阅读说明：本技术 选择用于旁路传输的资源的方法和装置 (Method and apparatus for selecting resources for bypass transmission ) 是由 裵正铉 Y.M.M.K.福亚德 于 2021-03-30 设计创作，主要内容包括：提供了由用户设备(UE)选择用于旁路(SL)传输的资源的方法,该方法包括：确定与用于SL传输的第一资源和第二资源之间的最大时间间隔相对应的信令窗口；向另一UE发信令通知第一资源和第二资源；从用于SL传输的候选资源的集合中排除导致第一资源和第二资源之间的时间间隔大于信令窗口的无资格的候选资源；识别该集合中的剩余候选资源的数量；确定该集合中的剩余候选资源的数量低于候选资源阈值；以及调整排除标准,以将否则基于初始排除标准有资格被排除的有资格的候选资源包括在该集合中。(There is provided a method of selecting resources for a bypass (SL) transmission by a User Equipment (UE), the method comprising: determining a signaling window corresponding to a maximum time interval between a first resource and a second resource for SL transmission; signaling the first resource and the second resource to another UE; excluding from the set of candidate resources for SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than a signaling window; identifying a number of remaining candidate resources in the set; determining that a number of remaining candidate resources in the set is below a candidate resource threshold; and adjusting the exclusion criteria to include in the set eligible candidate resources that are otherwise eligible for exclusion based on the initial exclusion criteria.)

1. A method of selecting resources by a user equipment, UE, for bypassing SL transmissions, the method comprising:

determining a signaling window corresponding to a maximum time interval between a first resource and a second resource for the SL transmission;

signaling the first resource and the second resource to another UE;

excluding from the set of candidate resources for the SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than the signaling window;

Identifying a number of remaining candidate resources in the set;

determining that a number of remaining candidate resources in the set is below a candidate resource threshold; and

the exclusion criteria are adjusted to include in the set eligible candidate resources that are eligible for exclusion based on the initial exclusion criteria.

2. The method of claim 1, further comprising repeating the adjusting of the exclusion criteria until remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to the signaling window and a number of remaining candidate resources in the set is above the candidate resource threshold.

3. The method of claim 1, wherein the eligible candidate resources that qualify to be excluded based on the initial exclusion criteria comprise:

candidate resources reserved for another SL transmission with an RSRP value higher than the priority-based RSRP threshold, or

Candidate resources corresponding to the allowed periodicity value.

4. The method of claim 3, wherein adjusting the exclusion criteria comprises increasing the priority-based RSRP threshold.

5. The method of claim 4, wherein the priority-based RSRP threshold is increased by 1 decibel dB to 3 dB.

6. The method of claim 4, wherein the priority-based RSRP threshold is increased by an amount based on a priority value corresponding to the SL transmission.

7. The method of claim 1, wherein adjusting the exclusion criteria comprises excluding fewer than all cycles corresponding to an allowed periodicity value.

8. The method of claim 7, wherein said excluding fewer than all periods corresponding to an allowed periodicity value comprises excluding a subset of the all periods based on frequency of use of the subset of the all periods in a geographic area.

9. The method of claim 1, wherein adjusting the exclusion criteria comprises decreasing a reselection counter value to increase a likelihood that candidate resources for periodic transmission are identified within a certain amount of time.

10. The method of claim 9, further comprising limiting a decrease to the reselection counter value to a threshold.

11. The method of claim 10, further comprising setting the threshold based on a priority value of the SL transmission.

12. The method of claim 1, further comprising:

comparing a usage duration of a first same set of resources used by a first other UE with a usage duration of a second same set of resources used by a second other UE; and

Include one or more resources corresponding to the first other UE or the second other UE in a set of candidate resources for the SL transmission based on the determination of the greater usage duration.

13. A user equipment, UE, for performing a method of selecting resources for bypassing SL transmissions, wherein the UE is configured to:

determining a signaling window corresponding to a maximum time interval between a first resource and a second resource for the SL transmission;

signaling the first resource and the second resource to another UE;

excluding from the set of candidate resources for the SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than the signaling window;

identifying a number of remaining candidate resources in the set;

determining that a number of remaining candidate resources in the set is below a candidate resource threshold; and

the exclusion criteria are adjusted to include in the set eligible candidate resources that are eligible for exclusion based on the initial exclusion criteria.

14. The UE of claim 13, wherein the UE is configured to repeat the adjustment of the exclusion criteria until remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to the signaling window and a number of remaining candidate resources in the set is above the candidate resource threshold.

15. The UE of claim 13, wherein the eligible candidate resources eligible to be excluded based on the initial exclusion criteria comprise:

candidate resources reserved for another SL transmission with an RSRP value higher than the priority-based RSRP threshold, or

Candidate resources corresponding to the allowed periodicity value.

16. The UE of claim 13, wherein adjusting the exclusion criteria comprises excluding fewer than all periods corresponding to an allowed periodicity value.

17. The UE of claim 13, wherein adjusting the exclusion criteria comprises decreasing a reselection counter value to increase a likelihood that candidate resources for periodic transmission are identified within a certain amount of time.

18. The UE of claim 13, wherein the UE is configured to:

comparing a usage duration of a first same set of resources used by a first other UE with a usage duration of a second same set of resources used by a second other UE; and

include one or more resources corresponding to the first other UE or the second other UE in a set of candidate resources for the SL transmission based on the determination of the greater usage duration.

19. A non-transitory computer readable medium embodied on a user equipment, UE, having computer code which, when executed on a processor, implements a method of selecting resources for bypassing SL transmissions in a system comprising the UE, a base station, and one or more other UEs, wherein the base station and/or the one or more other UEs are capable of communicatively coupling with the UE to configure the UE to perform a method of selecting resources for SL transmissions, the method comprising:

determining a signaling window corresponding to a maximum time interval between a first resource and a second resource for the SL transmission;

signaling the first resource and the second resource to another UE;

excluding from the set of candidate resources for the SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than the signaling window;

identifying a number of remaining candidate resources in the set;

determining that a number of remaining candidate resources in the set is below a candidate resource threshold; and

the exclusion criteria are adjusted to include in the set eligible candidate resources that are eligible for exclusion based on the initial exclusion criteria.

20. The non-transitory computer-readable medium of claim 19, wherein the computer code, when executed by the processor, further implements a method of selecting resources for the SL transmission by causing the UE to repeat the adjusting of the exclusion criteria until remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to the signaling window and a number of remaining candidate resources in the set is above the candidate resource threshold.

Technical Field

Aspects of some embodiments of the present disclosure relate to methods, apparatuses, and systems for bypass (SL) resource selection for wireless communications.

