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] This application is a divisional application of the invention application with the applicant being Interactive Digital Patent Holdings, LLC, the application date being April 25, 2023, the application number being 202380045874.6, and the title being "New Radio (NR) Positioning Method for Overlay Inner Link Positioning".

[0002] Cross - reference to related applications

[0003] 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. The entire contents of U.S. Provisional Patent Application No. 63 / 334,809 are incorporated herein by reference. The entire contents of U.S. Provisional Patent Application No. 63 / 395,406 are incorporated herein by reference. The entire contents of U.S. Provisional Patent Application No. 63 / 421,669 are incorporated herein by reference. The entire contents of U.S. Provisional Patent Application No. 63 / 445,340 are incorporated herein by reference. Background of the Invention

[0004] Sidelink communication enables device - to - device (D2D) communication. Sidelink communication can have various applications, such as, for example, vehicle - to - everything (V2X) applications. Sidelink communication can be used in both in - network - coverage scenarios and out - of - network - coverage scenarios. With the continuous progress of telecommunications, users expect faster response times and lower latency times. To meet these expectations, progress in sidelink communication is needed. Summary of the Invention

[0005] Communication between one or more user equipments (UEs) and a network is considered herein. 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 a network entity (e.g., a server, a node, a next - generation node B - gNB, etc.) and a WTRU are described herein. For example, scheduling procedures for a group of WTRUs (e.g., a target WTRU and an anchor WTRU) to perform sidelink positioning to reduce signaling overhead between a gNB and the WTRUs in the group are described herein.

[0006] In various examples, which will become apparent in the context of the description herein, to implement sidelink positioning, a WTRU may determine whether DCI is for a sidelink positioning reference signal (SL-PRS) based on an indication in downlink control information (DCI). 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-PRSs scheduled by the network. The WTRU may determine whether to request SL-PRS resources for another WTRU. The WTRU may determine values for parameters 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 to request / select sidelink resources for one or more members in a group. The WTRU may determine SL-PRS resources for the RTT positioning method. The WTRU may determine whether to forward 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 a positioning group to the network. The WTRU may indicate a synchronization offset based on the resource allocation patterns of two WTRUs. The WTRU may request periodic and / or aperiodic SL-PRS resources. The WTRU may trigger a change in the SL-PRS configuration (e.g., SL-PRS offset and / or periodicity). The WTRU may determine whether to measure a reference signal time difference (RSTD) between two radio access technologies (RATs). The WTRU may determine reference nodes for RSTD measurement. The WTRU may request other WTRUs to be silent during a measurement gap (MG) and / or a positioning processing window (PPW) of the WTRU in user-to-user (Uu) communication. When an MG / PPW configuration is received in Uu, the WTRU triggers resource reselection and / or preemption. When an MG and / or PPW is received in the Uu of a peer WTRU, the WTRU triggers resource reselection and / or preemption.

[0007] In various additional examples, which will become apparent in the context of the description herein, to implement sidelink positioning, the WTRU may determine the time gap between the initial transmission and retransmission of the SL-PRS. The WTRU may determine which SL-PRS configuration to use. The WTRU may prioritize the resource pool used by the peer WTRU. The WTRU may determine which ID to scramble / generate the SL-PRS sequence with. The WTRU may determine when to monitor the SL-PRS resource pool. The WTRU may determine whether the DCI is for SL-PRS or data transmission based on the radio network temporary identifier (RNTI). The WTRU may determine whether the DCI is for SL-PRS or data transmission based on the search space set. The WTRU may determine whether the DCI is for SL-PRS or data based on the indicated code point in the bit field. The WTRU may be scheduled for group common DCI for SL-PRS. The WTRU may determine whether to forward the scheduled SL-PRS for the member WTRUs in the group. The WTRU may determine whether to send the scheduled SL-PRS based on the acknowledgement (ACK) from the member WTRU. The WTRU may convey sidelink positioning group information to the network.

[0008] In various further examples, which will become apparent in the context of the description herein, to implement sidelink positioning, the WTRU may receive an SL-PRS configuration. The WTRU may determine the location of the 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 regarding 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 an ID / index (identity / index) associated with sidelink positioning to the network.

[0009] In various other examples, which will become apparent in the context of the description herein, to enable sidelink positioning, a 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 the parameters for SL-PRS transmission. The WTRU may determine the resource pool for the SL-PRS. The WTRU may determine the resource location for sidelink positioning. The WTRU may receive the 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 the 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 the resources for indicating and / or reporting SL-PRS resource usage. The WTRU may determine the information to be included in the SL-PRS measurement report. The WTRU may determine the information for indicating and / or reporting sidelink resource usage in the uplink. The WTRU may receive sidelink positioning resources for a group of WTRUs and forward those sidelink positioning resources to other WTRUs. The WTRU may receive the configuration for sidelink positioning. The WTRU may send the configuration for sidelink positioning to other WTRUs. The WTRU may determine the SL-PRS reception resources for each WTRU in the group. The WTRU may determine its SL-PRS transmission resources. The WTRU may determine the SL-PRS measurement report resources from each WTRU in the group. The WTRU may be configured with periodic and / or semi-static resources for sidelink positioning. The behavior of the WTRU may be based on the status of feedback from other WTRUs regarding SL-PRS resource usage. The WTRU may indicate the priority of the sidelink positioning service. The WTRU may report the SL-PRS resources of the WTRU to the network. The WTRU may determine whether to perform SL-PRS reception. The WTRU may request the MG and / or positioning processing window (PPW) for SL-PRS reception. The WTRU may indicate the SL-PRS reception resources of the WTRU to another WTRU. The WTRU may prioritize between SL-PRS reception and other types of sidelink transmission and / or reception.

[0010] 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 the allocated SL-PRS resources for the group of WTRUs via the transceiver. The WTRU may convey the 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 the 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 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 the number of SL-PRS transmission resources requested for the WTRU. The request for SL-PRS resources may include the number of SL-PRS transmission resources requested for the remaining WTRUs in the group of WTRUs. The second message may include a media 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.

[0011] The present disclosure further discloses at least one computer-readable storage medium having executable instructions stored thereon. When executed by a processor such as a WTRU, the instructions can cause the at least one computer-readable storage medium to send a first message that includes sidelink positioning information associated with a group of WTRUs. The sidelink positioning information can include an indication of a sidelink positioning method for determining the positioning of WTRUs in the group of WTRUs. When executed, the instructions can further cause the processor to send a second message that includes a request for sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs. When executed, the instructions can further cause the processor to receive an indication of the allocated SL-PRS resources for the group of WTRUs. When executed, the instructions can further cause the processor to convey the indication of the allocated SL-PRS resources to the group of WTRUs. The requested resources can be based 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. The sidelink positioning information in the first message can include a group identifier (ID) associated with the group of WTRUs. The request for SL-PRS resources in the second message can include the group ID. The sidelink positioning method can 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 can be one of the WTRUs in the group of WTRUs, and the request for SL-PRS resources can 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 can include the number of SL-PRS transmission resources requested for the WTRU. The request for SL-PRS resources can include the number of SL-PRS transmission resources requested for the remaining WTRUs in the group of WTRUs. The second message can include a media access control (MAC) control element (CE). When executed, the instructions can further cause the processor to perform a sidelink discovery procedure to identify the group of WTRUs. When executed, the instructions can further cause the processor to send the first message and the second message to a node. The node can include at least one of a network node, another WTRU, a roadside unit (RSU), or any suitable combination thereof.

[0012] In another example of a WTRU configured to perform sidelink positioning, the WTRU may receive an indication of resources for performing sidelink positioning for a group of WTRUs. The indication may be based on resources capable of transmitting and receiving sidelink positioning reference signals (SL-PRSs) and / or performing RTT-based sidelink positioning. The indication may be based on resources capable of transmitting SL-PRSs and / or performing positioning based on SL-PRS transmission, receiving SL-PRSs and / or performing positioning based on SL-PRS reception. 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 performing sidelink positioning for the group of WTRUs. The indication of the resources may be received via a downlink control information (DCI) transmission. Based on resources capable of receiving SL-PRSs, the WTRU may transmit the indication of the resources to at least one anchor WTRU. Based on resources capable of reporting SL-PRS measurements, the WTRU may transmit the indication of the resources to at least one anchor WTRU. Transmitting the indication of the resources to at least one anchor WTRU may utilize the group identifier of the group of WTRUs. 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.

[0013] 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 to which the WTRU belongs. The WTRU may receive the indication based on resources capable of transmitting and receiving sidelink positioning reference signals (SL-PRS). The WTRU may be configured to perform round-trip time (RTT)-based sidelink positioning based on resources capable of transmitting SL-PRS. The WTRU may be configured to perform SL-PRS transmission-based positioning based on resources capable of receiving SL-PRS. The WTRU may be configured to perform SL-PRS reception-based positioning. 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 for 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 the group of WTRUs to which the WTRU belongs. Downlink control information (DCI) transmission may receive an indication of the resources. Based on 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 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 an indication of the resources to at least one anchor WTRU may utilize the group identifier of the group of WTRUs.

[0014] 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 the following: 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 a respective SL-PRS measurement reporting configuration for each of the plurality of resources.

[0015] Each SL-PRS measurement reporting configuration may include at least one of the following: 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, and / or a multiplexing rule associated with the respective resource.

[0016] 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 a 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 a scheduled resource 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 following: the ID of each anchor WTRU, the number of WTRUs in the group of WTRUs, the OCC of each WTRU in the group of WTRUs, a set of sidelink resources for group scheduling, and / or a multiplexing rule associated with each resource among the plurality of resources. To perform SL-PRS measurements and / or derive the positioning of a 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 therebetween. The WTRU may determine the relative positioning of each WTRU in the group of WTRUs based on the calculated RTT. The WTRU may transmit an indication of the relative positioning to each WTRU in the group of WTRUs.

[0017] Each SL-PRS measurement report configuration may include at least one of the following: a bandwidth associated with a corresponding resource, a duration associated with a corresponding resource, a number of repetitions associated with a corresponding resource, a size of a corresponding resource, and / or a multiplexing rule associated with a 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 a 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 a scheduled resource 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 following: the ID of each anchor WTRU, the number of WTRUs in the group of WTRUs, the OCC of each WTRU in the group of WTRUs, a set of sidelink resources for group scheduling, and / or a multiplexing rule associated with each resource among the plurality of resources.

[0018] It 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 WTRUs 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 sidelink positioning reference signal (SL-PRS) resources for the group of WTRUs. The processor may be configured to receive an indication of the allocated SL-PRS resources for the group of WTRUs via the transceiver. The processor may be configured to convey the indication of the allocated SL-PRS resources to the group of WTRUs via the transceiver.

[0019] The resources requested by the WTRU may be at least partially based 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.

[0020] 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.

[0021] 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 group of WTRUs. The request for SL-PRS resources may include the quantity of SL-PRS transmission resources requested for the WTRU and / or the quantity of SL-PRS transmission resources requested for other WTRUs in the group of WTRUs.

[0022] The second message may include a media access control (MAC) control element (CE).

[0023] The processor is further configured to execute a sidelink discovery procedure to identify the group of WTRUs.

[0024] 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).

[0025] 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 that includes 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 that includes 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 convey the indication of the allocated SL-PRS resources to the group of WTRUs. The requested resources may be at least partially based 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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. The figures in such drawings are examples. Thus, the drawings and the detailed description should not be considered restrictive, and other equally valid examples are possible and contemplated. The same reference numerals (“ref.” or “refs.”) denote the same elements in the drawings.

[0027] Figure 1A An example system diagram depicting an example communication system in which one or more of the disclosed embodiments may be implemented is depicted.

[0028] Figure 1B An example system diagram depicting an example wireless transmit / receive unit (WTRU) that may be used within the Figure 1A illustrated communication system in accordance with an embodiment is depicted.

[0029] Figure 1C An example system diagram depicting an example radio access network (RAN) and an example core network (CN) that may be used within the Figure 1A illustrated communication system in accordance with an embodiment is depicted.

[0030] Figure 1D An example system diagram depicting a further example RAN and a further example CN that may be used within the Figure 1A illustrated communication system in accordance with an embodiment is depicted.

[0031] Figure 2Depicts an exemplary illustration of round-trip time (RTT) sidelink (SL) positioning, where a first WTRU (such as an anchor WTRU) may be instructed by a second WTRU (such as a target WTRU) to transmit a sidelink positioning reference signal (PRS) in one SL-PRS resource.

[0032] Figure 3 Depicts an exemplary illustration of sidelink control information (SCI) positions for a shared resource pool and a dedicated resource pool.

[0033] Figure 4 Depicts an exemplary illustration of pattern-based physical sidelink control channel / physical sidelink shared channel (PSCCH / PSSCH) and sidelink positioning reference signal (SL-PRS) multiplexing.

[0034] Figure 5 Depicts an exemplary illustration of time-frequency-based PSCCH / PSSCH and SL-PRS multiplexing.

[0035] Figure 6 Depicts an exemplary illustration of PSCCH / PSSCH with an associated SL-PRS.

[0036] Figure 7 Depicts an exemplary illustration where a WTRU embeds SCI in a pattern.

[0037] Figure 8 Depicts an exemplary illustration of potential scheduled and / or selected resources for SL positioning.

[0038] Figure 9 Depicts an exemplary illustration of potential scheduled / selected resources for SL positioning, where the SL-PRS transmission (Tx) resource is in the same time slot as its indication.

[0039] Figure 10 Depicts an exemplary illustration of downlink control information (DCI) for scheduling resources for SL positioning.

[0040] Figure 11 Depicts an exemplary illustration of providing feedback on the use of a sidelink positioning reference signal (SL-PRS) resource before the SL-PRS resource.

[0041] Figure 12 Depicts an exemplary illustration of providing feedback on the use of the SL-PRS resource after the SL-PRS resource.

[0042] Figure 13 Depicts an exemplary illustration of SL-PRS scheduling for a group of user equipment (UE) (also known as WTRU).

[0043] Figure 14Illustrates an example of an anchor WTRU using an orthogonal cover code (OCC) for a SL-PRS resource.

[0044] Figure 15 Illustrates an example of SL-PRS measurement report scheduling for a group of WTRUs.

[0045] Figure 16 Illustrates an example of semi-static resources for SL positioning.

[0046] Figure 17 Illustrates an example of an overlap between SL-PRS reception and the SL communication resource pool.

[0047] Figure 18 Illustrates an example of multiplexing of SL-PRS and SL-PRS measurement reports among WTRUs in a group.

[0048] Figure 19 Illustrates an example signal flow diagram for in-coverage round-trip time (RTT) positioning.

[0049] Figure 20 Illustrates an example signal flow diagram for in-coverage SL positioning based on a WTRU.

[0050] Figure 21 Illustrates an example flow diagram of SL positioning where WTRU information is provided by one or more anchor WTRUs.

[0051] Figure 22 Illustrates an example flow diagram of in-coverage SL positioning (WTRU-based), anchor WTRU information from a location management function (LMF), and PRS configuration to a target WTRU from the LMF.

[0052] Figure 23 Illustrates an example flow diagram of two-sided RTT SL positioning.

[0053] Figure 24 Illustrates an example diagram depicting a WTRU obtaining and providing sidelink resources associated with a group of WTRUs.

[0054] Figure 25 Illustrates another example diagram depicting a WTRU obtaining and providing SL resources associated with a group of WTRUs. Detailed implementation

[0055] Figure 1AFIG. is a diagram illustrating an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multi-access system that provides content such as voice, data, video, messaging, broadcasting, etc. to a plurality of wireless users. The communication system 100 may enable the plurality of wireless users to access such content through the 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 multicarrier (FBMC), etc.

[0056] As Figure 1A shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the 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 one of which may be referred to as a "station" and / or "STA") may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular telephones, personal digital assistants (PDAs), smart phones, laptop computers, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, 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 processing chain environment), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. Any one of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0057] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks such as CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, base stations 114a, 114b may be transceiver base stations (BTSs), Node Bs, evolved Node Bs, Home Node Bs, Home evolved Node Bs, gNBs, NR Node Bs, site controllers, access points (APs), wireless routers, etc. Although base stations 114a, 114b are each depicted as a single element, it should be understood that base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0058] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown) such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit 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 licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of wireless services to a particular geographic area, which may be relatively fixed or may change over time. A cell may further be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, 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 transmit and / or receive signals in a desired spatial direction.

[0059] Base stations 114a, 114b may communicate with one or more of WTRUs 102a, 102b, 102c, 102d via air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) may be used to establish air interface 116.

[0060] More specifically, as noted above, the communication system 100 can be a multi-access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can use Wideband CDMA (WCDMA) to establish the air interfaces 115 / 116 / 117. WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0061] In an embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement a radio technology (such as Evolved UMTS Terrestrial Radio Access (E-UTRA)), which can use Long-Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro) to establish the air interface 116.

[0062] In an embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as NR radio access, which can use New Radio (NR) to establish the air interface 116.

[0063] In an embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, the base stations 114a and the WTRUs 102a, 102b, 102c can implement LTE radio access and NR radio access together using, for example, the Dual Connectivity (DC) principle. Thus, the air interfaces used by the WTRUs 102a, 102b, 102c can be characterized by multiple types of radio access technologies and / or transmissions to / from multiple types of base stations (e.g., eNBs and gNBs).

[0064] 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.

[0065] Figure 1A The base station 114b in can be, for example, a wireless router, a home Node B, a home evolved Node B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a business premise, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. 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 pico cell or a femto cell. As Figure 1A shown, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0066] The RAN 104 / 113 may communicate with the CN 106 / 115, which can 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, location-based services for mobile devices, prepaid calls, Internet connectivity, video distribution, etc., and / or perform advanced security functions such as user authentication. Although not shown in Figure 1Ais shown, it should be understood that RAN 104 / 113 and / or CN 106 / 115 may communicate directly or indirectly with other RANs using the same RAT as RAN 104 / 113 or different RATs. For example, in addition to being connected to RAN 104 / 113 that may utilize NR radio technology, CN 106 / 115 may also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0067] CN 106 / 115 may also act as a gateway for 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 Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 may include a wired communication network and / or a wireless communication network owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, and the one or more RANs may use the same RAT as RAN 104 / 113 or a different RAT.

[0068] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, Figure 1A the illustrated WTRU 102c may be configured to communicate with a base station 114a that may use a cellular-based radio technology and with a base station 114b that may use IEEE 802 radio technology.

