTE 309. When the RLC _ LTE 309 of the UE receives the DL data, the UE or the RLC _ LTE 309 of the UE may update the PDCP sequence number of the DL data in the sequence numbers to the CBG mapping table.

The PDCP sequence number may be referred to as a mapping table sequence number. The PDCP sequence number to CBG mapping table may be maintained by RLC _ LTE 309 and RLC _ NR 307 within the UE. In an embodiment, the mapping table may reside in the network, i.e. at the base station. The mapping table of PDCP sequence numbers to CBGs may be referred to as a mapping table. When there is an error in the data received at the current RAT, the table may be used to find out whether data is received at other RATs. In operation 331, DL data may be transmitted to the PDCP 311 of the UE. The PDCP 311 of the UE may transmit the received DL data information (or, i.e., the received packet information) to the RLC _ LTE 309 in operation 333 and then to the RLC _ NR 307 in operation 335. The RLC _ NR 307 may further notify the MAC _ NR 308 of the received DL data information. At this time, the MAC _ NR 308 may update the "ACK received flag from other RAT" to TRUE. In operation 337, the RLC _ LTE 309 may transmit the status of the PDU to the RLC _ LTE 305 of the base station, which may be further transmitted to the PDCP 301 of the base station in operation 339. The PDCP 301 of the base station may transmit a PDU discard message to the RLC _ NR 303 of the base station upon receiving a status of the PDU. The above-described operation may be performed when the MAC _ NR 308 of the UE successfully decodes the received DL data.

Referring to fig. 3B, when the MAC _ NR 308 of the UE fails to decode the received DL data or finds an error in the received DL data in operation 341, the MAC _ NR 308 may request the RLC _ NR 307 to transmit the received DL data information (i.e., other RAT) from the RLC _ LTE 309 in operation 343. The RLC _ NR 307 may check DL information (i.e., other RATs) successfully received at the RLC _ LTE 309 using a sequence number to CBG mapping table, and may transmit the received DL data information in the received packet information message to the MAC _ NR 308 in operation 345. In checking the DL data information, the MAC _ NR 308 may transmit a second ACK signal (i.e., HARQ ACK) to the base station when a PDCP sequence number of the DL data is found in a sequence number to CBG mapping table. In an embodiment, when the UE detects an error in receiving data packets on the first RAT, the UE may check whether at least one data packet has been received in the second RAT, and if at least one data packet has been received on the second RAT, may send a message on the first RAT indicating that a plurality of data packets have been received. Here, the checking may be done by the UE by analyzing a mapping table maintained at the UE, which is updated with mapping table sequence numbers of data packets successfully received by the at least one RAT. However, in checking the DL data information, if the PDCP sequence number of the DL data is not found in the sequence number to CBG mapping table, the MAC _ NR 308 may transmit an HARQ NACK signal for the non-received DL data in operation 347.

In operation 349, the MAC _ NR 304 of the base station may receive the HARQ NACK signal from the MAC _ NR 308 of the UE. In operation 351, the MAC _ NR 308 may receive DL data, which is not received, from the MAC _ NR 304 of the base station. In an embodiment, when the base station receives the NACK signal, the RAT of the UE may receive only partial DL data from the base station instead of complete DL data. In return, the MAC _ NR 308 of the UE may transmit a third ACK signal (i.e., HARQ ACK signal) to acknowledge receipt of the DL data in operation 353. Subsequently, the complete DL data may be transmitted to the RLC _ NR 307 of the UE in operation 355 and transmitted to the PDCP of the UE in operation 359. The RLC _ NR 307 may transmit the status of the PDU to the RLC _ NR 303 of the base station in operation 357, and may further transmit it to the PDCP 301 of the base station in operation 361. The PDCP 301 of the base station may transmit a PDU discard message to the RLC _ NR 303 of the base station upon receiving the status of the PDU. The above operation may be performed when the MAC _ NR 308 of the UE fails to successfully decode the received DL data.