Background

In the field of wireless communications, such as with New Radio (NR) vehicle-to-everything (V2X) applications, User Equipment (UE) may be configured to communicate directly with neighboring UEs over a distributed system via a bypass (SL) transmission. That is, each UE is able to communicate with any other UE without first relaying communications through the base station.

Further, the UE in such a distributed system may select resources for future SL transmissions according to a resource selection procedure. Further, the UE may signal (signal) the neighboring UEs their selected future resources to reduce or minimize interference between UEs that might otherwise be caused by resource collisions, where two or more UEs attempt to transmit using the same resources at the same time.

Disclosure of Invention

Aspects of embodiments of the present disclosure relate to wireless communications and provide improvements to Mode 2(Mode 2) resource selection procedures to maintain chain integrity.

According to some embodiments of the present disclosure, there is provided a method of selecting, by a User Equipment (UE), a resource for a bypass (SL) transmission, the method comprising: determining a signaling window corresponding to a maximum time interval (time separation) between a first resource and a second resource for SL transmission; signaling the first resource and the second resource to another UE; excluding from the set of candidate resources for SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than a signaling window; identifying a number of remaining candidate resources in the set; determining that the number of remaining candidate resources in the set is below a candidate resource threshold; and adjusting the exclusion criteria to include in the set eligible candidate resources that are otherwise eligible for exclusion based on the initial exclusion criteria.

The method may further include iteratively adjusting the exclusion criteria until remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to a signaling window and a number of remaining candidate resources in the set is above a candidate resource threshold.

Otherwise candidate resources eligible for exclusion include: candidate resources reserved for another SL transmission with an RSRP value higher than the priority-based RSRP threshold, or candidate resources corresponding to an allowed periodicity value.

Adjusting the exclusion criteria may include increasing a priority-based RSRP threshold.

The priority-based RSRP threshold may be increased by about 1 decibel (dB) to about 3 dB.

The priority-based RSRP threshold may be increased by an amount based on a priority value corresponding to the SL transmission.

Adjusting the exclusion criteria may include excluding fewer than all cycles corresponding to the allowed periodicity value.

Excluding fewer than all periods may include excluding a subset of all periods based on frequency of use of the subset of all periods in the geographic area.

Adjusting the exclusion criteria may include decreasing a reselection counter value to increase a likelihood that candidate resources for periodic transmission are identified within a certain amount of time.

The method may further include limiting the decrease in the reselection counter value to a threshold value.

The method may also include setting a threshold based on a priority value of the SL transmission.

The method may also include comparing a usage duration of a first same set of resources used by the first other UE to a usage duration of a second same set of resources used by the second other UE, and including one or more resources corresponding to the first other UE or the second other UE in the set of candidate resources for SL transmission based on the determination of the greater usage duration.

According to other embodiments of the present disclosure, a User Equipment (UE) for performing a method of selecting resources for a bypass (SL) transmission is provided, wherein the UE is configured to determine a signaling window corresponding to a maximum time interval between a first resource and a second resource for the SL transmission; signaling the first resource and the second resource to another UE; excluding from the set of candidate resources for SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than a signaling window; identifying a number of remaining candidate resources in the set; determining that the number of remaining candidate resources in the set is below a candidate resource threshold; and adjusting the exclusion criteria to include in the set eligible candidate resources that are otherwise eligible for exclusion based on the initial exclusion criteria.

The UE may be configured to repeatedly adjust the exclusion criteria until the remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to a signaling window and a number of remaining candidate resources in the set is above a candidate resource threshold.

The candidate resources that are eligible for exclusion may otherwise include candidate resources reserved for another SL transmission having an RSRP value higher than the priority-based RSRP threshold, or candidate resources corresponding to an allowed periodicity value.

Adjusting the exclusion criteria may include excluding less than all of the periods corresponding to the allowed periodicity values.

Adjusting the exclusion criteria may include decreasing a reselection counter value to increase a likelihood that candidate resources for periodic transmission are identified within an amount of time.

The UE may be configured to compare a usage duration of a first same set of resources used by a first other UE to a usage duration of a second same set of resources used by a second other UE, and to include one or more resources corresponding to the first other UE or the second other UE in the set of candidate resources for SL transmission for determination of a longer usage duration.

In accordance with other embodiments of the present disclosure, there is provided a non-transitory computer-readable medium embodied on a User Equipment (UE), having computer code which, when executed on a processor, implements a method of selecting resources for bypass transmission in a system comprising the UE, a base station, and one or more other UEs, wherein the base station and/or the one or more other UEs are capable of communicatively coupling with the UE to configure the UE to perform a method of selecting resources for bypass transmission, the method comprising determining a signaling window corresponding to a maximum time interval between a first resource and a second resource for bypass transmission; signaling the first resource and the second resource to another UE; excluding from the set of candidate resources for SL transmission an unqualified candidate resource that results in a time interval between the first resource and the second resource being greater than a signaling window; identifying a number of remaining candidate resources in the set; determining that the number of remaining candidate resources in the set is below a candidate resource threshold; and adjusting the exclusion criteria to include in the set eligible candidate resources that are otherwise eligible for exclusion based on the initial exclusion criteria.

The computer code, when executed by the processor, may also implement a method of selecting resources for SL transmission by causing the UE to repeatedly adjust the exclusion criteria until the remaining candidate resources in the set allow the UE to select resources such that a time interval between the first resource and the second resource is less than or equal to a signaling window and a number of remaining candidate resources in the set is above a candidate resource threshold.

Accordingly, embodiments of the present disclosure provide improvements and advantages to bypass resource selection. For example, aspects of embodiments of the present disclosure provide improvements to the resource selection process to maintain resource chain integrity by effectively relaxing the resource selection process from excluding and limiting candidate resources for future SL transmissions, thereby increasing the number of resources available for resource selection, while also prioritizing chain integrity and reducing or minimizing resource conflicts.