[0069] Figure 1B is a system diagram of an exemplary WTRU 102. As Figure 1B shown, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripheral devices 138, etc. It should be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0070] The processor 118 can be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple 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 can 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 can be coupled to a transceiver 120, which can be coupled to a transmit / receive element 122. Although Figure 1B the processor 118 and the transceiver 120 are depicted as separate components, it should be understood that the processor 118 and the transceiver 120 can be integrated together in an electronic package or chip.

[0071] The transmit / receive element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via an air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 can be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 can be configured to transmit and / or receive both RF signals and optical signals. It should be understood that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0072] Although the transmit / receive element 122 is depicted as a single element in Figure 1B the WTRU 102 can include any number of transmit / receive elements 122. More specifically, the WTRU 102 can employ MIMO technology. Thus, in one embodiment, the WTRU 102 can include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0073] The transceiver 120 can be configured to modulate the signals to be transmitted by the transmit / receive element 122 and demodulate the signals received by the transmit / receive element 122. As noted above, the WTRU 102 can have multi-mode capabilities. For example, thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0074] The processor 118 of the WTRU 102 may be coupled to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from any type of suitable memory (such as non-removable memory 130 and / or removable memory 132) and store data in any type of suitable memory. The non-removable memory 130 may include random access memory (RAM), 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, etc. In other embodiments, the processor 118 may access information from a memory that is not physically located on the WTRU 102 (such as on a server or a home computer (not shown)) and store data in that memory.

[0075] The processor 118 may receive power from a power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry battery packs (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), a solar cell, a fuel cell, etc.

[0076] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to or instead of the information from the GPS chipset 136, the WTRU 102 may receive location information via an air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine the location of the WTRU based on the timing of signals received from two or more nearby base stations. It should be understood that, consistent with the embodiments, the WTRU 102 may obtain location information by any suitable location determination method.

[0077] The processor 118 may be further coupled to other peripheral devices 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 peripheral device 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, modules, 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. The 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 geographic location sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0078] The WTRU 102 may include a full-duplex radio for which the transmission and reception of some or all of the signals (e.g., associated with a particular subframe 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 that is used to reduce and / or substantially eliminate self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which the transmission and reception of some or all of the signals (e.g., associated with a particular subframe for UL (e.g., for transmission) or downlink (e.g., for reception)).

[0079] Figure 1C is a system diagram of the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c via the air interface 116. The RAN 104 may also communicate with the CN 106.

[0080] The RAN 104 may include eNodeBs 160a, 160b, 160c, but it should be understood that the RAN 104 may include any number of eNodeBs when consistent with the embodiments. Each of the eNodeBs 160a, 160b, 160c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, for example, the eNodeB 160a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0081] Each of the eNodeBs 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. As Figure 1C shown, the eNodeBs 160a, 160b, 160c may communicate with each other via the X2 interface.

[0082] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. Although each of the foregoing elements is depicted as 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.

[0083] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via the S1 interface and may act 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 the initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide control plane functions for switching between the RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0084] The SGW 164 can be connected via the S1 interface to each of the evolved Node Bs 160a, 160b, 160c in the RAN 104. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can perform other functions such as anchoring the user plane during handovers between evolved Node Bs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, etc.

[0085] The SGW 164 can be connected to the PGW 166, which can provide the WTRUs 102a, 102b, 102c with access to a packet switched network (such as the Internet 110) to facilitate communication between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0086] The CN 106 can facilitate communication with other networks. For example, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to a circuit switched network (such as the PSTN 108) to facilitate communication between the WTRUs 102a, 102b, 102c and traditional landline communication devices. For example, the CN 106 can include an IP gateway (such as an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108 or can communicate with the IP gateway. In addition, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to other networks 112, which can include other wired and / or wireless networks owned and / or operated by other service providers.

[0087] Although the WTRU is described as a wireless terminal in Figures 1A to 1D it is contemplated that in some representative embodiments, such a terminal can (e.g., temporarily or permanently) use a wired communication interface with the communication network.

[0088] In a representative embodiment, the other network 112 can be a WLAN.

[0089] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) 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 from the BSS. Traffic destined for an STA from outside the BSS may reach the STA through the AP and may be delivered to the STA. Traffic from an STA destined for a destination outside the BSS may be sent to the AP for delivery to the corresponding destination. Traffic between STAs within the BSS may be sent through the AP. For example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between a source STA and a destination STA (e.g., directly between them) using direct link setup (DLS). In some representative embodiments, DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using independent BSS (IBSS) mode may not have an AP, and STAs within the IBSS or using the IBSS (e.g., all STAs in the STA) may communicate directly with each other. The IBSS communication mode may sometimes be referred to as an "ad hoc" communication mode in this document.

[0090] When using 802.11ac infrastructure operation mode or a similar operation mode, the AP may send beacons on a fixed channel, such as the primary channel. The primary channel may be of a fixed width (e.g., a bandwidth of 20 MHz wide) or a width dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by the STA to establish a connection with the AP. In some representative embodiments, for example, carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented in an 802.11 system. For CSMA / CA, the 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 back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0091] High throughput (HT) STAs may communicate using a 40 MHz wide channel, e.g., via a combination of the primary 20 MHz channel and an adjacent or non-adjacent 20 MHz channel to form a 40 MHz wide channel.

[0092] A very high throughput (VHT) STA can support channels that are 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide. A 40 MHz channel and / or an 80 MHz channel can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining eight contiguous 20 MHz channels, or by combining two non - contiguous 80 MHz channels (which can be referred to as an 80+80 configuration). For the 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 separately processed by an inverse fast Fourier transform (IFFT) and time - domain processing. These streams can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations for the 80+80 configuration described above can be reversed, and the combined data can be delivered to the media access control (MAC).

[0093] 802.11af and 802.11ah support operating modes below 1 GHz. Compared to those used in 802.11n and 802.11ac, the channel operating bandwidth and carriers are reduced in 802.11af and 802.11ah. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the television white space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non - TVWS spectrum. According to a representative embodiment, 802.11ah can support meter - type control / machine - type communication, such as MTC devices in a macro - coverage area. MTC devices can have certain capabilities, for example, limited capabilities, including supporting (e.g., only supporting) certain bandwidths and / or limited bandwidths. MTC devices can include a battery with a battery life higher than a threshold (e.g., to maintain a very long battery life).

[0094] A WLAN system supporting multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) includes channels that can be designated as primary channels. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or restricted by an STA (which supports the minimum bandwidth operation mode) from all STAs operating in the BSS. In the example of 802.11ah, for an STA (e.g., an MTC-type device) that supports (e.g., only supports) the 1MHz mode, the primary channel can be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operation modes. Carrier sensing and / or network allocation vector (NAV) settings can depend on the state of the primary channel. If the primary channel is busy, for example, because an STA (only supporting the 1MHz operation mode) is transmitting to the AP, the entire available frequency band can be considered busy even if most of the frequency band remains idle and may be available.

[0095] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In 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 available bandwidth for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0096] Figure 1D FIG. is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 can employ NR radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 113 can also communicate with CN 115.

[0097] RAN 113 may include gNBs 180a, 180b, 180c, but it should be understood that, consistent with the embodiments, RAN 113 may include any number of gNBs. Each of gNBs 180a, 180b, 180c may include one or more transceivers for communicating with WTRUs 102a, 102b, 102c over air interface 116. In one embodiment, gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, 180c. Thus, gNB 180a, for example, may use multiple antennas to transmit wireless signals to WTRU 102a and / or receive wireless signals from that WTRU. In an embodiment, gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0098] WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a parameter set that can be scaled. For example, the OFDM symbol interval and / or the OFDM subcarrier interval may vary for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of various lengths or scalable lengths (e.g., containing different numbers of OFDM symbols and / or having an absolute time length that varies continuously).

[0099] gNBs 180a, 180b, 180c can be configured to communicate with WTRUs 102a, 102b, 102c in a stand-alone configuration and / or a non-stand-alone configuration. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c without accessing other RANs (e.g., such as evolved Node Bs 160a, 160b, 160c). In the stand-alone configuration, WTRUs 102a, 102b, 102c can use one or more of gNBs 180a, 180b, 180c as a mobility anchor. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In the non-stand-alone configuration, WTRUs 102a, 102b, 102c can communicate / connect with gNBs 180a, 180b, 180c while also communicating / connecting with another RAN (such as evolved Node Bs 160a, 160b, 160c). For example, WTRUs 102a, 102b, 102c can implement the DC principle to communicate with one or more of gNBs 180a, 180b, 180c and one or more of evolved Node Bs 160a, 160b, 160c substantially simultaneously. In the non-stand-alone configuration, evolved Node Bs 160a, 160b, 160c can act as the mobility anchor for WTRUs 102a, 102b, 102c, and gNBs 180a, 180b, 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, 102c.

[0100] Each of gNBs 180a, 180b, 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. As Figure 1D shown, gNBs 180a, 180b, 180c can communicate with each other via the Xn interface.

[0101] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly Data Networks (DN) 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.

[0102] The AMF 182a, 182b may be connected to one or more gNBs among 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 for network slicing (e.g., handling of different PDU sessions with different requirements), selection of a specific SMF 183a, 183b, management of the registration area, 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 service 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, and so on. The AMF 162 may provide control plane functions for handover between the RAN 113 and other RANs (not shown) employing other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0103] 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 notifications, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0104] UPF 184a and 184b can be connected to one or more gNBs among gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. The one or more gNBs can provide access to a packet switched network (such as the Internet 110) for WTRU 102a, 102b, and 102c to facilitate communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184a and 184b can perform other functions, such as routing and forwarding packets, implementing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0105] CN 115 can facilitate communication with other networks. For example, CN 115 can include an IP gateway (such as an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 115 and PSTN 108 or can communicate with the IP gateway. In addition, CN 115 can provide access to other networks 112 for WTRU 102a, 102b, and 102c. These other networks can include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU 102a, 102b, and 102c can be connected to DN 185a and 185b via UPF 184a and 184b through the N3 interface to UPF 184a and 184b and the N6 interface between UPF 184a and 184b and local data network (DN) 185a and 185b.

[0106] In view of Figures 1A to 1D and Figures 1A to 1D In view of the corresponding descriptions, one or more or all of the functions described herein with respect to one or more of the following can be performed by one or more emulation devices (not shown): WTRU 102a - 102d, base stations 114a - 114b, evolved Node Bs 160a - 160c, MME 162, SGW 164, PGW 166, gNBs 180a - 180c, AMF 182a - 182b, UPF 184a - 184b, SMF 183a - 183b, DN 185a - 185b, and / or any other device described herein. The emulation device can be one or more devices configured to mimic one or more or all of the functions described herein. For example, the emulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0107] A simulation device can 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 can 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 can perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. A simulation device can be directly coupled to another device for testing purposes and / or can perform tests using over-the-air wireless communication.

[0108] One or more simulation devices can perform one or more (including all) functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, a simulation device can be used in a test laboratory and / or in a test scenario in a non-deployed (e.g., test) wired and / or wireless communication network in order to implement tests of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0109] Wireless communication between one or more user equipments (UEs) and a network is considered 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.

[0110] Sidelink communication can support communication between different vehicles. Sidelink communication (e.g., transmitting, receiving, etc.) can be provided resources in various ways. For example, resources for sidelink transmission / reception can be structured as a resource pool. A resource pool can include a set of contiguous frequency resources that repeat in time according to a bitmap pattern. A WTRU can be configured via one or more resource pools. For an in-coverage WTRU (e.g., a WTRU within network coverage), the resource pool can be configured via a system information block (SIB), radio resource control (RRC), etc. and / or any suitable combination thereof. For an out-of-coverage WTRU (e.g., a WTRU not covered by the network), the resource pool can be pre-configured on the WTRU.

[0111] Each sidelink transmission can span within a time slot including a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), and / or any suitable combination thereof. The PSSCH and PSCCH can utilize frequency division multiplexing (FDM), time division multiplexing (TDM), and / or any suitable combination thereof.

[0112] Side link control information (SCI) can be divided into two parts. These two parts can be referred to as first-level SCI and second-level SCI. The first-level SCI can indicate resources for side link transmission, quality of service (QoS) for transmission (e.g., priority), demodulation reference signal (DMRS), phase tracking reference signal (PTRS) for side link transmission, and the second SCI format and / or any suitable combination thereof. The second-level SCI can indicate the remaining control information. The SCI can be used to reserve resources for future transmission within a resource pool.

[0113] Side link resources can be scheduled by the network (referred to herein as mode 1) and / or autonomously selected by the WTRU (referred to herein as mode 2). If the WTRU performs mode 2, the WTRU can perform sensing by decoding the SCI from other WTRUs before selecting side link resources to avoid selecting resources reserved by other WTRUs.

[0114] Side link channel state information reference signal (SL-CSI-RS) can be supported for unicast to support the transmitting WTRU (Tx WTRU) in determining transmission (Tx) parameters (e.g., power and rank). The Tx WTRU can indicate the presence of the SL-CSI-RS by using the SCI. Channel state information reference signal (CSI-RS) transmission can trigger channel state information (CSI) reporting. PC5-RRC can configure the CSI reporting latency. Each report can be associated with one SL-CSI-RS transmission.

[0115] Positioning techniques (e.g., determining the location / location of the WTRU) can be new radio (NR) universal mobile telecommunication 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. A geographic coordinate system (GCS), local coordinate system, etc. and / or any suitable combination thereof can represent the absolute positioning of the WTRU. The relative positioning of the WTRU (e.g., the target WTRU) can be represented according to distance, angle with another WTRU (e.g., the anchor WTRU), reference points with known locations, etc. and / or any suitable combination thereof.

[0116] In DL-based positioning, a downlink positioning reference signal (DL-PRS) can be transmitted from multiple transmit / receive points (TRPs) to a WTRU. Also, the WTRU can observe and measure the downlink signals from the TRPs. In an example referred to herein as the WTRU-B method, the WTRU can calculate its location. In another example referred to herein as the WTRU-A method, the WTRU can return downlink measurements to the network. In another example referred to herein as an angle-based method, the WTRU can report the angle of arrival (AoA) and reference signal received power (RSRP) of the downlink signals from the TRPs. In another example referred to herein as a timing-based method, the WTRU can report the reference signal time difference (RSTD). The above methods can depend on the transmission timing synchronization between the TRPs. The positioning calculation error can be the result of synchronization error and multipath.

[0117] In UL-based positioning (e.g., UL-based), the WTRU can transmit at least one uplink positioning reference signal (UL-PRS) configured for positioning via RRC to the TRP. The network can then calculate the location of the WTRU based on the coordination of all TRPs that receive the UL-PRS from the WTRU.

[0118] In UL and DL-based methods (e.g., DL+UL-based), the WTRU can measure the receive-transmit (Rx-Tx) time difference between the received DL-PRS and the transmitted UL-PRS. The Rx-Tx time difference and the RSRP can be reported to the network. The network can then coordinate the TRPs to calculate the location of the WTRU.

[0119] Other example SL positioning methods can include timing / angle positioning and round-trip time (RTT) positioning. Timing / angle positioning can refer to any positioning method that uses a reference signal such as an SL-PRS. The WTRU can receive multiple reference signals from the WTRU and can measure the RSTD, RSRP, and / or AoA. Examples of angle / timing positioning can include angle of departure (SL-AoD) positioning or sidelink time difference of arrival (SL-TDOA) positioning. In another example, the WTRU can send an SL-PRS to the WTRU, and the receiver can perform measurements (e.g., RSTD, AoA, RSRP) to determine the location of the WTRU that sent the SL-PRS.

[0120] RTT positioning can refer to any positioning method that requires two WTRUs to send SL-PRS to each other. In an example, an anchor WTRU may send SL-PRS to a target WTRU. Once the target WTRU receives the SL-PRS from the anchor WTRU, the target WTRU may send 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.

[0121] 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. Regarding resource allocation for sidelink positioning, network-scheduled resources may be utilized, in which the network may perform resource allocation for sidelink resources used for sidelink positioning. Supporting the network-scheduled resource allocation mode may allow the network to have full control over sidelink resources.

[0122] 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.

[0123] This document also describes scheduling procedures for a group of WTRUs (such as a target WTRU and at least one anchor WTRU). In these procedures, the group of WTRUs may perform sidelink positioning to reduce signaling overhead between the gNB and the WTRUs in the group.

[0124] This document describes methods and systems 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, WTRUs with LMF capabilities, WTRUs with the ability to process measurements and determine location information of other WTRUs, WTRUs with the ability to configure SL-PRS for other WTRUs and / or servers, etc.) and / or WTRUs within the group. An example of a server WTRU can be a WTRU that provides SL-PRS configuration to other WTRUs and / or receives measurement reports from WTRUs and determines the location information of other WTRUs based on the measurement reports. As described herein, positioning can be used for ranging, without any limitation. Positioning can be referred to as a method / scheme for estimating the geographical location of a WTRU. Ranging can 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" can be used interchangeably with "distance between WTRUs". Positioning of a WTRU and sidelink positioning can be applicable to ranging. Positioning of a WTRU can include absolute positioning, which can include coordinates and / or area ID, etc. Positioning of a WTRU can include relative positioning, which can include range, distance, propagation time, RTT to another entity and / or node (e.g., another WTRU, roadside unit (RSU), positioning reference unit (PRU), gNB, and / or any suitable combination thereof).

[0125] As described herein, a WTRU can 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 can be scheduled for one or more resources, where the one or more resources can be used interchangeably with the WTRU. The WTRU can select the one or more resources.

[0126] Any solution applicable for a WTRU to select one or more resources can be used for a WTRU to request one or more resources from another node. Additionally or alternatively, any solution applicable for a WTRU to request one or more resources can be used for a WTRU to request one or more resources. For example, any triggering condition for a WTRU to select one or more resources can be used for a WTRU to request one or more resources from another node. Any triggering condition for a WTRU to request one or more resources from another node can be used for a WTRU to select one or more resources by itself.

[0127] As used herein, the term "scheduled" can be used for situations where resources can be determined by another entity (e.g., other than the WTRU itself). As used herein, the term "selected" can be used for situations where resources can be determined by the WTRU itself. However, any applicable solution described for the case where the WTRU is scheduled for resources can be used interchangeably with the case where the WTRU makes its own resource selection.

[0128] The SL-PRS resources for reception by one WTRU (e.g., the target WTRU) can be used interchangeably with the SL-PRS for transmission by other WTRUs (e.g., the anchor WTRU).

