SIDELINK RESOURCE INDICATIONS AND USAGE

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE. The UE may schedule, from among the candidate sidelink resources based at least in part on signal-to-interference ratios for the candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The UE may transmit, to the second UE, an indication of the candidate sidelink resources and the one or more scheduled sidelink resources. Numerous other aspects are described.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for indicating and using sidelink resources.

BACKGROUND

SUMMARY

In some aspects, a method of wireless communication performed by a first user equipment (UE) includes selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, and scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The method may include transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a method of wireless communication performed by a first user UE includes receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a first UE for wireless communication includes a memory and one or more processors, coupled to the memory, configured to select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a first UE for wireless communication includes a memory and one or more processors, coupled to the memory, configured to receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a first UE, cause the first UE to select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a first UE, cause the first UE to receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

In some aspects, a first apparatus for wireless communication includes means for selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second apparatus to use for transmission to the first apparatus; means for scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first apparatus; and means for transmitting, to the second apparatus, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

In some aspects, a first apparatus for wireless communication includes means for receiving, from a second apparatus, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second apparatus and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and means for transmitting, to the second apparatus, a communication in one of the one or more candidate sidelink resources.

DETAILED DESCRIPTION

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, and/or an air interface. A frequency may also be referred to as a carrier, and/or a frequency channel. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, UE120amay indicate available sidelink resources to UE120e,and the UE120emay select a sidelink resource for transmission from these available sidelink resources. The UE120emay also sense a sidelink channel to determine which sidelink resources are available. The UE120emay select a sidelink resource for transmission from the sidelink resources that UE120aindicates as available and/or from the sidelink resources that UE120esenses are available. As described in various aspects herein, the UE102amay schedule one or more preferred sidelink resources on behalf of the UE102e.

FIG. 2is a diagram illustrating an example200of a base station110in communication with a UE120in a wireless network100, in accordance with the present disclosure. Base station110may be equipped with T antennas234athrough234t,and UE120may be equipped with R antennas252athrough252r,where in general T≥1 and R≥1.

Controller/processor280of UE120and/or any other component(s) ofFIG. 2may perform one or more techniques associated with indicating and using sidelink resources, as described in more detail elsewhere herein. For example, controller/processor280of UE120and/or any other component(s) ofFIG. 2may perform or direct operations of, for example, process1000ofFIG. 10, process1100ofFIG. 11, and/or other processes as described herein. Memory282may store data and program codes for UE120, respectively. In some aspects, memory282may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the UE120, may cause the one or more processors and/or the UE120to perform or direct operations of, for example, process1000ofFIG. 10, process1100ofFIG. 11, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, a first UE (e.g., UE120) includes means for selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, means for scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE, and/or means for transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources. The means for the first UE to perform operations described herein may include, for example, one or more of antenna252, demodulator254, MIMO detector256, receive processor258, transmit processor264, TX MIMO processor266, modulator254, controller/processor280, or memory282.

In some aspects, the first UE includes means for receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, and/or means for transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources. The means for the first UE to perform operations described herein may include, for example, one or more of antenna252, demodulator254, MIMO detector256, receive processor258, transmit processor264, TX MIMO processor266, modulator254, controller/processor280, or memory282.

FIG. 3is a diagram illustrating an example300of sidelink communications, in accordance with the present disclosure.

As shown inFIG. 3, a first UE302may communicate with a second UE304(and one or more other UEs) via one or more sidelink channels310. UE302and UE304may communicate using the one or more sidelink channels310for P2P communications, D2D communications, V2X communications (e.g., which may include V2V communications, V2I communications, and/or V2P communications) and/or mesh networking. In some aspects, UE302and UE304may correspond to one or more other UEs. In some aspects, the one or more sidelink channels310may use a PC5 interface and/or may operate in a high frequency band (e.g., the 5.9 gigahertz (GHz) band). Additionally, or alternatively, UE302and UE304may synchronize timing of transmission time intervals (TTIs) (e.g., frames, subframes, slots, or symbols) using global navigation satellite system (GNSS) timing.

As further shown inFIG. 3, the one or more sidelink channels310may include a physical sidelink control channel (PSCCH)315, a physical sidelink shared channel (PSSCH)320, and/or a physical sidelink feedback channel (PSFCH)325. The PSCCH315may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and/or a physical uplink control channel (PUCCH) used for cellular communications with a base station (e.g., base station110) via an access link or an access channel. The PSSCH320may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH) used for cellular communications with a base station via an access link or an access channel. For example, the PSCCH315may carry sidelink control information (SCI)330, which may indicate various control information used for sidelink communications, such as one or more resources (e.g., time resources, frequency resources, and/or spatial resources) where a transport block (TB)335may be carried on the PSSCH320. The TB335may include data. The PSFCH325may be used to communicate sidelink feedback340, such as hybrid automatic repeat request (HARD) feedback (e.g., acknowledgement or negative acknowledgement (ACK/NACK) information), transmit power control (TPC), and/or a scheduling request (SR).

