New radio (NR) positioning method for coverage inboard link positioning

Abstract

Side link positioning may be implemented by a wireless transmit / receive unit (WTRU). The WTRU may be configured to transmit a first message including sidelink positioning information associated with a group of WTRUs. The sidelink positioning information may include an indication of a sidelink positioning method for determining the positioning of the WTRUs in the group of WTRUs. The WTRU may be configured to transmit a second message including a request for a sidelink positioning reference signal (SL-PRS) resource for the group of WTRUs. The WTRU may be configured to receive an indication of an allocated SL-PRS resource for the group of WTRUs. The WTRU may be configured to transmit an indication of the allocated SL-PRS resource to the group of WTRUs.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 334,809 filed on April 26, 2022, U.S. Provisional Patent Application No. 63 / 395,406 filed on August 5, 2022, U.S. Provisional Patent Application No. 63 / 421,669 filed on November 2, 2022, and U.S. Provisional Patent Application No. 63 / 445,340 filed on February 14, 2023. U.S. Provisional Patent Application No. 63 / 334,809 is incorporated herein by reference in its entirety. U.S. Provisional Patent Application No. 63 / 395,406 is incorporated herein by reference in its entirety. U.S. Provisional Patent Application No. 63 / 421,669 is incorporated herein by reference in its entirety. U.S. Provisional Patent Application No. 63 / 445,340 is incorporated herein by reference in its entirety. Background Art

[0003] Sidelink communications allow device-to-device (D2D) communications. Sidelink communications may have various applications, such as, for example, vehicle-to-everything (V2X) applications. Sidelink communications may be used in both in-network coverage scenarios and out-of-network coverage scenarios. With the continuous advancement of telecommunications, users expect faster response times and lower latency. To meet these expectations, advancements in sidelink communications are needed. Summary of the invention

[0004] This document considers communication between one or more user equipment (UE) and a network. A UE may also be referred to as a wireless transmit / receive unit (WTRU). The terms UE and WTRU may be used interchangeably herein. Methods and systems for reducing signaling overhead between network entities (e.g., servers, nodes, next generation Node B-gNB, etc.) and WTRUs are described herein. For example, a scheduling procedure for a group of WTRUs (e.g., a target WTRU and an anchor WTRU) to perform sidelink positioning to reduce signaling overhead between the gNB and the WTRUs in the group is described herein.

[0005] In various examples, which will become apparent in the context of the description herein, to achieve sidelink positioning, a WTRU may determine, based on an indication in downlink control information (DCI), whether the DCI is for a sidelink positioning reference signal (SL-PRS). The WTRU may determine whether to send data and / or SL-PRS in scheduled sidelink resources. The WTRU may determine a positioning method based on a set of SL-PRS scheduled by the network. The WTRU may determine whether to request SL-PRS resources for another WTRU. The WTRU may determine a value for a parameter of SL-PRS transmission / reception resources for a group. In a round trip time (RTT) positioning method, the WTRU may use one SL-PRS transmission to multiple anchor WTRUs. For the RTT method, the WTRU may determine whether to use unicast or multicast to send the SL-PRS. The WTRU may determine which WTRU is to request / select sidelink resources for one or more members in the group. The WTRU may determine SL-PRS resources for the RTT positioning method. The WTRU may determine whether to forward the scheduled SL-PRS resources to another WTRU. The WTRU may determine SL-PRS transmission resources for other WTRUs. The WTRU may report synchronization offset information of the positioning group to the network. The WTRU may indicate synchronization offset based on the resource allocation pattern of the two WTRUs. The WTRU may request periodic and / or aperiodic SL-PRS resources. The WTRU may trigger a change in SL-PRS configuration (e.g., SL-PRS offset and / or periodicity). The WTRU may determine whether to measure the reference signal time difference (RSTD) between two radio access technologies (RATs). The WTRU may determine the reference node for RSTD measurement. The WTRU may request other WTRUs to be silent during the measurement gap (MG) and / or positioning processing window (PPW) of the WTRU in user-to-user (Uu) communication. When the MG / PPW configuration is received in Uu, the WTRU triggers resource reselection and / or preemption. When the MG and / or PPW are received in the Uu of the peer WTRU, the WTRU triggers resource reselection and / or preemption.

[0006] In additional various examples, which will become apparent in the context of the description herein, to achieve sidelink positioning, the WTRU may determine a time gap between an initial transmission and a retransmission of a SL-PRS. The WTRU may determine which SL-PRS configuration to use. The WTRU may prioritize a resource pool used by a peer WTRU. The WTRU may determine which ID to scramble / generate a SL-PRS sequence. The WTRU may determine when to monitor a SL-PRS resource pool. The WTRU may determine whether a DCI is for SL-PRS or for data transmission based on a radio network temporary identifier (RNTI). The WTRU may determine whether a DCI is for SL-PRS or data transmission based on a search space set. The WTRU may determine whether a DCI is for SL-PRS or data based on an indicated code point in a bit field. The WTRU may be scheduled for a group common DCI for SL-PRS. The WTRU may determine whether to forward a scheduled SL-PRS for a member WTRU in a group. The WTRU may determine whether to send a scheduled SL-PRS based on an acknowledgement (ACK) from a member WTRU. The WTRU may transmit sidelink positioning group information to the network.

[0007] In further various examples, which will become apparent in the context of the description herein, to implement sidelink positioning, the WTRU may receive a SL-PRS configuration. The WTRU may determine the location of a physical sidelink control channel / physical sidelink shared channel (PSCCH / PSSCH) for SL-PRS multiplexing. The WTRU may embed sidelink control information (SCI) in the SL-PRS pattern. The WTRU may receive information about sidelink positioning from one node and indicate the information to another node. The WTRU may provide a request for sidelink positioning. The WTRU may indicate to the network an ID / index associated with sidelink positioning.

[0008] In various other examples, which will become apparent in the context of the description herein, to implement sidelink positioning, the WTRU may determine whether to multiplex the SCI with the SL-PRS. The WTRU may determine the location of the SCI. The WTRU may determine parameters for SL-PRS transmission. The WTRU may determine a resource pool for the SL-PRS. The WTRU may determine a resource location for sidelink positioning. The WTRU may receive scheduled resources for sidelink positioning. The WTRU may determine which WTRU is to request resources for sidelink positioning. The WTRU may trigger resource allocation and / or request resources for sidelink positioning. The WTRU may determine information for indicating and / or reporting SL-PRS resource usage. The WTRU may determine whether to indicate and / or report SL-PRS resource usage. The WTRU may determine resources for indicating and / or reporting SL-PRS resource usage. The WTRU may determine information to include in a SL-PRS measurement report. The WTRU may determine information for indicating and / or reporting sidelink resource usage in an uplink. A WTRU may receive sidelink positioning resources for a group of WTRUs and forward these sidelink positioning resources to other WTRUs. A WTRU may receive a configuration for sidelink positioning. A WTRU may send a configuration for sidelink positioning to other WTRUs. A WTRU may determine SL-PRS reception resources for each WTRU in a group. A WTRU may determine its SL-PRS transmission resources. A WTRU may determine SL-PRS measurement reporting resources from each WTRU in a group. A WTRU may be configured with periodic and / or semi-static resources for sidelink positioning. The behavior of a WTRU may be based on the status of feedback on SL-PRS resource usage from other WTRUs. A WTRU may indicate a priority for a sidelink positioning service. A WTRU may report the WTRU's SL-PRS resources to the network. A WTRU may determine whether to perform SL-PRS reception. A WTRU may request an MG and / or positioning processing window (PPW) for SL-PRS reception. A WTRU may indicate the WTRU's SL-PRS reception resources to another WTRU. The WTRU may prioritize between SL-PRS reception and other types of sidelink transmission and / or reception.

[0009] An example WTRU may be configured to send a first message via a transceiver, the first message including sidelink positioning information associated with a group of WTRUs. The sidelink positioning information may include an indication of a sidelink positioning method for determining the positioning of WTRUs in the group of WTRUs. The WTRU may send a second message via the transceiver, the second message including a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs. The WTRU may receive an indication of allocated SL-PRS resources for the group of WTRUs via the transceiver. The WTRU may transmit an indication of the allocated SL-PRS resources to the group of WTRUs via the transceiver. The requested resources may be based on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and / or a quality of service (QoS) associated with the sidelink positioning method. The sidelink positioning information in the first message may include a group identifier (ID) associated with the group of WTRUs. The request for SL-PRS resources in the second message may include the group ID. The sidelink positioning method may include at least one of round trip time (RTT) positioning, sidelink time difference of arrival (SL-TDOA) positioning, and / or sidelink angle of departure (SL-AoD) positioning. The WTRU may be one of the WTRUs in a group of WTRUs, and the request for SL-PRS resources may include a request for SL-PRS transmission resources for the WTRU and a request for SL-PRS transmission resources for other WTRUs in the group of WTRUs. The request for SL-PRS resources may include a number of SL-PRS transmission resources requested for the WTRU. The request for SL-PRS resources may include a number of SL-PRS transmission resources requested for the remaining WTRUs in the group of WTRUs. The second message may include a medium access control (MAC) control element (CE). The WTRU may be configured to perform a sidelink discovery procedure to identify the group of WTRUs. The WTRU may be configured to send the first message and the second message to a node. The node may include at least one of a network node, another WTRU, a roadside unit (RSU), or any suitable combination thereof.

[0010] Further disclosed herein is at least one computer-readable storage medium having executable instructions stored thereon. When executed by, for example, a processor of a WTRU, the instructions may cause the at least one computer-readable storage medium to send a first message including sidelink positioning information associated with a group of WTRUs. The sidelink positioning information may include an indication of a sidelink positioning method for determining the positioning of WTRUs in the group of WTRUs. When executed, the instructions may further cause the processor to send a second message including a request for a sidelink positioning reference signal (SL-PRS) resource for the group of WTRUs. When executed, the instructions may further cause the processor to receive an indication of an allocated SL-PRS resource for the group of WTRUs. When executed, the instructions may further cause the processor to transmit an indication of the allocated SL-PRS resource to the group of WTRUs. The requested resources may be based on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and / or a quality of service (QoS) associated with the sidelink positioning method. The sidelink positioning information in the first message may include a group identifier (ID) associated with the group of WTRUs. The request for SL-PRS resources in the second message may include a group ID. The sidelink positioning method may include at least one of round trip time (RTT) positioning, sidelink time difference of arrival (SL-TDOA) positioning, and / or sidelink angle of departure (SL-AoD) positioning. The WTRU may be one of the WTRUs in the group of WTRUs, and the request for SL-PRS resources may include a request for SL-PRS transmission resources for the WTRU and a request for SL-PRS transmission resources for other WTRUs in the group of WTRUs. The request for SL-PRS resources may include a number of SL-PRS transmission resources requested for the WTRU. The request for SL-PRS resources may include a number of SL-PRS transmission resources requested for the remaining WTRUs in the group of WTRUs. The second message may include a medium access control (MAC) control element (CE). When executed, the instructions may further cause the processor to perform a sidelink discovery procedure to identify the group of WTRUs. When executed, the instructions may further cause the processor to send the first message and the second message to the node. The node may include at least one of a network node, another WTRU, a road side unit (RSU), or any suitable combination thereof.

[0011] In another example of a WTRU configured to perform sidelink positioning, the WTRU may receive an indication of resources for a group of WTRUs for performing sidelink positioning. The indication may be based on resources capable of sending and receiving a sidelink positioning reference signal (SL-PRS) and / or performing RTT-based sidelink positioning. The indication may be based on resources capable of sending SL-PRS and / or performing positioning based on SL-PRS sending, receiving SL-PRS and / or performing positioning based on SL-PRS receiving. The WTRU may determine at least one anchor WTRU in the group of WTRUs. The WTRU may determine a group identifier for the group of WTRUs. The WTRU may transmit sidelink positioning group information to a network node. The network node may include a gNB. The WTRU may request resources for the group of WTRUs for performing sidelink positioning. The indication of the resources may be received via downlink control information (DCI) transmission. Based on the resources capable of receiving the SL-PRS, the WTRU may transmit an indication of the resources to at least one anchor WTRU. Based on the resources capable of reporting SL-PRS measurements, the WTRU may transmit an indication of the resource to at least one anchor WTRU. The transmitting of the indication of the resource to at least one anchor WTRU may utilize a group identifier of a group of WTRUs. The WTRU may determine at least one anchor WTRU in the group of WTRUs. The WTRU may determine a group identifier of the group of WTRUs. The WTRU may transmit sidelink positioning group information to a network node. The network node may include a gNB.

[0012] An example computer readable storage medium may have executable instructions stored thereon. When executed by a processor, the executable instructions may configure the processor to facilitate sidelink positioning. When the executable instructions are executed, the processor may configure the WTRU to receive an indication of resources for performing sidelink positioning for a group of WTRUs. The WTRU may receive the indication based on resources capable of sending and receiving a sidelink positioning reference signal (SL-PRS). The WTRU may be configured to perform round trip time (RTT) based sidelink positioning based on resources capable of sending SL-PRS. The WTRU may be configured to perform positioning based on SL-PRS transmission based on resources capable of receiving SL-PRS. The WTRU may be configured to perform positioning based on SL-PRS reception. When the executable instructions are executed, the processor may configure the WTRU to determine at least one anchor WTRU in the group of WTRUs. When the executable instructions are executed, the processor may configure the WTRU to determine a group identifier of the group of WTRUs. When the executable instructions are executed, the processor may configure the WTRU to transmit sidelink positioning group information to a network node. The network node may include a gNB. When the executable instructions are executed, the processor may configure the WTRU to request resources for performing sidelink positioning for a group of WTRUs. Downlink control information (DCI) transmission may receive an indication of the resources. Based on the resources capable of receiving SL-PRS, when the executable instructions are executed, the processor may configure the WTRU to transmit an indication of the resources to at least one anchor WTRU. Based on the resources capable of reporting SL-PRS measurements, when the executable instructions are executed, the processor may configure the WTRU to transmit an indication of the resources to at least one anchor WTRU. Transmitting the indication of the resources to at least one anchor WTRU may utilize a group identifier of the group of WTRUs.

[0013] In an example, each WTRU in a group of WTRUs may be configured with a respective orthogonal cover code (OCC). Each OCC may be based on a respective identifier (ID) of each WTRU in the group of WTRUs. Each OCC may receive a respective sidelink positioning reference signal (SL-PRS) configuration for each of a plurality of resources. Each respective SL-PRS configuration may include at least one of: a bandwidth associated with the respective resource, a duration associated with the respective resource, a number of repetitions associated with the respective resource, a size of the respective resource, a multiplexing rule associated with the respective resource, and / or receiving a respective SL-PRS measurement report configuration for each of the plurality of resources.

[0014] Each SL-PRS measurement report configuration may include at least one of: a bandwidth associated with the corresponding resource, a duration associated with the corresponding resource, a number of repetitions associated with the corresponding resource, a size of the corresponding resource, and / or a multiplexing rule associated with the corresponding resource.

[0015] Each SL-PRS measurement reporting configuration may transmit an indication of each respective SL-PRS configuration and / or each respective SL-PRS measurement reporting configuration to each WTRU in the group of WTRUs, the indication utilizing a group ID identifying the group of WTRUs. Each SL-PRS measurement reporting configuration may receive an indication of scheduled resources from among a plurality of resources for performing sidelink positioning for the group of WTRUs, and / or determine SL-PRS resources and / or SL-PRS measurement reporting resources for each anchor WTRU in the group of WTRUs. The determination of the SL-PRS resources and / or SL-PRS measurement reporting resources for each anchor WTRU may be based on at least one of: an ID of each anchor WTRU, a number of WTRUs in the group of WTRUs, an OCC for each WTRU in the group of WTRUs, a set of sidelink resources scheduled for the group, and / or a multiplexing rule associated with each of the plurality of resources. To perform SL-PRS measurements and / or derive the position of the WTRU, the WTRU may calculate a round trip time (RTT) between each WTRU in the group of WTRUs and each anchor WTRU in the group of WTRUs based on the measured and reported transmit times and receive times between them. The WTRU may determine the relative position of each WTRU in the group of WTRUs based on the calculated RTT. The WTRU may transmit an indication of the relative position to each WTRU in the group of WTRUs.

[0016] Each SL-PRS measurement report configuration may include at least one of: a bandwidth associated with the corresponding resource, a duration associated with the corresponding resource, a number of repetitions associated with the corresponding resource, a size of the corresponding resource, and / or a multiplexing rule associated with the corresponding resource. Each SL-PRS measurement report configuration may transmit an indication of each corresponding SL-PRS configuration and / or each corresponding SL-PRS measurement report configuration to each WTRU in the group of WTRUs, the indication utilizing a group ID identifying the group of WTRUs. Each SL-PRS measurement report configuration may receive an indication of scheduled resources from among a plurality of resources for performing sidelink positioning for the group of WTRUs and / or determine SL-PRS resources and / or SL-PRS measurement report resources for each anchor WTRU in the group of WTRUs. The determination of the SL-PRS resources and / or SL-PRS measurement report resources for each anchor WTRU may be based on at least one of: the ID of each anchor WTRU, the number of WTRUs in the group of WTRUs, the OCC for each WTRU in the group of WTRUs, the set of side link resources for group scheduling, and / or a multiplexing rule associated with each of the multiple resources.

[0017] May include a transceiver and a processor. The processor may be configured to send a first message via the transceiver, the first message including sidelink positioning information associated with a group of WTRUs. The sidelink positioning information may include an indication of a sidelink positioning method for determining the positioning of a WTRU in the group of WTRUs. The processor may be configured to send a second message via the transceiver, the second message including a request for a sidelink positioning reference signal (SL-PRS) resource for the group of WTRUs. The processor may be configured to receive an indication of an allocated SL-PRS resource for the group of WTRUs via the transceiver. The processor may be configured to transmit an indication of the allocated SL-PRS resource to the group of WTRUs via the transceiver.

[0018] The resources requested by the WTRU may be based at least in part on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and / or the quality of service (QoS) associated with the sidelink positioning method.

[0019] The sidelink positioning information in the first message may include a group identifier (ID) associated with the group of WTRUs. The request for SL-PRS resources in the second message may include the group ID. The sidelink positioning method may include at least one of round trip time (RTT) positioning, sidelink time difference of arrival (SL-TDOA) positioning, and / or sidelink angle of departure (SL-AoD) positioning.

[0020] The request for SL-PRS resources may include a request for SL-PRS transmission resources for the WTRU. The request for SL-PRS resources may include a request for SL-PRS transmission resources for other WTRUs in the WTRU's group. The request for SL-PRS resources may include a number of SL-PRS transmission resources requested for the WTRU and / or a number of SL-PRS transmission resources requested for other WTRUs in the WTRU's group.

[0021] The second message may include a Medium Access Control (MAC) Control Element (CE).

[0022] The processor is further configured to perform a sidelink discovery procedure to identify a group of WTRUs.

[0023] The processor may be configured to send the first message and the second message to a node. The node may include at least one of a network node, another WTRU, and / or a roadside unit (RSU).

[0024] At least one computer-readable storage medium may have executable instructions stored thereon. When executed by a processor, the executable instructions may configure the processor to send a first message, the first message including sidelink positioning information associated with a group of WTRUs. The sidelink positioning information may include an indication of a sidelink positioning method for determining the positioning of WTRUs in the group of WTRUs. The processor may send a second message, the second message including a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs. The processor may receive an indication of the allocated SL-PRS resources for the group of WTRUs. The processor may transmit an indication of the allocated SL-PRS resources to the group of WTRUs. The requested resources may be based at least in part on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and / or a quality of service (QoS) associated with the sidelink positioning method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] A more detailed understanding can be obtained from the following detailed description, which is given by way of example in conjunction with its accompanying drawings. As with the detailed description, the figures in such drawings are examples. Therefore, the drawings and specific embodiments should not be considered limiting, and other equally effective examples are possible and intended. The same reference numerals ("ref." or "refs.") represent the same elements in the drawings.

[0026] Figure 1A Depicted is an example system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0027] Figure 1B Depicted is an example of an embodiment that can be Figure 1A An example system diagram of an example wireless transmit / receive unit (WTRU) for use within an example communication system.

[0028] Figure 1C Depicted is an example of an embodiment that can be Figure 1A An example system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system.

[0029] Figure 1D Depicted is an example of an embodiment that can be Figure 1A An example system diagram of a further example RAN and a further example CN for use within the illustrated communication system.

[0030] Figure 2An example illustration of round trip time (RTT) sidelink (SL) positioning is depicted, where a first WTRU (such as an anchor WTRU) may be instructed by a second WTRU (such as a target WTRU) to send a SL positioning reference signal (PRS) in a SL-PRS resource.

[0031] Figure 3 Depicted are example illustrations of sidelink control information (SCI) locations for shared resource pools and dedicated resource pools.

[0032] Figure 4 An example illustration of pattern-based physical sidelink control channel / physical sidelink shared channel (PSCCH / PSSCH) and sidelink positioning reference signal (SL-PRS) multiplexing is depicted.

[0033] Figure 5 An example illustration of time-frequency based PSCCH / PSSCH and SL-PRS multiplexing is depicted.

[0034] Figure 6 An example illustration of PSCCH / PSSCH with associated SL-PRS is depicted.

[0035] Figure 7 An example illustration is depicted in which the WTRU has the SCI embedded in a pattern.

[0036] Figure 8 Example illustrations of potential scheduled and / or selected resources for SL positioning are depicted.

[0037] Fig. 9 An example illustration of potential scheduled / selected resources for SL positioning is depicted, where the SL-PRS transmit (Tx) resource is in the same time slot as its indication.

[0038] Fig.10 Depicted is an example illustration of downlink control information (DCI) for scheduling resources for SL positioning.

[0039] Fig.11 An example illustration of providing feedback of SL Positioning Reference Signal (SL-PRS) resource usage prior to the SL-PRS resource is depicted.

[0040] Fig.12 An example illustration of feeding back SL-PRS resource usage after SL-PRS resource is depicted.

[0041] Fig.13 An example illustration of SL-PRS scheduling for a group of user equipments (UEs) (also referred to as WTRUs) is depicted.

[0042] Fig.14An example illustration of an anchor WTRU using an orthogonal cover code (OCC) for one SL-PRS resource is depicted.

[0043] Fig.15 An example illustration of SL-PRS measurement reporting scheduling for a group of WTRUs is depicted.

[0044] Fig.16 Depicted is an example illustration of semi-static resources for SL positioning.

[0045] Fig.17 An example illustration of overlap between SL-PRS reception and SL communication resource pools is depicted.

[0046] Fig.18 An example illustration of multiplexing of SL-PRS and SL-PRS measurement reports among WTRUs in a group is depicted.

[0047] Fig.19 Depicted is an example signal flow diagram for in-coverage round trip time (RTT) positioning.

[0048] Fig. 20 An example signal flow diagram for WTRU-based in-coverage SL positioning is depicted.

[0049] Fig.21 An example flow diagram for SL positioning is depicted, where WTRU information is provided by one or more anchor WTRUs.

[0050] Fig. 22 Depicted is an example flow diagram of in-coverage SL positioning (WTRU based), anchor WTRU information from location management function (LMF), PRS configuration from LMF to target WTRU.

[0051] Fig.23 An example flow diagram for bilateral RTT SL positioning is depicted.

[0052] Fig.24 An example diagram depicting a WTRU obtaining and providing side link resources associated with a group of WTRUs is depicted.

[0053] Fig.25 Another example diagram depicting a WTRU obtaining and providing SL resources associated with a group of WTRUs is depicted. DETAILED DESCRIPTION

[0054] Figure 1A1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0055] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0056] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device that is configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0057] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of licensed and unlicensed spectrums. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0058] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0059] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0060] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0061] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using New Radio (NR).

[0062] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0063] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0064] Figure 1A The base station 114b in the may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0065] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1AAlthough not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0066] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0067] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0068] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0069] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0070] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from the base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV or visible light signals. In another embodiment, the send / receive element 122 may be configured to send and / or receive both RF signals and optical signals. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0071] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0072] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0073] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, or the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0074] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0075] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine the WTRU's location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0076] The processor 118 may be further coupled to other peripherals 138, which may include one or more software modules and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0077] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes used for UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit 139 for reducing and / or substantially eliminating self-interference via signal processing performed via hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes used for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0078] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0079] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0080] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0081] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is depicted as being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0082] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0083] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0084] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0085] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include or may be in communication with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0086] Although the WTRU Figures 1A to 1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may (eg, temporarily or permanently) employ a wired communications interface with a communications network.

[0087] In a representative embodiment, the other network 112 may be a WLAN.

[0088] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or out of the BSS. Traffic from outside the BSS to the STA may be reached by the AP and may be delivered to the STA. Traffic from the STA to a destination outside the BSS may be transmitted to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be transmitted by the AP, for example, where the source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Direct link establishment (DLS) may be used to transmit point-to-point traffic between the source STA and the destination STA (e.g., directly between them). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (eg, all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0089] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may fall back. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0090] High throughput (HT) STAs may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0091] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and data can be sent by the transmitter STA. At the receiver of the receiver STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0092] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0093] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0094] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0095] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0096] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and the gNB 180b (and / or the gNB 180c).

[0097] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0098] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRU 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the evolved Node-B 160a, 160b, 160c. For example, the WTRU 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more evolved Node-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the evolved Node-B 160a, 160b, 160c may act as a mobility anchor for the WTRU 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRU 102a, 102b, 102c.

[0099] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0100] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0101] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0102] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure the traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0103] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0104] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and the N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0105] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with respect to one or more of the following may be performed by one or more simulation devices (not shown): WTRU102a-102d, base station 114a-114b, evolved Node B 160a-160c, MME 162, SGW 164, PGW 166, gNB 180a-180c, AMF 182a-182b, UPF 184a-184b, SMF 183a-183b, DN 185a-185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0106] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0107] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test lab and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0108] Wireless communications between one or more user equipment (UE) and a network are contemplated herein. A WTRU may also be referred to as a wireless transmit / receive unit (WTRU). The terms UE and WTRU may be used interchangeably herein.

[0109] Sidelink communications may support communications between different vehicles. Sidelink communications (e.g., transmission, reception, etc.) may be resourced in various ways. For example, resources for sidelink transmission / reception may be structured as a resource pool. A resource pool may include a collection of continuous frequency resources that are repeated in time according to a bitmap pattern. The WTRU may be configured via one or more resource pools. For an in-coverage WTRU (e.g., a WTRU within network coverage), the resource pool may be configured via a system information block (SIB), a radio resource control (RRC), etc. and / or any appropriate combination thereof. For an out-of-coverage WTRU (e.g., a WTRU not covered by the network), a resource pool may be pre-configured on the WTRU.

[0110] Each sidelink transmission may span a time slot comprising a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and / or any suitable combination thereof. PSSCH and PSCCH may utilize frequency domain multiplexing (FDM), time domain multiplexing (TDM), and / or any suitable combination thereof.

[0111] Sidelink control information (SCI) may be divided into two parts. These two parts may be referred to as first-level SCI and second-level SCI. The first-level SCI may indicate resources for sidelink transmission, quality of service (QoS) (e.g., priority) for transmission, demodulation reference signal (DMRS), phase tracking reference signal (PTRS) for sidelink transmission, and second SCI format and / or any appropriate combination thereof. The second-level SCI may indicate the remaining control information. SCI may be used to reserve resources for future transmissions within a resource pool.

[0112] The sidelink resources may be scheduled by the network (referred to herein as Mode 1) and / or selected autonomously by the WTRU (referred to herein as Mode 2). If the WTRU performs Mode 2, the WTRU may perform sensing by decoding SCIs from other WTRUs before selecting sidelink resources to avoid selecting resources reserved by other WTRUs.

[0113] Sidelink channel state information reference signal (SL-CSI-RS) may be supported for unicast to support a transmitting WTRU (Tx WTRU) in determining transmit (Tx) parameters (e.g., power and rank). The Tx WTRU may indicate the presence of the SL-CSI-RS by using the SCI. Channel state information reference signal (CSI-RS) transmission may trigger channel state information (CSI) reporting. PC5-RRC may configure CSI reporting latency. Each report may be associated with one SL-CSI-RS transmission.

[0114] The positioning technique (e.g., determining the position / location of the WTRU) may be New Radio (NR) Universal Mobile Telephone System (UMTS), air interface positioning, specified downlink (DL) based, uplink (UL) based, DL+UL based, timing and / or angle based, round trip time (RTT) based, and / or any suitable combination thereof. The absolute positioning of the WTRU may be expressed in a geographic coordinate system (GCS), a local coordinate system, etc., and / or any suitable combination thereof. The relative positioning of a WTRU (e.g., a target WTRU) may be expressed in terms of distance, angle to another WTRU (e.g., an anchor WTRU), a reference point with a known position, etc., and / or any suitable combination thereof.