Drawings

Non-limiting and non-exhaustive embodiments of the present disclosure are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

Fig. 1 is a system diagram depicting a possible system for bypass (SL) communication, in accordance with some embodiments of the present disclosure;

Fig. 2 is a timing diagram depicting bypass transmissions from more than one User Equipment (UE) and depicting resource conflicts, in accordance with some embodiments of the present disclosure;

fig. 3 is a flowchart depicting an overview of a mode 2 resource selection process in a New Radio (NR) vehicle-to-everything (V2X) communication according to the related art;

fig. 4A and 4B are timing diagrams depicting methods of selecting resources for SL transmission, in accordance with some embodiments of the present disclosure;

fig. 5A and 5B are flow diagrams depicting methods of selecting resources for SL transmission depicted in fig. 4A and 4B, in accordance with some embodiments of the present disclosure;

fig. 6A and 6B are timing diagrams depicting methods of selecting resources for SL transmission, in accordance with some embodiments of the present disclosure;

fig. 7 is a flow diagram depicting a method of selecting resources for SL transmission depicted in fig. 6A and 6B in accordance with some embodiments of the present disclosure;

fig. 8 is a timing diagram depicting a method of selecting resources for SL transmission in accordance with some embodiments of the present disclosure; and is

Fig. 9 is a flow diagram depicting a method of selecting resources for SL transmission depicted in fig. 8 in accordance with some embodiments of the present disclosure.

Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements, layers, and regions in the figures may be exaggerated relative to other elements, layers, and regions to help improve clarity and understanding of various embodiments. Additionally, common but well-understood elements and components that are not relevant to the description of the embodiments may not have been shown in order to facilitate a less obstructed view of these various embodiments, and to clarify the description.

Detailed Description

The features of the inventive concept and methods of accomplishing the same may be understood more readily by reference to the detailed description of the embodiments and the accompanying drawings. Hereinafter, embodiments will be described in more detail with reference to the accompanying drawings. The described embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey aspects and features of the inventive concept to those skilled in the art. Accordingly, processes, elements, and techniques not necessary to fully understand aspects and features of the inventive concepts may not be described by those of ordinary skill in the art.

Unless otherwise indicated, like reference numerals, characters, or sets thereof denote like elements throughout the drawings and written description, and thus the description thereof will not be repeated. In addition, portions irrelevant to the description of the embodiments may not be shown to clarify the description. In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity. In addition, cross-hatching and/or shading is often used in the drawings to clarify the boundaries between adjacent elements. Thus, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, dimension, proportion, commonality between illustrated elements, and/or any other feature, property, characteristic, or the like, of an element unless otherwise specified.

In the detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. It may be evident, however, that the various embodiments may be practiced without these specific details or with one or more equivalent arrangements.

It will be understood that, although the terms "zeroth," "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the spirit and scope of the present disclosure.

It will be understood that when an element, layer, region or component is referred to as being "on," "connected to" or "coupled to" another element, layer, region or component, it can be directly on, connected or coupled to the other element, layer, region or component, or one or more intervening elements, layers, regions or components may be present. However, "directly connected/directly coupled" means that one element is directly connected or coupled to another element without intervening elements. Meanwhile, other expressions describing a relationship between components, such as "between … …", "immediately. Further, it will also be understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "including" and "having," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As used herein, the terms "substantially," "about," "approximately," and the like are used as terms of approximation, not degree, and are intended to account for inherent deviations in measurements or calculations that would be recognized by one of ordinary skill in the art. As used herein, "about" or "approximately" includes values and means that are within an acceptable deviation of the specified value as determined by one of ordinary skill in the art, taking into account the measurement in question and the error associated with measurement of the specified quantity (i.e., limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ± 30%, ± 20%, ± 10%, ± 5% of the stated values. Furthermore, when describing embodiments of the present disclosure, the use of "may" refer to "one or more embodiments of the present disclosure.

While one or more embodiments may be practiced differently, a particular order of processing may be performed other than the order described. For example, two processes described in succession may be executed substantially concurrently or in the reverse order to that described.

Electronic or electrical devices and/or any other related devices or components according to embodiments of the disclosure described herein may be implemented using any suitable hardware, firmware (e.g., application specific integrated circuits), software, or combination of software, firmware, and hardware. For example, various components of these devices may be formed on an Integrated Circuit (IC) chip or on separate IC chips. In addition, various components of these devices may be implemented on a flexible printed circuit film, a Tape Carrier Package (TCP), a Printed Circuit Board (PCB), or formed on one substrate.

Further, the various components of these devices may be processes or threads running on one or more processors in one or more computing devices, executing computer program instructions and interacting with other system components to perform the various functions described herein. The computer program instructions are stored in a memory, which may be implemented in the computing device using standard memory devices, such as, for example, a Random Access Memory (RAM). The computer program instructions may also be stored in other non-transitory computer readable media, such as, for example, a CD-ROM, flash drive, or the like. Moreover, those skilled in the art will recognize that the functionality of the various computing devices may be combined or integrated into a single computing device, or that the functionality of a particular computing device may be distributed across one or more other computing devices, without departing from the spirit and scope of embodiments of the present disclosure.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concepts belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As described above, a User Equipment (UE) may be configured to communicate directly with a neighboring UE over a distributed system via a bypass (SL) transmission. Thus, each UE is able to communicate with any other UE using SL transmissions, rather than relaying communications through the base station via uplink and downlink transmissions. For example, communication with a base station (e.g., to a network) may be limited to communication associated with configuration (e.g., to determine how the system operates). Further, the base station may act as a sensing unit. However, the base station typically does not rely on relaying data from one UE to another for SL transmission.

Fig. 1 is a system diagram depicting a possible system for bypass (SL) communication, in accordance with some embodiments of the present disclosure.

Referring to fig. 1, a wireless communication system 10 may include one or more UEs (e.g., mobile handsets, wireless devices, wireless modems, etc.). The one or more UEs may include a first UE (UE1), a second UE (UE 2), a third UE (UE 3), and a fourth UE (UE 4). The UE may be a neighboring UE. The UE can transmit (Tx) data directly to the neighboring UE and/or receive (Rx) data directly from the neighboring UE. Further, one or more base stations 110 that correspond to one or more networks 120 and that may relay signals between UEs for downlink and uplink transmissions may be limited to providing configuration information for operation of the system or to serving as a sensing element related to SL transmissions between UEs. Further, for example, wireless communication system 10 may not include a base station when one or more UEs are operating out of coverage.

Thus, in a new radio vehicle to everything (NR V2X), a UE (e.g., UE1, UE 2, UE 3, or UE 4) may be configured to signal in a first stage (first stage) bypass Control Information (SCI) which resources are intended for future SL transmissions, thereby creating a chain of signaled resources. Signaling resources to neighboring UEs may reduce or minimize interference between UEs, as neighboring UEs may avoid the signaled resources when selecting their own resources for transmission in the future. Thus, resource collisions may be avoided, which improves transmission reliability and overall system throughput.