In some aspects, UE304may operate using a transmission mode where resource selection and/or scheduling is performed by UE302(e.g., rather than a base station). In some aspects, UE302and/or UE304may perform resource selection and/or scheduling by sensing channel availability for transmissions. For example, UE304may measure an RSSI parameter (e.g., a sidelink-RSSI (S-RSSI) parameter) associated with various sidelink channels, may measure an RSRP parameter (e.g., a PSSCH-RSRP parameter) associated with various sidelink channels, may measure an RSRQ parameter (e.g., a PSSCH-RSRQ parameter) associated with various sidelink channels, and/or may determine a signal-to-interference ratio (SIR) associated with another UE on a sidelink channel. UE304may select a channel for transmission of a sidelink communication based at least in part on the measurement(s).

Additionally, or alternatively, UE304may perform resource selection and/or scheduling using SCI330received in the PSCCH315, which may indicate occupied resources and/or channel parameters. Additionally, or alternatively, UE304may perform resource selection and/or scheduling by determining a channel busy rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that UE304can use for a particular set of subframes).

In the transmission mode where resource selection and/or scheduling is performed by UE302, UE302may generate sidelink grants, and may transmit the grants in SCI330. A sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for the upcoming sidelink transmission on the PSSCH320(e.g., for TBs335), one or more subframes to be used for the upcoming sidelink transmission, and/or a modulation and coding scheme (MCS) to be used for the upcoming sidelink transmission. In some aspects, UE302may generate a sidelink grant that indicates one or more parameters for semi-persistent scheduling (SPS), such as a periodicity of a sidelink transmission. Additionally, or alternatively, UE302may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

UE302and UE304may operate in sidelink resource allocation Mode 2, in which UE302and UE304schedule or reserve their own sidelink resources without the assistance or direction of a base station (Mode 1). In some aspects, UE302may indicate available sidelink resources to UE304, and UE304may select a sidelink resource for transmission from these available sidelink resources. UE304may also sense one or more of the sidelink channels310to determine which sidelink resources are available. UE304may select a sidelink resource for transmission from the sidelink resources that UE302indicates as available and/or from the sidelink resources that UE304senses are available. As described in various aspects herein, UE302may schedule one or more preferred sidelink resources on behalf of UE304.

As indicated above,FIG. 3is provided as an example. Other examples may differ from what is described with regard toFIG. 3.

FIG. 4is a diagram illustrating an example400of selecting sidelink resources, in accordance with the present disclosure. Example400shows a UE402(e.g., a UE302) that may receive communications on a sidelink channel from other UEs (e.g., a UE304), such as UE404, UE406, and/or UE408.

As described in connection withFIGS. 4-9, UE404is a transmitting UE that is transmitting communications to UE402, which is a receiving UE. UE404may use a report from UE402, which may act as a reporting UE that reports available sidelink resources. Example400shows an availability report from UE402to UE404and a communication from UE404to UE402.

If UE404is to transmit a communication to UE402, UE404may sense the sidelink channel in a sensing window to determine which sidelink resources (e.g., subcarriers, subchannels) are available. A sidelink resource may be considered available if the sidelink resource was clear or had a signal energy (e.g., RSRP) that satisfied an availability threshold (e.g., measured interference or energy on the channel is lower than a maximum decibel-milliwatts (dBm) or dB, RSRP threshold). The availability threshold may be configured per transmission priority and receive priority pair. UE404may measure DMRSs on a PSCCH or a PSSCH, according to a configuration.

For example, UE404may prepare to transmit a communication to UE402. UE404may have already sensed previous sidelink resources and successfully decoded SCI from UE406and UE408. UE404may try to reserve sidelink resources, and thus may check the availability of the future sidelink resources reserved by UE406and UE408by sensing the sidelink channel in the sensing window. UE404may measure an RSRP of a signal from UE408in sidelink resource410, and an RSRP of a signal from UE406in sidelink resource412. If an observed RSRP satisfies the RSRP threshold (e.g., is lower than a maximum RSRP), the corresponding sidelink resource may be available for reservations by UE404. UE404may reserve the sidelink resource (which may be a random selection from available resources). For example, UE404may select and reserve sidelink resource414for transmission. This may be in a time slot after which UE406and UE408had used sidelink resources, and UE404may have sensed these sidelink resources earlier.

There may be a resource selection trigger to trigger selection of sidelink resources after a processing time Tproc, 0, and before another processing time Tproc, 1before a resource selection window from which sidelink resources are available. The resource selection window may be a time window from which sidelink resources may be selected, and the resource selection window may extend for a remaining packet delay budget (PDB).

UE404may be power-sensitive and thus may not afford to continually sense all of the sidelink resources. UE402may be more capable of sensing and reporting on the sidelink resources because, for example, UE402may be a smart phone while UE404may be a smart watch. UE402may receive unicast communications from UE404, and UE402may report back available resources to UE404. UE402may continually sense the sidelink resources and measure interference levels involving neighboring UEs. For example, UE402may measure an RSRP of a signal from neighboring UE406as −92 dBm and an RSRP of a signal from neighboring UE408as −102 dBm. For a signal of a last transmission of UE404, UE402measured a target signal level with an RSRP that was −90 dBm. UE402may estimate an SIR of a signal between UE402and UE404as −90−(−92)=2 dB and an SIR between UE404and UE408as −90−(−102)=12 dB. If the SIR of a signal from UE404to UE402with interference from UE408is large enough (satisfies an availability threshold) for reliable communication between UE402and UE404, UE402may mark a sidelink resource that was reserved by UE408as available for use for a communication from UE404to UE402. This may be useful when UE404has more than one data stream with varying Quality of Service (QoS) requirements or transmissions with different MCS indices.