[0129] A resource can be used interchangeably with a set of resources. For example, a resource for SL-PRS transmission / reception can be used interchangeably with a set of resources for SL-PRS transmission / reception. The WTRU not performing SL-PRS reception in an SL-PRS resource can be equivalent to the WTRU not obtaining SL-PRS measurement results from the resource.

[0130] As used herein, the terms "indicate to another WTRU", "report to", and / or "send a message to" can be used interchangeably with the terms "indicate to another entity or node (e.g., gNB and / or RSU, etc.)", "report to", and / or "send a message to". As used herein, the WTRU receiving a message from another WTRU can be used interchangeably with the WTRU receiving a message from any other node (e.g., gNB and / or RSU, etc.). The SL-PRS reception time and / or duration can include the SL-PRS signal reception time and / or the SL-PRS processing time after receiving the SL-PRS signal.

[0131] As used herein, the term "SCI" can be used interchangeably with the terms "first-level SCI", "second-level SCI", and / or both "first-level SCI" and "second-level SCI". As used herein, the term "SCI" can be used interchangeably with the term "PSCCH".

[0132] As used herein, a group of WTRUs can refer to one or more WTRUs. A positioning group can refer to a group of two or more WTRUs. The SL-PRS reception resources for one WTRU (e.g., the target WTRU) can be used interchangeably with the SL-PRS transmission by another WTRU (e.g., the anchor WTRU). The positioning method based on SL-PRS Tx and / or the positioning method based on SL-Rx can be used interchangeably with the SL-TDOA positioning method. The SL-TDOA method can be used to describe a timing-based positioning method, where the target WTRU can be only a transmitter of SL-PRS (e.g., UL-like SL-TDOA) and / or only a receiver of SL-PRS (e.g., DL-like SL-TDOA).

[0133] The WTRU may use DMRS of the 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), reference signal (RS) designed for positioning purposes, etc. and / or any suitable combination thereof as the SL-PRS.

[0134] The WTRU may be configured and / or pre-configured. As used herein, the WTRU being envisioned and / or (pre)-configured may mean that the WTRU is pre-configured, the WTRU receives configuration from another entity (such as a node, gNB, another WTRU, etc.) and / or any suitable combination thereof. In an example, the resource pool for sidelink positioning may configure / pre-configure the WTRU.

[0135] One or any combination of the following resource pools for SL-PRS transmission / reception may configure / pre-configure the WTRU: one or more dedicated resource pools for SL-PRS transmission / reception, one or more shared resource pools with data for SL-PRS transmission / reception, 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 autonomous selection resource pools dedicated to SL-PRS transmission / reception, one or more WTRU autonomous selection resource pools for SL-PRS transmission shared with sidelink data communication, one or more WTRU autonomous selection resource pools for sidelink communication for facilitating sidelink positioning, one or more network-scheduled resource pools for sidelink communication for facilitating sidelink positioning, one or more resource pools for sidelink communication having SL-PRS in the transmission of data communication and / or any suitable combination thereof.

[0136] 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 one of the following individually or in any suitable 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 the SL-PRS sequence; time-frequency of the SL-PRS resource; SL-PRS resource element offset; SL-PRS resource slot offset; SL-PRS symbol offset;

[0137] SL-PRS QCL information; SL-PRS resource set ID; list of SL-PRS resources in the resource set;

[0138] Number of SL-PRS symbols; silence parameters for SL-PRS such as repetition factor, silence options; SL-PRS resource power; periodicity of SL-PRS transmission;

[0139] Number of periods of SL-PRS transmission; spatial direction information of SL-PRS transmission (e.g., beam information, transmission angle); spatial direction information of SL-RS reception (e.g., beam ID for receiving SL-RS, angle of arrival); frequency layer ID; WTRUID and / or SL-PRS ID.

[0140] The WTRU can determine whether to multiplex sidelink control information (SCI) with sidelink positioning reference signal (SL-RPS) in a transmission. In an example, the WTRU can determine whether to multiplex SCI with SL-PRS in a transmission (e.g., a transmission having SCI and SL-PRS in the same time slot, where the SCI can occur in the first few symbols of the transmission).

[0141] The WTRU can determine whether to multiplex SCI with SL-PRS based on the resource pool used for SL-PRS transmission. For example, if the WTRU uses a shared resource pool for sidelink data communication, the WTRU can determine to multiplex SCI with SL-PRS in a transmission. Otherwise, if the WTRU uses a dedicated resource pool for SL-PRS transmission, the WTRU can not multiplex SCI with SL-PRS in a transmission.

[0142] The WTRU can determine whether to multiplex SCI with SL-PRS based on the scheduling mode of the SL-PRS resources. For example, if the WTRU performs autonomous resource allocation for SL-PRS, the WTRU can determine to multiplex SCI with SL-PRS in a transmission. Otherwise, if the SL-PRS is scheduled by the network, the WTRU may not need to multiplex SCI with SL-PRS.

[0143] The WTRU can determine whether to multiplex sidelink control information (SCI) with sidelink positioning reference signal (SL-RPS) in a transmission based on whether another WTRU indicates the resource. For example, the WTRU can determine whether to multiplex SCI in an SL-PRS transmission based on whether the WTRU itself selects the SL-PRS and / or whether another WTRU selects the SL-PRS. If the WTRU autonomously selects the SL-PRS resource, the WTRU can determine to multiplex SCI in the SL-PRS transmission. Otherwise, if another WTRU indicates the resource, the WTRU can not multiplex SCI in the SL-PRS transmission.

[0144] The WTRU may determine whether to multiplex sidelink control information (SCI) with a sidelink positioning reference signal (SL-RPS) in a 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 a time slot, 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 time slot, the WTRU may not multiplex the SCI in the SL-PRS transmission. Such an SL-PRS resource may be indicated by another WTRU.

[0145] The WTRU may determine whether to multiplex sidelink control information (SCI) with a sidelink positioning reference signal (SL-RPS) in a transmission. The WTRU may make this determination based on whether the SL-PRS resource is an initial and / or repeated SL-PRS resource in the same and / or different time slots. For example, for an initial SL-PRS transmission, the WTRU may multiplex the SCI. Otherwise, for a repeated SL-PRS transmission in the same or a future time slot, 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.

[0146] In an example, the WTRU may determine not to multiplex the SCI with the SL-PRS in a transmission in a network-scheduled resource pool dedicated to SL-PRS transmission. The WTRU may determine to multiplex the SCI with the SL-PRS in a transmission in a WTRU-autonomous selection resource pool shared with sidelink data communication.

[0147] Figure 2 An example of an RTT-based sidelink positioning method is depicted, where a WTRU (e.g., an anchor WTRU) may be indicated by another WTRU (e.g., a target WTRU) to transmit an SL-PRS in an 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 or the last few symbols of a time slot. For example, if the indicated SL-PRS 202 is in the first few symbols of time slot 204 as depicted in Figure 2 Case 1, then 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 time slot 210, then the WTRU may not multiplex the SCI with the SL-PRS 208, as depicted in Figure 2 Case 2.

[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 an RTT-based positioning method). Specifically, if there is one or more previous SL-PRSs 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] 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 an RTT-based positioning method). For example, if there is one or more previous SL-PRSs 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.

[0150] The WTRU may determine the time gap between an initial transmission and a retransmission of the SL-PRS. The WTRU may select resources for the initial transmission and 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 the SL-PRS transmission that meet the (pre)-configured minimum gap. For example, the WTRU may be (pre)-configured with multiple SL-PRS resources in the time domain in a time slot. The WTRU may then select SL-PRS resources such that no two resources occupy the same time slot. 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 time slot.

[0151] Figure 3Depicts an example of SCI and SL-PRS multiplexing in a shared resource pool and a dedicated resource pool. The WTRU may determine the position of side link control information (SCI) in a transmission. For example, the WTRU may determine to multiplex SCI (e.g., first-level SCI) with SL-PRS in a transmission. Then, the WTRU may determine the position of SCI (e.g., first-level SCI) in the transmission based on one or any combination of the following: The WTRU may determine the position of SCI based on the resource pool used for the transmission of SL-PRS. At 302, the WTRU may place the SCI 304 associated with SL-PRS in the same position in the subchannel as the SCI communicating with other side link data 306 in the resource pool shared with side link communication. At 308, the WTRU may place the TDM of the SCI (e.g., first SCI) of SL-PRS in the resource pool dedicated to SL-PRS. The SCI 310 may occupy only a first symbol 312 of the transmission.

[0152] The WTRU may determine the position of SCI in the transmission based on the scheduling mode of SL-PRS. For example, if the WTRU autonomously selects SL-PRS, the WTRU may place the SCI associated with SL-PRS in the same position in the subchannel as the SCI of other side link communications. Otherwise, if the network schedules SL-PRS, the WTRU may time-division multiplex (TDM) the SCI (e.g., first SCI) with SL-PRS. In this case, the SCI may occupy only a first symbol of the transmission.

[0153] For each SL-PRS transmission, the WTRU may transmit the associated PSCCH and / or PSSCH to indicate information of the SL-PRS (e.g., SL-PRS mode, QoS associated with SL-PRS). The WTRU may determine the position (e.g., time-frequency resource) of the PSCCH and / or PSSCH to indicate information of the associated SL-PRS. For example, the WTRU may determine the time-frequency resource for transmitting the PSCCH and / or the time-frequency resource for transmitting the PSSCH to indicate information of the associated SL-PRS. The WTRU may transmit the PSCCH and / or PSSCH associated with SL-PRS.

[0154] The WTRU may determine the location of the PSCCH and / or PSSCH based on one or any combination of the following information regarding 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 which location to place the PSCCH and / or PSSCH based on the pattern of the SL-PRS and / or the time-frequency location of the SL-PRS. The WTRU may have one PSCCH and / or PSSCH resource to indicate one or more SL-PRS patterns. In this case, each SL-PRS pattern may be within the scope of time and frequency resources. The WTRU may then indicate which SL-PRS pattern the WTRU transmits in the SCI sent in the associated PSCCH and / or PSSCH.

[0155] The WTRU may be (pre)-configured with one PSCCH and / or PSSCH to indicate the SL-PRS pattern for 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 indicate more SL-PRS patterns for a (pre)-configured PSCCH / PSSCH occasion.

[0156] 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 the first pattern 406a, the WTRU may transmit the PSCCH 402a and / or PSSCH 404a in the first region (e.g., the first subchannel). If the WTRU uses the second pattern 406b, the WTRU may transmit in the second region (e.g., the second subchannel). If the WTRU selects the third pattern 406c, the WTRU may transmit the PSCCH 402c and / or PSSCH 404c in the third region (e.g., the 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.

[0157] Figure 5 depicts an exemplary illustration of time-frequency based PSCCH / PSSCH and SL-PRS multiplexing. In Figure 5 the example shown, the WTRU may be (pre)-configured with three time positions of SL-PRS 510 in a 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 positions 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 transmit the PSCCH 502c and / or PSSCH 504c in the third region (e.g., the third subchannel). The WTRU may reserve a period for 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 time slot between the SL-PRS patterns of different WTRUs.

[0158] Figure 6 depicts an exemplary illustration of PSCCH / PSSCH with associated SL-PRS. In 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 positions 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 sub-channel). 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 sub-channel). If the WTRU selects the third symbol 606c, the WTRU may transmit the PSCCH 602c and / or PSSCH 604c in the third region (e.g., the third sub-channel). The WTRU may reserve a period for 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 a resource pool, which may be a function of the SCS of the resource pool. The WTRU may place the ACG 612 time slot between the SL-PRS patterns of different WTRUs.

[0159] In the example, the WTRU may be (pre)-configured with multiple cyclic shifts for transmitting one SL-PRS pattern, where each cyclic shift may have an associated PSCCH and / or PSSCH position. The WTRU may determine the positions of the PSCCH and / or PSSCH based on the cyclic shift of the associated SL-PRS selected by the WTRU for transmission.

[0160] The WTRU may embed the SCI in the SL-PRS pattern, as Figure 7 depicted. The WTRU may embed the SCI 710 of the WTRU in this 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 transmit the SL-PRS. In Figure 5 one example shown, the WTRU may use the first three symbols to convey the SCI for the SL-PRS pattern.

[0161] The WTRU may determine the 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 time 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 transmission power parameters for SL-PRS transmission. In an example, if the WTRU is allowed to transmit at 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 at 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 there is no OLPC configured in the resource pool, the WTRU may use comb-1 (e.g., the WTRU transmits SL-PRS in all the REs of the SL-PRS bandwidth). Otherwise, if OLPC is configured in the resource pool, the WTRU may use comb-N (e.g., N>1).

[0162] Regarding 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.

[0163] The WTRU may determine which resource pool to use for SL-PRS transmission 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 the 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.

[0164] 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 SL-PRS configurations from another WTRU, gNB (e.g., via RRC, SIB, and / or location management function (LMF), etc.), from (pre)-configuration, etc., and / or any suitable combination thereof.

[0165] The WTRU may determine which SL-PRS configuration to use based on a (pre)-configured priority associated with each configuration or a predefined priority / precedence 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., the anchor WTRU) to provide an SL-PRS configuration instead of reading the SIB. The WTRU may then prioritize using the SL-PRS received from the peer WTRU.

[0166] The WTRU may determine which SL-PRS configuration to use based on the coverage state (e.g., whether the WTRU is inside or outside coverage). For example, if the WTRU is outside coverage, the WTRU may prioritize the SL-PRS configuration received from a peer WTRU. If the peer WTRU does not provide an SL-PRS configuration, the WTRU may use the (pre)-configured SL-PRS configuration. If the WTRU is inside coverage, the WTRU may prioritize any SL-PRS configuration provided by the network. The WTRU may then prioritize the SL-PRS configuration from another WTRU. If no such SL-PRS configuration exists, the WTRU may use the (pre)-configured SL-PRS configuration.

[0167] The WTRU may prioritize the resource pool used by a peer WTRU. 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, where one resource pool 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: dedicated resource pool and shared resource pool. The WTRU may prioritize the dedicated resource pool over the shared resource pool.

[0168] The WTRU may prioritize the resource pool based on the resource pool used by a peer WTRU. For example, the WTRU may prioritize the resource pool used by a peer WTRU for SL-PRS for its own SL-PRS transmission.

[0169] The WTRU can determine which ID can generate / scramble the SL-PRS sequence. The WTRU can determine that N_ID can generate / scramble the SL-PRS sequence. The WTRU can 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 the upper layer), etc. and / or any suitable combination thereof. The WTRU can indicate to another WTRU (e.g., a peer WTRU or group member) the ID used to generate / scramble the SL-PRS sequence.

[0170] The WTRU can determine when to monitor the SL-PRS resource pool. The WTRU can trigger the monitoring of the SL-PRS (e.g., monitor the dedicated resource pool for the SL-PRS) based on whether a positioning group and / or a positioning session is established. When a positioning session and / or a positioning group is established, the WTRU can start monitoring the SL-PRS (e.g., start monitoring the dedicated resource pool for the SL-PRS). When the positioning session terminates and / or an RLF is detected and / or an RLF is indicated from another node, the WTRU can stop monitoring the SL-PRS (e.g., stop monitoring the dedicated resource pool for the SL-PRS).

[0171] The WTRU can receive SL-PRS scheduling information from another node. For example, for the method based on receiving the SL-PRS, the WTRU can receive information about the SL-PRS resources for the group. The WTRU can then trigger the monitoring of the dedicated SL-PRS resource pool based on the reception of the SL-PRS scheduling information.

[0172] The WTRU can determine to transmit multiple SL-PRSs in one time slot, where each SL-PRS can consist of M symbols. The WTRU can then perform SL-PRS repetition in one time slot, where the WTRU can transmit multiple SL-PRSs, and each SL-PRS in the multiple SL-PRSs consists of M symbols. The WTRU can then determine the number of repetitions to be transmitted within the time slot based on the number of symbols (pre)-configured for the SL-PRS in one time slot and the duration of each SL-PRS (i.e., the value of M). The WTRU can transmit the SL-PRS until it fills all the symbols (pre)-configured for the SL-PRS. In one example, the WTRU can perform one SL-PRS consisting of three symbols in a time slot configured with nine symbols for the SL-PRS. The WTRU can then repeat the SL-PRS three times to complete the time slot (pre)-configured for the SL-PRS.

[0173] The WTRU may perform multiple transmissions of an SL-PRS within a time slot. The WTRU may use a PSCCH and / or PSSCH to indicate and / or reserve all transmissions of the SL-PRS within the time slot. The WTRU may indicate the number of repetitions and the SL-PRS pattern associated with the SL-PRS transmission. The method may be triggered to reduce the number of PSCCH / PSSCHs transmitted within a time slot for indicating multiple repetitions of the SL-PRS.

[0174] The WTRU may be configured / pre-configured for sidelink positioning. The WTRU may receive the configuration for sidelink positioning from the network via broadcast (e.g., via SIB) or unicast (e.g., via an access stratum (AS) message (e.g., RRC) or a non-access stratum (NAS) message (e.g., the Location Protocol (LPP))). The WTRU may receive one or any combination of the following configurations for sidelink positioning: a resource pool for sidelink communication 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 a single resource pool for both SL-PRS and sidelink communication to facilitate sidelink positioning (e.g., sidelink transmissions for indicating and / or reserving other sidelink transmissions, SL-PRS measurement reports, and / or SL-PRS resource usage reports).

[0175] In an example, the WTRU may be (pre)-configured with two resource pools, where one resource pool may be used for sidelink communication 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.

[0176] The WTRU may determine whether the network (e.g., gNB, Location Management Function (LMF), etc.) supports sidelink positioning. The WTRU (e.g., the target WTRU) may determine whether the network supports sidelink positioning based on the sidelink positioning SIB and / or the availability of the resource pool for SL-PRS transmission / reception in the SIB. 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).

[0177] A WTRU may determine a resource location for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may determine a resource allocation mode for sidelink positioning. The WTRU may determine whether to request resources from another node (e.g., the network or another WTRU) and / or perform autonomous resource allocation for sidelink positioning. The WTRU may determine a resource allocation mode for one or any combination of the following: 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.

[0178] The resource allocation mode for each type of resource for sidelink positioning may be based on one or any combination of factors. For example, the resource allocation mode for each type of resource 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 mode for one or more types of resources for sidelink positioning. The WTRU may request the WTRU to perform an autonomous resource allocation mode for SL-PRS transmission and / or reception. The WTRU may request the WTRU to perform a network-scheduled mode for SL-PRS measurement reporting. The resource allocation mode for each type of resource 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 mode. Otherwise, if the WTRU is outside coverage, the WTRU may perform autonomous resource allocation.