However, in the current SCI format, resources can only be signaled if they fit (fit) within a window of 32 slots. Further, the first level SCI includes three parameters that may be used to signal selected (selected) or reserved (reserved) resources to other UEs: (1) a frequency resource assignment operable to inform other UEs of the number of reserved subchannels and a starting subchannel of at most two selected resources for future transmissions; (2) a time resource assignment that can be used to inform other UEs of the time interval between the slot in which the SCI is sent and at most two selected resources for future transmissions; and (3) a resource reservation period (resource reservation period), which may be used to notify other UEs of the resource reservation period in case of periodic traffic (e.g., periodic transmission).

When the first UE receives an SCI from another one of the neighboring UEs, the first UE may identify a priority corresponding to the reserved resources indicated by the SCI. The first UE may use the signaled information indicated by the SCI to exclude reserved resources indicated by the SCI from a potential resource list (e.g., a set of candidate resources for future SL transmissions by the first UE) to avoid resource conflicts.

To signal to the neighboring UEs through the first level SCI, and to allow the neighboring UEs to exclude reserved resources to maintain chain integrity, the reserved resources may be selected to fall within a signaling window (e.g., a 32-slot signaling window), e.g., to fit within or within the signaling window.

However, the current NR mode 2 resource selection procedure, where resources are selected autonomously by the UE (see table 1 and fig. 3 below), does not take into account the resource signaling capabilities during the first operation of resource selection. For example, the current NR mode 2 resource selection procedure does not include operations, at least in the first operation, to determine whether the set of candidate resources selected by the UE for future SL transmissions may maintain chain integrity. For example, the first operation of the resource selection procedure, which may be performed by the physical layer (PHY), may not take into account the maximum slot spacing between consecutive slots (e.g., consecutive slots that have been selected as candidate resources for future SL transmissions) so that these slots may be signaled by the SCI. For example, the resource selection process may be completed in two operations. In a first operation, the PHY may select a set of resources that are suitable to be within the selection window and meet certain criteria without determining whether chain integrity may be maintained. In a second operation performed by a higher layer, the first, second or third resource may be selected from the set of candidate resources provided by the first operation, and may be expected to maintain chain integrity unless the UE cannot find sufficient resources to maintain chain integrity.

According to some embodiments of the present disclosure, when a maximum time interval between consecutive time slots (e.g., between a first resource in a resource chain for future SL transmissions and a second resource in the resource chain) is adapted to be within (e.g., less than or equal to) a signaling window, chain integrity for future SL transmissions may be maintained or maintained. On the other hand, when the maximum time interval between consecutive time slots is greater than or not within the signaling window, it may not be possible to maintain the chain integrity of future SL transmissions.

Fig. 2 is a timing diagram depicting bypass transmissions from more than one User Equipment (UE) and depicting resource conflicts, in accordance with some embodiments of the present disclosure.

Referring to fig. 2, a resource selection process as will be discussed in the next section provides a higher layer with a set of resources to be selected for resource reservation. Higher layers may refer to the Media Access Control (MAC) layer (e.g., a protocol layer above the signaling layer that handles the sensing and actual data transfer).

In this example, UE4 may have selected subchannel 0 in slots 3 and 37 from within the resource selection window as a candidate resource for future SL transmissions. When a higher layer performs the selection of resources for SL transmission and signals a reservation in slot 3 (e.g., in the first level SCI), the UE4 will not be able to signal a reservation for slot 37 to a neighboring UE (e.g., to UE 1, UE 2, or UE 3) because slot 37 is beyond or outside the 32-slot signaling window for signaling through the time resource assignment field (32-slot signaling window). Thus, UE 3 may attempt to use subchannel 0 of slot 37 (e.g., may attempt to transmit on subchannel 0 on slot 37, or may attempt to occupy subchannel 0 on slot 37) without prior notification to other UEs. Thus, resource collision may occur on subchannel 0 in slot 37.

In the event of resource collisions, the data (e.g., packets) transmitted on the time slots 37 may thus be lost. For example, when UE 1 listens (e.g., scans) to subchannel 0 on time slot 37, UE 1 may not be able to receive any data sent by UE 3 or UE 4, or UE 1 may only be able to decrypt data transmissions between UE 3 or UE 4 having the greatest signal strength. For example, and referring to fig. 1, UE 1 may be able to listen to UE 3 because UE 3 is closer than UE 4, and therefore UE 3 may have a greater signal strength measured by UE 1. Since transmissions overlap in time and frequency, resource collisions may cause interference.

Furthermore, the impact of resource collisions may be a loss of throughput and higher latency. For example, when a packet is lost, the UE may have two options: the packet is retransmitted or discarded altogether (e.g., ignored or discarded). If the UE retransmits, a delay may result (e.g., later in time) due to occupying additional resources, or the retransmission may cause interference with other UEs. If the packet is discarded, the packet reception rate may be reduced.

SL resource selection procedures according to some embodiments of the present disclosure may reduce or prevent resource conflicts. However, in a distributed communication system, (e.g., due to the complexity of many mobile UEs transmitting and receiving simultaneously, etc.), the prevention of resource conflicts may not be guaranteed 100%. Accordingly, embodiments of the present disclosure provide improvements and advantages for bypassing resource selection by excluding fewer resources to maintain chain integrity by adjusting resource exclusion criteria as appropriate, which enhances the ability of the resource selection process to reduce the risk of resource conflicts.

Fig. 3 is a flowchart depicting an outline of a mode 2 resource selection process in a New Radio (NR) vehicle-to-everything (V2X) communication according to a comparative example.

Referring to fig. 3 and table 1 (below), table 1 shows relevant information from the third generation partnership project (3GPP) specification 38.214 of 8.1.4 disclosing "steps" on seven processes, noting that the section indicating "TBD" has not been determined on the date of release of the specification (prior to U.S. provisional application No. 63/002,143 filed on 3/30 of 2020).

TABLE 1

The eight "steps" or operations of the above-described process may be summarized by the flow chart of fig. 3. For example, in operation (I), a selection window may be set; in operation (II), a sensing window may be set, and the UE may participate in measurement by decoding a physical bypass control channel (PSCCH)Monitoring all timeslots with reference to a signal received power (RSRP); in operation (III), the threshold (Th) may be set according to a priority value of transmission of the UE that is selecting resources; in operation (IV), the set of candidate resources may be initialized to all single-slot resources; in operation (V), certain exclusion rules/restrictions may be established to exclude candidate resources from the set; in operation (VI), some other exclusion rules may be established, e.g., excluding from the list resources occupied by UEs with higher priority and RSRP above a threshold (Th); in operation (VII), the UE may determine whether the remaining resources in the set are more than the total number M of, for example, single slot resources _total20% (determined by the configuration) and if not, the threshold (Th) may be increased by 3dB to retry and eliminate fewer resources; and in operation (VIII), if more than, for example, M remains after operation (VII)_total20% of the total number of resources, the candidate resource may be passed to higher layers for random selection.