As indicated above,FIG. 4is provided as an example. Other examples may differ from what is described with regard toFIG. 4.

FIG. 5is a diagram illustrating an example500of using a resource report for sidelink resources, in accordance with the present disclosure. Example500shows that UE402may transmit a report to UE404.

UE402may transmit a report502indicating an availability of each sidelink resource. Rows in the report502may represent subcarriers or subchannels, and columns may represent time units (e.g., slots, symbols). The report502may be a binary report, such as a bitmap. For example, UE402may report a 1 bit for available and a 0 bit for unavailable. UE404may decode the report502and select (e.g., randomly) N resources from the available sidelink resources for potential N transmissions of a newly generated packet, or a packet of a transport block that has not been transmitted before. As shown by selection504, UE404may select N=4 sidelink resources from the available sidelink resources indicated by the report502.

As indicated above,FIG. 5is provided as an example. Other examples may differ from what is described with regard toFIG. 5.

FIG. 6is a diagram illustrating an example600of indicating and using scheduled sidelink resources, in accordance with the present disclosure.

UE402may prefer that UE404use sidelink resources with lower expected interference levels over other sidelink resources. If so, according to various aspects described herein, UE402may schedule one or more sidelink resources on behalf of UE404when indicating available sidelink resources to UE404. UE402may still allow UE404to select other sidelink resources from the remaining available sidelink resources. By scheduling preferred sidelink resources for UE404that are available, UE402may cause UE404to conserve power, processing resources, and signaling resources because UE404performs less sensing and scheduling of sidelink resources. UE404may still have flexibility to sense the sidelink channel and select sidelink resources to avoid interference or collisions that degrade communications, which conserves power, processing resources, and signaling resources that would otherwise be wasted on failed transmissions and retransmissions.

For example, UE404may be configured to make a maximum of N transmissions for a packet or for a transport block. UE402may sense the channel and select a set of candidate sidelink resources in the resource selection window of UE404for the N transmissions. Within the set of candidate sidelink resources, UE402may select and schedule M scheduled sidelink resources, where M may be 0 or up to N of the candidate sidelink resources (0≤M≤N) of UE404. Example600shows a report602from UE402indicating the set of candidate sidelink resources (resources marked with a “1”). The report602also indicates a scheduled sidelink resource (resource marked with “S”) that UE402has scheduled for UE404based at least in part on sensing the sidelink channel and detecting lower interference for the scheduled sidelink resource.

In some aspects, if M is less than N, UE404may select other sidelink resources from the set of candidate sidelink resources for any remaining transmissions up to N (N−M sidelink resources for N−M transmissions). As shown by selection604, UE404may select the scheduled sidelink resource606for a first transmission and select another candidate sidelink resource608for a second transmission. If M=0, then report602may be similar to a report that is regularly transmitted.

In some aspects, UE404may sense the channel, and based at least in part on sensing the sidelink channel and measuring interference from the location of UE404, may not use the scheduled candidate sidelink resource indicated in the report602. Rather, UE404may select another candidate sidelink resource indicated as available in the report602.

In some aspects, if M=N, UE402may indicate N scheduled sidelink resources by listing the respective indices of the N scheduled sidelink resources in the corresponding resource selection window of UE404. UE402may send availability information in addition to the indices of the N scheduled sidelink resources. The additional availability information may include an indication of available candidate sidelink resources, which gives UE404flexibility to alter some selections from any scheduled sidelink resources indicated by UE402. For example, if UE404senses the sidelink channel partially or fully, UE404may combine its own sensing results with the additional availability information from UE402, in order to have a better picture of sidelink channel availability.

UE404may use the report602for an initial transmission of a transport block. For example, UE404may have received an indication of M=1 scheduled sidelink resource in the report602for an initial transmission of a transport block and a set of candidate sidelink resources in the form of a resource availability list or bitmap, as shown inFIG. 6. Then, UE404may make its initial transmission on the scheduled sidelink resource and have freedom to select from among the remaining candidate sidelink resources that are indicated as available in the report602from UE402to make remaining N−1 re-transmissions if needed. By using the scheduled sidelink resource indicated in the report602for the initial transmission for the transport block, the UE404may have a better chance of avoiding interference or a collision with the initial transmission, which may occur without prior knowledge of a preferred sidelink resource.

As indicated above,FIG. 6is provided as an example. Other examples may differ from what is described with regard toFIG. 6.

FIG. 7Ais a diagram illustrating an example700of indicating and using sidelink resources, in accordance with the present disclosure. Example700shows that UE402, UE404, and UE406may communicate with each other via one or more sidelink communications. In some aspects, UE402, UE404, and/or UE406may communicate (e.g., transmit an uplink transmission and/or receive a downlink transmission) with a base station. UE402, UE404, UE406, and any base station may be part of a wireless network (e.g., wireless network100). As described in connection withFIGS. 4-6, UE404is the reporting UE, and UE402is the UE transmitting a communication.