[0115] In DL-based positioning, a downlink positioning reference signal (DL-PRS) may be transmitted to the WTRU from multiple transmit / receive points (TRPs). Furthermore, the WTRU may observe and measure downlink signals from the TRPs. In an example referred to herein as the WTRU-B method, the WTRU may calculate its positioning. In another example referred to herein as the WTRU-A method, the WTRU may return downlink measurements to the network. In another example referred to herein as the angle-based method, the WTRU may report the angle of arrival (AoA) and reference signal received power (RSRP) of the downlink signal from the TRP. In another example referred to herein as the timing-based method, the WTRU may report the reference signal time difference (RSTD). The above methods may depend on the synchronization of the transmit timing between the TRPs. Positioning calculation errors may be the result of synchronization errors and multipath.

[0116] In UL-based positioning (e.g., UL-based), the WTRU may transmit at least one uplink positioning reference signal (UL-PRS) configured by RRC to the TRP for positioning. The network may then calculate the WTRU's positioning based on the coordination of all TRPs that receive the UL-PRS from the WTRU.

[0117] In the UL and DL based methods (e.g., DL+UL based), the WTRU may measure the receive-transmit (Rx-Tx) time difference between the received DL-PRS and the transmitted UL-PRS. The Rx-Tx time difference and RSRP may be reported to the network. The network may then coordinate the TRP to calculate the positioning of the WTRU.

[0118] Other example SL positioning methods may include timing / angle positioning and round trip time (RTT) positioning. Timing / angle positioning may refer to any positioning method that uses a reference signal such as a SL-PRS. The WTRU may receive multiple reference signals from the WTRU and may measure RSTD, RSRP, and / or AoA. Examples of angle / timing positioning may include angle of departure (SL-AoD) positioning or sidelink time difference of arrival (SL-TDOA) positioning. In another example, the WTRU may send a SL-PRS to the WTRU, and the receiver may perform measurements (e.g., RSTD, AoA, RSRP) to determine the location of the WTRU that sent the SL-PRS.

[0119] RTT positioning may refer to any positioning method that requires two WTRUs to send SL-PRS to each other. In an example, the anchor WTRU may send the SL-PRS to the target WTRU. Once the target WTRU receives the SL-PRS from the anchor WTRU, the target WTRU may send the SL-PRS to the anchor WTRU. The target WTRU may measure the WTRU Tx-Rx time difference, which is the difference between the transmission time of the SL-PRS from the target WTRU and the reception time of the SL-PRS sent from the anchor WTRU. The target WTRU may report the WTRU Tx-Rx time difference to the anchor WTRU.

[0120] Sidelink positioning may be applicable to WTRUs that are covered by the network, partially covered by the network, out of coverage, and / or any suitable combination thereof. Metrics used to represent sidelink positioning may include absolute positioning, relative positioning, and / or any suitable combination thereof. In an example, sidelink positioning may be SL-PRS transmission-based, SL-PRS reception-based, round-trip time (RTT)-based sidelink positioning, and / or any suitable combination thereof. With respect to resource allocation for sidelink positioning, network-scheduled resources may be utilized, among which the network may perform resource allocation for sidelink resources used for sidelink positioning. Supporting a network-scheduled resource allocation mode may allow the network to have full control over the sidelink resources.

[0121] Regarding resource allocation for sidelink positioning, using existing dynamic scheduling procedures may require each individual WTRU to separately request sidelink resources for SL-PRS transmission and / or sidelink measurement reporting. Therefore, existing dynamic scheduling procedures may require excessive signaling overhead, especially for large positioning groups and / or low latency positioning requirements. In addition, existing dynamic scheduling procedures may require the anchor WTRU to be in a connected state during the sidelink procedure.

[0122] Scheduling procedures for a group of WTRUs (such as a target WTRU and at least one anchor WTRU) are also described herein. In these procedures, the group of WTRUs may perform sidelink positioning to reduce signaling overhead between the gNB and the WTRUs in the group.

[0123] Methods and systems are described herein for improving existing scheduling procedures for a group of WTRUs (e.g., target WTRUs and / or anchor WTRUs) to perform sidelink positioning to reduce signaling overhead between network entities (e.g., gNBs, network nodes, server WTRUs, LMF-capable WTRUs, WTRUs with capabilities for processing measurements and determining location information of other WTRUs, WTRUs with capabilities for configuring SL-PRS to other WTRUs and / or servers, etc.) and / or WTRUs in the group. An example of a server WTRU may be a WTRU that provides SL-PRS configuration to other WTRUs and / or receives measurement reports from a WTRU and determines location information of the other WTRUs based on the measurement reports. As described herein, positioning may be used for ranging without any limitation. Positioning may be referred to as a method / scheme for estimating the geographic location of a WTRU. Ranging may be referred to as a method / scheme for estimating the distance between WTRUs. The terms "positioning of a WTRU" and / or "location information of a WTRU" may be used interchangeably with "distance between WTRUs". Positioning of a WTRU and sidelink positioning may be applicable to ranging. The positioning of the WTRU may include an absolute positioning, which may include coordinates and / or a region ID, etc. The positioning of the WTRU may include a relative positioning, which may include a range, distance, propagation time, RTT to another entity and / or node (e.g., another WTRU, a roadside unit (RSU), a positioning reference unit (PRU), a gNB, and / or any suitable combination thereof).

[0124] As described herein, a WTRU may indicate any type of device, such as an anchor WTRU, a target WTRU, an assistant WTRU, a server WTRU, a PRU, and / or an RSU, etc. In an example, a WTRU may be scheduled with one or more resources, wherein the one or more resources may be used interchangeably with a WTRU. The WTRU may select the one or more resources.

[0125] Any solution applicable for the WTRU to select one or more resources may be used by the WTRU to request one or more resources from another node. Additionally or alternatively, any solution applicable for the WTRU to request one or more resources may be used by the WTRU to request one or more resources. For example, any trigger condition for the WTRU to select one or more resources may be used by the WTRU to request one or more resources from another node. Any trigger condition for the WTRU to request one or more resources from another node may be used by the WTRU to select one or more resources on its own.

[0126] As used herein, the word scheduled may be used for situations where resources may be determined by another entity (e.g., other than the WTRU itself). As used herein, the word selected may be used for situations where resources may be determined by the WTRU itself. However, any applicable solutions described for the situation where the WTRU is scheduled with resources may be used interchangeably with the situation where the WTRU makes its own resource selection.

[0127] The SL-PRS resources used for reception by one WTRU (eg, the target WTRU) may be used interchangeably with the SL-PRS resources used for transmission by another WTRU (eg, the anchor WTRU).

[0128] A resource may be used interchangeably with a resource set. For example, a resource used for SL-PRS transmission / reception may be used interchangeably with a resource set used for SL-PRS transmission / reception. The WTRU not performing SL-PRS reception in a SL-PRS resource may be equivalent to the WTRU not obtaining SL-PRS measurements from the resource.

[0129] As used herein, the terms indicating, reporting and / or sending a message to another WTRU may be used interchangeably with the terms indicating, reporting and / or sending a message to another entity or node (e.g., gNB and / or RSU, etc.). As used herein, a WTRU receiving a message from another WTRU may be used interchangeably with a WTRU receiving a message from any other node (e.g., gNB and / or RSU, etc.). The SL-PRS reception time and / or duration may include the SL-PRS signal reception time and / or the SL-PRS processing time after receiving the SL-PRS signal.

[0130] As used herein, the term SCI may be used interchangeably with the term first level SCI, second level SCI and / or both first level SCI and second level SCI.As used herein, the term SCI may be used interchangeably with the term PSCCH.

[0131] As used herein, a group of WTRUs may refer to one or more WTRUs. A positioning group may refer to a group of two or more WTRUs. The SL-PRS reception resources of one WTRU (e.g., a target WTRU) may be used interchangeably with the SL-PRS transmission of another WTRU (e.g., an anchor WTRU). The SL-PRS Tx-based positioning method and / or the SL-Rx-based positioning method may be used interchangeably with the SL-TDOA positioning method. The SL-TDOA method may be used to describe a timing-based positioning method in which the target WTRU may be only a transmitter of the SL-PRS (e.g., UL-similar SL-TDOA) and / or only a receiver of the SL-PRS (e.g., DL-similar SL-TDOA).

[0132] The WTRU may use DMRS of PSSCH and / or PSCCH, sidelink synchronization signal (SLSS), sidelink primary synchronization signal (S-PSS), sidelink secondary synchronization signal (S-SSS), phase tracking reference signal (PTRS), sidelink channel state information reference signal (SL-CSI-RS), physical sidelink feedback channel (PSFCH), a reference signal (RS) designed for positioning purposes, etc. and / or any appropriate combination thereof as SL-PRS.

[0133] The WTRU may be configured and / or pre-configured. As used herein, the WTRU being envisioned and / or (pre)configured may refer to the WTRU being pre-configured, the WTRU receiving a configuration from another entity (such as a node, a gNB, another WTRU, etc.), and / or any suitable combination thereof. In an example, a resource pool for sidelink positioning may be configured / pre-configured with the WTRU.

[0134] The WTRU may be configured / preconfigured with one or any combination of the following resource pools for SL-PRS transmission / reception: one or more dedicated resource pools for SL-PRS transmission / reception, one or more shared resource pools for SL-PRS transmission / reception with data, one or more network-scheduled resource pools dedicated to SL-PRS transmission / reception, one or more network-scheduled resource pools for SL-PRS transmission shared with sidelink data communication, one or more WTRU autonomously selected resource pools dedicated to SL-PRS transmission / reception, one or more WTRU autonomously selected resource pools for SL-PRS transmission shared with sidelink data communication, one or more WTRU autonomously selected resource pools for sidelink communication to facilitate sidelink positioning, one or more network-scheduled resource pools for sidelink communication with SL-PRS in the transmission of data communication, and / or any appropriate combination thereof.

[0135] The WTRU may configure itself for SL-PRS positioning and / or position determination. The WTRU may receive the configuration from another entity (e.g., another WTRU, a network node such as a gNB, etc.). The SL-PRS configuration may include any of the following, alone or in any appropriate combination. Resource pool for SL-PRS transmission, reception and / or sidelink measurement reporting; SL-PRS resource ID; SL-PRS sequence ID, or other ID for generating SL-PRS sequence; time-frequency of SL-PRS resources; SL-PRS resource element offset; SL-PRS resource slot offset; SL-PRS symbol offset;

[0136] SL-PRS QCL information; SL-PRS resource set ID; list of SL-PRS resources in the resource set;

[0137] Number of SL-PRS symbols; muting pattern for SL-PRS, muting parameters such as repetition factor, muting options; SL-PRS resource power; periodicity of SL-PRS transmission;

[0138] The number of SL-PRS transmission cycles; the spatial direction information of SL-PRS transmission (e.g., beam information, transmission angle); the spatial direction information of SL-RS reception (e.g., beam ID and arrival angle for receiving SL-RS); frequency layer ID; WTRUID and / or SL-PRS ID.

[0139] The WTRU may determine whether to multiplex sidelink control information (SCI) with a sidelink positioning reference signal (SL-PRS) in one transmission. In an example, the WTRU may determine whether to multiplex SCI with SL-PRS in one transmission (e.g., a transmission with SCI and SL-PRS in the same timeslot, where the SCI may occur in the first few symbols of the transmission).

[0140] The WTRU may determine whether to multiplex the SCI with the SL-PRS based on the resource pool used for the SL-PRS transmission. For example, if the WTRU uses a shared resource pool with sidelink data communication, the WTRU may determine to multiplex the SCI with the SL-PRS in one transmission. Otherwise, if the WTRU uses a dedicated resource pool for the SL-PRS transmission, the WTRU may not multiplex the SCI with the SL-PRS in one transmission.

[0141] The WTRU may determine whether to multiplex the SCI with the SL-PRS based on the scheduling mode of the SL-PRS resources. For example, if the WTRU performs autonomous resource allocation for the SL-PRS, the WTRU may determine to multiplex the SCI with the SL-PRS in one transmission. Otherwise, if the SL-PRS is scheduled by the network, the WTRU may not need to multiplex the SCI with the SL-PRS.

[0142] A WTRU may determine whether to multiplex sidelink control information (SCI) with a sidelink positioning reference signal (SL-RPS) in a transmission based on whether another WTRU indicated the resource. For example, the WTRU may determine whether to multiplex the SCI in a SL-PRS transmission based on whether the WTRU itself selected the SL-PRS and / or whether another WTRU selected the SL-PRS. If the WTRU autonomously selects the SL-PRS resource, the WTRU may determine to multiplex the SCI in the SL-PRS transmission. Otherwise, if another WTRU indicates the resource, the WTRU may not multiplex the SCI in the SL-PRS transmission.

[0143] The WTRU may determine whether to multiplex the sidelink control information (SCI) with the sidelink positioning reference signal (SL-RPS) in one transmission based on the time / frequency location of the SL-PRS resource. For example, if the SL-PRS resource is in the first few symbols of the timeslot, the WTRU may determine to multiplex the SCI in the SL-PRS transmission. Otherwise, if the SL-PRS is in the last few symbols of the timeslot, the WTRU may not multiplex the SCI in the SL-PRS transmission. Such SL-PRS resources may be indicated by another WTRU.

[0144] The WTRU may determine whether to multiplex sidelink control information (SCI) with a sidelink positioning reference signal (SL-RPS) in one transmission. The WTRU may make this determination based on whether the SL-PRS resources are initial and / or repeated SL-PRS resources in the same and / or different time slots. For example, for an initial SL-PRS transmission, the WTRU may multiplex the SCI. Otherwise, for repeated SL-PRS transmissions in the same or future time slots, the WTRU may not multiplex the SCI. The SCI associated with the initial SL-PRS transmission may indicate information associated with the repeated SL-PRS.

[0145] In an example, the WTRU may determine not to multiplex SCI with SL-PRS in one transmission in a network scheduled resource pool dedicated for SL-PRS transmission. The WTRU may determine to multiplex SCI with SL-PRS in one transmission in a WTRU autonomously selected resource pool shared with sidelink data communications.

[0146] Figure 2 An example of an RTT-based sidelink positioning method is depicted in which a WTRU (e.g., an anchor WTRU) may be instructed by another WTRU (e.g., a target WTRU) to send a SL-PRS in a SL-PRS resource. The anchor WTRU may determine whether to multiplex the SCI with the SL-PRS based on whether the indicated resource is in the first few symbols of the slot or in the last few symbols of the slot. For example, if the indicated SL-PRS 202 is Figure 2 If the indicated SL-PRS 208 is in the first few symbols of the time slot 204 as depicted in case 1, the WTRU may multiplex the SCI 206 with the SL-PRS 202. Otherwise, if the indicated SL-PRS 208 is in the last few symbols of the time slot 210, the WTRU may not multiplex the SCI with the SL-PRS 208, as shown in case 2 Figure 2 The situation 2 is described.

[0147] In an example, the WTRU may determine whether to multiplex the SCI with the SL-PRS based on whether there is any previous SL-PRS transmission from a peer WTRU in the same time slot (e.g., for RTT-based positioning methods). Specifically, if there is one or more previous SL-PRS from a peer WTRU in the time slot, the WTRU may not multiplex the SCI in the SL-PRS transmission. Otherwise, if there is no previous SL-PRS transmission from a peer WTRU in the time slot, the WTRU may multiplex the SCI in the SL-PRS transmission.

[0148] In an example, the WTRU may determine whether to multiplex the SCI with the SL-PRS based on whether there is any previous SL-PRS transmission from a peer WTRU in the same time slot (e.g., for RTT-based positioning methods). For example, if there is one or more previous SL-PRS from a peer WTRU in the time slot, the WTRU may not multiplex the SCI in the SL-PRS transmission. Otherwise, if there is no previous SL-PRS transmission from a peer WTRU in the time slot, the WTRU may multiplex the SCI in the SL-PRS transmission.

[0149] The WTRU may determine a time gap between an initial transmission and a retransmission of a SL-PRS. The WTRU may select resources for the initial transmission and the retransmission of the SL-PRS. The WTRU may be (pre)configured with a minimum time gap between any two transmissions of the SL-PRS. The WTRU may then select resources for SL-PRS transmission that satisfy the (pre)configured minimum gap. For example, the WTRU may be (pre)configured with multiple SL-PRS resources in the time domain in a timeslot. The WTRU may then select SL-PRS resources such that no two resources occupy the same timeslot. This approach may reduce the half-duplex problem, where the WTRU does not miss two SL-PRS receptions if the WTRU prioritizes other sidelink transmissions and / or receptions in the same timeslot.

[0150] Figure 3An example of multiplexing of SCI with SL-PRS in a shared resource pool and a dedicated resource pool is depicted. The WTRU may determine the location of sidelink control information (SCI) in a transmission. For example, the WTRU may determine that SCI (e.g., first-level SCI) is multiplexed with SL-PRS in a transmission. The WTRU may then determine the location of the SCI (e.g., first-level SCI) in the transmission based on one or any combination of the following: The WTRU may determine the location of the SCI based on the resource pool used for the transmission of the SL-PRS. At 302, the WTRU may place the SCI 304 associated with the SL-PRS in the same location in the subchannel as the SCI for other sidelink data 306 communications in the resource pool shared with the sidelink communication. At 308, the WTRU may place the SCI (e.g., first SCI) TDM with the SL-PRS in the resource pool dedicated to the SL-PRS. The SCI 310 may occupy only one first symbol 312 of the transmission.

[0151] The WTRU may determine the location of the SCI in the transmission based on the scheduling mode of the SL-PRS. For example, if the WTRU autonomously selects the SL-PRS, the WTRU may place the SCI associated with the SL-PRS in the same location in the subchannel as the SCI for other sidelink communications. Otherwise, if the network schedules the SL-PRS, the WTRU may time division multiplex (TDM) the SCI (e.g., the first SCI) with the SL-PRS. In this case, the SCI may occupy only the first symbol of the transmission.

[0152] For each SL-PRS transmission, the WTRU may send an associated PSCCH and / or PSSCH to indicate information of the SL-PRS (e.g., SL-PRS mode, QoS associated with the SL-PRS). The WTRU may determine the location (e.g., time-frequency resources) of the PSCCH and / or PSSCH to indicate information of the associated SL-PRS. For example, the WTRU may determine the time-frequency resources for sending the PSCCH and / or the time-frequency resources for sending the PSSCH to indicate information of the associated SL-PRS. The WTRU may send the PSCCH and / or PSSCH associated with the SL-PRS.

[0153] The WTRU may determine the location of the PSCCH and / or PSSCH based on one or any combination of the following information about the SL-PRS: SL-PRS pattern (e.g., comb value, number of symbols used and / or RE offset pattern in each symbol, etc.). The WTRU may be (pre)configured to multiplex multiple SL-PRS patterns in time and / or frequency resources, where each pattern may have an associated PSCCH and / or PSSCH. The WTRU may then determine where to place the PSCCH and / or PSSCH based on the pattern of the SL-PRS and / or the time-frequency position of the SL-PRS. The WTRU may have a PSCCH and / or PSSCH resource to indicate one or more SL-PRS patterns. In this case, each SL-PRS pattern may be within the range of the time and frequency resources. The WTRU may then indicate which SL-PRS pattern the WTRU is sending in the SCI sent in the associated PSCCH and / or PSSCH.

[0154] The WTRU may be (pre)configured with a PSCCH and / or PSSCH to indicate a SL-PRS pattern of up to M symbols. The WTRU may then indicate any SL-PRS transmission with a duration from one symbol to M symbols. This may help the WTRU to indicate more SL-PRS patterns for one (pre)configured PSCCH / PSSCH opportunity.

[0155] Figure 4 An example illustration of pattern-based PSCCH and / or PSSCH and SL-PRS multiplexing is depicted. The WTRU may be (pre)configured with three SL-PRS patterns in a time slot, where each SL-PRS pattern may have an associated PSCCH 402a-c and / or PSSCH 404a-c. The WTRU may then determine the location of the PSCCH 402a-c and / or PSSCH 404a-c based on the selected SL-PRS pattern. If the WTRU transmits in a first pattern 406a, the WTRU may transmit the PSCCH 402a and / or PSSCH 404a in a first region (e.g., a first subchannel). If the WTRU uses a second pattern 406b, the WTRU may transmit in a second region (e.g., a second subchannel). If the WTRU selects a third pattern 406c, the WTRU may transmit the PSCCH 402c and / or PSSCH 404c in a third region (e.g., a third subchannel). The WTRU may reserve a period for ACG and transient time 408 between the PSCCH 402a-c and / or PSSCH 404a-c and the SL-PRS 410. The transient time may be (pre-)configured in the resource pool, which may be a function of the SCS of the resource pool.

[0156] Figure 5 An example illustration of time-frequency based PSCCH / PSSCH and SL-PRS multiplexing is depicted. Figure 5 In the example shown, the WTRU may be (pre)configured with three time positions of the SL-PRS 510 in one time slot, where each SL-PRS position may have an associated PSCCH 502a-c and / or PSSCH 504a-c. The WTRU may then determine the position of the PSCCH 502a-c and / or PSSCH 504a-c based on the selected SL-PRS 510 position. If the WTRU transmits in the first symbol 506a, the WTRU may need to transmit the PSCCH 502a and / or PSSCH 504a in the first PSCCH / PSSCH region (e.g., the first subchannel). If the WTRU uses the second symbol 506b, the WTRU may transmit the PSCCH 502b and / or PSSCH 504b in the second region (e.g., the second subchannel). If the WTRU selects the third symbol 506c, the WTRU may send the PSCCH 502c and / or PSSCH 504c in a third region (e.g., a third subchannel). The WTRU may reserve a period for the ACG and transient time 508 between the PSCCH 502a-c and / or PSSCH 504a-c and the SL-PRS 510. The transient time may be (pre)configured in the resource pool, which may be a function of the SCS of the resource pool. The WTRU may place the ACG timeslot between the SL-PRS patterns of different WTRUs.

[0157] Figure 6 An example illustration of PSCCH / PSSCH with associated SL-PRS is depicted. Figure 6In the example shown, the WTRU may be (pre)configured with three time positions of the SL-PRS 610 in a time slot, where each SL-PRS position may have an associated PSCCH 602a-c and / or PSSCH 604a-c. The WTRU may then determine the position of the PSCCH 602a-c and / or PSSCH 504a-c based on the selected SL-PRS 610 position. If the WTRU transmits in the first symbol 606a, the WTRU may need to transmit the PSCCH 602a and / or PSSCH 604a in the first PSCCH / PSSCH region (e.g., the first subchannel). If the WTRU uses the second symbol 606b, the WTRU may transmit the PSCCH 602b and / or PSSCH 604b in the second region (e.g., the second subchannel). If the WTRU selects the third symbol 606c, the WTRU may send the PSCCH 602c and / or PSSCH 604c in a third region (e.g., a third subchannel). The WTRU may reserve a period for the ACG and transient time between the PSCCH 602a-c and / or PSSCH 604a-c and the SL-PRS 610. The transient time may be (pre)configured in the resource pool, which may be a function of the SCS of the resource pool. The WTRU may place the ACG 612 slots between the SL-PRS patterns of different WTRUs.

[0158] In an example, the WTRU may be (pre)configured with multiple cyclic shifts for sending a SL-PRS pattern, where each cyclic shift may have an associated PSCCH and / or PSSCH position. The WTRU may determine the position of the PSCCH and / or PSSCH based on the cyclic shift that the WTRU selects to send the associated SL-PRS.

[0159] The WTRU may embed the SCI in the SL-PRS pattern, such as Figure 7 The WTRU may embed the WTRU's SCI 710 in the pattern. The WTRU may be (pre)configured with a region (e.g., time-frequency) for the SCI 710. The WTRU may then use the REs associated with the SL-PRS pattern in the (pre)configured SCI region to convey the SCI 710 information. The WTRU may then use the remaining REs to send the SL-PRS. Figure 5 In one example shown, the WTRU may use the first three symbols to convey the SCI for the SL-PRS pattern.

[0160] The WTRU may determine parameters for SL-PRS transmission. The WTRU may determine one or any combination of the following parameters for SL-PRS transmission: the number of subchannels for each SL-PRS resource, the number of symbols and / or slots for each SL-PRS transmission resource, the comb value and / or the number of repetitions. The WTRU may determine one or any combination of these parameters based on the (pre)configured transmit power parameters for SL-PRS transmission. In an example, if the WTRU is allowed to transmit full power (e.g., there is no (pre)configured open loop power control (OLPC) in the resource pool), the WTRU may perform SL-PRS in the maximum allowed bandwidth. Additionally or alternatively, if the WTRU is not allowed to transmit full power (e.g., OLPC is (pre)configured in the resource pool), the WTRU may perform SL-PRS in a smaller bandwidth. In an example, if OLPC is not configured in the resource pool, the WTRU may use comb-1 (e.g., the WTRU transmits SL-PRS in all REs of the SL-PRS bandwidth). Otherwise, if OLPC is configured in the resource pool, the WTRU may use Comb-N (eg, N>1).

[0161] With respect to the maximum number of subchannels allowed in the resource pool, the WTRU may be (pre-)configured with the maximum number of subchannels to be used for SL-PRS transmission. The WTRU may then perform SL-PRS transmission within the maximum allowed bandwidth.

[0162] The WTRU may determine which resource pool to send SL-PRS for sidelink positioning. The WTRU may determine which resource pool (e.g., which type of resource pool) to use for SL-PRS sidelink communication based on the QoS of the positioning service (e.g., latency, accuracy requirements). The WTRU may use a sidelink resource pool that requires SL-PRS within the sidelink data for low latency and / or low accuracy requirement sidelink positioning services. The WTRU may use a dedicated resource pool for SL-PRS for high accuracy and / or strict latency requirement sidelink positioning services.

[0163] The WTRU may determine which SL-PRS configuration to use. For example, the WTRU may be (pre)configured or receive multiple SL-PRS configurations. The WTRU may receive the SL-PRS configuration from another WTRU, a gNB (e.g., via RRC, SIB and / or location management function (LMF), etc.), from a (pre)configuration, etc., and / or any appropriate combination thereof.

[0164] The WTRU may determine which SL-PRS configuration to use based on a (pre)configured priority associated with each configuration or a predefined priority / priority order associated with each configuration. For example, the WTRU may prioritize the SL-PRS configuration indicated by a peer WTRU. The WTRU may then prioritize the SL-PRS configuration from the SIB, followed by the (pre)configured SL-PRS configuration. The WTRU may prioritize the SL-PRS configuration transmitted from the network via RRC. The WTRU may then prioritize the SL-PRS configuration provided by another WTRU, followed by the SL-PRS configuration from the SIB, and then the (pre)configured SL-PRS configuration. The WTRU may request another WTRU (e.g., an anchor WTRU) to provide the SL-PRS configuration instead of reading the SIB. The WTRU may then prioritize using the SL-PRS received from the peer WTRU.

[0165] The WTRU may determine which SL-PRS configuration to use based on the coverage status (e.g., whether the WTRU is in coverage or out of coverage). For example, if the WTRU is out of coverage, the WTRU may prioritize the SL-PRS configuration received from a peer WTRU. If the peer WTRU does not provide a SL-PRS configuration, the WTRU may use a (pre-)configured SL-PRS configuration. If the WTRU is in coverage, the WTRU may prioritize any SL-PRS configuration provided by the network. The WTRU may then prioritize a SL-PRS configuration from another WTRU. If no such SL-PRS configuration exists, the WTRU may use a (pre-)configured SL-PRS configuration.

[0166] The WTRU may prioritize resource pools used by peer WTRUs. The WTRU may be (pre)configured with multiple resource pools for SL-PRS transmission. The WTRU may determine which resource pool to select based on the priority and / or precedence of each resource pool. In an example, the WTRU may be (pre)configured to two resource pools, one of which is prioritized for use. The WTRU may use the prioritized resource pool for SL-PRS transmission. In an example, the WTRU may be (pre)configured with the following two types of resource pools for SL-PRS: a dedicated resource pool and a shared resource pool. The WTRU may prioritize a dedicated resource pool over a shared resource pool.

[0167] The WTRU may prioritize resource pools based on resource pools used by peer WTRUs. For example, a WTRU may prioritize resource pools used by peer WTRUs for SL-PRS for its SL-PRS transmission.