[0179] If the WTRU is within network coverage, the WTRU (e.g., the anchor WTRU) may perform network-scheduled resource allocation. Otherwise, if the WTRU is outside network coverage, if the network supports and / or allows forwarding of scheduling resources for sidelink positioning, the WTRU may receive scheduling information from another WTRU (e.g., the target WTRU). The resource allocation mode for each type of resource for sidelink positioning may be based on whether the network supports and / or allows forwarding of scheduling resources for sidelink positioning. For example, for an out-of-coverage scenario, if the network does not support and / or allow forwarding of scheduling resources for sidelink positioning, the WTRU may perform WTRU autonomous resource allocation. Otherwise, if the network supports and / or allows forwarding of scheduling resources for sidelink positioning, the WTRU may receive scheduling from another WTRU.

[0180] The resource allocation mode for each type of resource used for sidelink positioning can be based on the RRC state of the WTRU. For example, if the WTRU is in the RRC inactive and / or idle state, the WTRU can perform autonomous resource allocation or receive scheduling from another WTRU. Otherwise, if the WTRU is in the RRC connected state, the WTRU can perform network-scheduled resource allocation for sidelink positioning.

[0181] The resource allocation mode for each type of resource used for sidelink positioning can be determined based on the role of the WTRU in sidelink positioning. For example, the WTRU can determine the resource allocation mode 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 can perform a network-scheduled mode. Otherwise, if the WTRU is an anchor WTRU, the WTRU can receive scheduling from another WTRU (e.g., from the target WTRU).

[0182] The WTRU can determine the resources for sidelink positioning. For example, the WTRU can determine the resources for sidelink positioning (e.g., sidelink resources, uplink resources). The resources can be one or any combination of the following factors, including sidelink resources for indicating and / or requesting other resources for sidelink positioning. The indicated and / or reserved resources can 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 for indicating and / or reporting the usage of sidelink resources for sidelink positioning scheduling, and / or any suitable combination thereof.

[0183] The resources can be sidelink resources such as those for SL-PRS transmission, SL-PRS reception, for reporting SL-PRS positioning measurements, and / or for indicating and / or reporting the usage of sidelink resources for sidelink positioning scheduling (e.g., SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement report resources).

[0184] The WTRU can receive scheduled resources for sidelink positioning. For example, the WTRU (e.g., the target WTRU) can receive one or any combination of the following scheduled resources (e.g., sidelink resources and uplink resources) for sidelink positioning, and these scheduled resources can come from the network (e.g., gNB, LMF) or from another WTRU (e.g., the anchor WTRU).

[0185] Sidelink transmission resources for indicating and / or reserving 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 transmitted in this type of resource 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.

[0186] The WTRU may be scheduled for sidelink transmission resources to indicate SL-PRS transmission resources. The sidelink transmission resources may occur in the same time slot 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 time slot, the WTRU may use the SCI to indicate the SL-PRS transmission. Additionally or alternatively, the WTRU may use the SCI, MAC CE, RRC, and / or NAS (e.g., LPP) to indicate the associated SL-PRS reception resources and / or associated SL-PRS measurement reporting resources, which may occur in a different time slot compared to the scheduled sidelink SL-PRS transmission resources.

[0187] The WTRU may schedule one sidelink transmission resource to indicate 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 sidelink positioning resources (e.g., SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting resources).

[0188] The WTRU (e.g., the target WTRU) may receive one or more SL-PRS resources for SL-PRS transmission from the network (e.g., gNB or LMF). In an example, the WTRU (e.g., the anchor WTRU) may receive one or more SL-PRS resources for SL-PRS transmission from another WTRU (e.g., the target WTRU). The target WTRU may receive SL-PRS resources from the network (e.g., 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.

[0189] The network may indicate sidelink resources for SL-PRS reception to a WTRU (e.g., a target WTRU). The network may also schedule the same sidelink resources for an anchor WTRU to perform SL-PRS transmission.

[0190] 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.

[0191] 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.

[0192] The WTRU may be scheduled for sidelink resources before 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.

[0193] The target WTRU may be indicated and / or scheduled for two sidelink resources. The first resource may be used for SL-PRS reception (e.g., a sidelink resource for the anchor WTRU to perform SL-PRS transmission). The second sidelink resource may be used for 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.

[0194] The target WTRU may be indicated and / or scheduled for two sidelink resources. The first resource may be used for SL-PRS transmission. The second resource may be used for the anchor WTRU to indicate whether the anchor WTRU performs SL-PRS reception (e.g., whether the WTRU performs SL-PRS measurement in the indicated resources). The second resource may occur before the SL-PRS transmission resources. The anchor WTRU may then use the second resource to indicate whether the WTRU performs SL-PRS reception.

[0195] The WTRU may be scheduled for sidelink resources after 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.

[0196] The target WTRU may be instructed and / or scheduled for two sidelink resources. The first resource may be used for SL-PRS reception (e.g., a sidelink resource for the anchor WTRU to perform SL-PRS transmission). The second sidelink resource may be used for 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 transmitted 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 transmitted SL-PRS in the first resource.

[0197] The target WTRU may be instructed and / or scheduled for two sidelink resources. The first resource may be used for SL-PRS transmission, and the second resource may be used for the anchor WTRU to indicate whether the anchor WTRU performs SL-PRS reception (e.g., whether the WTRU performs SL-PRS measurement in the indicated resource). 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 measurement 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 performed SL-PRS reception in the second sidelink resource.

[0198] The WTRU (e.g., the target WTRU) may be scheduled and / or instructed for two sidelink resources, where one resource 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 resource for SL-PRS measurement reporting to perform such reporting. Positioning based on SL-PRS transmission may adopt this method. In the positioning method based on SL-PRS transmission, the target WTRU may perform SL-PRS transmission and / or receive a measurement report from the anchor WTRU.

[0199] A WTRU (e.g., a target WTRU) may be instructed and / or scheduled two sidelink resources (e.g., from an anchor WTRU). The target WTRU may use the first resource to perform SL-PRS reception. The target WTRU may use the second resource to perform SL-PRS measurement reporting. The network-initiated location request (NI-LR) sidelink positioning method may adopt this method. In NI-LR, the network may instruct and / or request the anchor WTRU to locate the target WTRU.

[0200] A WTRU (e.g., a target WTRU) may be instructed / scheduled 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 the round-trip time (RTT) sidelink positioning method, where the target WTRU may perform SL-PRS transmission, reception, and SL-PRS measurement report reception.

[0201] A WTRU (e.g., a target WTRU) may be instructed and / or scheduled three sidelink resources (e.g., from a gNB and / or 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 the target WTRU). The round-trip time (RTT) sidelink positioning may adopt 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 an SL-PRS measurement report (e.g., the 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 time of the SL-PRS from the anchor WTRU) to one of the anchor WTRUs in the anchor WTRU. The target WTRU may receive an indication and / or configuration from the network and / or the anchor WTRU guiding where the target WTRU may send the target WTRU's report. Additionally or alternatively, the target WTRU may send the SL-PRS measurement report to the network (e.g., LMF and / or gNB).

[0202] The uplink resources for indicating and / or reporting the use of scheduled sidelink resources for sidelink positioning may include any combination of the following factors: The WTRU may be scheduled an uplink resource to indicate and / or report the use of the scheduled sidelink resources after one or more scheduled SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement report 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 report are used. The WTRU may indicate and / or report whether the WTRU has correctly received an SL-PRS measurement report from another WTRU (e.g., the anchor WTRU) in the scheduled sidelink resources. The WTRU may indicate and / or report whether the WTRU needs more sidelink resources for sidelink positioning.

[0203] The uplink resources are for sidelink positioning reports (e.g., sidelink positioning and / or Uu positioning reports). For example, the WTRU may be scheduled an uplink resource for performing a sidelink positioning report. The sidelink positioning report may be a sidelink positioning measurement report and / or the relative position of the WTRU (e.g., the target WTRU) with respect to other WTRUs (e.g., the anchor WTRU).

[0204] Figure 8 An example illustration of potential scheduled and / or selected resources for sidelink positioning is depicted. As Figure 8As shown, 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) that occupy a different time slot than the SL-PRS transmission resources. In this example, a WTRU (e.g., a target WTRU) may be scheduled for 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 (e.g., by an anchor WTRU) SL-PRS resource usage. The second type of resource 804a-b may occur before (804a) or after (804b) SL-PRS transmission and / or reception. A third type of resource 806 and a fourth type of resource 808 (e.g., resources with index 3 or 4) may be used (e.g., by the target WTRU) for SL-PRS transmission and reception, respectively. A fifth type of resource 810 (e.g., a resource with index 5) may report (e.g., by the anchor WTRU) SL-PRS measurements. Finally, a sixth type of resource 812 (e.g., a resource with index 6) (which may be a UL resource) may indicate (e.g., by the target WTRU) sidelink resource usage for sidelink positioning.

[0205] Figure 9 An example of potentially 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. Sidelink resources for indicating and / or reserving other resources for sidelink communication may transmit in the same time slot and / or resource as the SL-PRS transmission. In this example, a 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 the example shown in

[0206] 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 methods based on SL-PRS transmission, methods based on SL-PRS reception, and / or methods based on sidelink RTT.

[0207] Based on the determined positioning method, a WTRU (e.g., a target WTRU) may further request other WTRUs (e.g., an anchor WTRU) 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.

[0208] Based on the determined positioning method, a WTRU (e.g., a target WTRU) may further determine to request other WTRUs (e.g., an anchor WTRU) 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.

[0209] Based on the determined positioning method, a WTRU (e.g., a target WTRU) may further determine to request other WTRUs (e.g., an anchor WTRU) to perform both SL-PRS transmission and / or reception. The WTRU may determine to perform a positioning method based on SL RTT. The WTRU may then request the anchor WTRU to perform both SL-PRS transmission and / or reception. Based on the determined positioning method, a WTRU (e.g., a target WTRU) may further determine to request other WTRUs (e.g., an anchor WTRU) to perform an SL-PRS measurement report.

[0210] The WTRU may request the anchor WTRU to report different measurement parameters based on the selected sidelink positioning method. For a 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 transmitted from the target WTRU. For a 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 a sidelink positioning method based on RTT, the WTRU may request the anchor WTRU to report the Tx-Rx difference, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA, RSTD, and / or DPoD.

[0211] The WTRU may determine a positioning method for a side link positioning group based on one or any combination of the following factors, including scheduled side link 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 scheduled side link resources from AS and / or NAS messages. The AS and / or NAS messages may include one or any combination of DCI, DL MAC CE, RRC, and / or LPP messages.

[0212] If the scheduled resources have both SL-PRS transmission and SL-PRS reception resources, the WTRU may perform RTT-based side link 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.

[0213] The WTRU may determine a positioning method based on a set of SL-PRSs scheduled by the network. The WTRU (e.g., the target WTRU) may determine a positioning method for the 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 a side link positioning group based on one or any suitable combination of the following factors: the set of scheduled SL-PRS resources scheduled by the network (e.g., the number of SL-PRS resources), the number of anchor WTRUs for transmitting SL-PRS, and / or the attributes of the scheduled SL-PRS resources. The number of anchor WTRUs for transmitting SL-PRS and / or the attributes of the scheduled SL-PRS resources may include the time gap between the first SL-PRS resource and the last SL-PRS resource and / or the time gap between two resources, etc.

[0214] 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.

[0215] 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 SL-PRS resource pairs is less than a threshold, the WTRU may determine to perform the RTT method.

[0216] Figure 10 An example illustration of downlink control information (DCI) for scheduling resources for side link positioning is depicted. As Figure 10As shown, in a resource scheduling message (e.g., DCI 1000), one or any combination of bit fields can be indicated to the WTRU to decode a type of resource. The combination of bit fields can 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 SL-PRS resources scheduled in the uplink.

[0217] The WTRU can 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 can 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 can determine that there are both SL-PRS transmission and reception resources. The WTRU can then determine to perform an RTT-based sidelink positioning method. In an example, in the scheduled message, the WTRU can determine that there is SL-PRS transmission (e.g., there are no SL-PRS reception resources). The WTRU can then determine to perform a sidelink positioning method based on SL-PRS transmission. In an example, in the scheduled message, the WTRU can determine that there is SL-PRS reception (e.g., there are no SL-PRS transmission resources). The WTRU can then determine to perform a sidelink positioning method based on SL-PRS reception.

[0218] The WTRU (e.g., the target WTRU) can be (pre)-configured with multiple resource scheduling formats (e.g., multiple DCI formats). Each format can include one or more types of resources for sidelink positioning. One type of resource for sidelink positioning can be sidelink resources for indicating / reserving resources for sidelink positioning, sidelink resources for SL-PRS transmission, sidelink resources for SL-PRS reception, sidelink resources for SL-PRS measurement reporting, and / or uplink resources for reporting the use of SL-PRS resources scheduled in the uplink.

[0219] The WTRU may then decode a DCI format for one or more types of resources for sidelink positioning (e.g., via RRC). The WTRU may decode a DCI format for a method based on SL-PRS transmission, where 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 a 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 a 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.

[0220] 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, where one scrambling code is for DCI scheduling SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting. Another scrambling code may be for SL-PRS reception. Another scrambling code may be for SL-PRS transmission.

[0221] The WTRU may be (pre)-configured (e.g., via RRC) with two scrambling codes. One scrambling code may be for dynamic SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting. Another scrambling code may be for semi-static SL-PRS transmission, SL-PRS reception, and / or SL-PRS measurement reporting.

[0222] The WTRU may be (pre)-configured with one or more resource scheduling formats (e.g., DCI formats). Each format may include one or more types of resources for sidelink positioning. The WTRU may then determine the resource scheduling format based on a 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.

[0223] 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., RNTIs) 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.

[0224] 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 for DCI that schedules SL-PRS transmission / reception, and another search space set may be for DCI that schedules normal sidelink data transmission.

[0225] 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 for SL-PRS scheduling, and another code point may be 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.

[0226] 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 for scheduling SL-PRS. The WTRU may use the scheduled SL-PRS transmission in the DCI. The DCI may indicate that the resource is for SL-PRS. Otherwise, the WTRU may not use the resource for SL-PRS.

[0227] The WTRU may determine whether the DCI is 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 for scheduling SL-PRS. The WTRU may use the scheduled SL-PRS transmission in the DCI. The DCI may indicate that the resource is for SL-PRS. Otherwise, the WTRU may not use the resource for SL-PRS.

[0228] The WTRU can determine whether to send data and / or SL-PRS on the scheduled sidelink resources. The WTRU can be scheduled for sidelink resources (e.g., in a shared resource pool between SL-PRS and data). The WTRU can perform resource selection to select sidelink resources. The WTRU can determine whether to send SL-PRS and / or sidelink data on 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.

[0229] The WTRU can determine whether to send SL-PRS and / or sidelink data on the scheduled / selected resources based on the attributes of the scheduled sidelink resources (e.g., the number of retransmissions and / or repetitions, the bandwidth of the resource, the time gap between the first resource and the last resource, the time gap between two consecutive resources, etc.). For example, the WTRU can determine whether to place the SL-PRS in the sidelink resources based on the attributes of the scheduled / selected sidelink resources. The WTRU can send an SL-PRS having a bandwidth greater than a (pre)-configured threshold and / or a number of repetitions greater than a (pre)-configured threshold. If a (pre)-configured condition is met, the WTRU can prioritize sending the SL-PRS. Otherwise, if the (pre)-configured condition is not met, the WTRU may not send the SL-PRS. The WTRU can then send the sidelink data. If a (pre)-configured condition is met, the WTRU can determine whether to send the SL-PRS and / or sidelink data based on the relative priority between the SL-PRSs. The WTRU can send the SL-PRS and / or sidelink data with a higher priority.

[0230] The WTRU can determine whether to send SL-PRS and / or sidelink data on 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 can place the sidelink data into the sidelink resources to send the SL-PRS together with the data. The WTRU can be (pre)-configured with a set of destination IDs for multiplexing with the SL-PRS. For unicast SL-PRS, if both the data and / or the SL-PRS are targeted at the same WTRU, the WTRU can send the data together with the SL-PRS. If the receiver of the SL-PRS receives the sidelink data, the WTRU can send the data together with the SL-PRS. For multicast SL-PRS, if the receiver of the sidelink data receives the SL-PRS, the WTRU can send the data together with the SL-PRS.

[0231] 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 sidelink data in a sidelink resource, the WTRU may determine to opportunistically place the SL-PRS in 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 for multiplexing 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, if both the sidelink data and / or the SL-PRS have the same destination ID (e.g., the same broadcast service), the WTRU may send the SL-PRS together with the sidelink data.

[0232] The WTRU may determine whether to send the SL-PRS and / or 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 a sidelink resource, the WTRU may determine to multiplex the sidelink data in that 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 use broadcast to send the SL-PRS, if the sidelink data is broadcast, the WTRU may send the sidelink data. 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 use multicast to send the SL-PRS, if the sidelink data is targeted to the same group, the WTRU may send the sidelink data. If the WTRU determines to send the sidelink data in a sidelink resource, the WTRU may determine to multiplex the SL-PRS in that 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 use unicast to send the sidelink data, if both the SL-PRS and / or the data are targeted to the same receiver, the WTRU may send the SL-PRS.

[0233] The WTRU may determine whether to send the SL-PRS and / or sidelink data in the scheduled / selected resources based on (pre)-configured restrictions. For example, the WTRU may be (pre)-configured to multiplex the SL-PRS with the sidelink data in a single transmission in a resource pool. In one (pre)-configuration, the WTRU may not be allowed to multiplex the SL-PRS with the sidelink data. In another (pre)-configuration, the SL-PRS may be multiplexed with the sidelink data.

[0234] The WTRU may determine whether to place the data or the SL-PRS in the resource first based on the priority associated with the data and / or the priority associated with the SL-PRS. For example, the WTRU may first place the data or the SL-PRS with a higher priority. If the SL-PRS and / or the data have the same priority, the WTRU may prioritize a (pre)-configured order of precedence (e.g., the data or the SL-PRS).

[0235] The WTRU scheduling may be based on the group common DCI for the SL-PRS. For example, the WTRU may be (pre)-configured to monitor the group common DCI (e.g., the DCI for the WTRU group) and / or the scheduling for the SL-PRS transmission and / or reception for the WTRU group. The WTRU may then receive the DCI that schedules the SL-PRS resources for the group of the WTRU.