As shown by reference number705, UE402may sense a sidelink channel in a sensing window for UE404(e.g., using antenna252, demodulator254, MIMO detector256, receive processor258, controller/processor280, and/or memory282). UE402may sense the sidelink channel based at least in part on past sidelink resources used by UE404or other UEs and/or future reserved sidelink resources for UE404or other UEs. As shown by reference number710, UE402may select candidate sidelink resources that are clear or at least satisfy an availability threshold (e.g., minimum SIR) and generate an indication (e.g., report, list, bitmap) of the candidate sidelink resources (e.g., using controller/processor280or memory282). UE402may also select one or more preferred sidelink resources for UE404and schedule the one or more of the preferred sidelink resources for UE404. UE402may mark the scheduled sidelink resources in the indication.

As shown by reference number715, UE402may transmit the indication via a radio resource control (RRC) message, a medium access control control element (MAC-CE), and/or downlink control information (DCI) (e.g., using antenna252, transmit processor264, TX MIMO processor266, modulator254, controller/processor280, and/or memory282). In some aspects, as shown by reference number720, UE404may receive an indication of reserved and/or available sidelink resources from another reporting UE, such as UE406(e.g., using antenna252, demodulator254, MIMO detector256, receive processor258, controller/processor280, and/or memory282). The indications from UE402and UE406may be in unicast transmissions to UE404.

As shown by reference number725, UE404may (optionally) sense the sidelink channel for scheduled sidelink resources indicated by UE402, other candidate sidelink resources indicated by UE402, reserved sidelink resources indicated by UE406, and/or any available sidelink resources indicated by UE406(e.g., using antenna252, demodulator254, MIMO detector256, receive processor258, controller/processor280, and/or memory282). As shown by reference number730, UE404may select sidelink resources from available sidelink resources indicated by UE402(e.g., using controller/processor280and/or memory282). UE404may use a scheduled sidelink resource indicated by UE402. For any remaining transmissions, UE404may select other candidate sidelink resources indicated by UE402. UE404may take into account any reserved sidelink resources or available sidelink resources indicated by UE406. As shown by reference number735, UE404may transmit a communication to UE402on a selected sidelink resource (e.g., using antenna252, transmit processor264, TX MIMO processor266, modulator254, controller/processor280, and/or memory282). UE404may transmit other communications to UE402with other selected sidelink resources.

In some aspects, availability information from UE406may conflict with availability information from UE402, and conflicted sidelink resources may include the scheduled sidelink resources and/or other candidate sidelink resources indicated by UE402. For example, UE402may indicate that a sidelink resource on the sidelink channel is available as a candidate sidelink resource, but UE406may indicate that the sidelink resource is not available. The sidelink resource may have interference or may be reserved. That is, some conflicts may exist for sidelink resources that are not disjoint in a time-frequency grid of a resource pool.

In some aspects, UE404may deduce the availability of sidelink resources by combining availability information (e.g., binary reports) from multiple UEs. For example, UE404may perform a resource-wise AND operation such that a sidelink resource is considered available if it is indicated as available by both UE402and UE406. For a sidelink resource with differing availability per UE (resource conflict), UE404has two options. In one option, UE404may consider a scheduled sidelink resource indicated by UE402as unavailable in order to protect the scheduled sidelink resource from a possible collision due to a missed reservation by UE402. UE404may not transmit a communication in the scheduled sidelink resource. In a second option, UE404may consider the scheduled sidelink resource as available and proceed with transmitting a communication in the scheduled sidelink resource based at least in part on sensing results rendering an interference level that satisfies the availability threshold, locations of UE402and/or UE406with respect to UE404, and/or a network layout of UE402and/or UE406with respect to UE404. That is, UE404may use information about the UE locations and the network layout to determine that the scheduled sidelink resource will not be interfered with and may use the scheduled sidelink resource.

In some aspects, if there is a conflict with scheduled sidelink resources and/or candidate sidelink resources, UE404may resolve a conflict and/or prioritize the scheduling sidelink resources of different UEs in various ways. For example, UE404may compare priorities of packets destined for each destination UE and use the sidelink resource scheduled by the UE whose packet has the highest priority. UE404may compare remaining PDBs of corresponding packets for each UE destination and use the scheduled sidelink resource for the packet with the shortest remaining PDB.

In some aspects, UE404may select a sidelink resource based at least in part on an application of a fairness rule between the UEs. For example, UE404may alternate between reporting UEs to select a different UE's scheduled sidelink resource at a given time (e.g., round-robin selection). UE404may compare a buffer status corresponding to each flow destined to the reporting UEs. For example, UE404may prefer using the sidelink resource for the longest queue.

In some aspects, UE404may use sidelink channel state information (SL-CSI) report values from conflicting reporting UEs. For example, UE404may prioritize a sidelink resource with a weaker link. UE404may select a sidelink resource based at least in part on a path loss, distance estimations between UE404and other reporting UEs (e.g., UE402, UE406, UE408), and/or zone identifiers (IDs) for the reporting UEs. For example, UE404may prioritize using a sidelink resource having a higher path loss and/or a greater distance.