In an embodiment, the first RAT may be at least one of a second generation (G), 3G, 4G, 5G, 6G, and non-third generation partnership project (3GPP) network, and the second RAT may be at least one of a 2G, 3G, 4G, 5G, 6G, and non-3 GPP network.

A technical advantage of the above-described embodiments is that the method reduces the number of HARQ retransmissions of received data or packets if data or packets have been received from other RATs. This therefore results in a reduction of resource consumption (for the UE) and battery consumption.

Fig. 4A and 4B illustrate timing diagrams of a UE internally notifying the RLC and MAC layers of LTE of received packet information according to an embodiment.

Fig. 4A and 4B illustrate PDCP 401, RLC _ NR 403, MAC _ NR 404, RLC _ LTE 405, and MAC _ LTE 406 of the base station 300. Similarly, the UE includes PDCP 411, RLC _ NR 407, MAC _ NR 408, RLC _ LTE 409, and MAC _ LTE 410. RLC _ NR 403, MAC _ NR 404, RLC _ NR 407, and MAC _ NR 408 may be included in a RAT (e.g., a first RAT) using a 5G NR communication standard. RLC _ LTE 405, MAC _ LTE 406, RLC _ LTE 409, and MAC _ LTE410 may be included in a RAT (e.g., a second RAT) that uses the LTE communication standard.

In an embodiment, at the PDCP 401 of the base station, a PDCP copy and split bearer copy function may be activated at operation 413. DL data may be transmitted from the PDCP 401 to the RLC _ NR 403 in operation 415, and transmitted to the RLC _ LTE 405 of the base station in operation 421. Operations 415 and 421 may occur in parallel or sequentially. DL data may also be referred to as DL packets. DL data from the RLC _ NR 403 may be transmitted to the MAC _ NR 404 of the base station in operation 417. Similarly, DL data from the RLC _ LTE 405 may be transmitted to the MAC _ LTE 406 of the base station in operation 423. DL data may be transmitted from the base station to the UE, i.e., to the MAC _ NR 408 in operation 419, and to the MAC _ LTE410 of the UE in operation 425. In an embodiment, the DL data may be a plurality of data packets. At this time, upon receiving the DL data, the MAC _ NR 408 may transmit a first ACK signal (i.e., HARQ ACK) to the MAC _ NR 404 in operation 427. The first ACK signal may indicate that the MAC _ NR 408 of the UE successfully received the DL data. In operation 429, the MAC _ NR 408 may transmit DL data to the RLC _ NR 407. When the RLC _ NR 407 of the UE receives the DL data, the UE or the RLC _ NR 407 of the UE may update the PDCP sequence number of the DL data in the sequence number to CBG mapping table. The PDCP sequence number may be referred to as a mapping table sequence number. The PDCP sequence number to CBG mapping table may be maintained by RLC _ NR 407 and RLC _ LTE 409 within the UE. The mapping table of PDCP sequence numbers to CBGs may be referred to as a mapping table. When there is an error in the data received at the current RAT, the table may be used to discover whether data is received at other RATs. In an embodiment, the mapping table may reside in the network, i.e. in the base station. In operation 431, the RLC _ NR 407 may transmit the status of the PDU to the RLC _ NR 403 of the base station, which may be further transmitted to the PDCP 401 of the base station in operation 435.

In operation 441, the PDCP 401 of the base station may transmit a PDU discard message to the RLC _ LTE 405 of the base station upon receiving a status of the PDU. In operation 433, DL data may be transmitted to the PDCP 411 of the UE through the RLC _ NR 407. The PDCP 411 of the UE may transmit the received DL data information (or, in other words, the received packet information) to the RLC _ LTE 409 in operation 437, and then transmit the received DL data information to the RLC _ NR 407 in operation 439. RLC _ LTE 409 may further inform MAC _ LTE410 of the received DL data information. At this time, the MAC _ LTE410 may update the "ACK reception flag from other RAT" to TRUE. The above-described operation may be performed when the MAC _ LTE410 of the UE successfully decodes the received DL data.