[0236] Based on the role of the WTRU in the group (e.g., whether the WTRU is the target WTRU or the anchor WTRU), based on the positioning method (e.g., whether the positioning method can be SL-PRS transmission-based, SL-PRS reception-based, and / or RTT-based), based on the order of the SL-PRS transmission and / or reception, based on the member ID of the WTRU in the group (e.g., the WTRU may determine which of the resources indicated in the DCI can 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, the WTRU (e.g., the target WTRU) may be a (pre)-configured SL-PRS reception-based positioning method for a group of five WTRUs. The WTRU that is the target WTRU may receive the SL-PRS from the other four anchor WTRUs. The group may be scheduled for four resources for the SL-PRS, where each anchor WTRU may select one resource based on the function of its member ID.

[0237] The WTRU may determine whether to forward a scheduled SL-PRS for a member WTRU in a group. For example, the WTRU (e.g., the target WTRU) may receive an SL-PRS schedule for SL-PRS transmission for the WTRU from a network (e.g., the gNB and / or the LMF). The WTRU may then determine whether to forward the scheduled SL-PRS transmission for a WTRU in the 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 multiple member WTRUs is outside network coverage, the WTRU may forward the scheduled SL-PRS to the peer WTRU of the member WTRU.

[0238] The determination of whether to forward the scheduled SL-PRS may be based on the RRC status 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.

[0239] The WTRU may determine to transmit a scheduled SL-PRS based on an acknowledgement (ACK) from a member WTRU. For example, the WTRU may be scheduled (e.g., by the gNB or the LMF) or may select one or more SL-PRSs on its own. The WTRU may convey information about the scheduled and / or selected SL-PRS resources. The WTRU may expect an acknowledgement from the peer WTRU and / or the member WTRU. If the WTRU does not receive an acknowledgement from the peer WTRU and / or the 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 an SL-PRS when no WTRU is to receive the SL-PRS.

[0240] A WTRU can determine which WTRU is to request resources for sidelink positioning. In one method, a WTRU (e.g., a target WTRU) can establish a group of WTRUs for sidelink positioning. The WTRU can then determine which WTRU is to request resources for sidelink positioning (e.g., sidelink and / or uplink) for the group of WTRUs. The WTRU can 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 to perform the resource request for the group. In one method, a target WTRU can request resources for sidelink positioning (e.g., for a mobile-originated location request (MO-LR) positioning service). In an example, an anchor WTRU connected to a network can request resources for sidelink positioning (e.g., for a network-initiated location request (NI-LR) positioning service).

[0241] A WTRU can trigger resource allocation and / or request resources for sidelink positioning. For example, a WTRU (e.g., a target WTRU) can trigger resource allocation and / or request resources for sidelink positioning, which can 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 the usage of scheduled SL-PRS resources, and / or uplink resources for sidelink positioning reporting (e.g., sidelink positioning and / or Uu positioning reporting).

[0242] A WTRU can use an AS message (e.g., a scheduling request (SR), an uplink medium access channel (UL MAC CE), an RRC, and / or an NAS message (e.g., LPP), either alone or in any combination) to transmit in the uplink direction to request resources for sidelink positioning (e.g., sidelink resources or uplink resources). The WTRU can use information related to group sidelink positioning (e.g., a group ID, a sidelink positioning service ID, and / or an L2 destination index, etc.) to request resources for sidelink positioning. The WTRU can 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:

[0243] A WTRU may initiate sidelink positioning services. For example, a WTRU may initiate sidelink positioning services (e.g., for MO-LR services). The WTRU may then trigger resource allocation and / or request resources for sidelink positioning.

[0244] A WTRU may receive an indication and / or request from the network to potentially perform sidelink positioning. For example, a 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.

[0245] A WTRU (e.g., a target WTRU) may receive an indication and / or request from another WTRU (e.g., an anchor WTRU) to perform sidelink positioning. For example, the anchor WTRU may initiate a sidelink positioning service for relative positioning of the target WTRU. The anchor WTRU may perform sidelink positioning and / or request the target WTRU to send and / or receive an SL-PRS by sending an SL-PRS. The target WTRU may then receive an indication and / or request from the anchor WTRU to perform sidelink positioning by sending and / or receiving an SL-PRS and / or performing an SL-PRS measurement report. The target WTRU may then trigger resource allocation and / or request resources for sidelink positioning.

[0246] 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 for sidelink positioning (e.g., SL-PRS transmission, SL-PRS reception, SL-PRS measurement report, and / or SL-PRS resource usage report). For a 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 report when receiving an SL-PRS transmission from the target WTRU. A WTRU (e.g., an anchor WTRU) may receive an SL-PRS from another WTRU (e.g., a target WTRU). When having SL-PRS measurement results, the WTRU may then trigger resource allocation and / or request resources for an SL-PRS measurement report. A WTRU (e.g., a target WTRU) may receive an SL-PRS resource usage report from another WTRU (e.g., an anchor WTRU), which may indicate that the WTRU does not 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 number of SL-PRS resources for sidelink positioning measurements.

[0247] 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.

[0248] The WTRU (e.g., a target WTRU) receives an SL-PRS resource usage report and / or an SL-PRS measurement report from another WTRU that implicitly and / or explicitly indicates that the scheduled resources may not be used and / or are insufficient.

[0249] The WTRU (e.g., a target WTRU) receives an SL-PRS measurement report from another WTRU (e.g., an anchor WTRU) that implicitly and / or explicitly indicates that the scheduled resources may be insufficient for SL-PRS measurement.

[0250] The WTRU may have available SL-PRS positioning measurement results. For example, the WTRU (e.g., an anchor WTRU) may request (e.g., via the target WTRU) to perform an 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., a target WTRU) may be (pre)-configured to perform SL-PRS measurements of at least N SL-PRS resources to generate an SL-PRS measurement report. Upon successful measurement of N SL-PRS resources, the WTRU may generate an SL-PRS measurement result. The WTRU may then trigger a request for resources and / or resource allocation for the transmission of the SL-PRS measurement report.

[0251] A WTRU may receive information regarding sidelink positioning from one node and may indicate such information to another node. For example, a WTRU may receive information regarding sidelink positioning implicitly and / or explicitly from one node (e.g., a network node, an LMF (Location Management Function), a gNB, another WTRU, etc.). For example, a WTRU may receive information regarding sidelink positioning from an LMF via an LPP message. For example, a WTRU may receive information regarding sidelink 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 that node to another node (e.g., a network node, an LMF, a gNB, and / or another WTRU, etc.). The information that a WTRU may receive from one node and / or indicate to another node may include information regarding sidelink positioning. The information may include one or any combination of the following:

[0252] QoS associated with sidelink positioning (e.g., accuracy, latency, reliability, and / or availability of sidelink positioning services).

[0253] The SL-PRS transmission and / or reception configuration may include one or any combination of the following: the number of subchannels for each SL-PRS resource, the number of symbols and / or time slots 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: latency SL-PRS measurement reports, and / or the periodicity of SL-PRS measurement reports.

[0254] In an example, 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., a gNB, an LMF, or the like) to obtain the relative and / or absolute positioning of a target WTRU. If the anchor WTRU transmits a request to the LMF, the request may be transmitted via an LPP message. In an example, the anchor WTRU may include the ID of the target WTRU to the network (e.g., the LMF, the gNB, etc.).

[0255] 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 a request to the LMF, the request may be transmitted via an LPP message. In an example, the target WTRU may include the ID of the anchor WTRU that can be utilized to determine the relative position in the request.

[0256] The target WTRU may transmit a request to one or more anchor WTRUs to determine the relative and / or absolute positioning 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 unicast, multicast, and / or broadcast. In one example associated with multicast and / or broadcast, the target WTRU may include in the request the ID of the anchor WTRU that can be used to determine the relative position.

[0257] The LMF and / or gNB may transmit a request for the relative and / or absolute positioning of the 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.

[0258] 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 can be used to determine the relative position.

[0259] The location service (LCS) client and / or application in the WTRU and / or in the network may transmit a request for determining the relative and / or absolute positioning of the target WTRU. Such a request may be transmitted as an LCS (e.g., MO-LR and / or Mobile Terminal Location Request (MT-LR)), LPP, and / or AS layer (e.g., RRC, PC5-, and / or RRC) message to the gNB, LMF, or anchor WTRU.

[0260] The WTRU may determine information for indicating and / or reporting SL-PRS resource usage. For example, the WTRU (e.g., an anchor WTRU) may receive (e.g., from the target WTRU) an indication and / or request to perform SL-PRS transmission and / or SL-PRS reception. The WTRU may then determine 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 to the sidelink positioning request.

[0261] The WTRU may use one or any combination of PSFCH, SCI, MAC CE, PC5-RRC, and / or NAS (e.g., LPP) to implicitly and / or explicitly feedback one or any combination of the following information: the WTRU has successfully decoded the sidelink positioning request message. For example, the target may receive an indication and / or reserve sidelink communication of the 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.

[0262] The WTRU may perform SL-PRS transmission and / or reception. For this case, the WTRU may feedback to the requesting WTRU before the SL-PRS transmission and / or reception resources. For example, the WTRU (e.g., the anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., the target WTRU) to perform SL-PRS transmission and / or reception. The WTRU may then 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.

[0263] The WTRU may not perform SL-PRS transmission and / or reception. For this case, the WTRU may feedback to the requesting WTRU before the SL-PRS transmission and / or reception resources. For example, the WTRU (e.g., the anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., the target WTRU) to perform SL-PRS transmission and / or reception. The WTRU may then 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 feedback such information.

[0264] The WTRU may have performed SL-PRS transmission and / or reception. For such a case, the WTRU may provide feedback to the requesting WTRU after the SL-PRS transmission and / or reception resources. For example, the WTRU (e.g., the anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., the 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.

[0265] The WTRU may have deprioritized one or more SL-PRS transmissions and / or receptions. For such a case, the WTRU may provide feedback to the requesting WTRU after the SL-PRS transmission and / or reception resources. For example, the WTRU (e.g., the anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., the target WTRU) to perform SL-PRS transmission and / or reception.

[0266] The WTRU may then deprioritize the 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 deprioritized the SL-PRS transmission and / or reception. The feedback message may occur after the SL-PRS transmission and / or reception resources.

[0267] The WTRU may require more resources for SL-PRS transmission and / or reception. In an example, the WTRU (e.g., the anchor WTRU) may receive an implicit and / or explicit request from another WTRU (e.g., the target WTRU) to perform SL-PRS transmission / reception. In an example, the WTRU may deprioritize the SL-PRS transmission / reception. In another example, the WTRU may not have received sufficient SL-PRS resources to perform SL-PRS transmission and / or reception. The WTRU may then provide feedback to the requesting WTRU (e.g., the target WTRU) to indicate that the WTRU may require more resources for SL-PRS transmission and / or reception.

[0268] The WTRU may determine whether to report and / or indicate SL-PRS resource usage. For example, the WTRU (e.g., the anchor WTRU) may receive an indication and / or request (e.g., from the target WTRU) to perform SL-PRS transmission and / or SL-PRS reception.

[0269] 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.

[0270] 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 an SL-PRS resource usage report to notify that the WTRU has 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 has successfully decoded the request message. Otherwise, if the WTRU fails to decode the request message, the WTRU may not perform an SL-PRS resource usage report.

[0271] In an example, regardless of whether the WTRU successfully decodes the request message, the WTRU may perform an SL-PRS resource usage report. For example, the WTRU may indicate whether the WTRU has successfully or failed to decode the request message. In an example, regardless of whether the WTRU has failed or successfully decoded the request message, the WTRU may determine not to indicate and / or report an SL-PRS resource usage report.

[0272] 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.

[0273] 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 an SL-PRS resource usage report.

[0274] In an example, regardless of whether the WTRU performs SL-PRS transmission and / or reception, the WTRU may perform a report on SL-PRS resource usage. For example, if the WTRU determines to perform SL-PRS transmission and / or reception, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the WTRU is capable of performing SL-PRS transmission and / or reception. Otherwise, if the WTRU determines not to perform SL-PRS transmission and / or reception, the WTRU may report the SL-PRS resource usage to indicate to the requesting WTRU that the WTRU is not capable of performing 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 the SL-PRS resource usage report.

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

[0276] In an example, if the WTRU has performed SL-PRS transmission and / or reception, the WTRU may determine to indicate and / or report the SL-PRS resource usage. Otherwise, if the WTRU has not performed SL-PRS transmission and / or reception, the WTRU may not perform the SL-PRS resource usage report.

[0277] In an example, regardless of whether the WTRU has performed SL-PRS transmission and / or reception, the WTRU may perform a report on SL-PRS resource usage. 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.

[0278] In an example, regardless of whether the WTRU has performed SL-PRS transmission / reception, the WTRU may determine not to indicate and / or report the SL-PRS resource usage report.

[0279] 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.

[0280] 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 deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may indicate and / or report that the WTRU has not deprioritized one or more SL-PRS transmissions and / or receptions.

[0281] 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 an SL-PRS resource usage report.

[0282] In an example, regardless of whether the WTRU has deprioritized one or more SL-PRS transmissions and / or receptions, the WTRU may perform an SL-PRS resource usage report. 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.

[0283] 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 SL-PRS resource / usage report.

[0284] The WTRU may then determine whether to report and / or indicate SL-PRS resource usage based on whether the WTRU needs more resources for SL-PRS transmission and / or reception.

[0285] 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 that it needs more SL-PRS transmission and / or reception resources.

[0286] In an example, if the WTRU needs more SL-PRS transmission and / or reception resources, the WTRU may not perform an SL-PRS resource usage report. Otherwise, if the WTRU does not need more SL-PRS transmission and / or reception resources, the WTRU may perform an SL-PRS resource usage report to indicate to another WTRU that the WTRU does not need more SL-PRS transmission and / or reception resources.

[0287] The WTRU may determine resources for indicating and / or reporting SL-PRS resource usage. For example, the WTRU may determine resources for providing feedback on the usage of SL-PRS transmission / reception resources. For example, the feedback resources may be determined based on one or any combination of the following, including: an indication from the requesting WTRU. For example, the requesting WTRU (e.g., the target WTRU) may indicate and / or reserve resources for the receiving WTRU to provide feedback on SL-PRS transmission and / or reception resource usage. The feedback resources may be indicated in the transmission indicating and / or reserving SL-PRS transmission and / or reception resources.

[0288] The feedback resources may be determined based on the resources indicating and / or reserving SL-PRS transmission / reception resources.

[0289] In an example, the WTRU may be (pre)-configured (e.g., in a resource pool) with a mapping between resources indicating and / or reserving SL-PRS transmission and / or reception and the associated feedback message. The WTRU may then determine a feedback request message in the associated feedback resources. This method may be used in scenarios where the WTRU uses the PSFCH to provide feedback on SL-PRS transmission and / or reception resource usage.

[0290] In an example, the WTRU (e.g., the anchor WTRU) may trigger resource allocation and / or request sidelink resources (e.g., request the gNB and / or LMF) to provide feedback on the request. If the WTRU requests sidelink resources from the network, the WTRU may implicitly indicate the latency requirement (e.g., PDB) of the feedback message to help the network correctly schedule the feedback resources. For example, the WTRU may implicitly indicate the priority of 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.

[0291] The latency requirement of the 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 resources reserved and / or indicated for SL-PRS transmission / reception and the feedback resources.

[0292] The latency of the feedback can be indicated from another WTRU. For example, a WTRU (e.g., an anchor WTRU) can receive a latency requirement for a feedback message from another WTRU (e.g., a target WTRU). The target WTRU can use PC5-RRC to convey the latency requirement for the feedback message.

[0293] The latency of the feedback can be indicated by the time gap between the resources indicating and / or reserving SL-PRS resources and the SL-PRS transmission and / or reception resources. For example, a WTRU can determine the maximum latency of a feedback message based on the time gap between the resources indicating and / or reserving SL-PRS resources and the actual SL-PRS resources. For example, considering WTRU processing, the WTRU can send feedback during the gap between the two resources (e.g., the WTRU may not be allowed to send feedback in N time slots before the SL-PRS resource, where N can be based on the WTRU processing capability). Sending feedback can allow the requesting WTRU to become aware of potential SL-PRS transmitting and / or receiving WTRUs.

[0294] The feedback resources can be determined based on the SL-PRS transmission / reception resources. For example, a WTRU can be (pre)-configured (e.g., in a resource pool) with an implicit mapping between the SL-PRS transmission and / or reception resources and the feedback resources to indicate and / or report SL-PRS resource usage. The WTRU can then send feedback based on the SL-PRS transmission and / or reception resources and the implicit mapping rule between the SL-PRS and / or feedback resources.

[0295] In an example, a WTRU can determine the feedback resources based on the SL-PRS transmission and / or reception resources and the latency requirement of the feedback. The WTRU can then provide feedback in the resources to meet the latency requirement.

[0296] The latency requirement of the feedback can be determined based on one or any combination of the following, including whether the WTRU is (pre)-configured. For example, a WTRU can be (pre)-configured (e.g., for each sidelink positioning service) with a fixed latency requirement for the time gap between the SL-PRS resources and / or the feedback resources.

[0297] The latency requirement of the feedback can be indicated from another WTRU. For example, a WTRU (e.g., an anchor WTRU) can receive a latency requirement for the feedback used to indicate SL-PRS resource usage from another WTRU (e.g., a target WTRU). For example, the target WTRU can use PC5-RRC to convey the latency requirement of the feedback message. The latency requirement can then be determined as the time gap between the SL-PRS resources and / or the feedback resources.

[0298] The latency requirement of the feedback can be indicated by the time gap between the SL-PRS resource and the measurement report resource. For example, the WTRU can 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, considering WTRU processing, the WTRU can send the feedback during the gap between the two resources (e.g., the WTRU may not be allowed to send the feedback in N time slots before the SL-PRS measurement report resource, where N can be based on the WTRU processing capability).

[0299] The feedback resource can be determined by the SL-PRS measurement report resource. For example, the WTRU can be (pre)-configured with an implicit mapping between the SL-PRS transmission and / or reception resource and the feedback resource (e.g., in a resource pool) to indicate and / or report the SL-PRS resource usage. The WTRU can then send the feedback to indicate and / or report the SL-PRS resource usage based on the implicit mapping rule between the SL-PRS transmission and / or reception resource and / or the SL-PRS and the feedback resource.

[0300] The feedback resource can be determined by the channel and / or message used to feedback the SL-PRS transmission / reception resource usage. The WTRU can 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 can then determine the resource for feedbacking the SL-PRS resource usage based on the type of the channel / message used to feedback the SL-PRS resource usage.