In some aspects, UE404may consider reliability requirements on each link to the reporting UEs. For example, UE404may select a sidelink resource of a link with a higher reliability than other links. UE404may consider power control levels used on each link. For example, UE404may select a sidelink resource of a link with a lower power level for a conflicted sidelink resource. UE404may consider a utilization state of a feedback message, such as a HARQ-ACK on flows to the reporting UEs. For example, UE404may select a sidelink resource of a flow that uses blind transmissions (non-HARQ-ACK). UE404may consider communication range requirements on each link. For example, UE404may select a sidelink resource having a longer range requirement than range requirements of other sidelink resources. UE404may consider a cast type (e.g., unicast, groupcast, broadcast) of communications for each flow. For example, UE404may prioritize sidelink resources associated with one of the cast types. In other words, UE404may have various options for resolving sidelink resource conflicts between UEs.

FIG. 7Bis a diagram illustrating an example of resolving report conflicts, in accordance with the present disclosure. In some scenarios, as shown by reference number740, there may be multiple sidelink resource reports (e.g., availability and/or scheduled) from multiple UEs (e.g., UE402, UE406, UE408). Availability reports and/or scheduled reports may be combined. For example, multiple availability reports may be combined via an AND operation of available sidelink resources in the reports. That is, sidelink resources that are available will be indicated as available in each of the reports, and the AND operation is used to identify the available sidelink resources that overlap among the reports (available throughout every report). If a report is removed from consideration, the removed report will not be part of the combining (e.g., AND operation).

The combining of multiple reports may not achieve the availability threshold (e.g., minimum percentage of sidelink resource availability for using the available sidelink resources). In some aspects, rather than combining all of the availability reports, UE404may combine reports per group of UEs, as shown by reference number745. For example, when UE404receives more than one report from members of a groupcast or broadcast session, UE404may combine reports only from UEs that are within a group. This may mean that separate output results are utilized for different groups. A given reporting UE may belong to more than one group. For reports received for a unicast session, UE404may directly use the reports individually, or combine any reports originating from nearby UEs based on zone identifiers (IDs) or locations (if known) of the nearby UEs. However, if the availability threshold is not satisfied in a given group, UE404may pursue another option.

In some aspects, as shown by reference number750, UE404may combine reports that belong to UEs in a cluster, which may be a geographical area, such as area752. The UEs in the cluster may be closely located to each other. UE404may use one specific AND-combined report per cluster if a UE from that cluster is an intended receiver. If the availability threshold (e.g., X % resource availability) cannot be satisfied in a given cluster, UE404may pursue other options.

In some aspects, if the availability threshold is not satisfied (e.g., the availability percentage is less than the availability percentage defined as the availability threshold), UE404may postpone sidelink resource selection for one of the transmissions. UE404may omit the corresponding report(s) received from the target UE402and recombine the remaining reports as described with respect to reference number745or reference number750. In other words, when combining reports, UE404may remove the report of the intended target (e.g., UE402) from consideration to satisfy the availability threshold. In this way, UE404may proceed with transmission to UE402while taking a chance that there may be a conflict. It may be that the transmission is a high priority transmission and thus the transmission may proceed in any event (and be retransmitted if necessary). UE404may iteratively follow the same approach with other reports until the availability threshold is satisfied. The rule for selecting the postponed transmission at any time may be based at least in part on parameters described above in connection withFIG. 7A.

In some aspects, if the availability threshold is not satisfied, as shown by reference number755, UE404may postpone sidelink resource selection for a group of transmissions, transmissions for a cluster of UEs, or for all transmissions. UE404may postpone transmissions for a given number of slots and recheck the report combining at a corresponding slot with new reports that are received during this time.

In some aspects, if a sidelink resource scheduled by a scheduled report is not available according to an availability report, as shown by reference number760, UE404may avoid a sidelink resource scheduled by UE402since the sidelink resource is indicated as unavailable according to at least one other UE. Then, UE404may select a sidelink resource from available sidelink resources indicated in an availability report from UE402, after combining the availability report with availability reports of other UEs. UE404may combine the availability reports by group or per cluster. UE404may mark the avoided sidelink resource as unavailable in other reports.

In some aspects, if a sidelink resource scheduled by a scheduled report is not available according to an availability report, as shown by reference number765, UE404may still use the scheduled sidelink resource. UE404may have the location information (e.g., the zone IDs or location coordinates) of UE402, UE406, and/or UE408. If the distance between UEs, such as between UE402and UE406, is smaller than a pre-configured threshold, UE404may avoid the scheduled resource.

UE404may select a sidelink resource based at least in part on the parameters described above in connection withFIG. 7A. A parameter may satisfy a parameter threshold that is specific to the parameter. For example, if the sidelink resource scheduled by UE402corresponds to a packet with a priority level higher than a pre-configured priority threshold, then UE404may use the scheduled sidelink resource.

In some aspects, if a scheduled sidelink resource conflicts with another scheduled sidelink resource, UE404may select the scheduled resource to be used with UE402and select other sidelink resources for other UEs after combining availability reports of the other UEs. The scheduled sidelink resource that is selected may be marked as unavailable in other availability reports. When the conflicting scheduled sidelink resources are received from members of the same groupcast or broadcast sessions, UE404may select one of the conflicting scheduled sidelink resources randomly. By following such rules for conflicting sidelink resource reports, UE404may improve throughput and reduce latency while attempting to reduce conflicts. As a result, UE404and other UEs conserve processing resources and signaling resources.