Referring to fig. 4B, when the MAC _ LTE410 of the UE fails to decode the received DL data or finds an error in the received DL data in operation 443, the MAC _ LTE410 may request the RLC _ LTE 409 to transmit the received DL data information (i.e., other RAT) from the RLC _ LTE 407 in operation 445. The RLC _ LTE 409 may check received DL information (i.e., other RATs) that has been successfully received at the RLC _ NR 407 using a sequence number to CBG mapping table in operation 447, and may transmit DL data information received in a received packet information message to the MAC _ LTE 410. When the PDCP sequence number of the DL data is found in the sequence number to CBG mapping table, the MAC _ LTE410 may transmit a second ACK signal (i.e., HARQ ACK) to the base station in operation 451 when the DL data information is checked in operation 449. Further, in operation 453, the RLC _ LTE 409 may transmit the status of the PDU to the RLC _ LTE 405 of the base station, which may be further transmitted to the PDCP 401 of the base station in operation 455.

In an embodiment, when the UE detects an error in receiving data packets on the first RAT, the UE may check whether at least one data packet has been received in the second RAT, and if at least one data packet has been received in the second RAT, may send a message on the first RAT indicating that a plurality of data packets have been received. Here, the UE may complete the check by analyzing a mapping table maintained at the UE, which is updated with mapping table sequence numbers of data packets successfully received by the at least one RAT. However, in checking the DL data information, if the PDCP sequence number of the DL data is not found in the sequence number to CBG mapping table, the MAC _ LTE410 may transmit an HARQ NACK signal of the DL data to the MAC _ LTE 406 of the base station in operation 457. In operation 459, the MAC _ LTE410 may receive complete DL data from the MAC _ LTE 406 of the base station. In an embodiment, when the base station receives the NACK signal, the RAT of the UE may receive full DL data from the base station, not just partial DL data. In return, the MAC _ LTE410 of the UE may transmit a third ACK signal (i.e., HARQ ACK) to acknowledge receipt of the DL data. In operation 461, the MAC _ LTE410 may perform error checking on the received complete DL data as described in operation 443, and may repeat the above operations in case of an error in the DL data. The above operation may be performed when the MAC _ LTE410 of the UE fails to successfully decode the received DL data.

In an embodiment, the first RAT may be at least one of a second generation (G), 3G, 4G, 5G, 6G, and non-third generation partnership project (3GPP) network, and the second RAT may be at least one of a 2G, 3G, 4G, 5G, 6G, and non-3 GPP network.

A technical advantage of the above-described embodiments is that the method reduces the number of HARQ retransmissions of received data or packets if data or packets have been received from other RATs. This therefore results in a reduction of resource consumption (for the UE) and battery consumption.

Fig. 5A and 5B show a flow chart of a method for optimizing radio resources of URLLC services in DC technology according to an embodiment.

As shown in fig. 5A and 5B, method 500 includes one or more operations for optimizing radio resources for URLLC services in DC technologies. The method 500 may be described in the general context of computer-executable instructions. Generally, computer-executable instructions can include routines, programs, objects, components, data structures, procedures, units, and functions that perform particular functions or implement particular abstract data types.

The order in which the method 500 is described is not intended to be construed as a limitation, and any number of the described method operations can be combined in any order to implement the method. Moreover, individual operations may be deleted from the methods without departing from the scope of the subject matter described herein. Further, the method may be implemented in any suitable hardware, software, firmware, or combination thereof.

In operation 501, the UE may receive DL data from a base station by using a first RAT.

In operation 503, the UE may transmit a first ACK signal to the base station using the first RAT. The transmission may be performed when the first RAT of the UE successfully receives the DL data.

In operation 505, the UE may update a mapping table sequence number of DL data in the mapping table. The update may be performed when DL data is received at a PDCP layer of the UE using the first RAT.

In operation 507, the UE may check the mapping table when an error is detected while receiving DL data using the second RAT.