[0301] In an example, the WTRU can use a (pre)-configured implicit mapping-based method to feedback the SL-PRS resource usage of the first type of feedback channel (e.g., the PSFCH feedback channel). For example, the WTRU can be (pre)-configured to indicate the mapping between the resource indicating the SL-PRS resource and the PSFCH resource or the mapping between the SL-PRS resource and the PSFCH feedback to report and / or indicate the SL-PRS resource usage. The WTRU can then determine the resource for feedbacking the SL-PRS resource usage based on the resource indicating the SL-PRS resource or the resource of the SL-PRS resource and the (pre)-configured mapping rule.

[0302] In an example, the WTRU may use a window-based method to feedback the SL-PRS resource usage of 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 the latency requirement for feedback transmission. The WTRU may then request sidelink resources in a time window and / or perform resource allocation for feedback transmission. The time window may be within the latency requirement for the feedback indicating and / or reporting the SL-PRS resource usage. The WTRU may then perform feedback transmission in the scheduled and / or selected feedback resources.

[0303] Figure 11 An example illustration of providing feedback on SL-PRS resource usage before the SL-PRS resources is depicted. In the example, as Figure 11 shown, the target WTRU may perform a sidelink transmission 1102 in the sidelink communication resource pool 1104 to indicate and / or reserve the SL-PRS resources 1106 in the SL-PRS resource pool 1108. The anchor WTRU may have two options to feedback the SL-PRS resource usage. In option 1 at 1110, the WTRU may use an implicit mapping between the sidelink transmission and the feedback resources. In option 2 at 1112, the WTRU may send feedback in one of the resources in the window between the sidelink communication indicating and / or reserving the SL-PRS resources and the SL-PRS resources.

[0304] Figure 12 An example illustration of feedbacking the SL-PRS resource usage after the SL-PRS resources is depicted. In Figure 12 the depicted example, the target WTRU may perform a sidelink transmission 1202. The anchor WTRU may have two options to feedback the SL-PRS resource usage. In option 1 at 1204, the WTRU may use an implicit mapping between the sidelink transmission and the feedback resources. In option 2 at 1206, the WTRU may send feedback in one of the resources in the window after the SL-PRS resources 1208.

[0305] The WTRU may determine the information to be included 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:

[0306] Information related to group sidelink positioning (e.g., anchor WTRU ID, target WTRU ID, group ID, and / or sidelink positioning service ID, etc.).

[0307] Information related to SL-PRS resources can be used for 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 the SL-PRS window that the WTRU uses to perform SL-PRS measurements.

[0308] SL-PRS positioning measurement parameters, which can be determined based on sidelink positioning methods. The WTRU may report the RSTD, ToA, AoA, PoA, DPoA, and / or SL-RSRP of the SL-PRS transmitted from the target WTRU based on the SL-PRS transmission method. For example, the WTRU may report the ToD, AoD, PoD, DPoD, and / or SL-PRS based on the sidelink positioning method of SL-PRS reception. For example, the WTRU may report the Tx-Rx difference, RSTD, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA, and / or DPoD based on the RTT-based sidelink positioning method.

[0309] 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-PSR measurement (e.g., maximum error and / or deviation of the error, etc.).

[0310] 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 measurement. For example, if the accuracy of the current SL-PRS measurement is less than a threshold and / or the WTRU does not have an available SL-PRS measurement, the WTRU may implicitly and / or explicitly request more SL-PRS measurement resources.

[0311] The WTRU may include sidelink positioning assistance information in its SL-PRS measurement report. For example, the WTRU (e.g., the anchor WTRU) may indicate the assistance information used to help the reported WTRU perform sidelink positioning. The assistance information may include: the location of the WTRU (e.g., the area ID of the WTRU and / or the absolute positioning of the WTRU), the movement attributes of the WTRU (e.g., the forward direction and / or speed, etc.), and / or the antenna placement of the WTRU.

[0312] The WTRU may discard the resources scheduled for the SL-PRS resource usage report. For example, the WTRU (e.g., the anchor WTRU) may request the network to schedule sidelink resources to indicate and / or report the SL-PRS resource usage report. 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.

[0313] The WTRU may determine the information for indicating and / or reporting the sidelink resource usage in the uplink transmission. For example, the WTRU may report to the network the sidelink resource usage for sidelink positioning. The WTRU may include in the network one or any combination of the following information: the WTRU has or has not received feedback for indicating the SL-PRS resource usage from one or more WTRUs and / or resources. For example, the WTRU (e.g., the target WTRU) may be scheduled for sidelink resources for a group of WTRUs (e.g., a group of anchor WTRUs). The WTRU may perform a sidelink transmission 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 the feedback indicating the SL-PRS resource usage from the WTRUs in the group. The WTRU may then report the set of WTRUs to the network.

[0314] The feedback that the WTRU may report to the network may have one or any combination of the following information: the set of WTRUs with ACK feedback, the set of WTRUs with NACK feedback, the set of WTRUs with DTX, the set of WTRUs that may perform SL-PRS transmission and / or reception, the set of WTRUs that may not perform SL-PRS transmission and / or reception, the set of WTRUs that have performed SL-PRS transmission and / or reception, the set of WTRUs that have deprioritized SL-PRS transmission and / or reception.

[0315] The WTRU may include in the information for indicating and / or reporting the sidelink resource usage in the uplink whether the WTRU has received the SL-PRS from one or more WTRUs / resources. For example, the WTRU (e.g., the target WTRU) may be scheduled for 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 the scheduled SL-PRS resources. The WTRU may then report the set of WTRUs that transmit the SL-PRS and / or the set of SL-PRS resources with SL-PRS measurement results. The WTRU may report the set of WTRUs that do not transmit the SL-PRS and / or the set of SL-PRS resources without SL-PRS measurement results.

[0316] The WTRU may include in the information for indicating and / or reporting sidelink resource usage in the uplink whether the WTRU has received an SL-PRS measurement report 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.

[0317] The WTRU may include in the information for indicating and / or reporting sidelink resource usage in the uplink whether the WTRU is capable of performing 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 the set of SL-PRS resources in which the WTRU is capable of performing SL-PRS transmission and / or reception. The WTRU may report the set of SL-PRS resources in which the WTRU is not capable of performing SL-PRS transmission and / or reception. In this case, the uplink resources may occur before the SL-PRS transmission and / or reception resources.

[0318] The WTRU may include in the information for indicating and / or reporting sidelink resource usage 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 of the scheduled SL-PRS resources, the WTRU may then report to the network the 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 the set of SL-PRS resources in which the WTRU has not performed SL-PRS transmission and / or reception. In this case, the uplink resources may occur after the SL-PRS transmission and / or reception resources.

[0319] The WTRU may include in the information for indicating and / or reporting sidelink resource usage in the uplink whether the WTRU may require additional sidelink resources for sidelink positioning. The WTRU may implicitly and / or explicitly indicate to the network whether the WTRU may or may not require more sidelink resources for sidelink positioning. The WTRU may indicate to the network an ACK / NACK of whether the WTRU requires more sidelink resources for sidelink positioning. These required sidelink resources may be associated with a sidelink positioning cycle. If the WTRU does not require more resources for sidelink positioning, the WTRU may report an ACK. Otherwise, if the WTRU requires more resources for sidelink positioning, the WTRU may report a NACK.

[0320] 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 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 indeed need more resources for sidelink positioning. Otherwise, if the WTRU receives fewer than N ACK feedbacks from other WTRUs for sending and / or receiving SL-PRS, the WTRU may report 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.

[0321] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on whether the WTRU has performed SL-PRS transmission / reception / has 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 ACK to the network. Otherwise, if the WTRU receives SL-PRS transmission and / or reception from fewer than N WTRUs and / or resources, the WTRU may report 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.

[0322] The WTRU may determine whether the WTRU needs more resources for sidelink positioning based on whether the WTRU has received ACK feedback from at least N WTRUs for indicating and / or reporting SL-PRS resource usage. For example, if the WTRU receives at least N ACK feedbacks from other WTRUs for indicating and / or reporting SL-PRS resource usage, the WTRU may report ACK to the network. Otherwise, the WTRU may report 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.

[0323] The WTRU may determine whether it 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 fewer than N WTRUs, the WTRU may report a NACK to the network. The value of N may be fixed, (pre)-configured based on positioning accuracy requirements and / or the total number of WTRUs in the sidelink positioning group.

[0324] The WTRU (e.g., the target WTRU) may perform SL-PRS measurement reporting to the network. The WTRU may report the WTRU's SL-PRS measurements and / or forward the SL-PRS measurements of other WTRUs to the network. The WTRU may use one or any combination of MAC CE, RRC, and / or NAS (e.g., LPP) to report sidelink positioning to the network. 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 the sidelink positioning group to the network. In another approach, 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: the maximum and / or minimum number of WTRUs / reports to be forwarded to the network. For example, the WTRU (e.g., the target WTRU) may be (pre)-configured with the 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 and / or WTRU measurement reports to be reported to the network based on the (pre)-configured value.

[0325] The WTRU may filter SL-PRS measurement reports, resources, and / or WTRUs from multiple WTRUs based on the availability of one or more parameters in the SL-PRS measurement report. For example, if the measurement report includes one or any combination of the following parameters, including the positioning of the reporting WTRU (e.g., the anchor WTRU), the WTRU may forward the measurement report and / or the WTRU's measurement report. For example, if the positioning information of the anchor WTRU is not available in the report, the WTRU may not report the SL-PRS measurement report of one anchor WTRU.

[0326] For an 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.

[0327] The WTRU may filter the SL-PRS measurement reports, resources, and / or WTRUs from multiple WTRUs based on whether one or more parameters in each SL-PRS measurement report are within a range. For example, if one or more measurement parameters are within the range, the WTRU may forward the SL-PRS measurement report of a WTRU. The parameters within the range may be (pre)-configured. The measurement parameters may be one or more of the following: RSTD, Tx-Rx, SL-RSRP, ToD, AoD, ToA, ToD, PoA, PoD, DPoA, and / or DPoD.

[0328] The 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. The WTRU (e.g., the target WTRU) may determine whether to request and / or select SL-PRS resources for another WTRU based on one or any suitable combination of the following, including: the 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 transmission resources. For example, when using an angle-based positioning method, the WTRU may determine not to request SL-PRS resources for another WTRU.

[0329] 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 another WTRU is out of coverage, the WTRU (e.g., the target WTRU) may request SL-PRS resources for the other WTRU.

[0330] 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 another WTRU is in the RRC idle and / or RRC inactive state, the WTRU (e.g., the target WTRU) may request SL-PRS resources for another WTRU.

[0331] 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 an out-of-coverage WTRU. In an example, the WTRU may request SL-PRS resources for a WTRU among RRC inactive and RRC idle WTRUs.

[0332] 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: the number of SL-PRS transmission and / or reception resources, the minimum, maximum, and / or exact time gap between two SL-PRS resources, the earliest and / or latest SL-PRS resources, and / or the SL-PRS measurement and processing window.

[0333] After determining one or more of the above parameters, the WTRU may indicate one or more of these parameters to the network (e.g., the LMF and / or gNB), which may help the network schedule SL-PRS resources. One or any combination of these parameters for SL-PRS transmission and / or reception may be resources for a group.

[0334] One or any combination of the above parameters may be determined by one or any suitable combination of the following, including the positioning method. 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., the LMF) may indicate the time gap and / or the threshold. In an example, for the RTT method, the WTRU may determine the maximum time gap between the SL-PRS and / or SL-PRS Rx. The network (e.g., the LMF) may indicate the maximum time gap.

[0335] The QoS of the positioning service may also determine the above parameters. For example, the WTRU may determine the number and / or the latest SL-PRS resources based on the latency requirement of the positioning service.

[0336] The WTRU processing capabilities and / or WTRU type may also determine the above parameters. For example, the WTRU may convey to the network the capabilities of the WTRU for transmitting and / or receiving the first SL-PRS. The network may then schedule the first SL-PRS for the WTRU to transmit and / or receive accordingly.

[0337] In the RTT method, the WTRU may use a single 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 the group ID in the transmission (e.g., SCI) associated with the SL-PRS to indicate the group information. Each receiving WTRU in the group may then send the SL-PRS back to the transmitter.

[0338] The SL-PRS transmission may be implemented via unicast, multicast, and / or broadcast. In one example, the WTRU may determine to transmit the SL-PRS via unicast based on a positioning method. For an RTT-based positioning method, the SL-PRS transmission via unicast may be applicable. The target WTRU and / or the anchor WTRU may send and / or receive the SL-PRS to / from each other.

[0339] In an example, for a TDOA-based positioning method, the SL-PRS transmission via multicast may be applicable. The Tx WTRU may send the SL-PRS to a group of WTRUs. The Tx WTRU may convey to the group of WTRUs a message notifying the PRS configuration for the multicast transmission (e.g., SL PRS resource ID, group ID, SL PRS ID, index and / or method for generating the SL-PRS sequence, where the sequence consists of complex symbols and / or real symbols and these symbols are mapped to resource elements).

[0340] In an example, for a TDOA-based positioning target, more than one Rx WTRU and broadcast SL-PRS transmission are applicable. The Tx WTRU may transmit SL-PRS to a potentially unknown number of Rx WTRUs. The Rx WTRU may measure the received SL-PRS (e.g., RSTD), where the Rx WTRU may be configured to receive 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 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 capabilities.

[0341] In an example, a WTRU (e.g., the target WTRU) may participate in the positioning procedure of a sidelink positioning group for an RTT-based positioning method. The positioning group may include one target WTRU and / or one or more anchor WTRUs. The WTRU (e.g., the target WTRU) may use multicast-based SL-PRS to transmit SL-PRS to one or more anchor WTRUs. Specifically, the WTRU may transmit one SL-PRS targeted at 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 destinations of the WTRU's SL-PRS transmission. For the transmission of SL-PRS from each anchor WTRU to the target WTRU, each anchor WTRU may use unicast-based transmission to transmit the associated SL-PRS to the target WTRU. Specifically, each anchor WTRU may use the target WTRU ID as the destination of each anchor WTRU's SL-PRS transmission. In an example, each anchor WTRU may use multicast-based transmission to transmit the associated SL-PRS. Specifically, each anchor UE may use the group ID to transmit SL-PRS to the target WTRU.

[0342] 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 multicast-based transmission to send SL-PRS to multiple target WTRUs and / or 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 target all target WTRUs and / or potential other anchor WTRUs in the group. For the transmission of SL-PRS from each target WTRU to the anchor WTRU, each target WTRU may use unicast-based transmission to send 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 multicast-based transmission to send the associated SL-PRS to the anchor WTRU. Specifically, each target WTRU may use the group ID to send SL-PRS to the anchor WTRU.

[0343] For an RTT method, the WTRU may determine whether to use unicast or multicast to send SL-PRS. 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 a low-latency positioning service, the WTRU (e.g., a target WTRU) may use multicast to send SL-PRS. Additionally or alternatively, for a less stringent positioning service, the WTRU may use a unicast type to send SL-PRS to the group.

[0344] Positioning result / output (e.g., whether the result / output is relative positioning or absolute positioning). For example, for an absolute positioning output, the WTRU may use a multicast message to send SL-PRS. For a relative positioning output, the WTRU may use a unicast message to send SL-PRS.

[0345] The WTRU may determine whether to use unicast and / or multicast to send SL-PRS for an RTT method based on the type of device. For example, when a positioning group is established, a roadside unit (RSU) may use multicast to send SL-PRS. Additionally or alternatively, when the WTRU does not participate in the positioning group and / or the SL-PRS is not intended for the group, the RSU may use broadcast to send SL-PRS.

[0346] The WTRU may determine whether to use unicast and / or multicast to send SL-PRS for an RTT method based on a network indication. The WTRU may determine to send SL-PRS via unicast, multicast, and / or broadcast based on an indication and / or configuration from the network.

[0347] The WTRU may determine whether to use unicast and / or multicast to transmit the SL-PRS for the RTT method based on the number of resources used to transmit the SL-PRS. The WTRU may select the number of resources used to transmit the SL-PRS. The network (e.g., gNB or LMF) may schedule the number of resources used to transmit the SL-PRS. For example, if the number of resources used to transmit the SL-PRS is less than a (pre)-configured threshold, the WTRU may use multicast-based transmission to transmit 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.

[0348] The WTRU may determine which WTRU is to request and / or select sidelink resources for one or more members in the group. The WTRU (e.g., the 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 initiated 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 to trigger the positioning of the target WTRU from the LMF. In this scenario, the anchor WTRU may request and / or select sidelink resources for other WTRUs (e.g., one or more target WTRUs).

[0349] The WTRU (e.g., the 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 the coverage status of the WTRU. If a WTRU is in coverage, that WTRU may request sidelink resources for the group.

[0350] The WTRU (e.g., the 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 the WTRU type. The RSU may request and / or select sidelink resources for another WTRU (e.g., the target WTRU).

[0351] The WTRU may determine the SL-PRS resources for the RTT positioning method. For the RTT positioning method, a WTRU (e.g., an anchor WTRU) may receive the SL-PRS Tx from another WTRU (e.g., a target WTRU). The WTRU may determine which resource to send back as 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 the mapping between the first SL-PRS and the second SL-PRS in a resource pool. The WTRU may then determine the resource for the second SL-PRS based on the resource for the first SL-PRS.

[0352] The WTRU may also determine which resource to send back as the SL-PRS based on an indication from another WTRU (e.g., a target WTRU).

[0353] The WTRU may also determine which resource to send back as 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 the second SL-PRS in the 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 the number of repetitions and / or retransmissions. Such parameters may be determined based on the SL-PRS configuration transmitted by the first SL-PRS. For example, the WTRU may be (pre)-configured with the 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.

[0354] A WTRU may request resources for sidelink positioning. For example, in a set of solutions, a WTRU (e.g., a target WTRU) may request sidelink positioning for itself and / or for a group of sidelink positioning. The WTRU may first establish group communication for sidelink communication, which may include the WTRU itself (e.g., the target WTRU) and other WTRUs (e.g., anchor WTRUs). The WTRU may be (pre)-configured and / or assigned one or more IDs and / or indexes (e.g., group ID, L2 ID, and / or L2 destination index) to communicate among the 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 use one or any combination of AS messages (e.g., one of or any combination in UCI, MAC CE, and / or RRC) and / or NAS messages (e.g., LPP) to request resources for sidelink positioning. 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.