Furthermore, to address the issue of chain integrity, in RAN1#100b, the related art suggests that the mode 2 resource selection procedure be limited, whereby the distance between any two resources can be forced to be less than 32 logical slots, thereby allowing signaling of the resources through the SCI. However, limiting the available resources to 32 logical slots may limit the available resources for selection and increase the risk of resource conflicts. For example, as described above, a UE looking for resources may transmit on resources that do not maintain chain integrity if insufficient resources are available within 32 time slots.

Accordingly, aspects of some embodiments of the present disclosure provide improvements to the resource selection process to maintain or improve resource chain integrity by effectively relaxing the exclusion and restriction of candidate resources for future SL transmissions to increase the number of resources for resource selection while maintaining chain integrity and reducing or minimizing the risk of resource conflicts.

Fig. 4A and 4B are timing diagrams describing methods of selecting resources for SL transmission according to some embodiments of the present disclosure.

In some embodiments, based on the pre-configuration, an associated physical bypass control channel (PSCCH) demodulation reference signal (DMRS) Reference Signal Received Power (RSRP) threshold (hereinafter referred to as an "RSRP threshold" or "priority-based RSRP threshold") for resource selection may be increased to allow the UE to access more resources (e.g., by excluding fewer resources) after determining whether chain integrity may be maintained for future SL transmissions.

In some embodiments, based on the pre-configuration, an associated physical bypass shared channel (PSSCH) demodulation reference signal (DMRS) Reference Signal Received Power (RSRP) threshold for resource selection (hereinafter referred to as "RSRP threshold" or "priority-based RSRP threshold") may be increased to allow the UE to access more resources (e.g., by excluding fewer resources) after determining whether chain integrity may be maintained for future SL transmissions.

For example, the UE may evaluate RSRP values (e.g., values indicating signal strength) from neighboring UEs with reference to priority-based RSRP thresholds to determine whether resources reserved by the neighboring UEs should be considered occupied or unoccupied. For example, the priority-based RSRP threshold may be a priority-affected RSRP threshold (e.g., not a priority threshold). For example, the RSRP threshold may be determined using the priority of the UE such that the RSRP threshold may be set higher because the UE has higher priority transmissions or may be set lower because the UE has lower priority transmissions. Thus, when a UE has a relatively low priority transmission, resources reserved by a neighboring UE with a relatively high RSRP value may be considered occupied by the UE, and when a UE has a relatively high priority transmission, resources reserved by a neighboring UE with a relatively low RSRP value may be considered unoccupied by the UE.

For example, the UE may compare a threshold (e.g., a priority-based RSRP threshold) to an RSRP value (e.g., signal strength) of neighboring UE transmission traffic to determine whether the resource may be considered occupied or unoccupied. Further, the threshold may be adjusted based on a determination that the remaining candidate resources may not maintain chain integrity. For example, one of the main reasons that chain integrity may not be maintained is that there is a limit to the amount of resources since many resources may be reserved by other UEs (e.g., other UEs signal their reserved resources through the SCI). Thus, in some cases, some resource selection procedures may not allow the UE to select resources sufficient to maintain chain integrity.

Thus, the resource selection process may be updated (e.g., modified or improved) by embodiments of the present disclosure to increase the RSRP threshold (e.g., by approximately 3dB), thereby enriching the set of available resources for resource selection. For example, when the resources available within the set of candidate resources to maintain chain integrity are not sufficient, then when chain integrity cannot be maintained in at least one or more subsets of resources (two or three resources, depending on the value of maxNumResource signaled in the SCI) within the set of resources passed to higher layers, for each priority value Th (p) is _i)，Th(p_i) May be increased (e.g., by 3 dB).

Further, Th (p)_i) The increase in (c) may occur in steps (e.g., about 1dB per step) and may be repeated until a sufficient number of resource subsets suitable for maintaining chain integrity can be selected at the end of the resource selection process. The determination of whether a sufficient number of subsets of resources are provided may be set to a percentage of the total number of resources desired to be delivered to higher layers (e.g., about 20%, depending on the configuration).

Furthermore, the above Th (p)_i) The increase in (d) may be based on a priority of a Transport Block (TB) (which may be referred to as TB priority) that initiates the resource selection process. For example, higher priority traffic may be paired with a threshold Th (p)_i) The allowed increases and step sizes have higher limits (e.g., larger increases and step sizes may be allowed). For example, a UE looking for resources for future SL transmissions with higher priority may be allowed to increase the threshold by about 4dB per step, while another UE looking for resources for future SL transmissions with lower priority may be allowed to increase only 1dB per step by the threshold.

Furthermore, when no resource is found to maintain chain integrity, Th (p) is increased based on TB priority according to the associated TB_i) To a particular limit, of candidate resources The set may or may not be passed to higher layers depending on the TB priority that initiated the resource selection. For example, some priorities may be allowed to proceed without maintaining chain integrity.

Referring to fig. 4A, one of the neighboring UEs (e.g., UE 1 in fig. 1) may set a resource selection window 202 corresponding to the resource pool 200 of candidate resources for SL transmission. UE 1 may set a sensing window 201 for monitoring SCI and for measuring signal strength of neighboring UEs (e.g., UE 2, UE 3, and UE 4 in fig. 1). For example, first SCI resource 210 within sensing window 201 may contain information for an aperiodic transmission that reserves first resource 211, and information for a periodic transmission that reserves second resource 212 (e.g., the transmission signaled by first SCI resource 210 may be a mix of aperiodic and periodic transmissions). The second SCI resource 220 within the sensing window 201 may correspond to an aperiodic transmission for reserving the third resource 221. Thus, the first resource 211, the second resource 212, and the third resource 221 may be Occupied Resources (OR). Thus, UE 1 may exclude first resource 211, second resource 212, and third resource 221 from the set of candidate resources for future SL transmissions for UE 1.

Furthermore, there may be other reserved resources within the resource selection window 202 in other embodiments, and there may be other SCIs within the sensing window 201, such that Unoccupied Resources (URs) (e.g., unreserved resources) may be relatively scarce. UE 1 may select a first unoccupied resource 231 and a second unoccupied resource 232 within the resource selection window 202. However, because the second unoccupied resource 232 may not be within the signaling window 203 (e.g., relative to the first unoccupied resource 231), selecting the first unoccupied resource 231 and the second unoccupied resource 232 may not preserve the chain integrity of the SL transmission of UE 1.