[0168] The WTRU may determine which ID may generate / scramble the SL-PRS sequence. The WTRU may determine which N_ID may generate / scramble the SL-PRS sequence. The WTRU may use one or any combination of the following IDs to generate / scramble the SL-PRS sequence: such as N_ID, group ID, link ID, destination ID, source ID, generated ID (e.g., from upper layers), etc. and / or any suitable combination thereof. The WTRU may indicate to another WTRU (e.g., a peer WTRU or a group member) the ID used to generate / scramble the SL-PRS sequence.

[0169] The WTRU may determine when to monitor the SL-PRS resource pool. The WTRU may trigger monitoring the SL-PRS (e.g., monitoring a dedicated resource pool for SL-PRS) based on whether a positioning group and / or positioning session is established. The WTRU may start monitoring the SL-PRS (e.g., start monitoring a dedicated resource pool for SL-PRS) when a positioning session and / or positioning group is established. The WTRU may stop monitoring the SL-PRS (e.g., stop monitoring a dedicated resource pool for SL-PRS) when the positioning session is terminated and / or an RLF is detected and / or indicated from another node.

[0170] The WTRU may receive SL-PRS scheduling information from another node. For example, for a method based on SL-PRS reception, the WTRU may receive information about SL-PRS resources for the group. The WTRU may then trigger monitoring of a dedicated SL-PRS resource pool based on the reception of the SL-PRS scheduling information.

[0171] The WTRU may determine to send multiple SL-PRSs in a slot, where each SL-PRS may consist of M symbols. The WTRU may then perform SL-PRS repetitions in a slot, where the WTRU may send multiple SL-PRSs, each of the multiple SL-PRSs consisting of M symbols. The WTRU may then determine the number of repetitions to send within the slot based on the number of symbols (pre)configured for the SL-PRS in a slot and the duration of each SL-PRS (i.e., the value of M). The WTRU may send the SL-PRS until it fills all the symbols (pre)configured for the SL-PRS. In one example, the WTRU may perform one SL-PRS consisting of three symbols in a slot of nine symbols configured for the SL-PRS. The WTRU may then repeat the SL-PRS three times to complete the slot (pre)configured for the SL-PRS.

[0172] The WTRU may perform multiple transmissions of one SL-PRS in a timeslot. The WTRU may use one PSCCH and / or PSSCH to indicate and / or reserve all transmissions of the SL-PRS in a timeslot. The WTRU may indicate the number of repetitions and the SL-PRS pattern associated with the SL-PRS transmission. The method may be motivated to reduce the number of PSCCH / PSSCHs sent in one timeslot to indicate multiple repetitions of the SL-PRS.

[0173] The WTRU may be configured / preconfigured for sidelink positioning. The WTRU may receive a configuration for sidelink positioning from the network via broadcast (e.g., via SIB) or unicast (e.g., through an access stratum (AS) message (e.g., RRC) or a non-access stratum (NAS) message (e.g., Position Positioning Protocol (LPP)). The WTRU may receive one or any combination of the following configurations for sidelink positioning: a resource pool for sidelink communications to facilitate sidelink positioning, a resource pool for SL-PRS transmission / reception, a positioning method, or any suitable combination thereof. For example, the WTRU may be (pre)configured via one resource pool for both SL-PRS and sidelink communications to facilitate sidelink positioning (e.g., sidelink transmissions to indicate and / or reserve other sidelink transmissions, SL-PRS measurement reports, and / or SL-PRS resource usage reports).

[0174] In an example, the WTRU may be (pre)configured with two resource pools, one of which may be used for sidelink communications to facilitate SL-PRS transmission and / or reception, and the other resource pool may be used for SL-PRS transmission and / or reception. When the WTRU is configured with two resource pools for sidelink positioning, the WTRU may use the sidelink communication resource pool.

[0175] The WTRU may determine whether the network (e.g., gNB, location management function (LMF), etc.) supports sidelink positioning. The WTRU (e.g., target WTRU) may determine whether the network supports sidelink positioning based on the availability of the sidelink positioning SIB and / or the resource pool in the SIB for SL-PRS transmission / reception. If the network does not support sidelink positioning, the WTRU may use the (pre-)configured resource pool for sidelink positioning. Additionally or alternatively, if the network supports sidelink positioning, the WTRU may use the configured resource pool in the unicast / broadcast message (e.g., SIB, RRC and / or LPP).

[0176] The WTRU may determine a resource location for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may determine a resource allocation pattern for sidelink positioning. The WTRU may determine whether to request resources from another node (e.g., a network or another WTRU) and / or perform autonomous resource allocation for sidelink positioning. The WTRU may determine a resource allocation pattern for one or any combination of: sidelink resources for indicating and / or requesting other resources for sidelink positioning, SL-PRS transmission, SL-PRS reception, SL-PRS resource usage reporting and / or indication, and / or SL-PRS measurement reporting.

[0177] The resource allocation pattern for each type of resource used for sidelink positioning may be based on one or any combination of factors. For example, the resource allocation pattern for each type of resource used for sidelink positioning may be determined based on an indication from the network. The WTRU may request the network to provide services for sidelink positioning (e.g., via LPP and / or RRC). The network may then determine the resource allocation pattern for one or more types of resources used for sidelink positioning. The WTRU may request the WTRU to perform an autonomous resource allocation pattern for SL-PRS transmission and / or reception. The WTRU may request the WTRU to perform a network scheduling pattern for SL-PRS measurement reporting. The resource allocation pattern for each type of resource used for sidelink positioning may be based on the coverage status of each WTRU in the sidelink positioning group. For example, if the WTRU is within network coverage, the WTRU (e.g., the target WTRU) may perform a network scheduled pattern. Otherwise, if the WTRU is outside coverage, the WTRU may perform autonomous resource allocation.

[0178] If the WTRU is within the network coverage, the WTRU (e.g., the anchor WTRU) may perform network-scheduled resource allocation. Otherwise, if the WTRU is outside the network coverage, the WTRU may receive scheduling information from another WTRU (e.g., the target WTRU) if the network supports and / or allows forwarding of scheduled resources for sidelink positioning. The resource allocation pattern for each type of resource used for sidelink positioning may be based on whether the network supports and / or allows forwarding of scheduled resources for sidelink positioning. For example, for an out-of-coverage scenario, if the network does not support and / or allow forwarding of scheduled resources for sidelink positioning, the WTRU may perform WTRU-autonomous resource allocation. Otherwise, if the network supports and / or allows forwarding of scheduled resources for sidelink positioning, the WTRU may receive scheduling from another WTRU.

[0179] The resource allocation pattern for each type of resource used for sidelink positioning may be based on the RRC state of the WTRU. For example, if the WTRU is in an RRC inactive and / or idle state, the WTRU may perform autonomous resource allocation or receive scheduling from another WTRU. Otherwise, if the WTRU is in an RRC connected state, the WTRU may perform network scheduled resource allocation for sidelink positioning.

[0180] The resource allocation pattern for each type of resource used for sidelink positioning may be determined based on the role of the WTRU in the sidelink positioning. For example, the WTRU may determine the resource allocation pattern based on whether the WTRU is a target WTRU or an anchor WTRU. For an in-coverage scenario, if the WTRU is a target WTRU, the WTRU may perform a network scheduling pattern. Otherwise, if the WTRU is an anchor WTRU, the WTRU may receive a schedule from another WTRU (e.g., from a target WTRU).

[0181] The WTRU may determine resources for sidelink positioning. For example, the WTRU may determine resources (e.g., sidelink resources, uplink resources) for sidelink positioning. The resources may be one or any combination of the following factors, including sidelink resources used to indicate and / or request other resources for sidelink positioning. The indicated and / or reserved resources may be one or any combination of the following resources: SL-PRS transmission, SL-PRS reception, SL-PRS resource usage report / indication, SL-PRS measurement report, uplink resources used to indicate and / or report the use of scheduled sidelink resources for sidelink positioning, and / or any appropriate combination thereof.

[0182] The resources may be side link resources such as those used for SL-PRS transmission, SL-PRS reception, for reporting SL-PRS positioning measurements, and / or for indicating and / or reporting the use of scheduling side link resources for side link positioning (e.g., SL-PRS transmission, SL-PRS reception and / or SL-PRS measurement reporting resources).

[0183] The WTRU may receive scheduled resources for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may receive one or any combination of the following scheduled resources (e.g., sidelink resources and uplink resources) for sidelink positioning, which may be from the network (e.g., gNB, LMF) or from another WTRU (e.g., an anchor WTRU).

[0184] The sidelink transmission resources used to indicate and / or reserve other resources for sidelink positioning may include resources for SL-PRS transmission, SL-PRS reception, SL-PRS resource usage reporting and / or indication, and / or SL-PRS measurement reporting. Messages sent in this type of resources may be referred to herein as sidelink positioning requests and / or request messages. The WTRU may use one or any combination of AS messages (e.g., SCI, MAC Control Element (MAC CE) and / or PC5-RRC messages) or NAS messages (e.g., LTE Positioning Protocol (LPP) messages) to indicate / reserve resources for sidelink resources.

[0185] The WTRU may be scheduled with sidelink transmission resources to indicate SL-PRS transmission resources. The sidelink transmission resources may occur in the same timeslot as the associated SL-PRS transmission resources. The WTRU may further use the scheduled sidelink resources to indicate SL-PRS reception resources and / or associated SL-PRS measurement reporting resources. For example, if the scheduled sidelink transmission and its associated SL-PRS transmission occupy the same timeslot, the WTRU may use SCI to indicate the SL-PRS transmission. Additionally or alternatively, the WTRU may use SCI, MAC CE, RRC and / or NAS (e.g., LPP) to indicate associated SL-PRS reception resources and / or associated SL-PRS measurement reporting resources, which may occur in a different timeslot than the scheduled sidelink SL-PRS transmission resources.

[0186] The WTRU may schedule a sidelink transmission resource to indicate a SL-PRS transmission in another time slot and / or resource. The WTRU may use any combination of SCI, MAC CE, PC5-RRC and / or NAS (e.g., LPP) to indicate a sidelink positioning resource (e.g., SL-PRS transmission, SL-PRS reception and / or SL-PRS measurement report resource).

[0187] A WTRU (e.g., a target WTRU) may receive one or more SL-PRS resources for SL-PRS transmission from a network (e.g., a gNB or LMF). In an example, a WTRU (e.g., an anchor WTRU) may receive one or more SL-PRS resources for SL-PRS transmission from another WTRU (e.g., a target WTRU). The target WTRU may receive the SL-PRS resources from the network (e.g., a gNB or LMF). Additionally or alternatively, the target WTRU may perform autonomous resource selection for the SL-PRS resources and / or indicate and / or forward these SL-PRS resources to the anchor WTRU.

[0188] The network may indicate to a WTRU (eg, a target WTRU) the sidelink resources for SL-PRS reception. The network may also schedule the same sidelink resources for the anchor WTRU to perform SL-PRS transmission.

[0189] The network (e.g., gNB, LMF) may indicate and / or schedule sidelink resources for SL-PRS reception to a WTRU (e.g., a target WTRU). The WTRU may then forward and / or indicate the scheduled SL-PRS reception resources to the anchor WTRU to perform SL-PRS transmission. The anchor WTRU may then perform SL-PRS transmission in the indicated / forwarded SL-PRS resources, and the target WTRU may then perform SL-PRS reception in the SL-PRS resources.

[0190] In an example, a WTRU (e.g., an anchor WTRU) may indicate sidelink resources for SL-PRS reception to another WTRU (e.g., a target WTRU). The network may schedule SL-PRS resources from the anchor WTRU. The anchor WTRU may autonomously select SL-PRS resources.

[0191] The WTRU may be scheduled with sidelink resources prior to the SL-PRS transmission and / or reception resources. The scheduled sidelink resources may indicate whether the WTRU performs SL-PRS transmission and / or reception in the scheduled SL-PRS resources.

[0192] The target WTRU may be indicated and / or scheduled with two sidelink resources. A first resource may be used for SL-PRS reception (e.g., a sidelink resource used by an anchor WTRU to perform SL-PRS transmission). A second sidelink resource may be used by the anchor WTRU to indicate whether the anchor WTRU performs SL-PRS transmission. The second resource may occur before the first resource. The anchor WTRU may then use the second resource to indicate whether the WTRU performs SL-PRS transmission.

[0193] The target WTRU may be indicated and / or scheduled with two sidelink resources. The first resource may be used for SL-PRS transmission. The second resource may be used by the anchor WTRU to indicate whether the anchor WTRU performs SL-PRS reception (e.g., whether the WTRU performs SL-PRS measurements in the indicated resources). The second resource may occur before the SL-PRS transmission resource. The anchor WTRU may then use the second resource to indicate whether the WTRU performs SL-PRS reception.

[0194] The WTRU may be scheduled with sidelink resources after the SL-PRS transmission and / or reception resources. The scheduled sidelink resources may indicate whether the WTRU performs SL-PRS transmission and / or reception in the scheduled SL-PRS resources.

[0195] The target WTRU may be indicated and / or scheduled with two sidelink resources. A first resource may be used for SL-PRS reception (e.g., a sidelink resource used by an anchor WTRU to perform SL-PRS transmission). A second sidelink resource may be used by the anchor WTRU to indicate whether the anchor performs SL-PRS transmission. The second resource may occur after the first resource. The WTRU may then determine whether to perform SL-PRS transmission in the first resource. The WTRU may use the second resource to indicate whether the WTRU performs SL-PRS transmission in the first resource. For example, if the WTRU performs SL-PRS transmission in the first resource, the WTRU may indicate that the WTRU has already sent SL-PRS in the first resource. Otherwise, if the WTRU deprioritizes SL-PRS transmission in the first resource, the WTRU may indicate that the WTRU has not yet sent SL-PRS in the first resource.

[0196] The target WTRU may be indicated and / or scheduled with two sidelink resources. The first resource may be used for SL-PRS transmission, and the second resource may be used by the anchor WTRU to indicate whether the anchor WTRU performs SL-PRS reception (e.g., whether the WTRU performs SL-PRS measurements in the indicated resources). The second resource may occur after the SL-PRS transmission resource. The anchor WTRU may then use the second resource to indicate whether the WTRU performs SL-PRS reception. For example, if the WTRU performs SL-PRS reception and / or measurements in the first SL-PRS resource, the WTRU may indicate that the WTRU has performed SL-PRS reception in the second resource. Otherwise, if the WTRU deprioritizes SL-PRS reception in the first resource, the WTRU may indicate that the WTRU has not yet performed SL-PRS reception in the second sidelink resource.

[0197] A WTRU (e.g., a target WTRU) may be scheduled and / or indicated with two sidelink resources, one of which may be used for the WTRU's own SL-PRS transmission and the other sidelink resource may be used for SL-PRS measurement reporting. The anchor WTRU may use the sidelink resources for SL-PRS measurement reporting to perform such reporting. Positioning based on SL-PRS transmission may employ this method. In a positioning method based on SL-PRS transmission, the target WTRU may perform SL-PRS transmission and / or receive measurement reports from the anchor WTRU.

[0198] A WTRU (e.g., a target WTRU) may be instructed and / or scheduled with two sidelink resources (e.g., from an anchor WTRU). The target WTRU may use a first resource to perform SL-PRS reception. The target WTRU may use a second resource to perform SL-PRS measurement reporting. A network initiated location request (NI-LR) sidelink positioning method may employ this method. In NI-LR, the network may instruct and / or request an anchor WTRU to locate a target WTRU.

[0199] A WTRU (e.g., a target WTRU) may be indicated / scheduled with three sidelink resources (e.g., from a gNB, LMF), where the first two resources may be used for SL-PRS transmission and SL-PRS reception, and the third resource may be used for reception of SL-PRS measurement reports (e.g., Tx-Rx difference reports from an anchor WTRU). This method may be used for a round trip time (RTT) sidelink positioning method, where the target WTRU may perform SL-PRS transmission, reception, and SL-PRS measurement report reception.

[0200] A WTRU (e.g., a target WTRU) may be indicated and / or scheduled with three sidelink resources (e.g., from a gNB and / or LMF), wherein the first two resources may be used for SL-PRS transmission and SL-PRS reception, and the third resource may be used for reception of SL-PRS measurement reports (e.g., Tx-Rx difference reports from the target WTRU). Round Trip Time (RTT) sidelink positioning may employ this method. In RTT, the target WTRU may perform SL-PRS transmission, reception, and / or SL-PRS measurement report transmission. The target WTRU may send a SL-PRS measurement report (e.g., Tx-Rx difference from the target WTRU, which is the time difference between the transmission of the SL-PRS from the target WTRU and the reception of the SL-PRS from the anchor WTRU) to one of the anchor WTRUs. The target WTRU may receive an indication and / or configuration from the network and / or the anchor WTRU directing the target WTRU where to send the target WTRU's report. Additionally or alternatively, the target WTRU may send a SL-PRS measurement report to the network (e.g., LMF and / or gNB).

[0201] The uplink resources used to indicate and / or report the use of scheduled sidelink resources for sidelink positioning may include any combination of the following factors: The WTRU may be scheduled with an uplink resource after one or more scheduled SL-PRS transmission, SL-PRS reception and / or SL-PRS measurement reporting resources to indicate and / or report the use of the scheduled sidelink resources. The WTRU may indicate whether the scheduled sidelink resources are used for sidelink positioning. For example, the WTRU may indicate whether the scheduled sidelink resources for SL-PRS transmission, reception and / or SL-PRS measurement reporting are used. The WTRU may indicate and / or report whether the WTRU correctly receives the SL-PRS measurement report from another WTRU (e.g., an anchor WTRU) in the scheduled sidelink resources. The WTRU may indicate and / or report whether the WTRU needs more sidelink resources for sidelink positioning.

[0202] The uplink resources are used for sidelink positioning reports (e.g., sidelink positioning and / or Uu positioning reports). For example, a WTRU may be scheduled with uplink resources for performing sidelink positioning reports. The sidelink positioning reports may be sidelink positioning measurement reports and / or relative positions of a WTRU (e.g., a target WTRU) with respect to other WTRUs (e.g., an anchor WTRU).

[0203] Figure 8 Depicted are example illustrations of potential scheduled and / or selected resources for sidelink positioning. Figure 8As shown, the sidelink resources may indicate and / or reserve other resources for sidelink communication (e.g., resources for SL-PRS transmission, SL-PRS reception, SL-PRS resource usage reporting / indication, and / or SL-PRS measurement reporting) occupying different time slots than the SL-PRS transmission resources. In this example, a WTRU (e.g., a target WTRU) may be scheduled with one or any combination of six types of resources for sidelink positioning. A first type of resource 802 (e.g., a resource with index 1) may implicitly and / or explicitly indicate one or any combination of the remaining types of resources. A second type of resource 804a-b (e.g., a resource with index 2) may indicate SL-PRS resource usage (e.g., by an anchor WTRU). The second type of resource 804a-b may occur before (804a) or after (804b) SL-PRS transmission and / or reception. The third type of resource 806 and the fourth type of resource 808 (e.g., a resource with index 3 or 4) may be used (e.g., by a target WTRU) for SL-PRS transmission and reception, respectively. The fifth type of resource 810 (e.g., a resource with index 5) may be used (e.g., by an anchor WTRU) to report SL-PRS measurements. Finally, the sixth type of resource 812 (e.g., a resource with index 6), which may be a UL resource, may be used (e.g., by a target WTRU) to indicate sidelink resource usage for sidelink positioning.

[0204] Fig. 9 An example of potential scheduled / selected resources for sidelink positioning is depicted, where the SL-PRS transmission resource 906 is in the same time slot as its indication 902. The sidelink resource used to indicate and / or reserve other resources for sidelink communication may be transmitted in the same time slot and / or resource as the SL-PRS transmission. In this example, the second type of resource 904a-b (e.g., a resource with index 2) may indicate (e.g., by an anchor WTRU) SL-PRS resource usage (e.g., whether the WTRU performs SL-PRS transmission and / or reception of resources with index 3 or 4 at 906 and 908, respectively). The second type of resource 904a-b may occur before (904a) or after (904b) the SL-PRS reception resource 908. Similar to Figure 8 In the example shown in , the fifth type of resource 910 may report SL-PRS measurements. The sixth type of resource 912 may indicate sidelink resource usage for sidelink positioning.

[0205] A WTRU (e.g., a target WTRU) may determine a positioning method for a positioning group. For example, the WTRU may determine one or any combination of sidelink positioning methods, including a method based on SL-PRS transmission, a method based on SL-PRS reception, and / or a method based on sidelink RTT.

[0206] Based on the determined positioning method, the WTRU (e.g., target WTRU) may further request other WTRUs (e.g., anchor WTRUs) to perform SL-PRS transmission. For example, the WTRU may determine to perform a sidelink positioning method based on SL-PRS reception. The WTRU may then request the anchor WTRU to perform SL-PRS transmission.

[0207] Based on the determined positioning method, the WTRU (e.g., target WTRU) may further determine to request other WTRUs (e.g., anchor WTRUs) to perform SL-PRS reception. For example, the WTRU may determine to perform a sidelink positioning method based on SL-PRS transmission. The WTRU may then request the anchor WTRU to perform SL-PRS reception.

[0208] Based on the determined positioning method, the WTRU (e.g., target WTRU) may further determine to request other WTRUs (e.g., anchor WTRUs) to perform both SL-PRS transmission and / or reception. The WTRU may determine to perform a SL RTT-based positioning method. The WTRU may then request the anchor WTRU to perform both SL-PRS transmission and / or reception. Based on the determined positioning method, the WTRU (e.g., target WTRU) may further determine to request other WTRUs (e.g., anchor WTRUs) to perform SL-PRS measurement reporting.

[0209] The WTRU may request the anchor WTRU to report different measurement parameters based on the selected sidelink positioning method. For the method based on SL-PRS transmission, the WTRU may request the anchor WTRU to report the reference signal time difference (RSTD), time of arrival (ToA), angle of arrival (AoA), phase of arrival (PoA), differential phase of arrival (DPoA), and / or SL-RSRP of the SL-PRS sent from the target WTRU. For the sidelink positioning method based on SL-PRS reception, the WTRU may request the anchor WTRU to report the time of departure (ToD), angle of departure (AoD), phase of departure (PoD), and / or differential phase of departure (DPoD) of the SL-PRS. For the sidelink positioning method based on RTT, the WTRU may request the anchor WTRU to report Tx-Rx difference, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA, RSTD, and / or DPoD.

[0210] The WTRU may determine the positioning method for the sidelink positioning group based on one or any combination of the following factors, including scheduled sidelink resources (e.g., SL-PRS resources and / or SL-PRS measurement report resources) from the network (e.g., gNB and / or LMF). The WTRU may receive the scheduled sidelink resources from an AS and / or NAS message. The AS and / or NAS message may include one or any combination of a DCI, a DL MAC CE, an RRC, and / or an LPP message.

[0211] If the scheduled resources have both SL-PRS transmission and SL-PRS reception resources, the WTRU may perform RTT-based sidelink positioning. If the scheduled resources have SL-PRS transmission resources, the WTRU may perform a SL-PRS transmission-based method. If the scheduled resources have SL-PRS reception resources, the WTRU may perform a SL-PRS reception-based method.

[0212] The WTRU may determine a positioning method based on a set of SL-PRS resources scheduled by the network. A WTRU (e.g., a target WTRU) may determine a positioning method for a group. The WTRU may indicate the determined positioning method to the WTRUs in the group. The WTRU may determine which positioning method to use for the sidelink positioning group based on one or any appropriate combination of the following factors: a set of scheduled SL-PRS resources scheduled by the network (e.g., the number of SL-PRS resources), the number of anchor WTRUs used to send SL-PRS, and / or the attributes of the scheduled SL-PRS resources. The number of anchor WTRUs used to send SL-PRS and / or the attributes of the scheduled SL-PRS resources may include a time gap between the first SL-PRS resource and the last SL-PRS resource and / or a time gap between two resources, etc.

[0213] If the number of resources is less than twice the number of anchor WTRUs, the WTRU may determine to perform SL-PRS SL-TDOA. If the number of SL-PRS resources is higher than twice the number of anchor WTRUs, the WTRU may determine to perform the RTT method.

[0214] If the time gap between the first SL-PRS resource and the last SL-PRS resource is less than a threshold, the WTRU may determine to perform a UL-like SL-TDOA positioning method. If the time gap between the SL-PRS resource pairs is less than a threshold, the WTRU may determine to perform an RTT method.

[0215] Fig.10 An example illustration of downlink control information (DCI) for scheduling resources for sidelink positioning is depicted. Fig.10As shown, in a resource scheduling message (e.g., DCI 1000), one or any combination of bit fields may be indicated to the WTRU to decode a type of resource. The combination of bit fields may include sidelink resources for indicating and / or reserving resources for sidelink positioning 1002, sidelink resources for SL-PRS transmission 1004, sidelink resources for SL-PRS reception 1006, sidelink resources for SL-PRS measurement reporting 1008, and / or uplink resources for reporting the use of scheduled SL-PRS resources in the uplink.

[0216] The WTRU may be (pre)configured with a value and / or code point in each bit field to indicate the unavailability of each type of resource in the scheduled message. The WTRU may then determine, for each type of resource in the scheduled message, whether there are scheduled resources in each bit field and / or any combination of bit fields. In an example, in the scheduled message, the WTRU may determine that there are both SL-PRS transmission and reception resources. The WTRU may then determine to perform an RTT-based sidelink positioning method. In an example, in the scheduled message, the WTRU may determine that there is an SL-PRS transmission (e.g., there are no SL-PRS reception resources). The WTRU may then determine to perform a sidelink positioning method based on SL-PRS transmission. In an example, in the scheduled message, the WTRU may determine that there is an SL-PRS reception (e.g., there are no SL-PRS transmission resources). The WTRU may then determine to perform a sidelink positioning method based on SL-PRS transmission. In an example, in the scheduled message, the WTRU may determine that there is an SL-PRS reception (e.g., there are no SL-PRS transmission resources). The WTRU may then determine to perform a sidelink positioning method based on SL-PRS reception.

[0217] A WTRU (e.g., a target WTRU) may be (pre)configured with multiple resource scheduling formats (e.g., multiple DCI formats). Each format may contain one or more types of resources for sidelink positioning. One type of resource for sidelink positioning may be a sidelink resource for indicating / reserving resources for sidelink positioning, a sidelink resource for SL-PRS transmission, a sidelink resource for SL-PRS reception, a sidelink resource for SL-PRS measurement reporting, and / or an uplink resource for reporting usage of scheduled SL-PRS resources in the uplink.

[0218] The WTRU may then (e.g., via RRC) decode one DCI format for one or more types of resources for sidelink positioning. The WTRU may decode one DCI format for a method based on SL-PRS transmission, wherein the WTRU may decode a DCI format that schedules sidelink resources for SL-PRS transmission and sidelink resources for SL-PRS measurement reporting. The WTRU may decode one DCI format for a method based on SL-PRS reception. The WTRU may decode a DCI format that schedules sidelink resources for SL-PRS reception. The WTRU may decode one DCI format for a method based on SL-PRS transmission. The WTRU may decode a DCI format that schedules sidelink resources for SL-PRS transmission and / or sidelink resources for SL-PRS measurement reporting.

[0219] The WTRU may be (pre)configured with different scrambling codes (e.g., Radio Network Temporary Identifier - RNTI) for different types of resource allocations for sidelink positioning. The WTRU may determine which type of resource allocation is used for sidelink positioning based on the decoded scrambling code. For example, the WTRU may be (pre)configured (e.g., via RRC) with three scrambling codes, one of which is used for DCI scheduling SL-PRS transmission, SL-PRS reception and / or SL-PRS measurement reporting. Another scrambling code may be used for SL-PRS reception. Another scrambling code may be used for SL-PRS transmission.

[0220] The WTRU may be (pre)configured (e.g., via RRC) with two scrambling codes. One scrambling code may be used for dynamic SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting. The other scrambling code may be used for semi-static SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting.

[0221] The WTRU may be (pre)configured with one or more resource scheduling formats (e.g., DCI formats). Each format may contain one or more types of resources for sidelink positioning. The WTRU may then determine the resource scheduling format based on the format indicator in the message. The message may implicitly indicate the sidelink positioning method to be used. For example, the WTRU may be configured with three resource scheduling formats. Each format may be associated with a sidelink positioning method including SL-PRS transmission-based, SL-PRS reception-based and / or sidelink RTT-based.