[0355] 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, total number of resources for SL-PRS transmission and / or reception, number of resources for SL-PRS transmission and / or reception per SL-PRS cycle, total number of resources for SL-PRS measurement reporting, number of SL-PRS transmission and / or reception cycles, duration of SL-PRS transmission and / or reception, duration of SL-PRS measurement reporting, periodicity of SL-PRS transmission and / or reception, periodicity of SL-PRS measurement reporting, number of WTRUs in the sidelink positioning group, amount of data for SL-PRS measurement reporting in the sidelink and / or uplink, QoS of sidelink positioning (e.g., priority, latency, and / or reliability).

[0356] The WTRU may transmit sidelink positioning group information to the network. This information may help the network with resource scheduling. The information may include a set of sidelink positioning members (including the WTRU itself), coverage status of one or more WTRUs in the group, positioning method, etc. and / or any combination.

[0357] 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 associated with sidelink positioning (e.g., a destination ID). 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 specific ID is assigned to the WTRU for sidelink positioning. The WTRU may then use this ID to communicate to the network the use of this ID for sidelink positioning. Specifically, the WTRU may then use this ID to transmit UCI, MAC CE, RRC, LPP, and / or NAS messages to the network. The WTRU may then determine, based on the associated and / or embedded ID in the message, whether any transmission from the network (e.g., DCI, MAC CE, RRC, LPP, and / or NAS) is available for sidelink positioning.

[0358] The WTRU may transmit UCI (e.g., SR) to request resources for sidelink positioning. The WTRU (e.g., the target WTRU) may first trigger UCI (e.g., SR) to request resources for sidelink positioning. In an example, the WTRU may be (pre)-configured with a dedicated UCI resource (e.g., a dedicated SR) to request resources for sidelink positioning. In this case, the WTRU may trigger the transmission of UCI (e.g., SR) to request resources for sidelink positioning, and the WTRU may not need to trigger MAC CE (e.g., SL-BSR). In another approach, the WTRU may be (pre)-configured with UCI (e.g., SR) to request resources for both sidelink positioning and / or other sidelink resources. In this case, the WTRU may trigger the transmission of both UCI (e.g., SR) and / or MAC CE (e.g., SL-BSR).

[0359] A WTRU may transmit a MAC CE (e.g., a sidelink buffer status report (SL-BSR)) to request resources for sidelink positioning. A WTRU (e.g., a target WTRU) may trigger a MAC CE (e.g., an 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 quantity of resources for sidelink positioning. In an example, the WTRU may report a MAC CE for sidelink positioning as part of another MAC CE (e.g., an SL-BSR). The WTRU may use a dedicated destination ID (e.g., a dedicated destination index) to report the required quantity of resources for sidelink positioning (e.g., SL-PRS transmission and / or reception, and / or SL-PRS measurement reports). The WTRU may implicitly indicate to the network a dedicated destination as the destination for sidelink positioning. Specifically, the WTRU may indicate (e.g., via an RRC message) a dedicated assigned destination ID and / or index as the destination for sidelink positioning.

[0360] 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).

[0361] A 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 dynamic authorization, an indication that scheduled resources may be used for a specific group ID may be provided to the WTRU in a DCI. For configured authorization, an indication of the group ID associated with the scheduled resources may be provided to the WTRU in a DCI and / or an RRC. 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.

[0362] The WTRU may forward the 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 assist other WTRUs (e.g., the anchor WTRU) in decoding the forwarded message. In an example, the WTRU may use a sidelink resource (e.g., a resource for indicating and / or reserving other resources for sidelink positioning) to forward the 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 the scheduling messages related to sidelink positioning in the scheduling message to be forwarded to the WTRUs in the group. In an example, the WTRU may process the message scheduling resources for sidelink positioning (e.g., DCI, DL MAC CE, RRC, and / or LPP). The WTRU may then perform transmission in the scheduled transmission resources. The WTRU may then forward the scheduled resources for the WTRU's reception and / or other WTRUs' transmission (e.g., using SCI, MAC CE, RRC, and / or NAS (e.g., LPP) messages in the sidelink resource for indicating and / or reserving other resources for sidelink positioning) to other WTRUs.

[0363] The WTRU may perform transmission in one or any combination of the following resources: a sidelink resource for indicating and / or reserving other resources for sidelink positioning, an SL-PRS transmission resource, an SL-PRS usage report resource in the sidelink direction, an SL-PRS usage report resource in the uplink direction, and / or an SL-PRS measurement report resource in the sidelink.

[0364] In an example, the WTRU may process the scheduling message and determine the scheduled resources for each WTRU. The WTRU may then use a unicast message (e.g., unicast PC5-RRC) to forward the scheduled resources to each individual WTRU. In an example, the WTRU may process the scheduling message (e.g., from the network) and / or determine the scheduled resources for a group of WTRUs (e.g., a group of anchor WTRUs). The WTRU may then use a multicast message (e.g., multicast PC5-RRC) to forward the scheduled resources for the group of WTRUs.

[0365] The WTRU may forward one or any combination of the following resources for the WTRU's reception and / or other WTRUs' transmission, including: an SL-PRS reception resource, an SL-PRS usage report resource in the sidelink direction, and / or an SL-PRS measurement report resource in the sidelink.

[0366] The WTRU can determine the resources scheduled for a group ID. The WTRU can maintain multiple positioning groups. The WTRU can determine whether the scheduled resources are for which group ID. An indication of the group ID can be provided to the WTRU in a resource scheduling message (e.g., DCI, MAC CE, and / or DCI). The WTRU can determine the group ID based on whether the WTRU requests SL-PRS for which positioning group. The WTRU can use the scheduled SL-PRS for the most recent group that requests SL-PRS resources (e.g., the group ID indicated in the SL-BSR).

[0367] The WTRU can determine whether to forward the scheduled SL-PRS resources to another WTRU. The WTRU (e.g., the anchor WTRU) can receive the scheduled SL-PRS that provides resources to other WTRUs (e.g., the anchor WTRU). The WTRU can 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 transmission and for the WTRU to perform SL-PRS reception), the WTRU may not forward the scheduled resources to other WTRUs. This method can be applicable when the scheduling message indicates whether the resources are available for the WTRU's transmission or for other WTRUs' transmission.

[0368] The WTRU can determine the SL-PRS transmission resources for other WTRUs. The WTRU can receive the scheduled SL-PRS resources from the network. The WTRU may not receive an indication of whether the resources are available for which WTRU's transmission. Based on the set of SL-PRS scheduled by the network, the WTRU can then determine one or any combination of the following: resources for itself and / or resources used by other WTRUs. For example, based on the resources scheduled for a group, the WTRU can select one or more resources for itself. The WTRU can then select resources for other WTRUs.

[0369] The WTRU can also determine the positioning method. For example, based on the characteristics of the resources scheduled for 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 can determine whether to perform SL-TDOA and / or RTT. Each cluster of resources can be defined as a set of consecutive resources and / or a set of resources that are close in the time domain.

[0370] A WTRU may determine the index and / or ID of each WTRU. A WTRU (e.g., a target WTRU) may determine the index and / or member ID of each WTRU in a 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 use one or any combination of AS (e.g., SCI, MAC CE, group PC5-RRC) and / or NAS (e.g., LPP) to convey the index and / or member ID to each WTRU in the group. Other WTRUs in the group (e.g., an anchor WTRU) may receive the index and / or member ID of each WTRU in the group and the number of WTRUs in the group.

[0371] A WTRU may receive a configuration for sidelink positioning. For example, a WTRU (e.g., a target WTRU) may receive from the network a configuration for sidelink positioning for a group of WTRUs. In an example, the WTRU may determine a configuration for sidelink positioning for a group of WTRUs. In an example, a 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.

[0372] The configuration may include one or any combination of the following: a resource pool for sidelink communication to facilitate sidelink positioning, a resource pool for SL-PRS transmission / reception, and / or attributes of an SL-PRS measurement report. For example, a WTRU may be (pre)configured with the number of subchannels for each SL-PRS measurement report.

[0373] The configuration may include multiplexing of SL-PRS measurement report resources and / or index order. For example, a WTRU may be (pre)configured with the index order for a group of SL-PRS measurement report resources. A WTRU may be (pre)configured with the index order from the frequency domain to the time domain. Additionally or alternatively, a WTRU may be (pre)configured with the index order from the time domain to the frequency domain.

[0374] The configuration may include attributes of an SL-PRS resource. For example, a WTRU may be (pre)configured with one or any combination of the following parameters of an SL-PRS resource: the bandwidth of an SL-PRS resource, the comb value and offset of an SL-PRS resource, the cyclic shift of an SL-PRS resource, the number of transmission symbols of an SL-PRS resource, the SL-PRS resource repetition pattern, and / or the coverage code associated with the resource.

[0375] The configuration may include the number of SL-PRS resources in the frequency domain, code domain, and / or coverage code domain.

[0376] The configuration may include multiplexing and / or indexing order of the SL-PRS resources. For example, the WTRU may be (pre)-configured for the indexing order of a group of SL-PRS resources. The WTRU may be (pre)-configured for an indexing order from time domain to frequency domain and / or then to code domain and / or overlaid code domain accordingly. Additionally or alternatively, the WTRU may be (pre)-configured for an indexing order from frequency domain to time domain, to overlaid code domain and / or then to code domain accordingly.

[0377] The WTRU may send the 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, the WTRU (e.g., the target WTRU) may send the configuration to other WTRUs (e.g., the anchor WTRU in the group). The WTRU may use one or any combination of AS messages (e.g., SCI, MAC CE, group PC5-RRC) and / or NAS messages (e.g., LPP) to convey the configuration for sidelink positioning of a group of WTRUs. 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 in the group.

[0378] The WTRU may determine the SL-PRS reception resources for each WTRU in the group. The WTRU (e.g., the target WTRU) may be scheduled for SL-PRS reception resources. The reception resources may be used by other WTRUs (e.g., a set of anchor WTRUs) to perform SL-PRS transmission. The WTRU may then determine the SL-PRS resources for each WTRU (e.g., each anchor WTRU).

[0379] The SL-PRS resources may be based on one or any combination of the following: a set of SL-PRS resources scheduled for the group, the index in the group and / or the member WTRU IDs, the ID of the WTRU that forwards and / or indicates the SL-PRS resources for the group, the number of WTRUs in the group, the number of OCCs assigned / (pre)-configured for each WTRU, the slot index of the scheduled SL-PRS resources, and / or the (pre)-configured multiplexing rule between multiple SL-PRS resources.

[0380] Figure 13 An example illustration of SL-PRS scheduling for a group of user WTRUs is depicted. In Figure 13In the example shown, the target WTRU can be scheduled for SL-PRS reception resources for a group of four WTRUs (e.g., from WTRU1 to WTRU4). Each SL-PRS resource can have a comb-4 pattern, and the WTRU can multiplex two SL-PRSs in the frequency domain. Each SL-PRS resource can occupy half a time slot. The WTRU can be (pre)-configured with an index from the frequency domain to the time domain. The target WTRU can then determine that the SL-PRS resources of WTRU1 1302 and / or WTRU2 1304 can be located in the first half of the time slot multiplexing with different offsets in the frequency domain. The target WTRU can then determine that the SL-PRS resources of WTRU3 1306 and / or WTRU4 1308 can be located in the second half of the time slot 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.

[0381] Figure 14 An example illustration depicting the anchor WTRU using an orthogonal cover code (OCC) for one SL-PRS resource is shown. As Figure 14 depicted, the target WTRU can be scheduled for one SL-PRS resource for a group of anchor WTRUs 1402a - 1402d. Each anchor WTRU 1402a - 1402d can apply a different OCC 1404a - 1404d to help the target WTRU distinguish different anchor WTRUs 1402a - 1402d. The OCC for each anchor WTRU can be (pre)-configured and / or determined by the target WTRU. The target WTRU can indicate to each anchor WTRU which OCC code to use. This method can help the target WTRU determine the transmissions from each anchor WTRU.

[0382] The WTRU can determine its SL-PRS transmission resources. The WTRU (e.g., the anchor WTRU) can receive scheduled SL-PRS transmission resources for a group of WTRUs including the WTRU itself. The WTRU can then determine its SL-PRS resources to perform SL-PRS transmission.

[0383] Similar to the target WTRU, the anchor WTRU can determine its SL-PRS based on one or any combination of the following: the set of SL-PRS resources scheduled for the group, the index and / or member WTRU IDs 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.

[0384] The WTRU can determine the SL-PRS measurement report resources for each WTRU in a group. The WTRU (e.g., the target WTRU) can be scheduled for the SL-PRS measurement report resources of a group of WTRUs (e.g., the anchor WTRU). The WTRU can then forward the resources for the group of WTRUs. The WTRU can determine the SL-PRS measurement report resources for each WTRU (e.g., each anchor WTRU) based on one or any combination of the following: the set of SL-PRS measurement report resources scheduled for the group, the index and / or member WTRU IDs in the group, the number of WTRUs in the group, the (pre)-configured index rules between multiple SL-PRS measurement report resources, the ID of the WTRU (e.g., the target WTRU) that forwards and / or indicates the SL-PRS resources for the group, and / or the time slot index of the scheduled SL-PRS measurement report resources.

[0385] Figure 15 An example illustration of SL-PRS measurement report scheduling for a group of WTRUs is depicted. As Figure 15 depicted, the target WTRU can be scheduled for SL-PRS measurement report resources. The SL-PRS measurement report resources can include four resources 1502a - 1502d for a group of four anchor WTRUs. The WTRU can be (pre)-configured to index the resources from frequency to time order. The WTRU (e.g., the target WTRU) can then determine the measurement report resources for each WTRU according to the (pre)-configured rules and the WTRU index.

[0386] The WTRU can determine the SL-PRS measurement report resources for itself. The WTRU (e.g., the anchor WTRU) can receive the SL-PRS measurement report resources for a group of WTRUs (e.g., the anchor WTRU) (e.g., from the target WTRU). Similar to the target WTRU, the anchor WTRU can then determine its SL-PRS measurement report resources based on one or any combination of the following: the set of SL-PRS measurement report resources scheduled for the group, the index and / or member WTRU IDs in the group, the number of WTRUs in the group, the (pre)-configured index rules between multiple SL-PRS measurement report resources, the ID of the WTRU (e.g., the target WTRU) that forwards and / or indicates the SL-PRS resources for the group, and / or the time slot index of the scheduled SL-PRS measurement report resources.

[0387] The WTRU may determine resources for reporting and / or indicating SL-PRS resource usage from SL-PRS resources scheduled for a group. The WTRU (e.g., the anchor WTRU) may determine feedback on SL-PRS resource usage from a set of SL-PRS resources scheduled for a group. The WTRU may determine resources for feedback on SL-PRS resource usage based on one or any combination of the following: an indication from the requesting WTRU, resources indicating and / or reserving SL-PRS transmit and / or receive resources, an index in the group and / or a member WTRU ID, the number of WTRUs in the group, the ID of the WTRU forwarding and / or indicating SL-PRS resources for the group (e.g., the target WTRU), the slot index of the scheduled SL-PRS measurement report resources, the slot index of the scheduled SL-PRS resources, the earliest and / or latest scheduled SL-PRS resources, and / or the channel and / or message for feedback on SL-PRS resource usage.

[0388] The WTRU may report synchronization offset information of a positioning group to the network. The WTRU (e.g., the target WTRU) may receive synchronization offset information from another WTRU (e.g., the anchor WTRU). Additionally or alternatively, the WTRU may derive the synchronization offset information itself. The synchronization offset information of the positioning group may include the synchronization offset between itself and another WTRU (e.g., the anchor WTRU), the synchronization offset between two other WTRUs in the group (e.g., two anchor WTRUs), or any suitable combination thereof.

[0389] The WTRU may report synchronization offset information of a positioning group to the network (e.g., the LMF). The WTRU may use one or any combination of MAC (e.g., MAC CE), RRC, and / or NAS (e.g., LPP) messages to convey the synchronization offset to the network (e.g., the LMF). The WTRU may trigger the transmission of such a report based on one or any suitable combination of the following, including periodic reporting. For example, the WTRU may periodically report synchronization offset information to the network (e.g., the LMF).

[0390] The WTRU may trigger the transmission of such a report based on the WTRU being able to report an SL-PRS measurement report to the network (e.g., the LMF). For example, the WTRU may report the synchronization offset information of the group in a measurement report message.

[0391] 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 the (pre)-configured threshold, the WTRU may report the synchronization offset between the two WTRUs (e.g., between two anchor WTRUs and / or between an anchor WTRU and a target WTRU).

[0392] The WTRU may indicate a synchronization offset based on the resource allocation patterns of two WTRUs. The WTRU (e.g., the target WTRU) may determine the synchronization offset between itself and another WTRU (e.g., the target WTRU). Additionally or alternatively, the WTRU may determine the synchronization offset between two other WTRUs (e.g., two anchor WTRUs). The WTRU may receive synchronization offset information from the anchor WTRU. If two WTRUs use two different resource allocation patterns, the WTRU may determine the synchronization offset information between the two WTRUs. For example, if the WTRU is using resource allocation for network scheduling of SL-PRS and the anchor WTRU autonomously selects resources, the WTRU may determine the synchronization offset information between itself and one of the anchor WTRUs.

[0393] The WTRU may be configured with periodic and / or semi-static resources for sidelink positioning. The WTRU (e.g., the target WTRU) may be scheduled one or more semi-static (e.g., periodic or semi-persistent) resources for sidelink positioning. For example, the WTRU may be scheduled 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. NAS messages (e.g., LPP) and / or via AS messages (e.g., RRC) may configure the periodic and / or semi-persistent resources. The semi-persistent resources may require the WTRU to receive MAC CE for resource activation and / or deactivation.

[0394] 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 the sidelink resources of the WTRU (e.g., resources for sending sidelink positioning request messages), SL-PRS transmission resources, SL-PRS reception resources (which may be used by one anchor WTRU or a group of anchor WTRUs for SL-PRS transmission), SL-PRS usage reporting resources in the sidelink direction (which may be used for reporting SL-PRS resource usage), SL-PRS usage reporting resources in the uplink direction, SL-PRS measurement reporting resources in the sidelink, and / or SL-PRS measurement reporting resources in the uplink direction.

[0395] Figure 16 An example illustration of semi-static resources for sidelink positioning is depicted. As Figure 16As shown, the WTRU may be configured for semi-static resources for sidelink positioning. The WTRU may be configured for 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 having 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.

[0396] The behavior of the WTRU may be based on the status of feedback on SL-PRS resource usage from other WTRUs. The WTRU (e.g., the target WTRU) may be scheduled for 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.