Referring to fig. 4B, UE 1 may adjust the threshold (e.g., by increasing the threshold by about 1dB to about 3dB or more) to exclude fewer resources. For purposes of illustration, the same resource reference numbers in fig. 4A are used in fig. 4B, although the resources in fig. 4B may depict resources that differ in time and frequency from the resources of fig. 4A. For example, the third resource 221 may have been associated with transmissions of UE 4 (see fig. 1), which may be relatively far from UE 1. Thus, the signal strength of the UE 4 may not correspond to a priority value (e.g., signal strength) that is higher than the increased threshold. Thus, (see fig. 4B) UE 1 may effectively declare that the third resource 221 is unoccupied based on the increased threshold, and thus, may not exclude the third resource 221 from the set of candidate resources. Thus, UE 1 may include the first unoccupied resource 231 and the third resource 221 as candidate resources (e.g., they are not excluded) because the first unoccupied resource 231 and the third resource 221 fall within the signaling window 203 (e.g., they may maintain chain integrity). Furthermore, because the signal strength of UE 4 that has reserved third resource 221 is below a threshold, resource collisions between UE 1 and UE 4 corresponding to third resource 221 may not result in significant interference.

In some embodiments, only a subset of the allowed resource reservation periods may be considered when excluding on a hypothetical (posterior) SCI reception due to the UE failing to monitor slot n. For example, only resources that have been indicated by a subset of allowed periods in the reservationPeriodAllowed may be excluded. Thus, fewer resources may be eliminated when there are insufficient resources to maintain chain integrity.

For example, the UE may not monitor slot n for potential SCI reception (e.g., because the potential SCI was transmitted in that slot). In this case, the UE may assume that the assumed SCI is received and may exclude periodicity values that are less than all possible periodicity values (e.g., resources may be excluded based on only a subset of the possible periodicity values). For example, assuming that reservationPeriodAllowed indicates ten possible periods, the UE may exclude only five periods when excluding resources based on the assumed SCI. In contrast, in the 3GPP specification, all periods indicated by reservationPeriodAllowed are considered when excluding resources (e.g., all possible periods of a hypothetical SCI may be excluded).

Further, the subset of periods selected from reservationPeriodAllowed may be based on the frequency with which they are used in a given geographic area. For example, the resource selection process may consider the five most frequently used period values in the set reservationPeriodAllowed for resource exclusion. Furthermore, because such exclusion may be based on an assumed SCI that is not actually received, the risk of resource collision is less compared to resources signaled by SCIs actually detected by the UE.

Referring again to fig. 4A, UE 1 may have transmitted during the time slot corresponding to the first hypothesized SCI resource 250 within sensing window 201. Thus, UE 1 may or may not miss a SCI signaling a reservation of resources from another UE, since the UE may not listen (e.g., receive) and transmit simultaneously at any given time slot, which may be referred to as a half-duplex constraint. Due to half-duplex constraints, a wireless communication system 10 (see fig. 1) including UE 1 may be configured to assume that the SCI containing all possible periods (e.g., as determined based on system configuration) is received while UE 1 is transmitting, and thus all possible periods may be excluded to protect the system. For example, the system may be configured with four possible periods: about 20 milliseconds (ms); about 40 ms; about 60 ms; and about 80ms, although the disclosure is not so limited. Thus, the UE may exclude all possible periods (n +20ms, n +40ms, n +60ms, and n +80ms), where n is an integer equal to or greater than 0.

For example, UE 1 may assume that SCIs are received in the slot corresponding to the first assumed SCI resource 250 and may exclude all possible periods corresponding to the assumed SCI resource 250 (e.g., fourth resource 251 and fifth resource 252).

Alternatively, referring to fig. 4B, UE 1 may exclude fewer than all possible periods corresponding to hypothetical SCI resource 250 (e.g., exclude only fourth resource 251) to provide access to more resources. Thus, UE 1 may include the first unoccupied resource 231 and the fifth resource 252 as candidate resources (e.g., without excluding them) because they fall within the signaling window 203 (e.g., because they may maintain chain integrity). Furthermore, UE 1 may exclude based on a subset of the periods, whether or not there are sufficient resources to maintain chain integrity. For example, the cycle-based exclusion of the subset may occur before checking whether the resource selection set has sufficient resources to maintain chain integrity.

Fig. 5A and 5B are flow diagrams depicting methods of selecting resources for SL transmission depicted in fig. 4A and 4B, according to some embodiments of the present disclosure.

Referring to fig. 5A, a method 500A of selecting resources for SL transmission may be performed, wherein a UE may be configured to: initializing a set of candidate resources (e.g., one or more of the resources within a resource selection window may be initially included in the set) (operation 510A); excluding a candidate resource from the set when the candidate resource may be restricted (e.g., based on one or more exclusion criteria, such as excluding one or more cycles corresponding to the hypothesized SCI, or based on an allowed periodicity value of the hypothesized SCI) (operation 520A); excluding candidate resources from the set according to one or more exclusion criteria related to occupied resources (e.g., based on a determination of whether a signal strength of a transmission associated with an occupied resource (which may be related to RSRP measurements) is below a priority threshold (Th)), determining whether a resource is unoccupied or occupied and/or excluding occupied resources (operation 530A); excluding from the set candidate resources that may not maintain chain integrity of the resource chain for the SL transmission (e.g., when a maximum time interval between a first resource and a second resource in the resource chain for the SL transmission is outside of, not suitable for within, or larger than a signaling window) (operation 540A); (e.g., based on a minimum number of candidate resources or a percentage of a number of resources (such as a total number of single slot resources) corresponding to a resource selection window and/or resource pool), determining whether remaining candidate resources in the set are suitable for selection by the UE for SL transmission (operation 550A); when the remaining resources in the set are not suitable for selection for SL transmission, adjusting (e.g., increasing) the threshold (Th) by a fraction (e.g., about 1dB or greater) to exclude fewer resources, and performing the previous operations again and increasing the threshold again until the remaining candidate resources in the set are suitable for selection by the UE for SL transmission (operation 560A); and when the remaining candidate resources in the set are suitable for selection by the UE for SL transmission, reporting the remaining candidate resources of the set to higher layers for selection (e.g., selection by the UE for SL transmission) (operation 570A). Further, the increase in the threshold in operation 560A may be based on TB priority (e.g., higher priority transmissions may be allowed to increase more above the threshold than lower priority transmissions for each iteration of the process). Thus, resource selection constraints (e.g., exclusion criteria) may be adjusted (e.g., relaxed) to help maintain chain integrity.