As indicated above,FIG. 7AandFIG. 7Bare provided as examples. Other examples may differ from what is described with regard toFIG. 7AandFIG. 7B.

FIG. 8is a diagram illustrating examples800and802of resources for requesting and reporting, in accordance with the present disclosure.

A UE may be configured to use certain resources for requesting resources and/or for reporting. Example800shows resources for requesting transmissions and/or reports. The resources for requesting are configured with a certain periodicity. The resources for reporting may also have a periodicity. Example800shows the resources for requesting in one sidelink slot, while example802shows the resources for reporting that are distributed over multiple sidelink slots. Each request resource may be in a single subchannel or in multiple subchannels.

As indicated above,FIG. 8provides some examples. Other examples may differ from what is described with regard toFIG. 8.

FIG. 9is a diagram illustrating an example900of indicating sidelink resources, in accordance with the present disclosure. Example900shows time and frequency sidelink resources (e.g., frequency subchannels and time slots) that may be marked as scheduled. A reporting period may be 8 slots.

UE402may have information of a periodic pattern for arrival of new packets with respect to UE404. For example, a new packet of a transport block may arrive in slot3(as a resource selection trigger). UE402may also have information that UE404is going to use a Report0from UE402at slot0for an initial resource selection for the transport block. Accordingly, UE402may mark a subset of resources in Report0, but not in Report1or Report2. Therefore, there may be no scheduled resources indicated in Report1or Report2, because only Report0applies to slot3. UE404may then make 4 sidelink resource selections based at least in part on the Report0received in slot0. In other words, UE402may use periodicity information for UE404to mark candidate sidelink resources and/or scheduled sidelink resources. If traffic at UE404is periodic, then the reporting of UE402may also be periodic. In this scenario, UE402may schedule (mark) resources only when UE402expects that UE404is going to use the scheduled resources for a newly generated packet. Therefore, the scheduling of resources may be selective and apply to only a subset of reports in time. This conserves signaling resources.

If traffic at UE404is aperiodic, UE404may request a sidelink resource availability report from UE402. UE402may use requests from UE404as triggering events to schedule sidelink resources for UE404. When there is no request, UE402may still generate a report due to some other triggering event (e.g., mobility operations, change in UE status, traffic conditions) and may leave some candidate sidelink resources unscheduled (unmarked) so that UE404may select other candidate sidelink resources if there is a need (e.g., for retransmissions).

As indicated above,FIG. 9is provided as an example. Other examples may differ from what is described with regard toFIG. 9.

FIG. 10is a diagram illustrating an example process1000performed, for example, by a first UE, in accordance with the present disclosure. Example process1000is an example where the UE (e.g., UE120, UE402) performs operations associated with sidelink resource indications and usage.

InFIG. 10, UE402may be referred to as a “first UE” and UE404may be referred to as a “second UE” when discussing operations from the viewpoint of UE402. InFIG. 11, UE404may be referred to as the “first UE” and UE402may be referred to as the “second UE” when discussing operations from the viewpoint of UE404.

As shown inFIG. 10, in some aspects, process1000may include selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE (block1010). For example, the UE (e.g., using selection component1208depicted inFIG. 12) may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE, as described above (e.g., operation710depicted inFIG. 7).

As further shown inFIG. 10, in some aspects, process1000may include scheduling, from among the one or more candidate sidelink resources based at least in part on SIRs for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE (block1020). For example, the UE (e.g., using scheduling component1210depicted inFIG. 12) may schedule, from among the one or more candidate sidelink resources based at least in part on SIRs for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE, as described above (e.g., operation710depicted inFIG. 7).

As further shown inFIG. 10, in some aspects, process1000may include transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources (block1030). For example, the UE (e.g., using transmission component1204depicted inFIG. 12) may transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources, as described above (e.g., operation715depicted inFIG. 7).

In a first aspect, process1000includes receiving a communication from the second UE on one of the one or more scheduled sidelink resources. In a second aspect, alone or in combination with the first aspect, the communication is an initial transmission of a transport block from the second UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, process1000includes receiving a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the indication includes a bitmap for the one or more candidate sidelink resources, and the one or more scheduled sidelink resources are marked in the indication. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the indication is transmitted according to a periodic pattern. In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the indication is transmitted for a generated packet that has not been transmitted.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the indication is transmitted based at least in part on a request from the second UE or a triggering event.

AlthoughFIG. 10shows example blocks of process1000, in some aspects, process1000may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG. 10. Additionally, or alternatively, two or more of the blocks of process1000may be performed in parallel.

FIG. 11is a diagram illustrating an example process1100performed, for example, by a first UE, in accordance with the present disclosure. Example process1100is an example where the UE (e.g., UE120, UE404) performs operations associated with sidelink resource indications and usage. The first UE ofFIG. 11(e.g., UE404) may be the second UE described in connection withFIG. 10.

As shown inFIG. 11, in some aspects, process1100may include receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources (block1110). For example, the UE (e.g., using reception component1302depicted inFIG. 13) may receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources, as described above (e.g., operation715depicted inFIG. 7).

As further shown inFIG. 11, in some aspects, process1100may include transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources (block1120). For example, the UE (e.g., using transmission component1304depicted inFIG. 13) may transmit, to the second UE, a communication in one of the one or more candidate sidelink resources, as described above (e.g., operation735depicted inFIG. 7).