[0222] The WTRU may determine whether the DCI is for SL-PRS or for data transmission based on the RNTI. For example, the WTRU may be (pre)configured with different scrambling codes (e.g., RNTI) for different types of DCI. One type of DCI may be used to schedule SL-PRS transmission and / or reception, and another type of DCI may be used to schedule normal data transmission. The WTRU may then determine whether to use the DCI for SL-PRS scheduling and / or normal data scheduling based on the associated RNTI.

[0223] The WTRU may determine whether the DCI is for SL-PRS and / or data transmission based on the search space set. For example, the WTRU may be (pre)configured with different search space sets for different types of DCI. One search space set may be used to schedule DCI for SL-PRS transmission / reception, and another search space set may be used to schedule DCI for normal sidelink data transmission.

[0224] The WTRU may determine whether the DCI is for SL-PRS and / or data based on the indicated code point in the bit field. For example, the WTRU may be configured with a bit field in the DCI. One code point may be used for SL-PRS scheduling and another code point may be used for normal data scheduling. The WTRU may then determine whether the DCI is for SL-PRS transmission / reception or for sidelink data based on the code point indicated in the DCI.

[0225] The WTRU may determine the DCI for SL-PRS based on the indication in the DCI. The WTRU may be configured with a bit indicator in the DCI. The bit indicator may explicitly indicate whether the DCI is used to schedule SL-PRS. The WTRU may use the scheduled SL-PRS sent in the DCI. The DCI may indicate that the resource is used for SL-PRS. Otherwise, the WTRU may not use the resource for SL-PRS.

[0226] The WTRU may determine whether the DCI is used for SL-PRS based on the indication in the DCI. The WTRU may be configured with a bit indicator in the DCI, where the bit indicator may explicitly indicate whether the DCI is used to schedule SL-PRS. The WTRU may use the scheduled SL-PRS transmission in the DCI. The DCI may indicate that the resource is used for SL-PRS. Otherwise, the WTRU may not use the resource for SL-PRS.

[0227] The WTRU may determine whether to send data and / or SL-PRS in the scheduled sidelink resources. The WTRU may be scheduled with sidelink resources (e.g., in a shared resource pool between SL-PRS and data). The WTRU may perform resource selection to select the sidelink resources. The WTRU may determine whether to send SL-PRS and / or sidelink data in the scheduled / selected resources based on one or any combination of the following factors, including the priority associated with the SL-PRS, the priority of the data, and the relative priority between the SL-PRS and the sidelink data.

[0228] The WTRU may determine whether to send SL-PRS and / or sidelink data in the scheduled / selected resources based on the attributes of the scheduled / selected sidelink resources (e.g., the number of retransmissions and / or repetitions, the bandwidth of the resources, the time gap between the first resource and the last resource, the time gap between two consecutive resources, etc.). For example, the WTRU may determine whether to place the SL-PRS in the sidelink resources based on the attributes of the scheduled / selected sidelink resources. The WTRU may send a SL-PRS with a bandwidth greater than a (pre)configured threshold and / or a number of repetitions greater than a (pre)configured threshold. If the (pre)configured conditions are met, the WTRU may prioritize sending the SL-PRS. Otherwise, if the (pre)configured conditions are not met, the WTRU may not send the SL-PRS. The WTRU may then send the sidelink data. If the (pre)configured conditions are met, the WTRU may determine whether to send the SL-PRS and / or sidelink data based on the relative priorities between the SL-PRSs. The WTRU may send the SL-PRS and / or sidelink data with a higher priority.

[0229] The WTRU may determine whether to send the SL-PRS and / or the sidelink data in the scheduled / selected resources based on the destination associated with the data in the buffer. For example, when the WTRU places the SL-PRS in the sidelink resources, the WTRU may place the sidelink data to the sidelink resources to send the SL-PRS with the data. The WTRU may be (pre)configured with a set of destination IDs to multiplex with the SL-PRS. For a unicast SL-PRS, if both the data and / or the SL-PRS are targeted to the same WTRU, the WTRU may send the data with the SL-PRS. If the receiver of the SL-PRS receives the sidelink data, the WTRU may send the data with the SL-PRS. For a multicast SL-PRS, if the receiver of the sidelink data receives the SL-PRS, the WTRU may send the data with the SL-PRS.

[0230] The WTRU may determine whether to send the SL-PRS and / or sidelink data in the scheduled / selected resources based on the destination associated with the SL-PRS. For example, when the WTRU determines to place the sidelink data in the sidelink resource, the WTRU may determine to opportunistically place the SL-PRS to the sidelink resource to send the SL-PRS together with the data. For each destination ID associated with the sidelink data, the WTRU may be (pre)configured with a set of destination IDs associated with the SL-PRS to be multiplexed with the sidelink data. For unicast sidelink data, if both the data and the SL-PRS are targeted to the same WTRU, the WTRU may send the data together with the SL-PRS. In another method, if the receiver of the sidelink data receives the SL-PRS, the WTRU may send the data together with the SL-PRS. For multicast sidelink data, if the receiver of the SL-PRS receives the sidelink data, the WTRU may send the data together with the SL-PRS. For broadcast sidelink data, the WTRU may send the SL-PRS together with the sidelink data if both the sidelink data and / or the SL-PRS have the same destination ID (eg, the same broadcast service).

[0231] The WTRU may determine whether to send the SL-PRS and / or the sidelink data in the scheduled / selected resources based on the broadcast type associated with the SL-PRS and / or the sidelink data. In an example, if the WTRU determines to send the SL-PRS in the sidelink resource, the WTRU may determine to multiplex the sidelink data in the resource based on the broadcast type associated with the SL-PRS and / or the broadcast type associated with the sidelink data. If the WTRU determines to send the SL-PRS using broadcast, the WTRU may send the sidelink data if the sidelink data is broadcast. If the SL-PRS and the sidelink data belong to the same service, the WTRU may send the broadcast sidelink data. If the WTRU determines to send the SL-PRS using groupcast, the WTRU may send the sidelink data if the sidelink data is targeted to the same group. If the WTRU determines to send the sidelink data in the sidelink resource, the WTRU may determine to multiplex the SL-PRS in the resource based on the broadcast type associated with the SL-PRS and / or the broadcast type associated with the sidelink data. If the WTRU determines to send the sidelink data using unicast, the WTRU may send the SL-PRS if both the SL-PRS and / or the data are targeted to the same receiver.

[0232] The WTRU may determine whether to send SL-PRS and / or sidelink data in the scheduled / selected resources based on (pre)configured constraints. For example, the WTRU may be (pre)configured to multiplex SL-PRS with sidelink data in one transmission in a resource pool. In one (pre)configuration, the WTRU may not allow SL-PRS to be multiplexed with sidelink data. In another (pre)configuration, SL-PRS may be multiplexed with sidelink data.

[0233] The WTRU may determine whether to place the data or SL-PRS first in the resource based on the priority associated with the data and / or the priority associated with the SL-PRS. For example, the WTRU may place the data or SL-PRS with a higher priority first. If the SL-PRS and / or the data have the same priority, the WTRU may prioritize one (pre)configured priority order (e.g., data or SL-PRS).

[0234] The WTRU scheduling may be based on a group-common DCI for the SL-PRS. For example, the WTRU may be (pre)configured to monitor a group-common DCI (e.g., a DCI for a group of WTRUs) and / or a scheduling of SL-PRS transmission and / or reception for a group of WTRUs. The WTRU may then receive a DCI for the group that schedules SL-PRS resources for the group of WTRUs.

[0235] Based on the role of the WTRU in the group (e.g., whether the WTRU is a target WTRU or an anchor WTRU), based on the positioning method (e.g., whether the positioning method may be SL-PRS transmission based, SL-PRS reception based, and / or RTT based), based on the order of SL-PRS transmission and / or reception, based on the member IDs of the WTRUs in the group (e.g., the WTRU may determine which of the resources indicated in the DCI may be scheduled for the WTRU based on its member ID), and / or based on any suitable combination thereof, the WTRU may determine the receiver and / or transmitter of each scheduled SL-PRS resource. For example, a WTRU (e.g., a target WTRU) may be a (pre-)configured SL-PRS reception based positioning method for a group of five WTRUs. The WTRU as a target WTRU may receive SL-PRS from the other four anchor WTRUs. The group may be scheduled with four resources for SL-PRS, where each anchor WTRU may select one resource based on a function of its member ID.

[0236] The WTRU may determine whether to forward a scheduled SL-PRS for a member WTRU in a group. For example, a WTRU (e.g., a target WTRU) may receive a SL-PRS schedule for SL-PRS transmissions of the WTRU from a network (e.g., a gNB and / or LMF). The WTRU may then determine whether to forward a scheduled SL-PRS transmission for a WTRU in a group (e.g., a peer WTRU or a member WTRU in a sidelink positioning group). The determination of whether to forward the scheduled SL-PRS may be based on the coverage status of the peer WTRU and / or the member WTRU. For example, if a peer WTRU or one of a plurality of member WTRUs is present outside of network coverage, the WTRU may forward the scheduled SL-PRS to a peer WTRU of the member WTRU.

[0237] The determination of whether to forward the scheduled SL-PRS may be based on the RRC state of the peer WTRU and / or the member WTRU. For example, if the peer WTRU or at least one member WTRU is not in the RRC_CONNECTED state, the WTRU may forward the scheduled SL-PRS to the peer WTRU and / or the member WTRU. Otherwise, the WTRU may not forward the scheduled SL-PRS to the peer WTRU and / or the member WTRU.

[0238] The WTRU may determine to send a scheduled SL-PRS based on an acknowledgment (ACK) from a member WTRU. For example, the WTRU may be scheduled (e.g., by a gNB or LMF) or self-select one or more SL-PRS. The WTRU may transmit information about the scheduled and / or selected SL-PRS resources. The WTRU may expect acknowledgments from peer WTRUs and / or member WTRUs. If the WTRU does not receive an acknowledgment from a peer WTRU and / or member WTRU in the group, the WTRU may discard and / or release one or more SL-PRS resources. This method may help prevent the WTRU from transmitting a SL-PRS when no WTRU is to receive the SL-PRS.

[0239] A WTRU may determine which WTRU is to request resources for sidelink positioning. In one approach, a WTRU (e.g., a target WTRU) may establish a group of WTRUs for sidelink positioning. The WTRU may then determine which WTRU is to request resources (e.g., sidelink and / or uplink) for the group of WTRUs for sidelink positioning. The WTRU may then indicate (e.g., using a group ID) to other WTRUs in the group (e.g., by using group PC5-RRC and / or LPP) the WTRU that is performing the resource request for the group. In one approach, a target WTRU may request resources for sidelink positioning (e.g., for a mobile initiated location request (MO-LR) positioning service). In an example, an anchor WTRU connected to a network may request resources for sidelink positioning (e.g., for a network initiated location request (NI-LR) positioning service).

[0240] The WTRU may trigger resource allocation and / or request resources for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may trigger resource allocation and / or request resources for sidelink positioning, which may include one or more of the following resources: sidelink resources for indicating and / or reserving other resources for sidelink positioning (e.g., sidelink resources for indicating and / or reserving resources for SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting), sidelink resources for SL-PRS transmission, sidelink resources for SL-PRS reception, sidelink resources for reporting SL-PRS resource usage, sidelink resources for SL-PRS measurement reporting, uplink resources for indicating and / or reporting usage of scheduled SL-PRS resources, and / or uplink resources for sidelink positioning reports (e.g., sidelink positioning and / or Uu positioning reports).

[0241] The WTRU may send in the uplink direction using an AS message (e.g., one or any combination of a scheduling request (SR), an uplink medium access channel (UL MAC CE), an RRC, and / or a NAS message (e.g., LPP)) to request resources (e.g., sidelink resources or uplink resources) for sidelink positioning. The WTRU may request resources for sidelink positioning using information related to group sidelink positioning (e.g., group ID, sidelink positioning service ID, and / or L2 destination index, etc.). The WTRU may trigger resource allocation and / or request resources for sidelink positioning based on one or any combination of the events described herein and / or one or any combination of the following events:

[0242] The WTRU may initiate a sidelink positioning service. For example, the WTRU may initiate a sidelink positioning service (eg, for a MO-LR service). The WTRU may then trigger resource allocation and / or request resources for sidelink positioning.

[0243] The WTRU may receive an indication and / or request from the network to potentially perform sidelink positioning. For example, the WTRU may receive a request and / or indication from the network (e.g., from the LMF via an LPP message) to potentially initiate sidelink positioning. The WTRU may then trigger resource allocation and / or request resources for sidelink positioning.

[0244] A WTRU (e.g., a target WTRU) may receive an indication and / or a request from another WTRU (e.g., an anchor WTRU) to perform sidelink positioning. For example, the anchor WTRU may initiate a sidelink positioning service to locate the relative position of the target WTRU. The anchor WTRU may perform sidelink positioning by sending a SL-PRS and / or request the target WTRU to send and / or receive a SL-PRS. The target WTRU may then receive an indication and / or a request from the anchor WTRU to perform sidelink positioning by sending and / or receiving a SL-PRS and / or performing a SL-PRS measurement report. The target WTRU may then trigger resource allocation and / or request resources for sidelink positioning.

[0245] A WTRU (e.g., an anchor WTRU) receives an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform sidelink transmission and / or reception (e.g., SL-PRS transmission, SL-PRS reception, SL-PRS measurement reporting, and / or SL-PRS resource usage reporting) for sidelink positioning. For the sidelink RTT-based method, the target WTRU may perform SL-PRS transmission. The anchor WTRU may then trigger resource allocation and / or request resources for SL-PRS transmission and / or SL-PRS measurement reporting upon receiving SL-PRS transmission from the target WTRU. A WTRU (e.g., an anchor WTRU) may receive SL-PRS from another WTRU (e.g., a target WTRU). Upon having SL-PRS measurement results, the WTRU may then trigger resource allocation and / or request resources for SL-PRS measurement reporting. A WTRU (e.g., a target WTRU) may receive a SL-PRS resource usage report from another WTRU (e.g., an anchor WTRU) that may indicate that the WTRU is not to perform SL-PRS reception and / or transmission in the scheduled and / or indicated sidelink resources. The target WTRU may then trigger resource allocation and / or request resources for SL-PRS transmission and / or reception, which may be used to increase the amount of SL-PRS resources used for sidelink positioning measurements.

[0246] A WTRU (e.g., a target WTRU) may determine that existing sidelink resources are insufficient for positioning services. For example, if the WTRU does not receive an expected SL-PRS resource usage report, SL-PRS reception, and / or SL-PRS measurement report, the WTRU (e.g., a target WTRU) may trigger resource allocation and / or request additional resources for sidelink positioning. For example, if the WTRU or a peer WTRU (e.g., an anchor WTRU) deprioritizes SL-PRS transmission, SL-PRS reception, SL-PRS resource usage report, and / or SL-PRS measurement report, the WTRU (e.g., a target WTRU) may trigger resource allocation and / or request additional resources for sidelink positioning.

[0247] A WTRU (eg, a target WTRU) receives a SL-PRS resource usage report and / or a SL-PRS measurement report from another WTRU that implicitly and / or explicitly indicates that scheduled resources may not be used and / or may be insufficient.

[0248] A WTRU (eg, a target WTRU) receives a SL-PRS measurement report from another WTRU (eg, an anchor WTRU) that implicitly and / or explicitly indicates that scheduled resources may be insufficient for SL-PRS measurement.

[0249] The WTRU may have available SL-PRS positioning measurement results. For example, the WTRU (e.g., the anchor WTRU) may request (e.g., through the target WTRU) to perform a SL-PRS measurement report. If the WTRU has available SL-PRS measurement results, the WTRU may then trigger a request (e.g., from the network) and / or resource allocation for the SL-PRS measurement report. For example, the WTRU (e.g., the target WTRU) may be (pre-)configured to perform SL-PRS measurements of at least N SL-PRS resources to generate a SL-PRS measurement report. Upon successfully measuring the N SL-PRS resources, the WTRU may generate the SL-PRS measurement results. The WTRU may then trigger a request for resources and / or resource allocation for the transmission of the SL-PRS measurement report.

[0250] The WTRU may receive information about side link positioning from one node and may indicate the information to another node. For example, the WTRU may implicitly and / or explicitly receive information about side link positioning from a node (e.g., a network node, LMF (location management function), gNB, another WTRU, etc.). For example, the WTRU may receive information about side link positioning from the LMF via an LPP message. For example, the WTRU may receive information about side link positioning from another node via the SL-PRS transmission of the WTRU. The WTRU may then indicate one or any combination of the information received from the node to another node (e.g., a network node, LMF, gNB, and / or another WTRU, etc.). The information that the WTRU may receive from one node and / or indicate to another node may include information about side link positioning. The information may include one or any combination of the following:

[0251] QoS associated with sidelink positioning (e.g., accuracy, latency, reliability and / or availability of the sidelink positioning service).

[0252] The SL-PRS transmission and / or reception configuration may include one or any combination of the following: the number of subchannels used for each SL-PRS resource, the number of symbols and / or time slots used for each SL-PRS transmission resource, the comb value, the number of repetitions, the periodicity of SL-PRS transmission and / or reception, and / or the number of anchor WTRUs transmitting / receiving SL-PRS. The SL-PRS measurement report configuration may include one or any combination of the following: delayed SL-PRS measurement reporting, and / or the periodicity of SL-PRS measurement reporting.

[0253] In an example, the sidelink positioning may be initiated based on at least one or a combination of the following: The anchor WTRU may transmit a request to the network (e.g., gNB, LMF, or the like) to obtain the relative and / or absolute positioning of the target WTRU. If the anchor WTRU transmits the request to the LMF, the request may be transmitted via an LPP message. In an example, the anchor WTRU may include an ID of the target WTRU to the network (e.g., LMF, gNB, etc.).

[0254] The target WTRU may transmit a request to the network to obtain the relative and / or absolute positioning of the target WTRU. If the target WTRU transmits the request to the LMF, the request may be transmitted via an LPP message. In an example, the target WTRU may include in the request the ID of the anchor WTRU that may be utilized to determine the relative position.

[0255] The target WTRU may transmit a request to one or more anchor WTRUs to determine the relative and / or absolute location of the target WTRU. If the target WTRU transmits a request to an anchor WTRU, the request may be transmitted via an LPP message (e.g., SL-LPP) or an AS layer message (e.g., PC5-RRC and / or MAC CE). Such a request may be transmitted in the sidelink via a unicast, multicast, and / or broadcast transmission. In one example associated with a multicast and / or broadcast transmission, the target WTRU may include in the request an ID of an anchor WTRU that may be utilized to determine the relative location.

[0256] The LMF and / or gNB may transmit a request for relative and / or absolute positioning of a target WTRU to the anchor WTRU. The request may be transmitted to the anchor WTRU via an LPP message. In one example, the anchor WTRU receives the ID of the target WTRU.

[0257] The LMF and / or gNB may transmit a request to the target WTRU to report the relative and / or absolute positioning of the target WTRU. In one example, the LMF and / or gNB includes in the request the ID of the anchor WTRU that may be used to determine the relative position.

[0258] A location service (LCS) client and / or application in the WTRU and / or in the network may transmit a request for determining a relative and / or absolute location of a target WTRU. Such a request may be transmitted as an LCS (e.g., MO-LR and / or for Mobile Terminal Location Request (MT-LR)), LPP and / or AS layer (e.g., RRC, PC5- and / or RRC) message to a gNB, LMF or anchor WTRU.

[0259] The WTRU may determine information for indicating and / or reporting SL-PRS resource usage. For example, a WTRU (e.g., an anchor WTRU) may receive an indication and / or request (e.g., from a target WTRU) to perform SL-PRS transmission and / or SL-PRS reception. The WTRU may then determine to provide feedback to the requesting WTRU regarding SL-PRS resource usage. The WTRU may indicate information related to group sidelink positioning (e.g., requesting WTRU ID, sidelink positioning group ID, sidelink positioning service ID, etc.) to feedback a request for sidelink positioning.

[0260] The WTRU may implicitly and / or explicitly feedback one or any combination of the following information using one or any combination of PSFCH, SCI, MAC CE, PC5-RRC and / or NAS (e.g., LPP): The WTRU has successfully decoded the sidelink positioning request message. For example, the target may receive a sidelink communication indicating and / or reserving SL-PRS resources for the anchor WTRU to perform SL-PRS transmission and / or reception. The anchor WTRU may feedback the SL-PRS resource usage based on the reception of such sidelink communication. The WTRU may feedback ACK / NACK based on the decoding status of the sidelink communication. For example, if the WTRU successfully receives the sidelink communication, the WTRU may feedback ACK. Otherwise, the WTRU may feedback NACK.

[0261] The WTRU may perform SL-PRS transmission and / or reception. For this case, the WTRU may provide feedback to the requesting WTRU before the SL-PRS transmission and / or reception resources. For example, a WTRU (e.g., an anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform SL-PRS transmission and / or reception. The WTRU may then provide feedback to the target WTRU that the WTRU may perform SL-PRS transmission and / or reception. The feedback resources may be transmitted after the request message and / or before the SL-PRS transmission and / or reception resources.

[0262] The WTRU may not perform SL-PRS transmission and / or reception. For this case, the WTRU may provide feedback to the requesting WTRU before the SL-PRS transmission and / or reception resources. For example, a WTRU (e.g., an anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform SL-PRS transmission and / or reception. The WTRU may then provide feedback to the target WTRU that the WTRU may not perform SL-PRS transmission and / or reception. The feedback resources may be transmitted after the request message and / or before the SL-PRS transmission and / or reception resources. Since the WTRU may deprioritize the SL-PRS transmission and / or reception resources and / or may fail to decode the request message, the WTRU may provide feedback of this information.

[0263] The WTRU may have already performed SL-PRS transmission and / or reception. For this case, the WTRU may provide feedback to the requesting WTRU after the SL-PRS transmission and / or reception resources. For example, a WTRU (e.g., an anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform SL-PRS transmission and / or reception. The WTRU may then perform SL-PRS transmission and / or reception in the SL-PRS transmission and / or reception resources. The SL-PRS transmission and / or reception may be indicated in the request message. The WTRU may then provide feedback to the requesting WTRU that the WTRU has performed SL-PRS transmission and / or reception. The feedback message may occur after the SL-PRS transmission and / or reception resources.

[0264] The WTRU may have de-prioritized one or more SL-PRS transmissions and / or receptions. For this case, the WTRU may provide feedback to the requesting WTRU after the SL-PRS transmission and / or reception resources. For example, a WTRU (e.g., an anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform SL-PRS transmission and / or reception.

[0265] The WTRU may then deprioritize SL-PRS transmission and / or reception in the SL-PRS transmission and / or reception resources. The SL-PRS transmission and / or reception may be indicated in the request message. The WTRU may then feedback to the requesting WTRU that the WTRU has deprioritized SL-PRS transmission and / or reception. The feedback message may occur after the SL-PRS transmission and / or reception resources.

[0266] The WTRU may require more resources for SL-PRS transmission and / or reception. In an example, a WTRU (e.g., an anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., a target WTRU) to perform SL-PRS transmission / reception. In an example, the WTRU may deprioritize SL-PRS transmission / reception. In another example, the WTRU may not receive enough SL-PRS resources to perform SL-PRS transmission and / or reception. The WTRU may then provide feedback to the requesting WTRU (e.g., a target WTRU) to indicate that the WTRU may require more resources for SL-PRS transmission and / or reception.

[0267] The WTRU may determine whether to report and / or indicate SL-PRS resource usage. For example, a WTRU (eg, an anchor WTRU) may receive an indication and / or request (eg, from a target WTRU) to perform SL-PRS transmission and / or SL-PRS reception.

[0268] The WTRU may then determine whether to report and / or indicate SL-PRS resource usage based on one or any combination of the following: the decoding status of the sidelink positioning request message.

[0269] In an example, if the WTRU successfully decodes the request message, the WTRU may determine not to report and / or indicate SL-PRS resource usage. Otherwise, if the WTRU fails to decode the request message, the WTRU may indicate and / or report SL-PRS resource usage reporting to inform the WTRU that it failed to decode the request message. In an example, the WTRU may determine to indicate and / or report SL-PRS resource usage to indicate that the WTRU successfully decoded the request message. Otherwise, if the WTRU fails to decode the request message, the WTRU may not perform SL-PRS resource usage reporting.

[0270] In an example, the WTRU may perform SL-PRS resource usage reporting regardless of whether the WTRU successfully decodes the request message. For example, the WTRU may indicate whether the WTRU successfully or failed to decode the request message. In an example, the WTRU may determine not to indicate and / or report SL-PRS resource usage reporting regardless of whether the WTRU failed or successfully decoded the request message.

[0271] The WTRU may determine whether to perform SL-PRS transmission and / or reception. For example, if the WTRU determines to perform SL-PRS transmission and / or reception, the WTRU may determine not to report and / or indicate SL-PRS resource usage. Otherwise, if the WTRU determines not to perform SL-PRS transmission and / or reception, the WTRU may indicate and / or report that the WTRU may not perform SL-PRS transmission and / or reception.

[0272] In an example, if the WTRU determines to perform SL-PRS transmission / reception, the WTRU may determine to indicate and / or report SL-PRS resource usage to indicate that the WTRU may perform SL-PRS transmission / reception. Otherwise, if the WTRU determines not to perform SL-PRS transmission / reception, the WTRU may not perform SL-PRS resource usage reporting.

[0273] In an example, the WTRU may perform SL-PRS resource usage reporting regardless of whether the WTRU performs SL-PRS transmission and / or reception. For example, if the WTRU determines to perform SL-PRS transmission and / or reception, the WTRU may report SL-PRS resource usage to indicate to the requesting WTRU that the WTRU may perform SL-PRS transmission and / or reception. Otherwise, if the WTRU determines not to perform SL-PRS transmission and / or reception, the WTRU may report SL-PRS resource usage to indicate to the requesting WTRU that the WTRU may not perform SL-PRS transmission and / or reception. In an example, regardless of whether the WTRU performs SL-PRS transmission and / or reception, the WTRU may determine not to indicate and / or report SL-PRS resource usage reporting.

[0274] The WTRU may determine whether to report and / or indicate SL-PRS resource usage based on whether the WTRU has already performed SL-PRS transmission and / or reception. In an example, if the WTRU has already performed SL-PRS transmission and / or reception, the WTRU may determine not to report and / or indicate SL-PRS resource usage. Otherwise, if the WTRU has not yet performed SL-PRS transmission and / or reception, the WTRU may indicate and / or report that the WTRU has not yet performed SL-PRS transmission / reception.

[0275] In an example, if the WTRU has performed SL-PRS transmission and / or reception, the WTRU may determine to indicate and / or report SL-PRS resource usage. Otherwise, if the WTRU has not performed SL-PRS transmission and / or reception, the WTRU may not perform SL-PRS resource usage reporting.

[0276] In an example, the WTRU may perform SL-PRS resource usage reporting regardless of whether the WTRU has performed SL-PRS transmission and / or reception. For example, if the WTRU has performed SL-PRS transmission and / or reception, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the WTRU has performed SL-PRS transmission and / or reception. Otherwise, if the WTRU has not performed SL-PRS transmission and / or reception, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the SL-PRS transmission / reception has not been performed.

[0277] In an example, regardless of whether the WTRU has performed SL-PRS transmission / reception, the WTRU may determine not to indicate and / or report a SL-PRS resource usage report.

[0278] The WTRU may then determine whether to report and / or indicate SL-PRS resource usage regarding whether the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions.

[0279] In an example, if the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may determine not to indicate and / or report SL-PRS resource usage. Otherwise, if the WTRU has not yet deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may indicate and / or report that the WTRU has not yet deprioritized one or more SL-PRS transmissions and / or receptions.

[0280] In an example, if the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may determine to indicate and / or report SL-PRS resource usage. Otherwise, if the WTRU has not deprioritized one or more SL-PRS transmissions / receptions, the WTRU may not perform SL-PRS resource usage reporting.

[0281] In an example, the WTRU may perform SL-PRS resource usage reporting regardless of whether the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions. For example, if the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions. Otherwise, if the WTRU has not deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the WTRU has not deprioritized one or more SL-PRS transmissions and / or receptions.

[0282] In an example, regardless of whether the WTRU has deprioritized one or more SL-PRS transmissions / receptions, the WTRU may determine not to indicate and / or report a SL-PRS resource / usage report.

[0283] The WTRU may then determine whether to report and / or indicate SL-PRS resource usage based on whether the WTRU requires more resources for SL-PRS transmission and / or reception.