Referring to fig. 5B, a method 500B of selecting resources for SL transmission may be performed, where a UE may be configured to: initializing a set of candidate resources (e.g., one or more of the resources within the resource selection window may be initially included in the set) (operation 510B); when the candidate resource may be restricted (e.g., based on one or more exclusion criteria, such as excluding one or more cycles corresponding to the hypothesized SCI, which may be based on an allowed cycle/periodicity value of the hypothesized SCI) (operation 520B); excluding candidate resources from the set according to one or more exclusion criteria related to occupied resources (e.g., determining whether a resource is unoccupied or occupied, and/or excluding occupied resources based on a determination of whether a signal strength of a transmission associated with an occupied resource (which may be related to RSRP measurements) may be below a priority threshold (Th) (operation 530B); excluding from the set candidate resources that may not maintain chain integrity of the chain of resources for the SL transmission (e.g., when a maximum time interval between a first resource and a second resource in the chain of resources for the SL transmission is outside of a signaling window) (operation 540B); determining whether remaining candidate resources in the set are suitable for selection by the UE for SL transmission (e.g., based on a minimum number of candidate resources or a percentage of a number of resources (such as a total number of single slot resources) corresponding to a resource selection window and/or resource pool (operation 550B); when the remaining resources in the set are not suitable for selection for SL transmission, adjusting the number of excluded cycles based on the assumed SCI (e.g., to at least all cycles, or to a subset of all cycles corresponding to a periodicity value) to exclude fewer resources, and performing the previous operation again and reducing the number of excluded cycles until the remaining candidate resources in the set are suitable for selection by the UE for SL transmission (operation 560B); and reporting the remaining candidate resources of the set to higher layers for selection (e.g., by the UE for SL transmission) when the remaining candidate resources of the set are suitable for selection by the UE for SL transmission (operation 570B). Further, the reduction in the number of cycles excluded may be based on the frequency with which the cycles are used in a given geographic area (e.g., more frequently used cycle values may be excluded from the set of candidate resources, while less frequently used cycle values may be included in the set of candidate resources). Thus, resource selection constraints (e.g., exclusion criteria) may be adjusted (e.g., relaxed) to help maintain chain integrity. Moreover, exclusion based on a subset of the periods may occur regardless of a determination that the candidate resources may not preserve chain integrity of the SL transmission.

Fig. 6A and 6B are timing diagrams depicting methods of selecting resources for SL transmission according to some embodiments of the present disclosure.

Referring to fig. 6A and 6B, a UE may be configured to temporarily reduce a reselection counter C corresponding to periodic transmissions when performing resource selection to increase the chance of finding a resource that maintains chain integrity_reselValue (e.g., reselection counter value C)_resel). For example, decrease reselection counter C_reselThe value may increase the number of resources available for selection.

When performing resource selection for periodic transmissions, the UE may need to find the first transmission and C for the UE_resel1 periodic transmission (e.g., given reselection counter C)_reselA value of 5, four periodic transmissions follow the first transmission of the UE). However, the UE may not be able to find a sufficient number of available resources to maintain chain integrity. Thus, the UE may be configured to reduce C (e.g., temporarily)_reselTo be able to pass more subsets of resources to higher layers that preserve chain integrity.

In addition, to maintain proper system performance, the reselection counter C_reselMay be limited to values above a certain threshold (e.g., a minimum value). For example, if C_reselIs set to a value that is too low (e.g., large) About 1), then a large number of UEs may change their resources frequently in any given time slot, thereby increasing the chance of collisions and reducing the benefits of the resource selection process.

In addition, lower reselection counter C_reselThe value threshold may be based on the priority value prio_TX. For example, the UE may be based on having a higher priority value prio_TXWill reselect the counter C_reselThe value decreases to a lower minimum (e.g., lower threshold and limit).

For example, and referring to fig. 6A, UE 1 may look for periodic resources for periodic SL transmissions with a period of approximately 20 (e.g., 20 ms). When reselecting counter C_reselWith a value configured to be approximately 5, UE 1 may look for resources corresponding to slot X, slot X +20, slot X +40, slot X +60, and slot X +80 (e.g., before being able to transfer to a different resource). For example, reselection counter C_reselThe value may be a number that may determine how many cycles of periodic transmission UE 1 may consider to discover reservations on the first set of resources before transitioning to the second set of resources (e.g., based on a probabilistic determination when the reselection counter reaches zero). However, it may be difficult for UE 1 to find a suitable amount of resources (e.g., when there are many neighboring UEs).

For example, and referring to FIG. 6B, UE 1 may look for a resource corresponding to C following the first unoccupied resource at slot X_reselFour unoccupied resources of 1 cycle. However, there may not be unoccupied resources available at slot X + 80. Thus, UE 1 may be configured to decrease reselection counter C_reselValue (e.g., decreased by 1) such that the counter C is reselected_reselThe value is equal to about 4 to increase the chance of finding sufficient resources. For example, when reselecting counter C_reselWhen the value is adjusted (e.g., decreased) to about 4, UE 1 may look for a corresponding C following the first unoccupied resource at slot Y_reselThree unoccupied resources of 1 cycle. Thus, the occupied resource at slot Y +80 does not reduce the chance that UE 1 finds sufficient resources. Thus, UE 1 may send multiple retransmissions per cycle that preserve chain integrity (e.g., maintaining chain integrityAperiodic retransmission).

Fig. 7 is a flow diagram depicting a method of selecting resources for SL transmission depicted in fig. 6A and 6B in accordance with some embodiments of the present disclosure.