In a first aspect, transmitting the communication includes transmitting the communication to the second UE in one of the one or more scheduled sidelink resources. In a second aspect, alone or in combination with the first aspect, the communication is an initial transmission of a transport block to the second UE.

In a third aspect, alone or in combination with one or more of the first and second aspects, process1100includes sensing the sidelink channel, and transmitting the communication includes transmitting the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the indication includes a bitmap for the one or more candidate sidelink resources, and the one or more scheduled sidelink resources are marked in the indication as scheduled. In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the communication is a generated packet that has not been transmitted.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process1100includes transmitting a request for the one or more candidate sidelink resources.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process1100includes selecting the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE. In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the third UE.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of a packet priority or a remaining PDB.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of an application of a fairness rule to the second UE and the third UE or a buffer status corresponding to flows from the first UE to the second UE and the third UE.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of sidelink channel state information reports for the second UE and the third UE, pathloss information for the second UE and the third UE, distance estimations for the second UE and the third UE, or zone identifiers for the second UE and the third UE.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on, for links to the second UE and the third UE, one or more of reliability requirements, power control levels, feedback message utilization states, communication range requirements, or communication cast types.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes considering a conflicted scheduled sidelink resource as unavailable for transmission and transmitting the communication on another scheduled sidelink resource or candidate sidelink resource indicated by the second UE.

In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and process1100includes considering a conflicted candidate sidelink resource or a conflicted scheduled sidelink resource as available for transmission and proceeding with transmitting the communication on the conflicted scheduled sidelink resource, based at least in part on one or more of a location of the third UE with respect to one or more of the first UE or the second UE, a network layout of the third UE with respect to one or more of the first UE or the second UE, or a sensing result for the conflicted scheduled sidelink resource satisfying an interference threshold.

In a fifteenth aspect, alone or in combination with one or more of the first through fourteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per group of UEs.

In a sixteenth aspect, alone or in combination with one or more of the first through fifteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per geographical cluster of UEs.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process1100includes postponing selection of the one of the one or more candidate sidelink resources for transmission.

In a seventeenth aspect, alone or in combination with one or more of the first through sixteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs, without consideration of the one or more candidate sidelink resources indicated by the second UE.

In an eighteenth aspect, alone or in combination with one or more of the first through seventeenth aspects, process1100includes iteratively removing sidelink resource information for individual UEs of the other UEs from consideration until an availability threshold is satisfied.

In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs based at least in part on a specified parameter for the first UE satisfying a parameter threshold.

In a twentieth aspect, alone or in combination with one or more of the first through nineteenth aspects, the sidelink resource information from one or more other UEs includes one or more scheduled sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and process1100includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by candidate sidelink resources in the sidelink resource information from the one or more other UEs.

AlthoughFIG. 11shows example blocks of process1100, in some aspects, process1100may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG. 11. Additionally, or alternatively, two or more of the blocks of process1100may be performed in parallel.

FIG. 12is a block diagram of an example apparatus1200for wireless communication. The apparatus1200may be a first UE, or a first UE may include the apparatus1200. In some aspects, the apparatus1200includes a reception component1202and a transmission component1204, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus1200may communicate with another apparatus1206(such as a UE, a base station, or another wireless communication device) using the reception component1202and the transmission component1204. As further shown, the apparatus1200may include one or more of a selection component1208and/or a scheduling component1210, among other examples.

The selection component1208may select one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE (apparatus1200). The reception component1202may sense the sidelink channel. The scheduling component1210may schedule, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE. The transmission component1204may transmit, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

The reception component1202may receive a communication from the second UE on one of the one or more scheduled sidelink resources. The reception component1202may receive a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

FIG. 13is a block diagram of an example apparatus1300for wireless communication. The apparatus1300may be a first UE, or a first UE may include the apparatus1300. In some aspects, the apparatus1300includes a reception component1302and a transmission component1304, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus1300may communicate with another apparatus1306(such as a UE, a base station, or another wireless communication device) using the reception component1302and the transmission component1304. As further shown, the apparatus1300may include a selection component1308, among other examples.

The reception component1302may receive, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources. The transmission component1304may transmit, to the second UE, a communication in one of the one or more candidate sidelink resources.

The reception component1302may sense the sidelink channel, and the transmission component1304may transmit the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel. The transmission component1304may transmit a request for the one or more candidate sidelink resources.

The selection component1308may select the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE.

The number and arrangement of components shown inFIG. 13are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG. 13. Furthermore, two or more components shown inFIG. 13may be implemented within a single component, or a single component shown inFIG. 13may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown inFIG. 13may perform one or more functions described as being performed by another set of components shown inFIG. 13.

Aspect 1: A method of wireless communication performed by a first user equipment (UE), comprising: selecting one or more candidate sidelink resources, from within a resource selection window after sensing a sidelink channel, that are available for a second UE to use for transmission to the first UE; scheduling, from among the one or more candidate sidelink resources based at least in part on signal-to-interference ratios for the one or more candidate sidelink resources, one or more scheduled sidelink resources that are preferred for transmission to the first UE; and transmitting, to the second UE, an indication of the one or more candidate sidelink resources and the one or more scheduled sidelink resources.