[0284] In an example, if the WTRU does not need more SL-PRS transmission and / or reception resources, the WTRU may determine not to report and / or indicate SL-PRS resource usage. Otherwise, if the WTRU needs more SL-PRS transmission / reception resources, the WTRU may indicate and / or report the need for more SL-PRS transmission and / or reception resources.

[0285] In an example, if the WTRU requires more SL-PRS transmission and / or reception resources, the WTRU may not perform SL-PRS resource usage reporting. Otherwise, if the WTRU does not require more SL-PRS transmission and / or reception resources, the WTRU may perform SL-PRS resource usage reporting to indicate to another WTRU that the WTRU does not require more SL-PRS transmission and / or reception resources.

[0286] The WTRU may determine resources for indicating and / or reporting SL-PRS resource usage. For example, the WTRU may determine resources for feedback usage of SL-PRS transmit / receive resources. For example, the feedback resources may be determined based on one or any combination of the following, including: an indication from a requesting WTRU. For example, the requesting WTRU (e.g., a target WTRU) may indicate and / or reserve resources for use by a receiving WTRU for feedback SL-PRS transmit and / or receive resource usage. The feedback resources may be indicated in the transmission of indicating and / or reserving SL-PRS transmit and / or receive resources.

[0287] The feedback resources may be determined based on resources indicating and / or reserving SL-PRS transmission / reception resources.

[0288] In an example, the WTRU may be (pre)configured (e.g., in a resource pool) to indicate and / or reserve a mapping between resources for SL-PRS transmission and / or reception and associated feedback messages. The WTRU may then determine to feedback the request message in the associated feedback resources. This method may be used in a scenario where the WTRU uses the PSFCH to feedback the SL-PRS transmission and / or reception resource usage.

[0289] In an example, a WTRU (e.g., an anchor WTRU) may trigger resource allocation and / or request sidelink resources (e.g., requesting a gNB and / or LMF) to feedback the request. If the WTRU requests sidelink resources from the network, the WTRU may implicitly indicate a latency requirement (e.g., PDB) for the feedback message to help the network properly schedule the feedback resources. For example, the WTRU may implicitly indicate a priority for the feedback. Additionally or alternatively, if the WTRU performs resource allocation, the WTRU may determine a resource allocation window for the feedback message based on the latency requirement of the feedback message.

[0290] The latency requirement for feedback may be determined based on one or any combination of the following: Whether the WTRU is (pre)configured. For example, the WTRU may be (pre)configured with a fixed latency requirement for the time gap between the resource reserved and / or indicating SL-PRS transmission / reception and the feedback resource.

[0291] The latency of the feedback may be indicated from another WTRU. For example, a WTRU (e.g., an anchor WTRU) may receive latency requirements for the feedback message from another WTRU (e.g., a target WTRU). The target WTRU may communicate latency requirements for the feedback message using PC5-RRC.

[0292] The latency of the feedback may be indicated by a time gap between the resources indicating and / or reserving the SL-PRS resources and / or the SL-PRS transmission and / or reception resources. For example, the WTRU may determine the maximum latency of the feedback message based on the time gap between the resources indicating and / or reserving the SL-PRS resources and the actual SL-PRS resources. For example, taking into account WTRU processing, the WTRU may send feedback in the gap between two resources (e.g., the WTRU may not be allowed to send feedback in N time slots before the SL-PRS resource, where N may be based on the WTRU processing capability). Sending feedback may allow the requesting WTRU to be aware of potential SL-PRS transmission and / or reception WTRUs.

[0293] The feedback resources may be determined based on the SL-PRS transmit / receive resources. For example, the WTRU may be (pre-)configured (e.g., in a resource pool) with an implicit mapping between SL-PRS transmit and / or receive resources and feedback resources to indicate and / or report SL-PRS resource usage. The WTRU may then send feedback based on the implicit mapping rules between the SL-PRS transmit and / or receive resources and the SL-PRS and / or feedback resources.

[0294] In an example, the WTRU may determine the feedback resources based on the SL-PRS transmission and / or reception resources and the latency requirement of the feedback. The WTRU may then provide feedback in the resources to meet the latency requirement.

[0295] The latency requirement for feedback may be determined based on one or any combination of the following, including whether the WTRU is (pre)configured. For example, the WTRU may be (pre)configured (e.g., per side link location service) with a fixed latency requirement for the time gap between SL-PRS resources and / or feedback resources.

[0296] The latency requirement for the feedback may be indicated from another WTRU. For example, a WTRU (e.g., an anchor WTRU) may receive a latency requirement for feedback indicating the use of SL-PRS resources from another WTRU (e.g., a target WTRU). For example, the target WTRU may use PC5-RRC to communicate the latency requirement for the feedback message. The latency requirement may then be determined as a time gap between SL-PRS resources and / or feedback resources.

[0297] The latency requirement for feedback may be indicated by the time gap between the SL-PRS resource and the measurement report resource. For example, the WTRU may determine the maximum latency of the feedback message based on the time gap between the SL-PRS resource and the SL-PRS measurement report resource. For example, the WTRU may send feedback in the gap between the two resources to take into account WTRU processing (e.g., the WTRU may not be allowed to send feedback in N time slots before the SL-PRS measurement report resource, where N may be based on the WTRU processing capability).

[0298] The feedback resources may be determined by the SL-PRS measurement report resources. For example, the WTRU may be (pre-)configured (e.g., in a resource pool) with an implicit mapping between SL-PRS transmit and / or receive resources and feedback resources to indicate and / or report SL-PRS resource usage. The WTRU may then send feedback to indicate and / or report SL-PRS resource usage based on the SL-PRS transmit and / or receive resources and / or the implicit mapping rules between SL-PRS and feedback resources.

[0299] The feedback resources may be determined by the channels and / or messages used to feedback the SL-PRS transmission / reception resource usage. The WTRU may be (pre)configured with two or more types of channels and / or messages to feedback the SL-PRS transmission and / or reception resource usage. The WTRU may then determine the resources used to feedback the SL-PRS resource usage based on the type of channel / message used to feedback the SL-PRS resource usage.

[0300] In an example, the WTRU may use a (pre)configured implicit mapping-based method to feedback SL-PRS resource usage of a first type of feedback channel (e.g., a PSFCH feedback channel). For example, the WTRU may be (pre)configured with a mapping between resources indicating SL-PRS resources and PSFCH resources or a mapping between SL-PRS resources and PSFCH feedback to report and / or indicate SL-PRS resource usage. The WTRU may then determine the resources for feedback SL-PRS resource usage based on the resources indicating SL-PRS resources or SL-PRS resources and the (pre)configured mapping rules.

[0301] In an example, the WTRU may use a window-based approach to feedback SL-PRS resource usage for a second type of feedback channel (e.g., feedback using one or any combination of SCI, MAC CE, PC5-RRC, and / or LPP). For example, the WTRU may first determine a latency requirement for feedback transmission. The WTRU may then request sidelink resources and / or perform resource allocation for feedback transmission within a time window. The time window may be within the latency requirement for feedback for indicating and / or reporting SL-PRS resource usage. The WTRU may then perform feedback transmission in the scheduled and / or selected feedback resources.

[0302] Fig.11 An example illustration of providing feedback on SL-PRS resource usage prior to SL-PRS resource usage is depicted. In the example, Fig.11 As shown, the target WTRU may perform a sidelink transmission 1102 in a sidelink communication resource pool 1104 to indicate and / or reserve SL-PRS resources 1106 in a SL-PRS resource pool 1108. The anchor WTRU may have two options to feedback SL-PRS resource usage. In option 1 at 1110, the WTRU may use an implicit mapping between the sidelink transmission and feedback resources. In option 2 at 1112, the WTRU may send feedback in one of the resources in the window between the sidelink communication and the SL-PRS resources indicating and / or reserving the SL-PRS resources.

[0303] Fig.12 An example illustration of feedback of SL-PRS resource usage after SL-PRS resource usage is depicted. Fig.12 In the depicted example, the target WTRU may perform a sidelink transmission 1202. The anchor WTRU may have two options to feedback SL-PRS resource usage. In option 1 at 1204, the WTRU may use an implicit mapping between the sidelink transmission and feedback resources. In option 2 at 1206, the WTRU may send feedback in one of the resources in the window after the SL-PRS resource 1208.

[0304] The WTRU may determine the information to include in the SL-PRS measurement report. For example, the WTRU may include one or any combination of the following information in the SL-PRS measurement report:

[0305] Information related to group sidelink positioning (eg, anchor WTRU ID, target WTRU ID, group ID and / or sidelink positioning service ID, etc.).

[0306] Information related to SL-PRS resources may be used to perform measurements (e.g., SL-PRS transmission resources and / or SL-PRS reception resources). The WTRU may indicate a resource index that the WTRU uses to perform measurements and / or measurement reports. The WTRU may indicate the number of resources that the WTRU uses to perform SL-PRS measurements. The WTRU may indicate a SL-PRS window that the WTRU uses to perform SL-PRS measurements.

[0307] SL-PRS positioning measurement parameters, which may be determined based on the sidelink positioning method. The WTRU may report RSTD, ToA, AoA, PoA, DPoA and / or SL-RSRP of the SL-PRS sent from the target WTRU for a method based on SL-PRS transmission. For example, the WTRU may report ToD, AoD, PoD, DPoD and / or SL-PRS for a sidelink positioning method based on SL-PRS reception. For example, the WTRU may report Tx-Rx difference, RSTD, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA and / or DPoD for a sidelink positioning method based on RTT.

[0308] The WTRU may include the accuracy of the SL-PRS measurement in its SL-PRS measurement report. For example, the WTRU may indicate the error bounds of the SL-PRS measurement (e.g., maximum error and / or error deviation, etc.).

[0309] The WTRU may include the necessity of additional SL-PRS resources in its SL-PRS measurement report. For example, the WTRU may implicitly and / or explicitly indicate whether the WTRU needs additional SL-PRS resources to perform SL-PRS measurements. The WTRU may determine whether to request more resources for SL-PRS measurements based on the accuracy and / or availability of the SL-PRS measurements. For example, if the accuracy of the current SL-PRS measurement is less than a threshold and / or the WTRU does not have available SL-PRS measurements, the WTRU may implicitly and / or explicitly request more SL-PRS measurement resources.

[0310] The WTRU may include sidelink positioning assistance information in its SL-PRS measurement report. For example, a WTRU (e.g., an anchor WTRU) may indicate assistance information to assist the reporting WTRU in sidelink positioning. The assistance information may include: the location of the WTRU (e.g., the region ID of the WTRU and / or the absolute position of the WTRU), the mobility attributes of the WTRU (e.g., heading and / or speed, etc.), and / or the antenna placement of the WTRU.

[0311] The WTRU may discard scheduled resources for SL-PRS resource usage reporting. For example, a WTRU (e.g., an anchor WTRU) may request the network to schedule sidelink resources to indicate and / or report SL-PRS resource usage reporting. If the scheduled resources do not meet the latency requirements of the report, the WTRU may determine not to perform the transmission of the SL-PRS resource usage report.

[0312] The WTRU may determine information for indicating and / or reporting sidelink resource usage in uplink transmissions. For example, the WTRU may report sidelink resource usage for sidelink positioning to the network. The WTRU may include one or any combination of the following information to the network: the WTRU has or has not received feedback indicating SL-PRS resource usage from one or more WTRUs and / or resources. For example, a WTRU (e.g., a target WTRU) may be scheduled for sidelink resources for a group of WTRUs (e.g., a group of anchor WTRUs). The WTRU may perform sidelink transmissions to indicate and / or reserve resources for sidelink positioning. The WTRU may expect to receive feedback from all WTRUs in the group. The WTRU may then decode feedback indicating SL-PRS resource usage from the WTRUs in the group. The WTRU may then report the set of WTRUs to the network.

[0313] The feedback that the WTRU may report to the network may have one or any combination of the following information: a set of WTRUs with ACK feedback, a set of WTRUs with NACK feedback, a set of WTRUs with DTX, a set of WTRUs that can perform SL-PRS transmission and / or reception, a set of WTRUs that may not perform SL-PRS transmission and / or reception, a set of WTRUs that have performed SL-PRS transmission and / or reception, and a set of WTRUs that have deprioritized SL-PRS transmission and / or reception.

[0314] The WTRU may include in the information used to indicate and / or report the sidelink resource usage in the uplink whether the WTRU has received a SL-PRS from one or more WTRUs / resources. For example, a WTRU (e.g., a target WTRU) may be scheduled with a set of SL-PRS reception resources from one or more anchor WTRUs. The WTRU may then perform SL-PRS reception in the set of scheduled SL-PRS resources. The WTRU may then report the set of WTRUs that transmit SL-PRS and / or the set of SL-PRS resources that have SL-PRS measurements. The WTRU may report the set of WTRUs that do not transmit SL-PRS and / or the set of SL-PRS resources that do not have SL-PRS measurements.

[0315] The WTRU may include in the information used to indicate and / or report the sidelink resource usage in the uplink whether the WTRU has received SL-PRS measurement reports from and / or for one or more WTRUs / resources. The WTRU may indicate to the network the set of WTRUs that report SL-PRS measurement results. The WTRU may indicate to the network the set of WTRUs that do not report SL-PRS measurement results.

[0316] The WTRU may include in the information used to indicate and / or report the sidelink resource usage in the uplink whether the WTRU may perform SL-PRS transmission and / or reception in one or more SL-PRS resources. For example, the WTRU may be scheduled by the network for a set of SL-PRS transmission and / or reception resources. The WTRU may then report to the network a set of SL-PRS resources in which the WTRU may perform SL-PRS transmission and / or reception. The WTRU may report a set of SL-PRS resources in which the WTRU may not perform SL-PRS transmission and / or reception. In this case, the uplink resources may occur before the SL-PRS transmission and / or reception resources.

[0317] The WTRU may include in the information used to indicate and / or report the use of sidelink resources in the uplink whether the WTRU has performed SL-PRS transmission and / or reception in one or more SL-PRS resources. For example, the WTRU may be scheduled by the network for a set of SL-PRS transmission / reception resources. After performing SL-PRS transmission and / or reception in zero or more scheduled SL-PRS resources, the WTRU may then report to the network a set of SL-PRS resources in which the WTRU has performed SL-PRS transmission and / or reception. The WTRU may then report to the network a set of SL-PRS resources in which the WTRU has not yet performed SL-PRS transmission and / or reception. In this case, the uplink resources may occur after the SL-PRS transmission and / or reception resources.

[0318] The WTRU may include in the information used to indicate and / or report the use of sidelink resources in the uplink whether the WTRU may need additional sidelink resources for sidelink positioning. The WTRU may implicitly and / or explicitly indicate to the network that the WTRU may or may not need more sidelink resources for sidelink positioning. The WTRU may indicate to the network an ACK / NACK whether the WTRU needs more sidelink resources for sidelink positioning. These required sidelink resources may be associated with a sidelink positioning cycle. If the WTRU does not need more resources for sidelink positioning, the WTRU may report an ACK. Otherwise, if the WTRU needs more resources for sidelink positioning, the WTRU may report a NACK.

[0319] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on one or any combination of the following: The WTRU has received at least N ACK feedbacks from other WTRUs for sending and / or receiving SL-PRS. For example, the WTRU may report an ACK. If the WTRU receives at least N ACK feedbacks from other WTRUs for sending and / or receiving SL-PRS, the WTRU may use the ACK to indicate to the network that the WTRU does need more resources for sidelink positioning. Otherwise, if the WTRU receives less than N ACK feedbacks from other WTRUs for sending and / or receiving SL-PRS, the WTRU may report a NACK. The value of N may be fixed, (pre)configured based on the positioning accuracy requirement and / or the total number of WTRUs in the sidelink positioning group.

[0320] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on whether the WTRU has performed SL-PRS transmission / reception / received SL-PRS transmission / reception from at least N WTRUs / resources. For example, if the WTRU receives SL-PRS transmission and / or reception from at least N WTRUs and / or N resources, the WTRU may report an ACK to the network. Otherwise, if the WTRU receives SL-PRS transmission and / or reception from less than N WTRUs and / or resources, the WTRU may report a NACK. The value of N may be fixed, (pre)configured based on the positioning accuracy requirement, the total number of WTRUs in the sidelink positioning group, and / or the total number of scheduled SL-PRS transmission and / or reception resources.

[0321] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on whether the WTRU has received ACK feedbacks from at least N WTRUs indicating and / or reporting SL-PRS resource usage. For example, if the ACK receives at least N ACK feedbacks from other WTRUs indicating and / or reporting SL-PRS resource usage, the WTRU may report an ACK to the network. Otherwise, the WTRU may report a NACK. The value of N may be fixed, (pre)configured based on the positioning accuracy requirement and / or the total number of WTRUs in the sidelink positioning group.

[0322] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on whether the WTRU has received SL-PRS measurement reports (e.g., with valid / usable measurement results) from at least N WTRUs. For example, if the WTRU receives SL-PRS measurement reports (e.g., with valid / usable measurement results) from at least N WTRUs, the WTRU may report an ACK to the network. Otherwise, if the WTRU receives SL-PRS measurement reports from less than N WTRUs, the WTRU may report a NACK to the network. The value of N may be fixed, (pre-)configured based on the positioning accuracy requirement and / or the total number of WTRUs in the sidelink positioning group.

[0323] A WTRU (e.g., a target WTRU) may perform SL-PRS measurement reporting to a network. The WTRU may report the WTRU's SL-PRS measurements to the network and / or forward SL-PRS measurements of other WTRUs. The WTRU may report the sidelink positioning to the network using one or any combination of MAC CE, RRC, and / or NAS (e.g., LPP). In an example, the WTRU may send all SL-PRS measurement reports (e.g., including the WTRU's SL-PRS measurements) from one or more WTRUs in a sidelink positioning group to the network. In another method, the WTRU may filter SL-PRS measurement reports, resources, and / or WTRUs from multiple WTRUs (e.g., including the WTRU itself) to the network based on one or any combination of the following: a maximum and / or minimum number of WTRUs / reports to be forwarded to the network. For example, a WTRU (e.g., a target WTRU) may be (pre-)configured with a maximum and / or minimum number of reports and / or WTRU measurement reports in a message for reporting to the network. The WTRU may then select the number of reports to the network and / or WTRU measurement reports based on the (pre-)configured values.

[0324] The WTRU may filter SL-PRS measurement reports from multiple WTRUs, resources and / or WTRUs based on the availability of one or more parameters in the SL-PRS measurement report. For example, the WTRU may forward the measurement report and / or the measurement report of the WTRU if the measurement report includes one or any combination of the following parameters, including the location of the reporting WTRU (e.g., the anchor WTRU). For example, the WTRU may not report the SL-PRS measurement report of an anchor WTRU if the location information of the anchor WTRU is not available in the report.

[0325] For the RTT-based sidelink positioning method, the measurement report may include one or more SL-PRS measurement parameters from one or more WTRUs, such as RSTD, Tx-Rx, SL-RSRP, SL reference signal power per path (SL-RSRPP), ToD, AoD, ToA, ToD, PoA, PoD, DPoA and / or DPoD. For example, for the RTT method, if the Tx-Rx between the SL-PRS transmission and / or reception measured from the target WTRU is not available, the WTRU may not forward the SL-PRS measurement report (e.g., Tx-Rx) of an anchor WTRU.

[0326] The WTRU may filter SL-PRS measurement reports from multiple WTRUs, resources and / or WTRUs based on whether one or more parameters in each SL-PRS measurement report are within a range. For example, the WTRU may forward a SL-PRS measurement report of a WTRU if one or more measurement parameters are within a range. The parameters within the range may be (pre)configured. The measurement parameters may be one or more of: RSTD, Tx-Rx, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA and / or DPoD.

[0327] A WTRU may determine whether to request SL-PRS resources for another WTRU. In an example, each WTRU in a positioning group may request SL-PRS resources for itself. In an example, one WTRU may request SL-PRS resources for multiple WTRUs. A WTRU (e.g., a target WTRU) may determine whether to request and / or select SL-PRS resources for another WTRU based on one or any appropriate combination of the following, including: positioning method. For example, if the group uses the SL-TDOA positioning method, the target WTRU may request SL-PRS resources for the WTRUs in the group. Additionally and alternatively, if the group uses the RTT method, each WTRU may independently select its transmit resources. For example, when utilizing an angle-based positioning method, the WTRU may determine not to request SL-PRS resources for another WTRU.

[0328] The WTRU may determine whether to request and / or select SL-PRS resources for another WTRU based on the coverage status of each WTRU in the group. For example, if the other WTRU is out of coverage, the WTRU (e.g., the target WTRU) may request SL-PRS resources for the other WTRU.

[0329] The WTRU may determine whether to request and / or select SL-PRS resources for another WTRU based on the RRC state of each WTRU. For example, if the other WTRU is in RRC idle and / or RRC inactive state, the WTRU (e.g., the target WTRU) may request SL-PRS resources for another WTRU.

[0330] In an example, for the SL-TDOA positioning method, the WTRU may request SL-PRS for all WTRUs in the positioning group. In an example, the WTRU may request SL-PRS resources for out-of-coverage WTRUs. In an example, the WTRU may request SL-PRS resources for WTRUs in RRC-inactive and RRC-idle WTRUs.

[0331] The WTRU may determine values ​​of parameters for SL-PRS transmission and / or reception resources for a group. The WTRU may determine values ​​of one or any suitable combination of the following parameters for SL-PRS transmission and / or reception resources for a group: number of SL-PRS transmission and / or reception resources, minimum, maximum and / or exact time gap between two SL-PRS resources, earliest and / or latest SL-PRS resources, and / or SL-PRS measurement and processing window.

[0332] After determining one or more of the above parameters, the WTRU may indicate one or more of these parameters to the network (e.g., LMF and / or gNB), which may help the network schedule SL-PRS resources. One or any combination of these parameters sent and / or received by the SL-PRS may be a resource for the group.

[0333] One or any combination of the above parameters may be determined by one or any appropriate combination of the following, including positioning methods. In an example, for a DL-like SL-TDOA method, the WTRU may determine that the maximum time gap between the first resource and the last SL-PRS resource is less than a threshold. The network (e.g., LMF) may indicate the time gap and / or the threshold. In an example, for an RTT method, the WTRU may determine the maximum time gap between SL-PRS and / or SL-PRS Rx. The network (e.g., LMF) may indicate the maximum time gap.

[0334] The QoS of the positioning service may also determine the above parameters. For example, the WTRU may determine the number and / or latest SL-PRS resources based on the latency requirements of the positioning service.

[0335] The WTRU processing capabilities and / or WTRU type may also determine the above parameters. For example, the WTRU may transmit to the network the WTRU's capabilities for sending and / or receiving the first SL-PRS. The network may then schedule the first SL-PRS for the WTRU to send and / or receive accordingly.

[0336] In the RTT method, the WTRU may use one SL-PRS transmission to multiple anchor WTRUs. The WTRU (e.g., the target WTRU) may use unicast to perform the SL-PRS for the RTT method (e.g., the SL-PRS is targeted to only one WTRU). In another method, the WTRU may use multicast to perform the SL-PRS for the RTT method (e.g., the SL-PRS is targeted to a group of WTRUs). The WTRU may convey a group ID in a transmission (e.g., SCI) associated with the SL-PRS to indicate the group information. Each receiver WTRU in the group may then send the SL-PRS back to the transmitter.

[0337] The SL-PRS transmission may be implemented via unicast, multicast and / or broadcast. In one example, the WTRU may determine to send the SL-PRS via unicast based on the positioning method. For RTT-based positioning methods, SL-PRS transmission via unicast may be applicable. The target WTRU and / or anchor WTRU may send and / or receive SL-PRS to each other.

[0338] In an example, for a TDOA-based positioning method, SL-PRS transmission via multicast may be applicable. The Tx WTRU may transmit the SL-PRS to a group of WTRUs. The Tx WTRU may transmit a message to a group of WTRUs informing of a PRS configuration for multicast transmission (e.g., SL PRS resource ID, group ID, SL PRS ID, an index and / or method for generating a SL-PRS sequence, wherein the sequence consists of complex symbols and / or real symbols and these symbols are mapped to resource elements).

[0339] In an example, for a TDOA-based positioning target, more than one Rx WTRU, broadcast SL-PRS transmission may be applicable. The Tx WTRU may send the SL-PRS to a potentially unknown number of Rx WTRUs. The Rx WTRU may make measurements (e.g., RSTD) on the received SL-PRS, where the Rx WTRU may be configured to receive the SL-PRS and / or PRS from a reference WTRU and / or TRP. The Rx WTRU may measure the ToA of the SL-PRS and / or PRS received from the reference WTRU / TRP and the target WTRU / TRP, and determine the RSTD based on these ToAs. The Rx WTRU may receive a broadcast ID from the network and / or a peer WTRU based on the generated PRS sequence. The peer WTRU may be an anchor WTRU / Tx WTRU / positioning reference unit (PRU) and / or a WTRU with LMF capability.

[0340] In an example, a WTRU (e.g., a target WTRU) may participate in a positioning procedure for a sidelink positioning group for an RTT-based positioning method. The positioning group may include a target WTRU and / or one or more anchor WTRUs. A WTRU (e.g., a target WTRU) may use a multicast-based SL-PRS to send a SL-PRS to one or more anchor WTRUs. Specifically, the WTRU may send a SL-PRS that targets one or more anchor WTRUs. For example, the WTRU may use a group ID to indicate the destination of the WTRU's SL-PRS. All anchor WTRUs in the group may be the destination of the WTRU's SL-PRS transmission. For the transmission of the SL-PRS from each anchor WTRU to the target WTRU, each anchor WTRU may use a unicast-based transmission to send the associated SL-PRS to the target WTRU. Specifically, each anchor WTRU may use the target WTRU ID as the destination of the SL-PRS transmission of each anchor WTRU. In an example, each anchor WTRU may use a multicast-based transmission to send the associated SL-PRS. Specifically, each anchor UE may use the group ID to send the SL-PRS to the target WTRU.

[0341] In an example, a WTRU (e.g., an anchor WTRU) may participate in a positioning procedure of a sidelink positioning group for an RTT-based positioning method. The positioning group may include one or more anchor WTRUs and / or multiple target WTRUs. The WTRU (e.g., an anchor WTRU) may use a groupcast-based transmission to send a SL-PRS to multiple target WTRUs and potential other anchor WTRUs in the group. For example, the WTRU (e.g., an anchor WTRU) may use a group ID to indicate the destination of the WTRU's SL-PRS, which may be targeted to all target WTRUs and / or potential other anchor WTRUs in the group. For the transmission of the SL-PRS from each target WTRU to the anchor WTRU, each target WTRU may use a unicast-based transmission to send the SL-PRS to the anchor WTRU. Specifically, each target WTRU may use the anchor WTRU ID as the destination for the SL-PRS transmission of each target WTRU. In an example, each target WTRU may use a groupcast-based transmission to send an associated SL-PRS to the anchor WTRU. Specifically, each target WTRU may use the group ID to send the SL-PRS to the anchor WTRU.

[0342] For the RTT method, the WTRU may determine whether to send the SL-PRS using unicast or multicast. The WTRU may make this determination based on one or any combination of the following, including the QoS requirements (e.g., latency) of the positioning service. For example, for low latency positioning services, the WTRU (e.g., the target WTRU) may send the SL-PRS using multicast. Additionally or alternatively, for less stringent positioning services, the WTRU may send the SL-PRS to the group using a unicast type.

[0343] Positioning result / output (e.g., whether the result / output is relative positioning or absolute positioning). For example, for absolute positioning output, the WTRU may send the SL-PRS using a multicast message. For relative positioning output, the WTRU may send the SL-PRS using a unicast message.

[0344] The WTRU may determine whether to use unicast and / or multicast to send the SL-PRS for the RTT method based on the type of device. For example, when a positioning group is established, a road side unit (RSU) may use multicast to send the SL-PRS. Additionally or alternatively, when the WTRU is not participating in a positioning group and / or the SL-PRS is not intended for a group, the RSU may use broadcast to send the SL-PRS.

[0345] The WTRU may determine whether to send the SL-PRS using unicast and / or multicast for the RTT method based on network indications.The WTRU may determine whether to send the SL-PRS via unicast, multicast and / or broadcast based on indications and / or configurations from the network.

[0346] The WTRU may determine whether to use unicast and / or multicast to send the SL-PRS for the RTT method based on the number of resources used to send the SL-PRS. The WTRU may select the number of resources used to send the SL-PRS. The network (e.g., gNB or LMF) may schedule the number of resources used to send the SL-PRS. For example, if the number of resources used to send the SL-PRS is less than a (pre)configured threshold, the WTRU may use multicast-based transmission to send the SL-PRS. Otherwise, the WTRU may apply unicast-based SL-PRS transmission. The (pre)configured threshold may be a function of the WTRUs in the group.