Referring to fig. 7, a method 700 of selecting resources for SL transmission may be performed, wherein a UE may be configured to: initializing a set of candidate resources (e.g., one or more of the resources within a resource selection window may be initially included in the set) (operation 710); excluding a candidate resource from the set when the candidate resource may be restricted (e.g., based on one or more exclusion criteria, such as excluding one or more cycles corresponding to the hypothesized SCI, e.g., based on an allowed periodicity value of the hypothesized SCI) (operation 720); excluding candidate resources from the set according to one or more exclusion criteria related to occupied resources (e.g., determining whether a resource is unoccupied or occupied, and/or excluding occupied resources based on a determination of whether a signal strength of a transmission associated with an occupied resource (which may be related to RSRP measurements) may be below a priority threshold (Th) (operation 730); excluding from the set candidate resources that may not maintain chain integrity of the chain of resources for the SL transmission (e.g., when a maximum time interval between a first resource and a second resource in the chain of resources for the SL transmission is outside of a signaling window) (operation 740); determining whether remaining candidate resources in the set are suitable for selection by the UE for SL transmission (e.g., based on a minimum number of candidate resources or a percentage of a number of resources (such as a total number of single slot resources) corresponding to a resource selection window and/or resource pool (operation 750); adjusting (e.g., temporarily reducing) reselection counter C corresponding to a periodic portion of SL transmission _reselTo improve the chance of finding sufficient resources (e.g., to reduce the delay of finding sufficient resources), and to perform the previous operation again and reduce the reselection counter C_reselValues until the remaining candidate resources in the set are suitable for selection by the UE for SL transmission (operation 760); and when the remaining candidate resources in the set are suitable for selection by the UE for SL transmission, reporting the remaining candidate resources of the set to higher layers for selection (e.g., by the UE for SL transmission) (operations770). In addition, a reselection counter C_reselThe reduction in the number (e.g., amount) of values may be based on the priority (e.g., TB priority) of SL transmissions. For example, the minimum value established for lower priority SL transmissions (e.g., about 4) may be higher than the minimum value established for higher priority SL transmissions (e.g., about 2). Accordingly, resource selection criteria may be adjusted (e.g., relaxed) to help maintain chain integrity.

Fig. 8 is a timing diagram depicting a method of selecting resources for SL transmission in accordance with some embodiments of the present disclosure.

Referring to fig. 8, in some embodiments, it may be assumed that UEs that have performed a large number of periodic transmissions on a given set of resources have reached or are close to reaching their reselection counter C _reselThe value is obtained. For example, in the event of a resource shortage, the UE may first attempt to select resources that have been continuously used by neighboring UEs for a large number of periods, since these neighboring UEs are more likely to have reached their reselection counter C_reselThe value is obtained.

For example, the reselection counter values of neighboring UEs may be unknown (e.g., agnostic). Thus, the UE may not be able to identify the time slot at which a neighboring UE may attempt to select a different set of resources (e.g., when reselection counter C is present)_reselAt expiration). Thus, a UE may assume (e.g., over a large number of cycles) that neighboring UEs that have used the same set of resources for a large number of periodic transmissions are close to their reselection counter C_reselThe value is obtained. Thus, when a UE lacks sufficient resources to maintain resource chain integrity, the UE may attempt to reuse (reuse) resources occupied by neighboring UEs that consistently use the same resources for a relatively long duration. Although this resource selection method may not guarantee that the selected resources do not collide, it may still reduce the risk of collisions compared to using resources of neighboring UEs that are more recently handed over to the new set of resources.

In order to reuse resources occupied by neighboring UEs that consistently use the same resources (e.g., over a large number of cycles) for a large number of periodic transmissions, the UE may count the number of times the neighboring UEs use the resources through a sensing window. Further, before attempting to select resources, the UE may check that neighboring UEs have used the same set of resources for multiple periods above a given threshold.

For example, and referring to fig. 8, UE 1 may receive first SCI1 and second SCI2 in sensing window 201. SCI1 may correspond to a first set of resources OR1 occupied by UE 2, and SCI2 may correspond to a second set of resources OR2 occupied by UE 3. Further, UE 2 may have occupied the first set of resources OR1 approximately 8 times (e.g., approximately 8 cycles), while UE 3 may only occupy the second set of resources OR2 approximately 2 times (e.g., approximately 2 cycles). Thus, UE 1 may assume (e.g., determine) that UE 2 is closer to reaching its reselection counter C than UE 3_reselValue because UE 2 has used the same set of resources for a longer duration. Thus, when occupying the resources of UE 2, UE 1 may determine that the risk of resource collision is unlikely. Further, based on the minimum usage period threshold, UE 1 may determine that the first set of resources OR1 is suitable for selection (e.g., because the minimum usage period threshold may be about 2 cycles, and the first set of resources OR1 may have the same resource set usage value of about 8 cycles, which is higher than the minimum usage period threshold).

Fig. 9 is a flow diagram depicting a method of selecting resources for SL transmission depicted in fig. 8 in accordance with some embodiments of the present disclosure.

Referring to fig. 9, a method 900 of selecting resources for SL transmission may be performed, wherein a UE may be configured to: initializing a set of candidate resources (e.g., one or more of the resources within a resource selection window may be initially included in the set) (operation 910); excluding a candidate resource from the set when the candidate resource may be restricted (e.g., based on one or more exclusion criteria, such as excluding one or more cycles corresponding to the hypothesized SCI, e.g., based on an allowed periodicity value of the hypothesized SCI) (operation 920); according to whether one or more exclusion criteria related to occupied resources (e.g., based on signal strength of transmissions associated with occupied resources (which may be related to RSRP measurements) may be below a priority thresholdDetermination of a value (Th), determination of whether a resource is unoccupied or occupied and/or excluded from being occupied), excluding candidate resources from the set (operation 930); excluding from the set candidate resources that may not maintain chain integrity of the resource chain for the SL transmission (e.g., when a maximum time interval between a first resource and a second resource in the resource chain for the SL transmission is outside of a signaling window (e.g., not within the signaling window or larger than the signaling window) (operation 940); determining whether remaining candidate resources in the set are suitable for selection by the UE for SL transmission (e.g., based on a minimum number of candidate resources or a percentage of a number of resources (such as a total number of single slot resources) corresponding to a resource selection window and/or resource pool (operation 950); comparing the number of usage periods of the same set of resources of one or more UEs with the number of usage periods of the same set of resources of one or more other neighboring UEs to enable more resources to be included in the set (operation 960); including resources of neighboring UEs having a greater number of usage cycles of the same resource set in the set (e.g., based on a minimum usage cycle threshold), and again performing previous operations and comparing resource usage of the neighboring UEs until remaining candidate resources in the set are suitable for selection by the UE for SL transmission (operation 961); and when the remaining candidate resources in the set are suitable for selection by the UE for SL transmission, reporting the remaining candidate resources of the set to higher layers for selection (e.g., by the UE for SL transmission) (operation 970). Furthermore, the neighbor-based UE may be closer to its reselection counter C _reselCandidate resources added by the inferred determination of values may not be excluded in subsequent iterations of the selection process. Accordingly, resource selection/exclusion criteria may be adjusted (e.g., relaxed) to help maintain chain integrity.

Accordingly, embodiments of the present disclosure provide improvements to bypass resource selection procedures in communication systems such that resource conflicts may be reduced (e.g., avoided), delays may be reduced, and throughput may be increased.

While embodiments of the present disclosure have been particularly shown and described with reference to the embodiments described herein, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as set forth in the following claims and their equivalents.