Aspect 2: The method of Aspect 1, further comprising receiving a communication from the second UE on one of the one or more scheduled sidelink resources.

Aspect 3: The method of Aspect 2, wherein the communication is an initial transmission of a transport block from the second UE.

Aspect 4: The method of Aspect 1, further comprising receiving a communication from the second UE on one of the one or more candidate sidelink resources that is not one of the one or more scheduled sidelink resources.

Aspect 5: The method of any of Aspects 1-4, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication.

Aspect 6: The method of any of Aspects 1-5, wherein the indication is transmitted according to a periodic pattern.

Aspect 7: The method of any of Aspects 1-6, wherein the indication is transmitted for a generated packet that has not been transmitted.

Aspect 8: The method of any of Aspects 1-7, wherein the indication is transmitted based at least in part on a request from the second UE or a triggering event.

Aspect 9: A method of wireless communication performed by a first user equipment (UE), comprising: receiving, from a second UE, an indication of one or more candidate sidelink resources in a resource selection window of a sidelink channel that are available for transmission to the second UE and one or more scheduled sidelink resources from among the one or more candidate sidelink resources; and transmitting, to the second UE, a communication in one of the one or more candidate sidelink resources.

Aspect 10: The method of Aspect 9, wherein transmitting the communication includes transmitting the communication to the second UE in one of the one or more scheduled sidelink resources.

Aspect 11: The method of Aspect 9 or 10, wherein the communication is an initial transmission of a transport block to the second UE.

Aspect 12: The method of any of Aspects 9-11, further comprising sensing the sidelink channel, and wherein transmitting the communication includes transmitting the communication to the second UE in one of the one or more candidate sidelink resources that is not among the one or more scheduled sidelink resources, based at least in part on the sensing of the sidelink channel.

Aspect 13: The method of any of Aspects 9-12, wherein the indication includes a bitmap for the one or more candidate sidelink resources, and wherein the one or more scheduled sidelink resources are marked in the indication as scheduled.

Aspect 14: The method of any of Aspects 9-13, wherein the communication is a generated packet that has not been transmitted.

Aspect 15: The method of any of Aspects 9-14, further comprising transmitting a request for the one or more candidate sidelink resources.

Aspect 16: The method of any of Aspects 9-15, further comprising selecting the one of the one or more candidate sidelink resources based at least in part on sidelink resource information from a third UE.

Aspect 17: The method of Aspect 16, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the third UE.

Aspect 18: The method of Aspect 16 or 17, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of a packet priority or a remaining packet delay budget.

Aspect 19: The method of any of Aspects 16-18, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of an application of a fairness rule to the second UE and the third UE or a buffer status corresponding to flows from the first UE to the second UE and the third UE.

Aspect 20: The method of any of Aspects 16-19, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on one or more of sidelink channel state information reports for the second UE and the third UE, pathloss information for the second UE and the third UE, distance estimations for the second UE and the third UE, or zone identifiers for the second UE and the third UE.

Aspect 21: The method of any of Aspects 16-20, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method includes selecting the one of the one or more candidate sidelink resources for transmission based at least in part on, for links to the second UE and the third UE, one or more of reliability requirements, power control levels, feedback message utilization states, communication range requirements, or communication cast types.

Aspect 22: The method of any of Aspects 16-21, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises considering a conflicted scheduled sidelink resource as unavailable for transmission and transmitting the communication on another scheduled sidelink resource or candidate sidelink resource indicated by the second UE.

Aspect 23: The method of any of Aspects 16-22, wherein the sidelink resource information from the third UE conflicts with the one or more candidate sidelink resources or the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises considering a conflicted scheduled sidelink resource as available for transmission and proceeding with transmitting the communication on a conflicted candidate sidelink resource or a conflicted scheduled sidelink resource, based at least in part on one or more of: a location of the third UE with respect to one or more of the first UE or the second UE; a network layout of the third UE with respect to one or more of the first UE or the second UE; or a sensing result for the conflicted scheduled sidelink resource satisfying an interference threshold.

Aspect 24: The method of any of Aspects 9-23, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per group of UEs.

Aspect 25: The method of any of Aspects 9-24, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs per geographical cluster of UEs.

Aspect 26: The method of any of Aspects 9-25, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises postponing selection of the one of the one or more candidate sidelink resources for transmission.

Aspect 27: The method of any of Aspects 9-26, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with the one or more candidate sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs, without consideration of the one or more candidate sidelink resources indicated by the second UE.

Aspect 28: The method of Aspect 27, further comprising iteratively removing sidelink resource information for individual UEs of the other UEs from consideration until an availability threshold is satisfied.

Aspect 29: The method of any of Aspects 9-28, wherein the sidelink resource information from one or more other UEs includes one or more candidate sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by the sidelink resource information from the one or more other UEs based at least in part on a specified parameter for the first UE satisfying a parameter threshold.

Aspect 30: The method of any of Aspects 9-29, wherein the sidelink resource information from one or more other UEs includes one or more scheduled sidelink resources that conflict with one of the one or more scheduled sidelink resources indicated by the second UE, and wherein the method further comprises selecting the one of the one or more candidate sidelink resources for transmission that is also indicated as available by candidate sidelink resources in the sidelink resource information from the one or more other UEs.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software.