[0347] The WTRU may determine which WTRU is to request and / or select sidelink resources for one or more members in the group. A WTRU (e.g., a target WTRU) may determine which WTRU (including itself) is to request and / or select sidelink resources for one or more WTRUs in the group based on one or any combination of the following, including whether the WTRU initiates a positioning session. In an example, if the WTRU triggers a sidelink positioning session and / or procedure to locate its own position, the target WTRU may request and / or select sidelink resources for the group. In an example, if the anchor WTRU triggers a sidelink positioning session and / or procedure to locate one or more target WTRUs, the anchor WTRU may request and / or select sidelink resources for the group. The anchor WTRU may receive a request from the LMF to trigger positioning of the target WTRU. In this scenario, the anchor WTRU may request and / or select sidelink resources for other WTRUs (e.g., one or more target WTRUs).

[0348] A WTRU (e.g., a target WTRU) may determine which WTRU (including itself) to request and / or select sidelink resources for one or more WTRUs in a group based on the coverage status of the WTRU. If a WTRU is in coverage, the WTRU may request sidelink resources for the group.

[0349] A WTRU (e.g., a target WTRU) may determine which WTRU (including itself) to request and / or select sidelink resources for one or more WTRUs in the group based on the WTRU type. An RSU may request and / or select sidelink resources for another WTRU (e.g., a target WTRU).

[0350] The WTRU may determine the SL-PRS resources for the RTT positioning method. For the RTT positioning method, one WTRU (e.g., anchor WTRU) may receive SL-PRS Tx from another WTRU (e.g., target WTRU). The WTRU may determine which resource to send back the SL-PRS based on a (pre)configured mapping between a first SL-PRS transmission resource and a second SL-PRS transmission resource. For example, the WTRU may be (pre)configured with a mapping between a first SL-PRS and a second SL-PRS in a resource pool. The WTRU may then determine the resources for the second SL-PRS based on the resources for the first SL-PRS.

[0351] The WTRU may also determine which resource to send back the SL-PRS based on an indication from another WTRU (eg, a target WTRU).

[0352] The WTRU may also determine which resource to send back the SL-PRS based on resources scheduled by the network based on a request from the WTRU. For example, the WTRU may request the network to schedule SL-PRS resources. The WTRU may implicitly and / or explicitly indicate the purpose of the requested resources (e.g., for sending a second SL-PRS in an RTT positioning method). The WTRU may then further indicate information about the requested SL-PRS resources, such as bandwidth, SL-PRS mode, latency and / or number of repetitions and / or retransmissions. Such parameters may be determined based on the SL-PRS configuration of the first SL-PRS transmission. For example, the WTRU may be (pre)configured with a maximum gap between two resources. The WTRU may then indicate the latency of the second SL-PRS resource based on the timing of the first SL-PRS resource.

[0353] A WTRU may request resources for sidelink positioning. For example, in one solution set, a WTRU (e.g., a target WTRU) may request sidelink positioning for itself and / or for a group for sidelink positioning. The WTRU may first establish a group communication for sidelink communication, which may include the WTRU itself (e.g., the target WTRU) and other WTRUs (e.g., the anchor WTRU). The WTRU may be (pre)configured and / or assigned one or more IDs and / or indexes (e.g., a group ID, an L2 ID, and / or an L2 destination index) to communicate between WTRUs in the group for sidelink positioning and / or to communicate with the network (e.g., via UCI, MAC CE, RRC, and / or LPP). The WTRU may request resources for sidelink positioning using one or any combination of AS messages (e.g., one or any combination of UCI, MAC CE, and / or RRC) and / or NAS messages (e.g., LPP). The WTRU may use information related to group sidelink positioning (e.g., group ID, L2 ID, and / or L2 destination index) to request resources for sidelink positioning. The WTRU may be (pre-)configured with one or more group IDs. Each group ID may be associated with a group in which the WTRU participates in sidelink positioning.

[0354] The WTRU may implicitly and / or explicitly include one or any combination of the following information to request resources for sidelink positioning: sidelink positioning method, the total number of resources for SL-PRS transmission and / or reception, the number of resources for SL-PRS transmission and / or reception per SL-PRS period, the total number of resources for SL-PRS measurement reporting, the number of SL-PRS transmission and / or reception periods, the duration of SL-PRS transmission and / or reception, the duration of SL-PRS measurement reporting, the periodicity of SL-PRS transmission and / or reception, the periodicity of SL-PRS measurement reporting, the number of WTRUs in the sidelink positioning group, the amount of data in the sidelink and / or uplink for SL-PRS measurement reporting, and the QoS of sidelink positioning (e.g., priority, latency and / or reliability).

[0355] The WTRU may transmit sidelink positioning group information to the network. This information may help the network with resource scheduling. This information may include a set of sidelink positioning members (including the WTRU itself), the coverage status of one or more WTRUs in the group, the positioning method, etc. and / or any combination thereof.

[0356] The WTRU may indicate to the network an ID and / or index associated with sidelink positioning. For example, the WTRU may indicate to the network an ID and / or index (e.g., a destination ID) associated with sidelink positioning. The WTRU may transmit a message (e.g., an RRC message and / or a sidelink WTRU information message, etc.) to the network to indicate that a particular ID is assigned to the WTRU for sidelink positioning. The WTRU may then use such an ID to communicate to the network using the ID for sidelink positioning. Specifically, the WTRU may then use the ID to transmit UCI, MAC CE, RRC, LPP, and / or NAS messages to the network. The WTRU may then determine whether any transmission from the network (e.g., DCI, MAC CE, RRC, LPP, and / or NAS) may be used for sidelink positioning based on the ID associated and / or embedded in the message.

[0357] The WTRU may transmit a UCI (e.g., an SR) to request resources for sidelink positioning. The WTRU (e.g., a target WTRU) may first trigger a UCI (e.g., an SR) to request resources for sidelink positioning. In an example, the WTRU may be (pre)configured with dedicated UCI resources (e.g., a dedicated SR) to request resources for sidelink positioning. In this case, the WTRU may trigger the sending of a UCI (e.g., an SR) to request resources for sidelink positioning, and the WTRU may not need to trigger a MAC CE (e.g., an SL-BSR). In another method, the WTRU may be (pre)configured with a UCI (e.g., an SR) to request resources for both sidelink positioning and / or other sidelink resources. In this case, the WTRU may trigger the sending of both a UCI (e.g., an SR) and / or a MAC CE (e.g., an SL-BSR).

[0358] The WTRU may transmit a MAC CE (e.g., a sidelink buffer status report (SL-BSR)) to request resources for sidelink positioning. The WTRU (e.g., a target WTRU) may trigger a MAC CE (e.g., a SL-BSR) to request resources for sidelink positioning. In an example, the WTRU may use a dedicated MAC CE to request resources for sidelink positioning. The WTRU may implicitly and / or explicitly indicate the number of resources for sidelink positioning. In an example, the WTRU may report the MAC CE for sidelink positioning as part of another MAC CE (e.g., SL-BSR). The WTRU may use a dedicated destination ID (e.g., a dedicated destination index) to report the required number of resources for sidelink positioning (e.g., SL-PRS transmission and / or reception, and / or SL-PRS measurement report). The WTRU may implicitly indicate to the network a dedicated destination as a destination for sidelink positioning. Specifically, the WTRU may indicate (e.g., via an RRC message) a dedicated assigned destination ID and / or index as a destination for sidelink positioning.

[0359] A WTRU may receive sidelink positioning resources for a group of WTRUs and forward them to other WTRUs. A WTRU may receive sidelink positioning resources for a group of WTRUs. A WTRU may forward sidelink positioning resources to other WTRUs. A WTRU (e.g., a target WTRU) may receive sidelink positioning resources scheduled for a group of WTRUs (e.g., one or more WTRUs in a group of sidelink positioning WTRUs).

[0360] The WTRU may receive one or any combination of the following sidelink positioning resources for a group of WTRUs, including a group ID associated with a scheduled SL-PRS. For example, for a dynamic grant, an indication may be provided to the WTRU in the DCI that the scheduled resources may be used for a particular group ID. For a configuration grant, an indication may be provided to the WTRU in the DCI and / or RRC of the group ID associated with the scheduled resources. Additional resources for sidelink positioning that the WTRU may receive for a group of WTRUs include sidelink resources for indicating and / or reserving other resources for sidelink positioning, SL-PRS transmission resources, SL-PRS reception resources, SL-PRS usage report resources in the sidelink direction, SL-PRS usage report resources in the uplink direction, SL-PRS measurement report resources in the sidelink, and SL-PRS measurement report resources in the uplink direction.

[0361] The WTRU may forward scheduled resources for sidelink positioning to a sidelink positioning group. The WTRU may use one or more IDs (e.g., target WTRU ID, group ID, sidelink positioning service ID, L2 destination index and / or anchor WTRU ID, etc.) to be included in the forwarded message to help other WTRUs (e.g., anchor WTRUs) decode the forwarded message. In an example, the WTRU may use one sidelink resource (e.g., a resource used to indicate and / or reserve other resources for sidelink positioning) to forward scheduled resources for sidelink positioning to other WTRUs in the group. The WTRU may use one or any combination of sidelink messages (e.g., SCI, MAC CE, PC5-RRC and / or NAS (e.g., LPP)) to include all scheduled messages related to sidelink positioning in the scheduled messages to be forwarded to the WTRUs in the group. In an example, the WTRU may process the message scheduling resources (e.g., DCI, DL MAC CE, RRC and / or LPP) for sidelink positioning. The WTRU may then perform transmission in the scheduled transmission resources. The WTRU may then forward scheduled resources for reception by the WTRU and / or transmission by other WTRUs to other WTRUs (e.g., using SCI, MAC CE, RRC and / or NAS (e.g., LPP) messages in side link resources used to indicate and / or reserve other resources for side link positioning).

[0362] The WTRU may perform transmission in one or any combination of the following resources: side link resources for indicating and / or reserving other resources for side link positioning, SL-PRS transmission resources, SL-PRS usage report resources in the side link direction, SL-PRS usage report resources in the uplink direction and / or SL-PRS measurement report resources in the side link.

[0363] In an example, the WTRU may process a scheduling message and determine scheduled resources for each WTRU. The WTRU may then forward the scheduled resources to each individual WTRU using a unicast message (e.g., unicast PC5-RRC). In an example, the WTRU may process a scheduling message (e.g., from the network) and / or determine scheduled resources for a group of WTRUs (e.g., a group of anchor WTRUs). The WTRU may then forward the scheduled resources for the group of WTRUs using a groupcast message (e.g., groupcast PC5-RRC).

[0364] The WTRU may forward one or any combination of the following resources for reception by the WTRU and / or transmission by other WTRUs, including: SL-PRS reception resources, SL-PRS usage report resources in the sidelink direction, and / or SL-PRS measurement report resources in the sidelink.

[0365] The WTRU may determine scheduled resources for a group ID. The WTRU may maintain multiple positioning groups. The WTRU may determine whether scheduled resources are for which group ID. An indication of the group ID may be provided to the WTRU in a resource scheduling message (e.g., DCI, MAC CE, and / or DCI). The WTRU may determine the group ID based on whether the WTRU requested SL-PRS for which positioning group. The WTRU may use the scheduled SL-PRS for the latest group requesting SL-PRS resources (e.g., the group ID indicated in the SL-BSR).

[0366] A WTRU may determine whether to forward scheduled SL-PRS resources to another WTRU. A WTRU (e.g., an anchor WTRU) may receive a scheduled SL-PRS that provides resources to other WTRUs (e.g., the anchor WTRU). The WTRU may first determine whether to forward the scheduled SL-PRS to other WTRUs based on the content of the scheduled SL-PRS resources. If the scheduled resources do not have SL-PRS Rx resources (e.g., resources for other WTRUs to perform SL-PRS transmissions and for WTRUs to perform SL-PRS receptions), the WTRU may not forward the scheduled resources to other WTRUs. This method may be applicable when the scheduling message indicates whether the resources are available for transmission by the WTRU or for transmission by other WTRUs.

[0367] The WTRU may determine resources for SL-PRS transmission for other WTRUs. The WTRU may receive scheduled SL-PRS resources from the network. The WTRU may not receive an indication of whether resources are available for transmission by which WTRU. Based on the set of SL-PRS scheduled by the network, the WTRU may then determine one or any combination of: resources for itself and / or resources used by other WTRUs. For example, based on the resources scheduled for the group, the WTRU may select one or more resources for itself. The WTRU may then select resources for other WTRUs.

[0368] The WTRU may also determine a positioning method. For example, based on the characteristics of the resources used for scheduling of SL-PRS (e.g., the number of SL-PRS resources, the distance between two SL-PRS resources, the number of clusters of resources, etc.), the WTRU may determine whether to perform SL-TDOA and / or RTT. Each cluster of resources may be defined as a set of contiguous resources and / or a set of resources that are close in the time domain.

[0369] The WTRU may determine the index and / or ID of each WTRU. The WTRU (e.g., the target WTRU) may determine the index and / or member ID of each WTRU in the sidelink positioning group. The WTRU may make these determinations based on the WTRU ID and / or the number of WTRUs in the group. The WTRU may then indicate the index and / or member ID to each WTRU in the group. The WTRU may communicate the index and / or member ID to each WTRU in the group using one or any combination of AS (e.g., SCI, MAC CE, group PC5-RRC) and / or NAS (e.g., LPP). Other WTRUs in the group (e.g., the anchor WTRU) may receive the index and / or member ID of each WTRU in the group and the number of WTRUs in the group.

[0370] The WTRU may receive a configuration for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may receive a configuration for sidelink positioning for a group of WTRUs from a network. In an example, the WTRU may determine a configuration for sidelink positioning for a group of WTRUs. In an example, the WTRU (e.g., a target WTRU) and / or the network may configure sidelink positioning for a group of WTRUs. The network and / or the WTRU (e.g., a target WTRU) may determine one or more parameters.

[0371] The configuration may include one or any combination of the following: a resource pool for sidelink communications to facilitate sidelink positioning, a resource pool for SL-PRS transmission / reception, and / or attributes of an SL-PRS measurement report. For example, the WTRU may be (pre-)configured with the number of subchannels for each SL-PRS measurement report.

[0372] The configuration may include multiplexing and / or indexing order of SL-PRS measurement report resources. For example, the WTRU may be (pre)configured with an indexing order for a group of SL-PRS measurement report resources. The WTRU may be (pre)configured with an indexing order from the frequency domain to the time domain. Additionally or alternatively, the WTRU may be (pre)configured with an indexing order from the time domain to the frequency domain.

[0373] The configuration may include attributes of an SL-PRS resource. For example, the WTRU may be (pre-)configured with one or any combination of the following parameters of an SL-PRS resource: bandwidth of an SL-PRS resource, comb value and offset of an SL-PRS resource, cyclic shift of an SL-PRS resource, number of transmitted symbols of an SL-PRS resource, SL-PRS resource repetition pattern and / or cover code associated with the resource.

[0374] The configuration may include the number of SL-PRS resources in the frequency domain, code domain and / or coverage code domain.

[0375] The configuration may include multiplexing and / or indexing order of SL-PRS resources. For example, the WTRU may be (pre)configured with an indexing order for a group of SL-PRS resources. The WTRU may be (pre)configured with an indexing order from the time domain to the frequency domain and / or then to the code domain and / or to the cover code domain accordingly. Additionally or alternatively, the WTRU may be (pre)configured with an indexing order from the frequency domain to the time domain, to the cover code domain and / or then to the code domain accordingly.

[0376] A WTRU may send a configuration for sidelink positioning to other WTRUs. Upon receiving the configuration for sidelink positioning from the network and / or its own determination of one or more parameters of the configuration for sidelink positioning, a WTRU (e.g., a target WTRU) may send the configuration to other WTRUs (e.g., an anchor WTRU in a group). The WTRU may communicate the configuration for sidelink positioning of a group of WTRUs using one or any combination of AS messages (e.g., SCI, MAC CE, group PC5-RRC) and / or NAS messages (e.g., LPP). The anchor WTRU may then receive the configuration from the target WTRU and / or apply the configuration to the sidelink positioning of the group of WTRUs. The anchor WTRU may be one of the members of the group.

[0377] The WTRU may determine the SL-PRS reception resources for each WTRU in the group. A WTRU (e.g., a target WTRU) may be scheduled with the SL-PRS reception resources. The reception resources may be used by other WTRUs (e.g., a set of anchor WTRUs) to perform SL-PRS transmissions. The WTRU may then determine the SL-PRS resources for each WTRU (e.g., each anchor WTRU).

[0378] The SL-PRS resources may be based on one or any combination of: a set of SL-PRS resources scheduled for a group, an index and / or member WTRU ID in the group, an ID of the WTRU forwarding and / or indicating the SL-PRS resources for the group, the number of WTRUs in the group, the number of OCCs assigned / (pre-)configured for each WTRU, a time slot index of the scheduled SL-PRS resources, and / or a (pre-)configured multiplexing rule between multiple SL-PRS resources.

[0379] Fig.13 An example illustration of SL-PRS scheduling for a group of user WTRUs is depicted. Fig.13In the example shown, the target WTRU may be scheduled for SL-PRS reception resources for a group of four WTRUs (e.g., from WTRU1 to WTRU4). Each SL-PRS resource may have a comb-4 pattern and the WTRU may multiplex two SL-PRSs in the frequency domain. Each SL-PRS resource may occupy half a timeslot. The WTRU may be (pre)configured as an index from the frequency domain to the time domain. The target WTRU may then determine that the SL-PRS resources of WTRU1 1302 and / or WTRU2 1304 may be located in the first half of the timeslot multiplexing with different offsets in the frequency domain. The WTRU may then determine that the SL-PRS resources of WTRU3 1306 and / or WTRU4 1308 may be located in the second half of the timeslot multiplexing with different offsets in the frequency domain. The SL-PRS resources of WTRU1 1302 and / or WTRU2 1304 are multiplexed with the SL-PRS resources of WTRU3 1306 and / or WTRU4 1308 in the time domain.

[0380] Fig.14 An example illustration of an anchor WTRU using an orthogonal cover code (OCC) for one SL-PRS resource is depicted. Fig.14 As depicted, a target WTRU may be scheduled with one SL-PRS resource for a group of anchor WTRUs 1402a-1402d. Each anchor WTRU 1402a-1402d may apply a different OCC 1404a-1404d to help the target WTRU distinguish between the different anchor WTRUs 1402a-1402d. The OCC for each anchor WTRU may be (pre)configured and / or determined by the target WTRU. The target WTRU may indicate to each anchor WTRU which OCC code to use. This method may help the target WTRU determine the transmissions from each anchor WTRU.

[0381] The WTRU may determine its SL-PRS transmission resources. A WTRU (eg, an anchor WTRU) may receive scheduled SL-PRS transmission resources for a group of WTRUs including the WTRU itself. The WTRU may then determine its SL-PRS resources to perform SL-PRS transmission.

[0382] Similar to the target WTRU, the anchor WTRU may determine its SL-PRS based on one or any combination of: a set of SL-PRS resources scheduled for the group, an index and / or member WTRU ID in the group, the ID of the WTRU forwarding / indicating the SL-PRS resources for the group, the number of WTRUs in the group, the OCC assigned / (pre-)configured for each WTRU, the time slot index of the scheduled SL-PRS resources, and / or the (pre-)configured multiplexing rules between multiple SL-PRS resources.

[0383] The WTRU may determine SL-PRS measurement reporting resources from each WTRU in the group. A WTRU (e.g., a target WTRU) may be scheduled with SL-PRS measurement reporting resources for a group of WTRUs (e.g., an anchor WTRU). The WTRU may then forward the resources for the group of WTRUs. The WTRU may determine SL-PRS measurement reporting resources for each WTRU (e.g., each anchor WTRU) based on one or any combination of: a set of SL-PRS measurement reporting resources scheduled for the group, an index and / or member WTRU IDs in the group, the number of WTRUs in the group, a (pre)configured indexing rule between multiple SL-PRS measurement reporting resources, an ID of the WTRU forwarding and / or indicating the SL-PRS resources for the group (e.g., a target WTRU ID), and / or a slot index of the scheduled SL-PRS measurement reporting resources.

[0384] Fig.15 An example illustration of SL-PRS measurement reporting scheduling for a group of WTRUs is depicted. Fig.15 As depicted, a target WTRU may be scheduled with SL-PRS measurement reporting resources. The SL-PRS measurement reporting resources may include four resources 1502a-1502d for a group of four anchor WTRUs. The WTRUs may be (pre)configured to index the resources in frequency to time order. The WTRU (e.g., target WTRU) may then determine the measurement reporting resources for each WTRU according to the (pre)configured rules and the WTRU index.

[0385] A WTRU may determine SL-PRS measurement reporting resources for itself. A WTRU (e.g., an anchor WTRU) may receive SL-PRS measurement reporting resources for a group of WTRUs (e.g., the anchor WTRU) (e.g., from a target WTRU). Similar to the target WTRU, the anchor WTRU may then determine its SL-PRS measurement reporting resources based on one or any combination of: a set of SL-PRS measurement reporting resources scheduled for the group, an index and / or member WTRU IDs in the group, the number of WTRUs in the group, a (pre-)configured indexing rule between multiple SL-PRS measurement reporting resources, an ID of the WTRU (e.g., the target WTRU) that forwards and / or indicates the SL-PRS resources for the group, and / or a timeslot index of the scheduled SL-PRS measurement reporting resources.

[0386] The WTRU may determine resources for reporting and / or indicating SL-PRS resource usage from the scheduled SL-PRS resources for the group. A WTRU (e.g., an anchor WTRU) may determine to feedback SL-PRS resource usage from a set of scheduled SL-PRS resources for the group. The WTRU may determine resources for feedback SL-PRS resource usage based on one or any combination of: an indication from a requesting WTRU, resources indicating and / or reserving SL-PRS transmit and / or receive resources, an index and / or member WTRU ID in the group, the number of WTRUs in the group, an ID of a WTRU forwarding and / or indicating SL-PRS resources for the group (e.g., a target WTRU), a timeslot index of a scheduled SL-PRS measurement report resource, a timeslot index of a scheduled SL-PRS resource, the earliest and / or latest scheduled SL-PRS resource, and / or a channel and / or message for feedback SL-PRS resource usage.

[0387] The WTRU may report synchronization offset information for the positioning group to the network. A WTRU (e.g., a target WTRU) may receive synchronization offset information from another WTRU (e.g., an anchor WTRU). Additionally or alternatively, the WTRU may derive the synchronization offset information itself. The synchronization offset information for the positioning group may include the synchronization offset between itself and another WTRU (e.g., an anchor WTRU), the synchronization offset between two other WTRUs in the group (e.g., two anchor WTRUs), or any suitable combination thereof.

[0388] The WTRU may report synchronization offset information of the positioning group to the network (e.g., LMF). The WTRU may communicate the synchronization offset to the network (e.g., LMF) using one or any combination of MAC (e.g., MAC CE), RRC and / or NAS (e.g., LPP) messages. The WTRU may trigger the transmission of such reports based on one or any appropriate combination of the following, including periodic reporting. For example, the WTRU may periodically report synchronization offset information to the network (e.g., LMF).

[0389] The WTRU may trigger the transmission of such a report based on the WTRU may report a SL-PRS measurement report to the network (eg, LMF). For example, the WTRU may report synchronization offset information of the group in a measurement report message.

[0390] The WTRU may trigger the transmission of such a report based on a synchronization offset greater than a (pre-)configured threshold. For example, if the synchronization offset between two WTRUs is greater than a (pre-)configured threshold, the WTRU may report the synchronization offset between two WTRUs (e.g., between two anchor WTRUs and / or between an anchor WTRU and a target WTRU).

[0391] The WTRU may indicate a synchronization offset based on the resource allocation pattern of the two WTRUs. A WTRU (e.g., a target WTRU) may determine a synchronization offset between itself and another WTRU (e.g., a target WTRU). Additionally or alternatively, the WTRU may determine a synchronization offset between two other WTRUs (e.g., two anchor WTRUs). The WTRU may receive synchronization offset information from an anchor WTRU. If the two WTRUs are using two different resource allocation patterns, the WTRU may determine the synchronization offset information between the two WTRUs. For example, if the WTRU is using network scheduled resource allocation for SL-PRS and the anchor WTRU autonomously selects resources, the WTRU may determine the synchronization offset information between itself and an anchor WTRU.

[0392] A WTRU may be configured with periodic and / or semi-persistent resources for sidelink positioning. A WTRU (e.g., a target WTRU) may be scheduled with one or more semi-static (e.g., periodic or semi-persistent) resources for sidelink positioning. For example, a WTRU may be scheduled with one or more semi-persistent resources (e.g., uplink resources, sidelink resources) and / or one or more periodic resources (e.g., uplink resources, sidelink resources) for sidelink positioning. Periodic and / or semi-persistent resources may be configured via NAS messages (e.g., LPP) and / or via AS messages (e.g., RRC). Semi-persistent resources may require the WTRU to receive a MAC CE for resource activation and / or deactivation.

[0393] The WTRU may be (pre)configured with one or more semi-static resources, where each semi-static resource may be used for one or more of the following: for indicating, reserving and / or requesting other resources for sidelink positioning and / or sidelink resources of the WTRU (e.g., resources used to send a sidelink positioning request message), SL-PRS transmission resources, SL-PRS reception resources (which may be used by an anchor WTRU or a group of anchor WTRUs for SL-PRS transmission), SL-PRS usage report resources in the sidelink direction (which may be used to report SL-PRS resource usage), SL-PRS usage report resources in the uplink direction, SL-PRS measurement report resources in the sidelink and / or SL-PRS measurement report resources in the uplink direction.

[0394] Fig.16 An example illustration of semi-static resources for sidelink positioning is depicted. Fig.16As shown, the WTRU may be configured with semi-static resources for sidelink positioning. The WTRU may be configured with semi-static SL-PRS transmission, SL-PRS reception, SL-PRS usage reporting and / or SL-PRS measurement reporting. The WTRU may be configured with semi-static SL-PRS transmission 1602 and reception 1604 resources with the same period. The WTRU may be configured with semi-static SL-PRS resource usage reporting resources, which may occur periodically after every N (e.g., N=2) SL-PRS transmission / reception periods. After every N (e.g., N=4) SL-PRS transmission and / or reception periods, the WTRU may be configured with SL-PRS measurement reporting resources.

[0395] The behavior of the WTRU may be based on the status of feedback on SL-PRS resource usage from other WTRUs. A WTRU (e.g., a target WTRU) may be scheduled with SL-PRS resources. The WTRU may forward the scheduled SL-PRS resources for a group of WTRUs. The WTRU may receive SL-PRS resource usage reports from zero or more WTRUs in the group.

[0396] The WTRU may trigger one or any combination of the following procedures, including performing resource allocation and / or requesting additional dynamic resources for sidelink positioning (e.g., SL-PRS resources, sidelink positioning request message, etc.). For example, if the WTRU deprioritizes one or more SL-PRS transmissions and / or receptions, the WTRU may request additional dynamic SL-PRS transmission and / or reception resources in one SL-PRS transmission / reception period. For example, if the WTRU has not received at least N ACK feedbacks (e.g., from the set of anchor WTRUs in the sidelink positioning group), the WTRU may request additional resources for sending the sidelink positioning request message.

[0397] The WTRU may trigger a procedure for reporting SL-PRS resource usage to the network. The WTRU may trigger a procedure for initializing SL-PRS transmission and / or reception. For example, if the WTRU has received at least N ACK feedbacks (e.g., from the set of anchor WTRUs in the sidelink positioning group), the WTRU may initialize SL-PRS transmission and / or reception.

[0398] The WTRU may trigger a procedure for not performing SL-PRS transmission and / or reception in scheduled resources. For example, in an RTT-based sidelink positioning method, in a SL-PRS transmission and / or reception cycle, if the WTRU deprioritizes SL-PRS reception in the cycle, the WTRU may determine to deprioritize all SL-PRS transmissions.

[0399] The WTRU may trigger a procedure for requesting the network to release one or more semi-static resources used for sidelink positioning. For example, if one or more WTRUs leave the sidelink positioning group, the WTRU may request the network to release one or more semi-static SL-PRS reception resources. For example, if the WTRU terminates the sidelink positioning session, the WTRU may request the network to release all semi-static resources for itself.

[0400] The WTRU may trigger a procedure for requesting the network to activate one or more semi-static resources for sidelink positioning.