In operation 509, the UE may transmit a second ACK signal to the base station using a second RAT of the UE. This operation may be performed when the mapping table sequence number of the DL data is found in the mapping table.

The first RAT and the second RAT may be at least one of 2G, 3G, 4G, 5G, 6G, and non-3 GPP network communication standards. Further, the first RAT may be different from the second RAT or may be the same as the second RAT. The UE may enable PDCP replication and split bearer replication functions to receive DL data in CBG format.

Fig. 5B illustrates a flow diagram of a method of receiving full or partial DL data when a mapping table sequence number of the DL data is not found in a mapping table according to an embodiment.

In operation 511, the UE may transmit a NACK signal to the base station using the second RAT. This operation may be performed when the mapping table sequence number of the DL data is not found in the mapping table.

In operation 513, when the base station receives the NACK signal, the UE using the second RAT may receive the complete DL data from the base station.

In operation 515, when the base station receives the NACK signal, the UE using the second RAT may receive partial DL data from the base station.

Operation 513 or operation 515 may be performed while the UE receives DL data. This may depend on the RAT communication standard. For example, if the RAT receiving the DL data is the LTE communication standard, the RAT may receive the complete DL data from the base station when the base station receives the NACK signal. However, if the RAT receiving the DL data is the 5G NR communication standard, the RAT may receive partial DL data from the base station when the base station receives the NACK signal.

The present disclosure is applicable to multi-RAT dual connectivity (MR-DC) and new radio-new radio (NR-NR) DC scenarios. Furthermore, the present disclosure may not be limited to the LTE communication standard and the 5G NR communication standard discussed herein, but may be extended to any future communication standard. Further, while the description describes dual RAT operation, the invention is not limited to dual RATs and may be used for multiple RATs as disclosed.

Some advantages of the present disclosure are mentioned below.

The present disclosure reduces resource consumption by reducing the number of HARQ retransmissions of received data or packets, making it advantageous for delay sensitive applications of fifth generation wireless networks when applying PDCP and splitting bearers.

The present disclosure reduces resource consumption, thereby saving radio resources that other UEs may use.

The present disclosure improves the spectral efficiency and spectral reuse of cellular networks due to the reduction of HARQ retransmission times.

By virtue of the above advantages, URLLC applications such as factory automation, remote motion control, smart grid and autonomous vehicles will certainly benefit from this.

Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer-readable storage medium refers to any type of physical memory that can store information or data readable by a processor. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing one or more processors to perform operations or stages consistent with embodiments described herein. The term "computer readable medium" should be understood to include tangible articles and not include carrier waves and transient signals, i.e., non-transitory signals. Examples include Random Access Memory (RAM), Read Only Memory (ROM), volatile memory, non-volatile memory, hard drives, CD ROMs, DVDs, flash drives, diskettes, and any other known physical storage medium.

The described operations may be implemented as a method, system or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The described operations may be implemented as code maintained in a "non-transitory computer readable medium", where a processor may read and execute the code from the computer readable medium. The processor is at least one of a microprocessor and a processor capable of processing and executing queries. Non-transitory computer-readable media may include, for example, magnetic storage media (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, DVDs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, flash memory, firmware, programmable logic, etc.), and so forth. Moreover, non-transitory computer readable media includes all computer readable media except transitory media. The code implementing the described operations may further be implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.).

The terms "an embodiment," "embodiments," "the embodiment," "the embodiments," "one or more embodiments," "some embodiments," and "one embodiment" mean "one or more (but not all) embodiments of the one or more inventions" unless expressly specified otherwise.

The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise.

The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

A description of an embodiment with several components in communication with each other does not imply that all such components are not required. On the contrary, the various optional components are described to illustrate the various possible embodiments of the invention.

When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used in place of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the present invention need not include the device itself.

The illustrated operations of fig. 5A and 5B show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, operations may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Further, however, the operations may be performed by a single processing unit or by distributed processing units.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the scope of the invention is not limited by this detailed description, but by any claims based on this application. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and not limitation, with the true scope and spirit being indicated by the following claims.