[0401] The WTRU may trigger a procedure for requesting the network to change the configuration of one or more semi-static resources. For example, if the WTRU receives feedback from at least N WTRUs requesting additional resources for SL-PRS measurements, the WTRU may request the network to reduce the periodicity of one semi-static resource or increase the number of SL-PRS transmission resources in the SL-PRS transmission period.

[0402] The triggering event may be based on one or any combination of the events described herein and / or one or any combination of the following, including whether the WTRU has received ACK feedback for the request message from at least N WTRUs. For example, for the ACK / NACK method for positioning request messages, if the WTRU receives N ACKs (e.g., N is equal to the number of anchor WTRUs in the group) from other WTRUs (e.g., anchor WTRUs), the WTRU may initialize SL-PRS transmission and / or reception.

[0403] The triggering event may be based on whether the WTRU has received less than N ACK feedbacks for the request message. For example, if the WTRU receives less than N ACK feedbacks, the WTRU may be triggered to request more sidelink resources for the request message. The method may be triggered to help the WTRU find enough anchor WTRUs to support sidelink positioning.

[0404] The triggering event may be based on whether the WTRU has received at least N WTRUs' NACK feedback for the request message. For example, if the WTRU receives at least N NACK feedback for the request message (eg, N=1), the WTRU may be triggered to request more sidelink resources for the request message.

[0405] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU may perform SL-PRS transmission and / or reception. For example, if the WTRU receives feedback from at least N WTRUs indicating that the WTRU may perform SL-PRS transmission / reception, the WTRU may initialize SL-PRS transmission and / or reception.

[0406] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU may not perform SL-PRS transmission and / or reception. For example, if the WTRU receives feedback from at least N WTRUs indicating that the WTRU may not perform SL-PRS transmission and / or reception, the WTRU may trigger a request for more sidelink resources for the request message.

[0407] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU has performed SL-PRS transmission and / or reception. For example, if at least N WTRUs indicate that the WTRU has performed SL-PRS transmission and / or reception, the WTRU may trigger a SL-PRS resource usage report to the network.

[0408] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU has not performed SL-PRS transmission / reception. For example, if at least N WTRUs indicate that the WTRU has not performed SL-PRS transmission and / or reception, the WTRU may trigger a request for more SL-PRS resources. For example, if at least N WTRUs indicate that the WTRU has not performed SL-PRS transmission and / or reception, the WTRU may trigger a SL-PRS resource usage report to the network.

[0409] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU has deprioritized SL-PRS transmission and / or reception. For example, if at least N WTRUs indicate that the WTRU has deprioritized SL-PRS transmission and / or reception, the WTRU may trigger a request for more SL-PRS resources. For example, if at least N WTRUs indicate that the WTRU has deprioritized SL-PRS transmission and / or reception, the WTRU may trigger a SL-PRS resource usage report to the network.

[0410] The triggering event may be based on whether the WTRU has received feedback from at least N WTRUs indicating that the WTRU needs more resources for SL-PRS transmission / reception. For example, if the WTRU receives feedback from at least N WTRUs indicating that the WTRU needs more resources for SL-PRS transmission and / or reception, the WTRU may trigger a request for more sidelink resources for the request message.

[0411] The triggering event may be based on whether the WTRU has changed the set of WTRUs in the sidelink positioning group. For example, if the set of WTRUs in the sidelink positioning group has changed, the WTRU may request the network to increase and / or decrease the number of SL-PRS reception resources and / or the number of SL-PRS measurement reporting resources in each period.

[0412] The triggering event may be based on whether the WTRU completes the sidelink positioning session. For example, if the WTRU determines to terminate the sidelink positioning session, the WTRU may request the network to deactivate and / or release all semi-static resources associated with the WTRU.

[0413] The value of N in the triggering event may be determined based on one or any combination of the following: whether the resources are fixed and / or (pre)configured. For example, if the WTRU does not receive ACK feedback from one WTRU (e.g., N=1), the WTRU may trigger a request for more resources until the WTRU receives ACK feedback from all WTRUs. For example, in some scenarios, if the WTRU receives NACK feedback from one WTRU (e.g., N=1), the WTRU may trigger a request for more resources until the WTRU receives ACK feedback from that WTRU.

[0414] The value of N in the trigger event may be determined based on the number of WTRUs and / or the number of anchor WTRUs in the group. For example, in some scenarios, if the WTRU does not receive ACK feedback from one WTRU (e.g., N=1), the WTRU may request more resources for transmission and / or reception until the WTRU receives ACK feedback from all WTRUs.

[0415] The value of N in the triggering event may be determined based on the QoS (eg, latency, accuracy) requirements of the positioning service.

[0416] For relaxed sidelink positioning accuracy requirements, the WTRU may need support from a small number of anchor WTRUs. However, for high sidelink positioning accuracy requirements, the WTRU may need support from a large number of anchor WTRUs.

[0417] The WTRU may request periodic and / or aperiodic SL-PRS resources. The WTRU may request and / or select periodic and / or aperiodic SL-PRS resources (e.g., the WTRU may request SL-PRS from the network (e.g., gNB and / or LMF) and / or another WTRU (e.g., RSU, peer WTRU, target WTRU and / or anchor WTRU)). The WTRU may determine one and / or any suitable combination of parameters (e.g., offset, periodicity and / or delay) in the SL-PRS configuration for periodic SL-PRS based on one and / or any combination of the following:

[0418] Selected, requested and / or available SL-PRS configuration from a peer WTRU. For example, for an RTT positioning method, one WTRU (e.g., a target WTRU) may first request and / or select periodic SL-PRS resources. The WTRU may then notify other WTRUs (e.g., an anchor WTRU) of the requested, selected and / or scheduled periodic SL-PRS resources. The other WTRUs (e.g., an anchor WTRU) may then determine parameters in its SL-PRS configuration (e.g., offset, delay, periodicity, bandwidth of the SL-PRS and / or SL-PRS pattern) based on the requested, selected and / or scheduled periodic SL-PRS resources from the peer WTRU.

[0419] In an example, if the WTRU determines to request and / or select periodic SL-PRS resources, the WTRU may select and / or request a SL-PRS configuration that is similar to the SL-PRS configuration of the target WTRU. However, the offset may have a gap with the requested, selected and / or scheduled SL-PRS from the peer WTRU. The gap may be (pre)configured and / or determined by the WTRU based on the QoS of the positioning service (e.g., latency and / or accuracy).

[0420] In an example, if the WTRU determines to request and / or select aperiodic SL-PRS resources, the WTRU may select a SL-PRS configuration that is similar to the SL-PRS configuration of the target WTRU, except for latency and / or periodicity. Specifically, the WTRU may not request and / or select periodic resources, and the WTRU may request and / or select an aperiodic SL-PRS with a smaller latency than the periodicity of the periodic SL-PRS. The WTRU may select and / or request an aperiodic SL-PRS based on the timing of the periodic SL-PRS of other WTRUs and / or the QoS requirements of the positioning service.

[0421] The WTRU may trigger a change in the SL-PRS configuration (e.g., SL-PRS offset and / or periodicity). The WTRU (e.g., target WTRU and / or anchor WTRU) may trigger a request and / or selection of a new SL-PRS, which may be a new periodic SL-PRS and / or a new aperiodic SL-PRS, based on one and / or any suitable combination of the following:

[0422] The SL-PRS configuration of another WTRU may have changed. For example, for the RTT positioning method, the WTRU may select a periodic SL-PRS based on a periodic SL-PRS from another WTRU. If the WTRU detects that the associated periodic SL-PRS has changed, the WTRU may trigger a request and / or selection of a new periodic SL-PRS (e.g., with a new offset and / or periodicity value).

[0423] The WTRU may have detected a collision with an existing periodic SL-PRS. For example, if the WTRU detects a collision with another SL-PRS transmission, the WTRU may trigger the selection of a new SL-PRS.

[0424] A WTRU receives an indication from another WTRU to change the WTRU's SL-PRS configuration. For example, another WTRU (e.g., a target WTRU) may instruct a WTRU (e.g., an anchor WTRU) to change the WTRU's SL-PRS configuration. The WTRU may then trigger a request and / or select a new periodic SL-PRS to accommodate the other WTRU (e.g., the target WTRU).

[0425] The WTRU may indicate a priority for a sidelink positioning service. A WTRU (e.g., a target WTRU) may initialize a sidelink positioning service for the WTRU. In an example, the WTRU may determine a priority for the sidelink positioning of the WTRU and / or indicate the WTRU's decision to the network. In an example, the WTRU may suggest, indicate, and / or request a priority level for the sidelink positioning of the WTRU. The WTRU may then receive an assigned priority for the sidelink positioning of the WTRU from the network. The WTRU may then determine a priority for one or any combination of the following transmissions and / or receptions, which may be based on the priority of the sidelink positioning service:

[0426] Sidelink positioning request sending, SL-PRS sending, SL-PRS reception, SL-PRS measurement report, SL-PRS resource usage report in the sidelink and / or SL-PRS resource usage report in the uplink.

[0427] The WTRU may report the SL-PRS resources of the WTRU to the network. In an example, the WTRU may receive a request from another WTRU (e.g., an anchor WTRU) to perform SL-PRS reception (e.g., semi-static SL-PRS reception). The WTRU may then indicate and / or report the SL-PRS reception resources to the network. The WTRU may indicate to the network the processing time for each SL-PRS resource. This method may help the network avoid scheduling Uu transmission and / or reception during the SL-PRS reception time. In an example, the WTRU may receive a measurement gap (MG) and / or a positioning processing window (PPW) configuration from the network. In an example, if the WTRU has not received feedback from the network regarding the prioritization of SL-PRS reception, the WTRU may deprioritize SL-PRS reception. In one example, during the measurement gap, the WTRU may not send or receive a channel or signal and only perform measurements. During the positioning processing window, the WTRU may determine to receive SL-PRS or other channels (e.g., SLCCH, SLSCH) or signals (e.g., SSB) based on the priority level associated with the signal or channel.

[0428] The WTRU may determine whether to perform SL-PRS reception. When a SL-PRS reception request is received from another WTRU, the WTRU may determine whether to perform SL-PRS reception. The WTRU may then indicate and / or report the WTRU's decision to other nodes (e.g., a gNB or another WTRU).

[0429] The WTRU may determine whether to perform SL-PRS reception based on one or any combination of the following, including the priority of the SL-PRS. For example, if the priority of the SL-PRS is greater than a threshold, the WTRU may determine to perform SL-PRS reception. The threshold may be (pre)configured and / or determined based on its existing sidelink communication service in the PC5 interface and / or existing Uu service in the Uu interface.

[0430] The WTRU may determine whether to perform SL-PRS reception based on the priority of overlapping sidelink communications (e.g., sidelink transmissions and / or receptions). For example, if the priority of the SL-PRS is greater than the priority of the overlapping sidelink communications, the WTRU may determine to perform SL-PRS reception. The WTRU may then trigger a resource reselection for its overlapping sidelink transmission. The WTRU may instruct and / or request the WTRU performing overlapping sidelink communications to reselect and / or de-prioritize overlapping sidelink communications. For example, if the priority of the SL-PRS is less than the priority of the overlapping sidelink communications, the WTRU may determine to de-prioritize SL-PRS reception. The WTRU may then indicate its decision to de-prioritize SL-PRS reception to the SL-PRS sender WTRU. The SL-PRS sender WTRU may change the configuration of the SL-PRS transmission resources.

[0431] The WTRU may determine whether to perform SL-PRS reception based on the duration of SL-PRS reception in one cycle. For example, if the duration of SL-PRS reception in one cycle is less than a threshold, the WTRU may determine to perform SL-PRS reception. Otherwise, the WTRU may determine not to perform SL-PRS reception.

[0432] The WTRU may determine whether to perform SL-PRS reception based on the periodicity of the SL-PRS reception resource. For example, if the periodicity of SL-PRS reception is less than a threshold, the WTRU may determine to perform SL-PRS reception. Otherwise, the WTRU may determine not to perform SL-PRS reception.

[0433] The WTRU may determine whether to perform SL-PRS reception based on the number and / or duration of existing SL-PRS receptions in a period. For example, the WTRU may determine whether to perform SL-PRS reception based on the number and / or duration of existing SL-PRS receptions in a period. For example, the WTRU may be (pre)configured to receive a maximum of N SL-PRS receptions in a period. The WTRU may then determine whether to perform additional SL-PRS receptions. Determining whether to perform additional SL-PRS receptions may be based on whether the additional SL-PRS receptions may result in exceeding its configured and / or preconfigured SL-PRS reception capability.

[0434] Fig.17 An example illustration of the overlap between SL-PRS reception and SL communication resource pools is depicted. Fig.17 As shown, the WTRU may perform SL-PRS reception in one resource pool 1702 and perform sidelink communication in another resource pool 1704. When the WTRU performs SL-PRS reception 1706 (e.g., for a SL-PRS signal), the WTRU may require more time for SL-PRS processing. Therefore, the WTRU may not perform other sidelink transmission and / or reception 1708.

[0435] The WTRU may request a MG and / or PPW for SL-PRS reception. The WTRU may determine to perform SL-PRS reception for SL-PRS resources (e.g., semi-static SL-PRS resources). The WTRU may then request a MG / PPW configuration from the network. The MG and / or PPW configuration may include one and / or any combination of the periodicity of the MG and / or PPW and / or the duration of the MG and / or PPW in each periodicity.

[0436] In an example, the WTRU may request one MG and / or PPW for each semi-static SL-PRS reception. In an example, the WTRU may determine the MG and / or PPW configuration based on multiple (e.g., all) semi-static SL-PRS reception resources. The WTRU may then request the determined MG and / or PPW to perform reception of multiple semi-static SL-PRS reception resources.

[0437] A WTRU may indicate the WTRU's SL-PRS reception resources to other WTRUs. In an example, upon receiving a request to perform SL-PRS reception, the WTRU may indicate the WTRU's (e.g., semi-static) SL-PRS reception resources to other nodes (e.g., a WTRU with existing sidelink communications to the WTRU or gNB). This approach may help other nodes avoid scheduling and / or sending resources that overlap with the WTRU's SL-PRS reception resources.

[0438] The WTRU may prioritize between SL-PRS reception and / or other sidelink transmission and / or reception. In an example, the WTRU may perform prioritization between SL-PRS reception and / or another overlapping transmission and / or reception in Uu and / or sidelink. In an example, the WTRU may determine whether to perform SL-PRS reception and / or Tx and / or Rx in Uu and / or SL. The WTRU may make this determination based on the relative priority between the Tx and / or Rx resources in SL-PRS and / or Uu and / or SL. For example, if the priority of SL-PRS is greater than the priority of Tx / Rx resources in SL and / or Uu, the WTRU may prioritize SL-PRS reception. Otherwise, the WTRU may de-prioritize SL-PRS reception.

[0439] In an example, if the priority of Tx and / or Rx in Uu and / or SL is greater than a threshold, the WTRU may prioritize Tx and / or Rx in Uu and / or SL. Otherwise, the WTRU may prioritize SL-PRS reception. The threshold may be (pre)configured. In an example, if the priority of SL-PRS is greater than a threshold, the WTRU may prioritize SL-PRS reception. Otherwise, the WTRU may prioritize Tx and / or Rx in Uu and / or SL. The threshold may be (pre)configured.

[0440] In an example, if the priority of SL-PRS reception is greater than a first threshold, the WTRU may prioritize SL-PRS reception. Otherwise, if the priority of Tx and / or Rx in Uu and / or SL is greater than a second threshold, the WTRU may prioritize Tx and / or Rx in Uu and / or SL. Otherwise, if both SL-PRS reception and Tx and / or Rx in Uu and / or SL are less than their respective thresholds, the WTRU may randomly determine which one to prioritize. The WTRU may base the prioritization on other criteria. The thresholds may be (pre)configured.

[0441] In an example, if the priority of Tx and / or Rx in Uu and / or SL is greater than a first threshold, the WTRU may prioritize Tx and / or Rx in Uu and / or SL. Otherwise, if the priority of SL-PRS reception is greater than a second threshold, the WTRU may prioritize SL-PRS reception. Otherwise, if both SL-PRS reception and Tx and / or Rx in Uu and / or SL are less than their respective thresholds, the WTRU may base the prioritization on other criteria. The thresholds may be (pre)configured.

[0442] For hybrid positioning, the WTRU may be independently configured with SL and / or Uu positioning. In an example, the WTRU may report measurements related to SL positioning (e.g., RSRP, RSTD, and / or Rx-Tx time difference associated with SL PRS) and / or Uu positioning (e.g., RSRP, RSTD, and / or Rx-Tx time difference associated with PRS sent from TRP or gNB) in the same report associated with a timestamp. The network may use timestamps to track when measurement reports containing measurements related to SL positioning and / or Uu positioning are transmitted. For example, the target WTRU may determine that it is located in a corner of a room based on Uu positioning results (e.g., location information, region ID, SSB measurements, etc.). If the target WTRU determines that it is located in a corner of a room (e.g., based on region ID and / or location information), the target WTRU may determine to initiate SL positioning and / or use one or more anchor WTRUs for SL positioning.

[0443] The WTRU may determine whether to measure RSTD between two RATs. The WTRU may use a node in one radio access technology (RAT) as a reference node to measure the difference in measurement quantities (e.g., RSTD and / or PDOA) between the reference node and / or the measured node. The measurement may occur in both the same RAT and / or different RATs compared to the reference node. The WTRU may use a node in one RAT as a reference to a node in the same RAT. The WTRU may determine whether to use a node in one RAT as a reference for nodes in two RATs. The WTRU may make this determination based on whether the PC5 RAT is (pre) configured to use the same BWP as Uu. If the PC5-RAT is (pre) configured to use the same carrier as Uu, the WTRU may use a node (e.g., a serving gNB) as a reference node for nodes in the two RATs. Otherwise, if the PC5 RAT is (pre) configured to use a different BWP from Uu, the WTRU may use nodes in each RAT as a reference for all nodes in the same RAT.

[0444] The WTRU may determine a reference node for RSTD measurement. The WTRU may determine which node to use as a reference node to measure the measurement difference. The WTRU may make this determination based on one and / or a combination of the type of WTRU, where the WTRU may prioritize RSU as a reference node, coverage status, and / or where the WTRU may prioritize in-coverage WTRUs as reference nodes.

[0445] The WTRU may trigger resource reselection and / or preemption when a MG and / or PPW configuration is received in Uu. A WTRU (e.g., a target WTRU) may receive a MG and / or PPW configuration from a network (e.g., a gNB). If the WTRU detects that one or more of the WTRU's reserved sidelink resources are within the MG and / or PPW duration in Uu, the WTRU may then trigger resource reselection and / or preemption. The WTRU may then select another resource taking into account the configured MG and / or PPW. The WTRU may first exclude all candidate resources within the configured MG and / or PPW and then select a resource outside the configured MG / PPW.

[0446] The WTRU may trigger resource reselection and / or preemption when a MG and / or PPW is received in the Uu of the peer. When a MG and / or PPW is received in the Uu of each WTRU, if the WTRU detects that its reserved sidelink transmit resources for the peer WTRU are within the MG and / or PPW of the peer WTRU, the WTRU may determine to perform triggered resource reselection and / or preemption. The WTRU may then select another resource outside the MG and / or PPW of the peer WTRU.

[0447] The WTRU may avoid transmitting to a peer WTRU during the MG and / or PPW of the peer WTRU. The WTRU may avoid transmitting to a peer WTRU during the duration of the MG and / or PPW of the peer WTRU. The WTRU may perform an LCP procedure in which the WTRU may not select data and / or SL-PRS to send to the peer WTRU for any resource within the MG and / or PPW of the peer WTRU. The WTRU may select data and / or SL-PRS to send to the peer WTRU outside the MG and / or PPW period of the peer WTRU. The WTRU may trigger resource reselection if one of the WTRU's reserved resources is within the MG and / or PPW of the peer WTRU.

[0448] The WTRU may indicate the MG and / or PPW of the WTRU to the network (e.g., LMF). The WTRU may indicate one or any suitable combination of the following MG and / or PPW to another node (e.g., to another WTRU, to the network such as LMF and / or gNB), including the MG and / or PPW of the WTRU in Uu. For example, the WTRU may indicate the MG and / or PPW of the WTRU to another WTRU so that the other WTRU and / or gNB may avoid sending channels (e.g., SLCCH and / or SLSCH) and / or signals to the WTRU and / or request the WTRU to send / receive signals (e.g., SL-PRS) during the MG and / or PPW duration.

[0449] The WTRU may indicate the WTRU's MG and / or PPW in the sidelink. For example, the WTRU may indicate the WTRU's MG and / or PPW to another WTRU so that the other WTRU and / or the gNB may avoid transmitting to the WTRU during the MG and / or PPW duration. Alternatively, the gNB may avoid scheduling Uu resources in the sidelink during the WTRU's MG and / or PPW.

[0450] A WTRU may indicate the MG and / or PPW of one or more other WTRUs. For example, a WTRU may indicate the MG and / or PPW of another WTRU in a sidelink to a gNB. The gNB may implicitly request the gNB to schedule transmit resources (e.g., sidelink transmit resources and / or SL-PRS transmit resources) to one or more WTRUs outside of the indicated MG and / or PPW period.

[0451] In positioning methods such as multi-RTT, SL-TDOA, SL-AoD, and / or SL-AoA, the target WTRU may receive configuration for more than one anchor WTRU. When the target WTRU determines the relative positioning relative to a reference node (e.g., distance and angle relative to the reference node), the WTRU may define what to use as the reference node. If the reference node is a mobile node (e.g., a vehicle), the relative position relative to such a node may quickly become outdated and / or inaccurate.

[0452] Given a set of anchor WTRUs, the target WTRU may determine a reference node based on at least one of the following conditions: the reference node may be an anchor WTRU, indicated by one of the anchor WTRU and / or the network (e.g., gNB, LMF). The reference node may be a stationed anchor WTRU (e.g., roadside unit, positioning reference unit). In one example, if the target WTRU receives a configuration for more than one anchor WTRU and one of these anchor WTRUs is a stationed WTRU (e.g., roadside unit), the target WTRU may use that WTRU as a reference node. If there is more than one stationed WTRU, the target WTRU may randomly select one of them and report to the network and / or anchor WTRU which WTRU the target WTRU selected. Additionally or alternatively, the target WTRU may use measurement results (e.g., RSRP) to select a WTRU as a reference node.

[0453] The target WTRU determines the reference node based on the measurement of the SL-PRS sent by the anchor WTRU. For example, the target WTRU may determine to use the anchor WTRU with the highest SL-PRS RSRP as the reference node.

[0454] Given a set of anchor WTRUs, the target WTRU may determine the reference node based on whether the target WTRU receives a list of priority levels associated with the anchor WTRUs. The target WTRU may determine the reference node based on the priority level (e.g., the anchor WTRU with the highest priority level is selected as the reference node). If the anchor WTRU with the highest priority level is not available for PRS transmission, and / or the anchor is a mobile anchor WTRU, the target WTRU may determine to use the anchor WTRU with the second highest priority level as the reference node.

[0455] Given a set of anchor WTRUs, a target WTRU may determine a reference node based on the location of the reference node and / or an identification of the reference node (e.g., anchor WTRU ID). The network may indicate the reference node, and / or the anchor WTRU and / or target WTRU may determine to report a relative location relative to the reference node.

[0456] Given a set of anchor WTRUs, a target WTRU may determine a reference node based on whether the reference node is one of the sources used for SL positioning and / or SL communication (e.g., a synchronization source, and / or a reference WTRU utilized to determine RSTD). In an example, the target WTRU may receive priority levels associated with these sources. For example, the priority level of the synchronization source may have a higher priority level than the level associated with the reference WTRU for calculating RSTD.

[0457] In an example, the target WTRU may indicate information related to the reference node in the relative position information (e.g., a WTRU ID associated with a SL-PRS sent by the reference node, a SL PRS resource ID, and / or a SL PRS ID). In an example, during positioning, the target WTRU may determine to change the reference node. In this case, the target WTRU may transmit a request to the anchor WTRU and / or the network to terminate the current positioning session and restart the session.

[0458] In an example, when there is a change in the reference node, the WTRU may determine to include information related to the reference node. If the reference node has not changed, the target WTRU may determine to include a timestamp in the measurement report, wherein the timestamp may indicate the time when the reference node was configured. For example, if the target WTRU may determine to use anchor WTRU_A as the reference node at time T1, the target WTRU may indicate to the network that WTRU_A was used as the reference node at time T1. At time T2, which is later than T1, if the reference node has not changed, the target WTRU may associate T1 with the relative location information determined at T2. The network may refer to the report at T1 to determine which reference node to use. If at time T3, which is later than T2, the target WTRU may determine to change the reference node (e.g., to anchor WTRU_B), the target WTRU may indicate the reference node information (e.g., information related to anchor WTRU_B, such as location information, WTRU ID, and / or PRS resource ID of anchor WTRU_B) in its report, thereby associating T3 with the information. At time T4 which is later than T3, if the reference node has not changed, the target WTRU may indicate T3 to the network to obtain the reference node information.

[0459] In an example, for each reference node, the target WTRU may receive an effective period during which the target WTRU may use the reference node to obtain a relative position. In an example, the target WTRU may determine to use more than one reference node based on the above conditions. The target WTRU may include relative position information corresponding to each reference node in the report it transmits to the anchor WTRU and / or the network.

[0460] The WTRU may request resources for sidelink positioning and forward the schedule to the group. In an example, a WTRU (e.g., a target WTRU) may receive (e.g., via a DCI) scheduled sidelink resources for sidelink positioning for a group of WTRUs. The WTRU may then determine a positioning method for the group based on a set of scheduled sidelink resources (e.g., in the DCI). The target WTRU may then forward the scheduled SL-PRS reception (if available) and / or SL-PRS measurement reporting resources (if available) indicated in the scheduled sidelink resources (e.g., DCI) using a multicast message associated with the group of potential SL-PRS transmissions and / or measurement reports for the anchor WTRU.

[0461] In this case, the WTRU may perform the following steps: The WTRU may perform a discovery procedure to determine a set of anchor WTRUs and / or determine a group ID to represent a positioning group. The WTRU may notify the gNB of the positioning group information. The WTRU may request sidelink resources for the group of WTRUs to perform sidelink positioning. The WTRU may receive (e.g., via DCI) scheduled sidelink resources for the group of WTRUs to perform sidelink positioning.

[0462] The WTRU may determine the positioning method based on the content of the scheduled sidelink resources. For example, if the scheduled resources have both SL-PRS transmission and / or SL-PRS reception resources, the WTRU may perform RTT-based sidelink positioning. If the scheduled resources have SL-PRS transmission resources, the WTRU may perform a method based on SL-PRS transmission. If the scheduled resources have SL-PRS reception resources, the WTRU may perform a method based on SL-PRS reception.

[0463] If the scheduled sidelink resources have SL-PRS reception and / or SL-PRS measurement reporting resources, then additional steps that the WTRU may perform occur, the WTRU may forward the scheduled resources for the anchor WTRU using the multicast ID. The WTRU may perform SL-PRS transmission in the scheduled resources for SL-PRS transmission. The WTRU may perform SL-PRS reception in the scheduled resources for SL-PRS reception.

[0464] The WTRU may determine the sidelink resources for each WTRU in the group. In an example, for an RTT-based approach, a WTRU (e.g., a target WTRU) may perform SL-PRS reception and / or SL-PRS measurement report reception from a group of WTRUs (e.g., a group of anchor WTRUs). The WTRU may determine the SL-PRS and / or measurement report resources for each anchor WTRU based on the anchor WTRU ID, the number of WTRUs in the group, the (pre-)configured OCC for each WTRU, the set of sidelink resources scheduled for the group, and / or the (pre-)configured multiplexing rules. The WTRU may then send the derived positioning (e.g., relative positioning) using a multicast message associated with the group.

[0465] For example, the WTRU may perform one or any combination of the following steps: the WTRU may determine a group of WTRUs for sidelink positioning, the WTRU may configure an OCC for each anchor WTRU (e.g., based on the WTRU ID), the WTRU may receive a SL-PRS resource configuration and / or a SL-PRS measurement report configuration from the gNB, both of which may include: the bandwidth, duration, comb size, number of repetitions for each SL-PRS resource, and / or the resource size for each measurement report. The SL-PRS resource configuration and / or the SL-PRS measurement report configuration from the gNB may also include an order of SL-PRS multiplexing for the group of resources (e.g., OCC, then frequency, then time) and / or an order of multiplexing of SL-PRS measurement report resources (e.g., time, then frequency).

[0466] The WTRU may also forward the configuration to the group using the group ID. The WTRU may receive (e.g., via DCI) scheduled sidelink resources for performing sidelink positioning for the group of WTRUs and / or forward the scheduled resources to the anchor WTRU. The WTRU may perform SL-PRS transmission in the scheduled sidelink resources for the WTRU's SL-PRS transmission. The WTRU may determine the SL-PRS and measurement report resources for each anchor WTRU based on the anchor WTRU ID, the number of WTRUs in the group, the (pre)configured OCC for each WTRU, the set of sidelink resources scheduled for the group, and / or the (pre)configured multiplexing rules. The WTRU may calculate the RTT between each WTRU based on the measured Tx-Rx of the WTRU of the SL-PRS and the reported Tx-Rx from each anchor WTRU. The WTRU may include the calculated relative positioning with respect to the anchor WTRU in a message and / or send it to the group using the group ID.

[0467] Fig.18An example illustration of multiplexing of SL-PRS 1802 and SL-PRS measurement reports 1804 between WTRUs in a group is depicted. Fig.18 As shown, the WTRU may be scheduled with SL-PRS resources 1806a-1806d and SL-PRS measurement reporting resources 1808a-1808d for a group of WTRUs. The WTRU may then determine the SL-PRS resources 1806a-1806d and SL-PRS measurement reporting resources 1808a-1808d for each WTRU.

[0468] The WTRU may determine the WTRU's SL-PRS and / or SL-PRS measurement reporting resources from the resources for the group. In an example, for an RTT-based approach, a WTRU (e.g., an anchor WTRU) may receive (e.g., from a target WTRU) a set of resources for SL-PRS transmission and a set of resources for SL-PRS measurement reporting. The WTRU may then determine its SL-PRS transmission resources and / or its SL-PRS measurement reporting resources (e.g., to report Tx-Rx differences) based on its WTRU ID, the number of WTRUs in the group, the OCC (pre-)configured to the WTRU, and / or the (pre-)configured multiplexing rules.

[0469] For example, in order to determine its SL-PRS transmission resources and / or its SL-PRS measurement reporting resources, the WTRU may perform one or any combination of the following: determine the WTRU ID of the WTRU in the group and the number of WTRUs in the positioning group, receive a dedicated OCC for SL-PRS transmission (for example, based on the WTRU ID), receive a SL-PRS resource configuration and / or SL-PRS measurement reporting configuration from a target WTRU, receive side link resources for performing scheduling of the group of WTRUs and / or from the target WTRU, determine the SL-PRS and measurement reporting resources of the WTRU for each anchor WTRU based on the WTRU's WTRU ID, the number of WTRUs in the group, the WTRU's configured OCC, the set of side link resources for group scheduling and / or (pre-)configured multiplexing rules, and / or perform SL-PRS transmission and / or SL-PRS measurement reporting in the determined resources.

[0470] Fig.19An example signal flow diagram for in-coverage round trip time (RTT) positioning is depicted. At 1902, a target WTRU may transmit a positioning request, for example, to a network (e.g., LMF or the like). Such a request may include a MO-LR request (e.g., transmitted in an LPP or LCS message), an LPP message (e.g., an LPP request for sidelink positioning, an LPP request for assistance data, LPP capability information), and / or an AS layer message (e.g., an RRC message, a MAC CE).

[0471] At 1904, the anchor WTRU may receive a PRS configuration (e.g., PRS parameters such as comb value, number of slots, bandwidth, and / or positioning method) for the anchor WTRU and / or the target WTRU. At 1906, the anchor WTRU may transmit a request to the gNB to schedule resources for PRS transmission for the anchor WTRU and / or the target WTRU. At 1908, the gNB may respond to the anchor WTRU with SL-PRS resources and / or SL-PRS configuration.

[0472] At 1910, the target WTRU may receive resource information (e.g., the location of the SL-PRS in the time domain and / or frequency domain) from the anchor WTRU. Fig.19 , but the target WTRU may receive a set of resources and / or SL PRS configuration from the anchor WTRU and / or the gNB. In an example, the target WTRU may receive an indication of a sidelink positioning method (e.g., RTT) to be applied from the anchor WTRU and / or the gNB. The target WTRU may determine the resources and / or configuration for SL-PRS transmission of the target WTRU based on the set of resources and / or SL PRS configuration described above. The target WTRU may receive such information and / or indication in any one of, for example, an SCI, MAC-CE, PC5-RRC, and / or LPP message.

[0473] At 1912, the target WTRU may monitor the SCI from the anchor WTRU and / or may receive the SL-PRS from the anchor WTRU at the resources indicated in the SCI. At 1914, the target WTRU may make measurements (e.g., receive timing, RSRP, and / or AoA) of the received PRS. At 1914, the target WTRU may send the SL-PRS to the anchor WTRU.

[0474] At 1918, the target WTRU may report the target WTRU Rx-Tx time difference to the anchor WTRU (e.g., via any one of an LPP message, a PC5-RRC message, a SL MAC CE, and / or an SCI), where the target WTRU Tx-Rx time difference may be the difference between the time when the target WTRU receives the SL-PRS from the anchor WTRU and the time when the target WTRU sends the SL-PRS. In an example, the target WTRU may report the target WTRU Tx-Rx time difference and / or other measurements (e.g., RSRP per SL-PRS resource) to the LMF via an LPP message.

[0475] At 1920, the anchor WTRU may receive the SL-PRS from the target WTRU and / or may make measurements (e.g., receive timing, RSRP, AoA, and / or anchor WTRU Rx-Tx time difference), where the anchor WTRU Rx-Tx time difference may be the difference between the time when the anchor WTRU sends the SL-PRS and / or the time when the anchor WTRU receives the SL-PRS from the target WTRU. In an example, the anchor WTRU may transmit the anchor WTRU Rx-Tx time difference to the LMF in an LPP message.

[0476] At 1922, the anchor WTRU may transmit measurements made by the anchor WTRU and the target WTRU to the LMF. In an example, the anchor WTRU may determine a relative position between the anchor WTRU and the target WTRU and / or an absolute position of the target WTRU and may transmit the position to the LMF in an LPP message. At 1924, the LMF may then receive the position determination and / or position information determined based on the measurements. At 1926, the target WTRU may receive position information determined by the LMF based on the measurements.

[0477] Fig. 20 An example signal flow diagram for WTRU-based in-coverage SL positioning (e.g., SL-TDOA and / or SL-AoD) is depicted. At 2002, a target WTRU may transmit a request for location information of the target WTRU to a network (e.g., LMF and / or gNB). For example, the WTRU may transmit a request for location information in an LCS message (e.g., MT-LR), an LPP message (e.g., LPP request for sidelink positioning, LPP request for location information, and / or LPP request for capability information), and / or in an AS layer message (e.g., RRC and / or MACCE).

[0478] At 2004, the target WTRU may receive assistance information related to the SL-PRS configuration (eg, comb values, number of slots and / or symbols containing the SL-PRS) and the WTRU-based positioning method from the anchor WTRU.

[0479] At 2006, the anchor WTRU may receive SL-PRS resource information (e.g., the location of the SL-PRS in the time domain and / or frequency domain) from the gNB. The target WTRU may then receive a SL-PRS configuration for performing SL-PRS measurements from one or more anchor WTRUs. At 2008, the target WTRU may receive SL-PRS configuration information from the anchor WTRU. At 2010, if the anchor WTRU is stationary (such as, for example, an RSU, via an LPP message including but not limited to LPP assistance data), the target WTRU may receive the anchor WTRU location from the LMF. In an example, if some of the anchor WTRUs are mobile, the target may receive location information from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0480] At 2012, the target WTRU may monitor the SCI (e.g., received from the gNB and / or the anchor WTRU) for the SL-PRS sent from the anchor WTRU. At 2014, the target WTRU may receive the SL-PRS from the anchor WTRU. At 2016, the target WTRU may make measurements (e.g., RSRP and / or RSTD) on the received SL-PRS. At 2018, the target WTRU may determine an absolute position based on the measurements.

[0481] At 2020, the target WTRU may report the absolute positioning to the LMF (eg, via an LPP message). In an example, if the WTRU is configured with a WTRU-assisted SL positioning method, the WTRU may return a measurement report to the LMF.

[0482] Fig.21 An example process for SL positioning is depicted, where WTRU information may be provided by an anchor WTRU and / or multiple WTRUs. For example, if the anchor WTRU is mobile, the target WTRU may receive the anchor WTRU location.

[0483] At 2102, the target WTRU may receive a request for location information of the target WTRU from the network (e.g., LMF and / or gNB). For example, the WTRU may receive the request for location information in an LCS message (e.g., MT-LR), an LPP message (e.g., LPP request for sidelink positioning, LPP request for location information, LPP request for capability information), and / or in an AS layer message (e.g., RRC and / or MAC CE).

[0484] At 2104, the target WTRU may receive assistance information related to the SL-PRS configuration (eg, comb values, number of slots and / or symbols containing the SL-PRS) and the WTRU-based positioning method from the anchor WTRU.

[0485] At 2106, the anchor WTRU may receive SL-PRS resource information (e.g., location of the SL-PRS in the time domain and / or frequency domain) from the anchor WTRU. At 2108, the target WTRU may receive the anchor WTRU location from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0486] At 2110, the target WTRU may monitor the SCI (e.g., received from the gNB and / or the anchor WTRU) for the SL-PRS sent from the anchor WTRU. At 2112, the target WTRU may receive the SL-PRS from the anchor WTRU. At 2114, the target WTRU may make measurements (e.g., RSRP and / or RSTD) on the received SL-PRS. At 2116, the target WTRU may determine an absolute position based on the measurements.

[0487] The target WTRU may report the absolute positioning to the LMF (eg, via an LPP message) at 2118. In an example, if the WTRU is configured with a WTRU-assisted SL positioning method, the WTRU may return a measurement report to the LMF.

[0488] Fig. 22 An example flow diagram of in-coverage SL positioning (WTRU-based), anchor WTRU information from LMF, PRS configuration from LMF to target WTRU is depicted. At 2202, the target WTRU may transmit a request for SL positioning data to the LMF. At 2204, the target WTRU may receive the PRS configuration from the LMF in an LPP message (e.g., in any of an LPP assistance data message and / or an LPP request for location information message). For example, the WTRU may receive the request for location information in an LCS message (e.g., MT-LR), an LPP message (e.g., an LPP request for sidelink positioning, an LPP request for location information, and / or an LPP request for capability information), and / or in an AS layer message (e.g., RRC and / or MAC CE).

[0489] At 2206, the target WTRU may receive assistance information related to the SL-PRS configuration (e.g., comb values, number of slots and / or symbols containing SL-PRS) and the WTRU-based positioning method from the LMF. At 2208, the gNB may receive assistance information related to the SL-PRS configuration (e.g., comb values, number of slots and / or symbols containing SL-PRS) and the WTRU-based positioning method from the LMF.

[0490] At 2210, the anchor WTRU may receive SL-PRS resource information (e.g., location of the SL-PRS in the time domain and / or frequency domain) from the gNB. At 2212, if the anchor WTRU is stationary (such as, for example, an RSU, via an LPP message including but not limited to LPP assistance data), the target WTRU may receive the anchor WTRU location from the LMF. In an example, if some of the anchor WTRUs are mobile, the target may receive location information from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0491] At 2214, the target WTRU may monitor the SCI (e.g., received from the gNB and / or the anchor WTRU) for the SL-PRS sent from the anchor WTRU. At 2216, the target WTRU may receive the SL-PRS from the anchor WTRU. At 2218, the target WTRU may make measurements (e.g., RSRP and / or RSTD) on the received SL-PRS. At 2220, the target WTRU may determine an absolute position based on the measurements.

[0492] At 2222, the target WTRU may report the absolute positioning to the LMF (eg, via an LPP message). In an example, if the WTRU is configured with a WTRU-assisted SL positioning method, the WTRU may return a measurement report to the LMF.

[0493] Fig.23 An example process for dual-sided RTT SL positioning is depicted. At 2302, the target WTRU may transmit a request for positioning in an LPP message to the LMF. At 2304, the anchor WTRU may receive a PRS configuration from the LMF (e.g., in an LPP assistance data message). At 2306, the anchor WTRU may transmit a request for time and / or frequency resources for sending SL-PRS from the anchor WTRU and / or the target WTRU. At 2308, the anchor WTRU may receive SL-PRS resources and / or configuration from the gNB in ​​response to the request. At 2310, the target WTRU may receive resource information from the anchor WTRU (e.g., via any of LPP, PC5-RRC, MAC CE and / or SCI). At 2312, the target WTRU may monitor the SCI (e.g., received from the gNB and / or anchor WTRU) for the sent SL-PRS.

[0494] At 2314, the target WTRU may receive the SL-PRS sent by the anchor WTRU, wherein the resources used for the SL-PRS are indicated in the SCI. At 2316, the target WTRU may make measurements (e.g., RSRP and / or ToA) on the SL-PRS. At 2318, the target WTRU may perform resource selection based on the measurements. At 2320, the target WTRU may send the SL-PRS based on the resources the target WTRU determines to use. At 2322, the target WTRU may transmit a first measurement report in an LPP message to the LMF, wherein the report includes, for example, the target WTRU Tx-Rx time, RSRP per SL-PRS resource, and / or associated AoA measurements.

[0495] At 2324, the anchor WTRU may perform measurements on the SL-PRS sent by the target WTRU. At 2326, the target WTRU may monitor the SCI (e.g., received from the gNB and / or anchor WTRU) for the sent SL-PRS. At 2328, the anchor WTRU may transmit a measurement report (e.g., anchor WTRU Rx-Tx time, AoA, and / or RSRP). At 2330, the target WTRU may receive a second SL-PRS from the anchor WTRU, wherein resource information of the second SL-PRS is indicated in the SCI. At 2332, the target WTRU may perform measurements on the SL-PRS (e.g., RSRP and / or ToA). At 2334, the target WTRU may transmit a second measurement report to the LMF in an LPP message, wherein the report may include, for example, the target WTRU Rx-Tx time, RSRP per SL-PRS resource, and / or associated AoA measurements.

[0496] The second target WTRU Rx-Tx time may be defined by the difference between the reception time of the second SL-PRS (from the anchor WTRU) and the transmission time of the SL-PRS (from the target WTRU).In an example, the target WTRU may combine the first measurement report and the second measurement report and transmit the combined measurement report to the LMF.

[0497] At 2336, the LMF may determine the location of the target WTRU based on the measurement report. At 2338, the target WTRU may receive the location information determined by the LMF.

[0498] The sidelink positioning methods described herein may support SL-TDOA methods and / or RTT methods. To ensure positioning QoS (such as accuracy and latency), resources may be coordinated to reduce the time gap between SL-PRS Tx and / or Rx for the RTT method. Each WTRU may be required to request its sidelink Tx resources independently. This may result in uncoordinated SL-PRS transmissions in SL-TDOA and / or extended time gaps between SL-PRS Tx and / or Rx in RTT.

[0499] In an example, a WTRU (eg, a target WTRU) may request resources (eg, SL-PRS Tx resources) for a group of WTRUs. Fig.24 An example diagram depicting a WTRU obtaining and providing side link resources associated with a group of WTRUs is depicted. Fig.25 Another example diagram depicting a WTRU obtaining and providing side link resources associated with a group of WTRUs is depicted.

[0500] like Fig.24 As depicted, a WTRU 2402 (e.g., a target WTRU as depicted) may request sidelink positioning reference signal (SL-PRS) transmission (Tx) resources for a group of WTRUs 2404a-2404d (e.g., anchor WTRUs as depicted). The target WTRU 2402 may indicate in the request the amount of resources required for itself and the anchor WTRUs 2404a-2404d. The target WTRU 2402 may receive an indication of the requested resources and forward the scheduled SL-PRS resources to the group (e.g., anchor WTRUs 2404a-2404d). The target WTRU 2402 may request a change in SL-PRS configuration based on the measurement reporting status of other WTRUs 2404a-2404d in the group. For network-assisted positioning, the target WTRU 2402 may determine a set of measurements received and / or a set of WTRUs to report to the network based on one or more (pre)configured conditions.

[0501] The target WTRU 2402 may form a sidelink positioning group via a discovery procedure. The target WTRU 2402 may determine a positioning method (e.g., an RTT method, a SL-TDOA method, and / or any suitable combination thereof). The target WTRU 2402 may indicate positioning group information, such as a group identifier (ID) and / or a WTRU number, to a network entity.

[0502] The network entity may include any network entity, such as gNB1 2406a and / or gNB2 2406b. The target WTRU 2402 may request SL-PRS resources for a group of WTRUs from the network entity (e.g., gNB1 2406a and / or gNB2 2406b). The request may include a group ID, a number of resources for SL-PRS Tx for the target WTRU 2402, a number of resources for SL-PRS Tx for the anchor WTRUs 2404a-2404d, and / or any combination thereof.

[0503] like Fig.24 As depicted, the target WTRU 2402 may provide a request 2408 directly to gNB1 2406a. The target WTRU 24042 may go indirectly to gNB2 2406b via another network entity (e.g., LMF 2410). The target WTRU 2402 may receive the requested resources from the network entity. The target WTRU 2402 may receive SL-PRS resources for the group from gNB1 2406a. The resources may be received via DCI.

[0504] The target WTRU 2402 may provide and / or forward scheduled resources for the SL-PRS to the group. The scheduled resources may be provided and / or forwarded via any mechanism (eg, PC5-RRC interface).

[0505] like Fig.25 As depicted, a WTRU 2502 (e.g., a target WTRU as depicted) may request sidelink positioning reference signal (SL-PRS) transmission (Tx) 2504 resources for a group of WTRUs 2504 (e.g., anchor WTRUs as depicted). The target WTRU 2502 may indicate in the request the amount of resources required for itself and the anchor WTRUs 2504a-2504d. The target WTRU 2502 may receive an indication of the requested resources and forward the scheduled SL-PRS resources to the group (e.g., anchor WTRUs 2504a-2504d). The target WTRU 2402 may request a change in SL-PRS configuration based on the measurement reporting status of the other WTRUs 2504a-2504d in the group. For network-assisted positioning, the target WTRU 2502 may determine a set of measurements received and / or a set of WTRUs to report to the network based on one or more (pre)configured conditions.

[0506] like Fig.25As depicted, the target WTRU 2502 may form a sidelink positioning group via a discovery procedure. The target WTRU 2502 may determine a positioning method (e.g., an RTT method, a SL-TDOA method, and / or any suitable combination thereof). The target WTRU 2502 may indicate positioning group information, such as a group identifier (ID) and / or a WTRU number, to a network entity.

[0507] The network entity may include any network entity, such as, for example, gNB1 2506. The target WTRU 2502 may request SL-PRS resources for a group of WTRUs from the network entity (e.g., gNB1 2506a). The request may include a group ID, a number of resources for the SL-PRS Tx 2508 for the target WTRU 2502, a number of resources for the SL-PRS Tx 2510a-2510d for the anchor WTRUs 2504a-2504d, and / or any combination thereof.

[0508] Fig.25 An RTT-based positioning method is depicted in which the target WTRU 2502 may determine to send the SL-PRS 2508 in a multicast-based transmission. Each SL-PRS transmission 2508 may be targeted to all anchor WTRUs 2504a-2504d. Each anchor WTRU 2504a-2504d may then send back the SL-PRS 2510a-2510d using a unicast-based transmission.

[0509] Although features and elements are provided above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. The present disclosure is not limited to the specific embodiments described in this patent application, which are intended to be illustrative of various aspects. Many modifications and variations can be made without departing from the essence and scope of the present invention, as they will be obvious to those skilled in the art. Unless explicitly provided as such, any element, action or description used in the present application specification should not be understood as being essential or necessary to the present invention. According to the foregoing description, in addition to those listed herein, within the scope of the present disclosure, functionally equivalent methods, devices and products will be obvious to those skilled in the art. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only to the terms of the appended claims and the full range of equivalent forms of such entitled claims. It should be understood that the present disclosure is not limited to a specific method or system.

[0510] Although the foregoing embodiments may be discussed with respect to specific terminology and structures (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.) for simplicity, the embodiments discussed are not limited thereto and may be applied to other systems using, for example, other forms of electromagnetic waves or non-electromagnetic waves such as sound waves.

[0511] It should also be understood that the terms used herein are used only for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, a single image, and / or multiple images displayed on a time basis, or any suitable combination thereof. For example, when referred to herein, the term "user equipment" and its abbreviation "UE", the term "remote" and / or the term "head-mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of the multiple embodiments of the WTRU; (iii) a wireless and / or wired (e.g., tetherable) device configured with (in particular) some or all of the structure and functionality of the WTRU; (iii) a wireless and / or wired device configured with less than all of the structure and functionality of the WTRU; or (iv), etc. References herein Figures 1A to 1D Details of an example WTRU are described that may represent any WTRU described herein. As another example, various disclosed embodiments herein above and below are described as utilizing a head mounted display. One skilled in the art will recognize that devices other than head mounted displays may be utilized and that some or all of the embodiments of the present disclosure and various disclosed embodiments may be modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an adapted reality experience.

[0512] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via a wired connection or a wireless connection) and computer-readable storage media. Unlike signals, examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

[0513] Variations of the methods, devices, articles, and systems provided above are possible without departing from the scope of the present invention. In view of the various embodiments that may be applied, it should be understood that the illustrated embodiments are merely examples and should not be considered to limit the scope of the following claims. For example, the embodiments provided herein include handheld devices that may include or be utilized with any suitable voltage source (such as a battery, etc.) that provides any suitable voltage.

[0514] In addition, in the embodiments provided herein, processing platforms, computing systems, controllers and other devices comprising processors are indicated. These devices may include at least one central processing unit ("CPU") and memory. According to the practice of those skilled in the art of computer programming, reference to the symbolic representation of actions and operations or instructions may be performed by various CPUs and memories. Such actions and operations or instructions may be considered to be "executed", "computer executed" or "CPU executed".

[0515] Those of ordinary skill in the art will appreciate that the actions and symbolic representations of operations or instructions include the manipulation of electrical signals by the CPU. The electrical system represents data bits, which may result in the final transformation of electrical signals or the reduction of electrical signals and the retention of data bits at memory locations in the memory system, thereby reconfiguring or otherwise changing the operation of the CPU and performing other processing of signals. The memory location that holds the data bit is a physical location that has a specific electrical property, magnetic property, optical property, or organic property corresponding to or representing the data bit. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs, and other platforms and CPUs may also support the provided methods.

[0516] The data bits may also be maintained on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory ("RAM")) or non-volatile (e.g., read-only memory ("ROM")) mass storage system readable by the CPU. The computer-readable media may include cooperating or interconnected computer-readable media that reside solely on the processing system or distributed across multiple interconnected processing systems that may be local or remote relative to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories, and other platforms and memories may also support the provided methods.

[0517] In an exemplary embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0518] The above detailed description has listed various embodiments of the device and / or process by using block diagrams, flow charts and / or examples. In the case where such block diagrams, flow charts and / or examples include one or more functions and / or operations, it should be understood by those skilled in the art that each function and / or operation within such block diagrams, flow charts or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware or almost any combination thereof. In example embodiments, several parts of the subject matter described herein can be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs) and / or other integrated formats. Those skilled in the art will recognize that some aspects of the embodiments disclosed herein can be implemented in whole or in part in an integrated circuit as one or more computer programs running on one or more computers (e.g., one or more programs running on one or more computer systems), one or more programs running on one or more processors (e.g., one or more programs running on one or more microprocessors), firmware, or almost any combination thereof, and according to the present disclosure, designing circuit systems and / or writing codes for software and / or firmware will be within the technical scope of those skilled in the art. Those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed as a program product in various forms, and that the illustrative embodiments of the subject matter described herein apply regardless of the specific type of signal-bearing medium used to actually implement the distribution. Examples of signal-bearing media include, but are not limited to, the following: reco...

Claims

1. A wireless transmit receive unit (WTRU), the wireless transmit receive unit (WTRU) comprising a transceiver and a processor, the processor being configured to: sending, via the transceiver, a first message including sidelink positioning information associated with a group of WTRUs, wherein the sidelink positioning information includes an indication of a sidelink positioning method used to determine a location of the WTRUs in the group of WTRUs; sending, via the transceiver, a second message comprising a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs; receiving, via the transceiver, an indication of allocated SL-PRS resources for the group of WTRUs; and An indication of the allocated SL-PRS resources is transmitted to the group of WTRUs via the transceiver.

2. The WTRU of claim 1 , wherein the requested resources are based at least in part on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and a quality of service (QoS) associated with the sidelink positioning method.

3. The WTRU of claim 1 , wherein: The sidelink positioning information in the first message includes a group identifier (ID) associated with the group of WTRUs; and The request for SL-PRS resources in the second message includes the group ID.

4. The WTRU of claim 1, wherein the sidelink positioning method comprises at least one of round trip time (RTT) positioning, sidelink time difference of arrival (SL-TDOA) positioning, or sidelink angle of departure (SL-AoD) positioning.

5. The WTRU of claim 1 , wherein: The WTRU is one of the WTRUs in the group of WTRUs; The request for SL-PRS resources comprises a request for SL-PRS transmission resources for the WTRU; and The request for SL-PRS resources includes a request for SL-PRS transmission resources for other WTRUs in the group of WTRUs.

6. The WTRU of claim 5, wherein the request for SL-PRS resources further comprises: the number of SL-PRS transmission resources requested by the WTRU; and The number of SL-PRS transmission resources requested by the other WTRUs in the group of WTRUs.

7. The WTRU of claim 1, wherein the second message comprises a medium access control (MAC) control element (CE).

8. The WTRU of claim 1 , the processor being further configured to perform a sidelink discovery procedure to identify the group of WTRUs.

9. The WTRU of claim 1, wherein the processor is configured to send the first message and the second message to a node, wherein the node comprises at least one of a network node, another WTRU, or a road side unit (RSU).

10. A method performed by a wireless transmit receive unit (WTRU), the method comprising: sending a first message including sidelink positioning information associated with a group of WTRUs, wherein the sidelink positioning information includes an indication of a sidelink positioning method used to determine the positioning of the WTRUs in the group of WTRUs; sending a second message comprising a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs; receiving an indication of allocated SL-PRS resources for the group of WTRUs; and An indication of the allocated SL-PRS resources is transmitted to the group of WTRUs.

11. The method of claim 10, wherein the requested resources are based at least in part on the sidelink positioning method, a number of WTRUs in the group of WTRUs, and a quality of service (QoS) associated with the sidelink positioning method.

12. The method according to claim 10, wherein: The sidelink positioning information in the first message includes a group identifier (ID) associated with the group of WTRUs; and The request for SL-PRS resources in the second message includes the group ID.

13. The method of claim 10, wherein the sidelink positioning method comprises at least one of round trip time (RTT) positioning, sidelink time difference of arrival (SL-TDOA) positioning, or sidelink angle of departure (SL-AoD) positioning.

14. The method of claim 10, wherein: The WTRU is one of the WTRUs in the group of WTRUs; The request for SL-PRS resources comprises a request for SL-PRS transmission resources for the WTRU; and The request for SL-PRS resources includes a request for SL-PRS transmission resources for other WTRUs in the group of WTRUs.

15. The method of claim 14, wherein the request for SL-PRS resources further comprises: the number of SL-PRS transmission resources requested by the WTRU; and The number of SL-PRS transmission resources requested by the other WTRUs in the group of WTRUs.

16. The method of claim 10, wherein the second message comprises a medium access control (MAC) control element (CE).

17. The method of claim 10, further comprising performing a sidelink discovery procedure to identify the group of WTRUs.

18. The method of claim 10, further comprising sending the first message and the second message to a node, wherein the node comprises at least one of a network node, another WTRU, or a roadside unit (RSU).

19. At least one computer-readable storage medium having executable instructions stored thereon, which when executed by a processor configure the processor to: sending a first message including sidelink positioning information associated with a group of WTRUs, wherein the sidelink positioning information includes an indication of a sidelink positioning method used to determine the positioning of the WTRUs in the group of WTRUs; sending a second message comprising a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs; receiving an indication of allocated SL-PRS resources for the group of WTRUs; and An indication of the allocated SL-PRS resources is transmitted to the group of WTRUs.

20. At least one computer-readable storage medium according to claim 19, wherein the requested resources are based at least in part on the sidelink positioning method, the number of WTRUs in the group of WTRUs, and a quality of service (QoS) associated with the sidelink positioning method.

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