[0397] 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 messages, 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 a set of anchor WTRUs in a sidelink positioning group), the WTRU may request additional resources for transmitting a sidelink positioning request message.

[0398] 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 a set of anchor WTRUs in a sidelink positioning group), the WTRU may initialize SL-PRS transmission and / or reception.

[0399] The WTRU may trigger a procedure for not performing SL-PRS transmission and / or reception in the scheduled resources. For example, in an RTT-based sidelink positioning method, in one SL-PRS transmission and / or reception period, if the WTRU deprioritizes SL-PRS reception in that period, the WTRU may determine to deprioritize all SL-PRS transmissions.

[0400] A WTRU may trigger a procedure for requesting the network to release one or more semi-static resources for sidelink positioning. For example, if one or more WTRUs leave a 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 a sidelink positioning session, the WTRU may request the network to release all semi-static resources for itself.

[0401] A WTRU may trigger a procedure for requesting the network to activate one or more semi-static resources for sidelink positioning.

[0402] A 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 measurement, 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.

[0403] 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 from at least N WTRUs for a request message. For example, for an ACK / NACK method for a positioning request message, 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 initiate SL-PRS transmission and / or reception.

[0404] The triggering event may be based on whether the WTRU has received fewer than N ACK feedbacks for a request message. For example, if the WTRU receives fewer than N ACK feedbacks, the WTRU may trigger a request for more sidelink resources for the request message. This method may be motivated to help the WTRU find sufficient anchor WTRUs to support sidelink positioning.

[0405] The triggering event may be based on whether the WTRU has received at least N NACK feedbacks for a request message. For example, if the WTRU receives at least N NACK feedbacks for a request message (e.g., N = 1), the WTRU may trigger a request for more sidelink resources for the request message.

[0406] 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 at least N WTRUs indicating that the WTRU may perform SL-PRS transmission / reception, the WTRU may initiate SL-PRS transmission and / or reception.

[0407] 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.

[0408] 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 an 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 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 an 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 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 an SL-PRS resource usage report to the network.

[0411] 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.

[0412] 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 report resources in each period.

[0413] The triggering event may be based on whether the WTRU has completed a 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.

[0414] 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 an ACK feedback from a WTRU (e.g., N = 1), the WTRU may trigger a request for more resources until the WTRU receives an ACK feedback from all WTRUs. For example, in some scenarios, if the WTRU receives a NACK feedback from a WTRU (e.g., N = 1), the WTRU may trigger a request for more resources until the WTRU receives an ACK feedback from that WTRU.

[0415] The value of N in the triggering 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 an ACK feedback from a WTRU (e.g., N = 1), the WTRU may request more resources for transmission and / or reception until the WTRU receives an ACK feedback from all WTRUs.

[0416] The value of N in the triggering event may be determined based on the QoS (e.g., latency, accuracy) requirements of the positioning service.

[0417] For loose sidelink positioning accuracy requirements, the WTRU may require the support of a small number of anchor WTRUs. However, for high sidelink positioning accuracy requirements, the WTRU may require the support of a large number of anchor WTRUs.

[0418] 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 appropriate combination of the parameters (e.g., offset, periodicity, and / or latency) in the SL-PRS configuration for the periodic SL-PRS based on one and / or any combination of the following:

[0419] Selected, requested, and / or available SL-PRS configurations from a peer WTRU. For example, for an RTT positioning method, a 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 WTRU (e.g., the anchor WTRU) may then determine parameters (e.g., offset, latency, periodicity, bandwidth of the SL-PRS, and / or SL-PRS mode) in its SL-PRS configuration based on the requested, selected, and / or scheduled periodic SL-PRS resources from the peer WTRU.

[0420] In an example, if the WTRU determines to request and / or select periodic SL-PRS resources, the WTRU may select and / or request an SL-PRS configuration 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).

[0421] In an example, if the WTRU determines to request and / or select aperiodic SL-PRS resources, in addition to latency and / or periodicity, the WTRU may select an SL-PRS configuration similar to the SL-PRS configuration of the target WTRU. 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 latency smaller than the periodicity of the periodic SL-PRS. The WTRU may select and / or request the aperiodic SL-PRS based on the timing of the periodic SL-PRS of other WTRUs and / or the QoS requirements of the positioning service.

[0422] The WTRU may trigger a change in the SL-PRS configuration (e.g., SL-PRS offset and / or periodicity). The WTRU (e.g., the target WTRU and / or the 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 of the following and / or any suitable combination:

[0423] The SL-PRS configuration of another WTRU may have changed. For example, for RTT positioning methods, a WTRU may select a periodic SL-PRS based on the 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 select a new periodic SL-PRS (e.g., with a new offset and / or periodicity value).

[0424] The WTRU may have detected a conflict with an existing periodic SL-PRS. For example, if the WTRU detects a conflict with the transmission of another SL-PRS, the WTRU may trigger the selection of a new SL-PRS.

[0425] The WTRU receives an indication from another WTRU to change the SL-PRS configuration of the WTRU. For example, another WTRU (e.g., the target WTRU) may instruct the WTRU (e.g., the anchor WTRU) to change the SL-PRS configuration of the WTRU. 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).

[0426] The WTRU may indicate the priority of the sidelink positioning service. The WTRU (e.g., the target WTRU) may initiate the sidelink positioning service of the WTRU. In an example, the WTRU may determine the priority of the sidelink positioning of the WTRU and / or indicate the decision of the WTRU to the network. In an example, the WTRU may recommend, indicate, and / or request a priority level for the sidelink positioning of the WTRU. The WTRU may then receive the assigned priority of the sidelink positioning of the WTRU from the network. The WTRU may then determine the priority of one or any combination of the following transmissions and / or receptions, which may be based on the priority of the sidelink positioning service:

[0427] Sidelink positioning request transmission, SL-PRS transmission, 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.

[0428] 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 positioning processing window (PPW) configuration from the network. In an example, if the WTRU has not received feedback from the network regarding SL-PRS reception prioritization, the WTRU may deprioritize SL-PRS reception. In one example, during a measurement gap, the WTRU may not transmit or receive a channel or signal and may only perform measurements. During a 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.

[0429] The WTRU may determine whether to perform SL-PRS reception. When receiving an SL-PRS reception request from another WTRU, the WTRU may determine whether to perform SL-PRS reception. The WTRU may then indicate and / or report its decision to other nodes (e.g., a gNB or another WTRU).

[0430] 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 services at the PC5 interface and / or its existing Uu services at the Uu interface.

[0431] The WTRU may determine whether to perform SL-PRS reception based on the priority of overlapping sidelink communication (e.g., sidelink transmission and / or reception). For example, if the priority of the SL-PRS is greater than the priority of the overlapping sidelink communication, the WTRU may determine to perform SL-PRS reception. The WTRU may then trigger resource reselection for its overlapping sidelink transmission. The WTRU may indicate and / or request the WTRU performing the overlapping sidelink communication to reselect and / or deprioritize the overlapping sidelink communication. For example, if the priority of the SL-PRS is less than the priority of the overlapping sidelink communication, the WTRU may determine to deprioritize SL-PRS reception. The WTRU may then indicate its decision to deprioritize SL-PRS reception to the SL-PRS transmitting WTRU. The SL-PRS transmitting WTRU may change the configuration of the SL-PRS transmission resources.

[0432] The WTRU may determine whether to perform SL-PRS reception based on the duration of SL-PRS reception in a period. For example, if the duration of SL-PRS reception in a period 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 periodicity of the SL-PRS reception resources. 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.

[0434] 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 reception. Determining whether to perform additional SL-PRS reception may be based on whether the additional SL-PRS reception may result in exceeding its configured and / or pre-configured SL-PRS reception capability.

[0435] Figure 17 An example illustration depicting the overlap between SL-PRS reception and the SL communication resource pool is shown. As Figure 17 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 an SL-PRS signal), the WTRU may require more time for SL-PRS processing. Therefore, the WTRU may not perform other sidelink transmissions and / or receptions 1708.

[0436] The WTRU may request 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 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.

[0437] 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 the reception of multiple semi-static SL-PRS reception resources.

[0438] The 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 (e.g., semi-static) SL-PRS reception resources of the WTRU to other nodes (e.g., WTRUs having an existing sidelink communication to the WTRU or gNB). This method may help other nodes avoid scheduling and / or transmitting resources that overlap with the WTRU's SL-PRS reception resources.

[0439] The WTRU may prioritize between SL-PRS reception and / or other sidelink transmissions and / or receptions. In an example, the WTRU may perform prioritization between SL-PRS reception and / or another overlapping transmission and / or reception in Uu and / or the 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 priorities between SL-PRS and / or Tx and / or Rx resources in 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 deprioritize SL-PRS reception.

[0440] 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.

[0441] In an example, if the priority of the SL-PRS reception is greater than a first threshold, the WTRU may prioritize the 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 the 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 to prioritize. The WTRU may base the prioritization on other criteria. The thresholds may be (pre)-configured.

[0442] 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 the SL-PRS reception is greater than a second threshold, the WTRU may prioritize the SL-PRS reception. Otherwise, if both the 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.

[0443] For hybrid positioning, the WTRU may be independently configured for 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 related to SL PRS) and / or Uu positioning (e.g., RSRP, RSTD, and / or Rx-Tx time difference related to PRS sent from a TRP or gNB) in the same report associated with a timestamp. The network may use the timestamp to track when a measurement report containing measurements related to SL positioning and / or Uu positioning is 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, area ID, SSB measurements, etc.). If the target WTRU determines that it is located in a corner of a room (e.g., based on the area 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.

[0444] The WTRU may determine whether to measure the RSTD between two RATs. The WTRU may use a node in one radio access technology (RAT) as a reference node to measure the measurement quantity difference (e.g., RSTD and / or PDOA) between the reference node and / or the node to be measured. The measurement may occur in both the same RAT and / or a different RAT compared to the reference node. The WTRU may use a node in one RAT as a reference for a node in the same RAT. The WTRU may determine whether to use a node in one RAT as a reference for a node 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., the serving gNB) as the reference node for a node in two RATs. Otherwise, if the PC5 RAT is (pre)-configured to use a different BWP from Uu, the WTRU may use a node in each RAT as a reference for all nodes in the same RAT.

[0445] The WTRU may determine the reference node for RSTD measurement. The WTRU may determine which node to use as the reference node to measure the measurement quantity difference. The WTRU may make this determination based on one and / or a combination of the types of the WTRU, where the WTRU may prioritize the RSU as the reference node, the coverage status, and / or where the WTRU may prioritize the in-coverage WTRU as the reference node.

[0446] When receiving the MG and / or PPW configuration in Uu, the WTRU may trigger resource reselection and / or preemption. The WTRU (e.g., the target WTRU) may receive the MG and / or PPW configuration from the network (e.g., the gNB). If the WTRU detects one or more of the reserved sidelink resources of the WTRU 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 considering 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.

[0447] When receiving the MG and / or PPW in the Uu of a peer, the WTRU may trigger resource reselection and / or preemption. When receiving the MG and / or PPW in the Uu of each WTRU, if the WTRU detects that its reserved sidelink transmission resources for the peer WTRU are within the MG and / or PPW of the peer WTRU, the WTRU may determine to trigger resource reselection and / or preemption. The WTRU may then select another resource outside the MG and / or PPW of the peer WTRU.

[0448] 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 execute an LCP procedure in which, for any resources within the MG and / or PPW of the peer WTRU, the WTRU may not select data and / or SL-PRS to transmit to the peer WTRU. The WTRU may select data and / or SL-PRS to transmit to the peer WTRU outside of the MG and / or PPW period of the peer WTRU. If one of the reserved resources of the WTRU is within the MG and / or PPW of the peer WTRU, the WTRU may trigger resource reselection.

[0449] The WTRU may indicate the MG and / or PPW of the WTRU to the network (e.g., the LMF). The WTRU may indicate one or any suitable combination of the following MGs and / or PPWs to another node (e.g., to another WTRU, to a network such as the 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 such that the other WTRU and / or gNB may avoid transmitting channels (e.g., SLCCH and / or SLSCH) and / or signals and / or requesting the WTRU to transmit / receive signals (e.g., SL-PRS) to the WTRU during the duration of the MG and / or PPW.

[0450] The WTRU may indicate the MG and / or PPW of the WTRU in the sidelink. For example, the WTRU may indicate the MG and / or PPW of the WTRU to another WTRU such that the other WTRU and / or gNB may avoid transmitting to the WTRU during the duration of the MG and / or PPW. Alternatively, the gNB may avoid scheduling Uu resources in the sidelink during the MG and / or PPW of the WTRU.

[0451] The WTRU may indicate the MG and / or PPW of one or more other WTRUs. For example, the WTRU may indicate the MG and / or PPW of another WTRU in the sidelink to the gNB. The gNB may implicitly request the gNB to schedule transmission resources (e.g., sidelink transmission resources and / or SL-PRS transmission resources) to one or more WTRUs outside of the indicated MG and / or PPW period.

[0452] In positioning methods such as multi-RTT, SL-TDOA, SL-AoD, and / or SL-AoA, a target WTRU may receive configurations for more than one anchor WTRU. When the target WTRU determines its relative positioning with respect to a reference node (e.g., distance and angle with respect 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 with respect to such a node may become quickly outdated and / or inaccurate.

[0453] Given a set of anchor WTRUs, the target WTRU may determine the 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 WTRUs and / or the network (e.g., gNB, LMF). The reference node may be a stationary anchor WTRU (e.g., a roadside unit, a positioning reference unit). In one example, if the target WTRU receives configurations for more than one anchor WTRU and one of the anchor WTRUs is a stationary WTRU (e.g., a roadside unit), the target WTRU may use that WTRU as the reference node. If there are more than one stationary WTRUs, the target WTRU may randomly select one of them and report to the network and / or the anchor WTRUs which WTRU the target WTRU has selected. Additionally or alternatively, the target WTRU may use measurement results (e.g., RSRP) to select a WTRU as the reference node.

[0454] The target WTRU determines the reference node based on measurements of SL-PRS sent by the anchor WTRUs. For example, the target WTRU may determine to use the anchor WTRU with the highest SL-PRS RSRP as the reference node.

[0455] Given a set of anchor WTRUs, the target WTRU may determine the reference node based on whether the target WTRU has received a list of priority levels associated with the anchor WTRUs. The target WTRU may determine the reference node based on the priority levels (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.

[0456] Given a set of anchor WTRUs, the target WTRU may determine the reference node based on the location of the reference node and / or the identity of the reference node (e.g., anchor WTRU ID). The network may indicate the reference node, and / or the anchor WTRUs and / or the target WTRU may determine to report the relative position with respect to the reference node.

[0457] 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 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 a priority level associated with these sources. For example, the priority level of a synchronization source may have a higher priority level than the level associated with a reference WTRU for calculating RSTD.

[0458] In an example, the target WTRU may indicate information related to the reference node in the relative position information (e.g., the WTRU ID associated with the SL-PRS sent by the reference node, the SL PRS resource ID, and / or the SL PRS ID). In an example, during positioning, the target WTRU may determine to change the reference node. In such a case, the target WTRU may send a request to the anchor WTRU and / or the network to terminate the current positioning session and restart the session.

[0459] 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 does not change, the target WTRU may determine to include a timestamp in the measurement report, where 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 a later time T2 than T1, if the reference node does not change, the target WTRU may associate T1 with the relative position information determined at T2. The network may refer to the report at T1 to determine which reference node to use. If at a time T3 later than T2, the target WTRU may determine to change the reference node (e.g., change to anchor WTRU_B), then the target WTRU may indicate the reference node information in its report (e.g., information related to anchor WTRU_B, such as the location information of anchor WTRU_B, the WTRU ID, and / or the PRS resource ID), thereby associating T3 with this information. At a later time T4 than T3, if the reference node does not change, the target WTRU may indicate T3 to the network to obtain the reference node information.

[0460] In an example, for each reference node, the target WTRU may receive a validity period during which the target WTRU may use the reference node to obtain the 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 the relative position information corresponding to each reference node in its report sent to the anchor WTRU and / or the network.

[0461] A WTRU may request resources for sidelink positioning and forward the scheduling to a group. In an example, the WTRU (e.g., a target WTRU) may receive (e.g., via DCI) sidelink resources scheduled for sidelink positioning for a group of WTRUs. The WTRU may then determine a positioning method for the group based on a set of the scheduled sidelink resources (e.g., in the DCI). The target WTRU may then forward the scheduled sidelink resources (e.g., DCI) indicating the scheduled SL-PRS reception (if available) and / or SL-PRS measurement report resources (if available) using a multicast message associated with the group for potential SL-PRS transmission and / or measurement reporting for the anchor WTRU.

[0462] 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 for representing 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) sidelink resources scheduled for performing sidelink positioning for the group of WTRUs.

[0463] The WTRU may determine a 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.

[0464] If the scheduled sidelink resources have SL-PRS reception and / or SL-PRS measurement report resources, additional steps that the WTRU may perform occur. The WTRU may forward the scheduled resources for the anchor WTRU using a 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.

[0465] The WTRU can determine sidelink resources for each WTRU in a group. In an example, for an RTT-based method, the WTRU (e.g., the target WTRU) can 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 can 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 can then use a multicast message associated with the group to send the derived positioning (e.g., relative positioning).

[0466] For example, the WTRU can perform one or any combination of the following steps: The WTRU can determine a group of WTRUs for sidelink positioning, the WTRU can configure an OCC for each anchor WTRU (e.g., based on the WTRU ID), the WTRU can receive an SL-PRS resource configuration and / or an SL-PRS measurement report configuration from the gNB, and these two configurations can 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 can also include the order of SL-PRS multiplexing for the group of resources (e.g., OCC, then frequency, then time) and / or the order of multiplexing of the SL-PRS measurement report resources (e.g., time, then frequency).

[0467] The WTRU can also forward the configuration to the group using the group ID. The WTRU can receive (e.g., via DCI) the scheduled sidelink resources for performing sidelink positioning for the group of WTRUs and / or forward the scheduled resources to the anchor WTRUs. The WTRU can perform SL-PRS transmission in the scheduled sidelink resources for SL-PRS transmission of the WTRU. The WTRU can 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 can calculate the RTT between each WTRU based on the measured Tx-Rx of the WTRU for the SL-PRS and the reported Tx-Rx from each anchor WTRU. The WTRU can include the calculated relative positioning with respect to the anchor WTRU in a message and / or use the group ID to send it to the group.

[0468] Figure 18Illustrates an example of multiplexing between SL-PRS 1802 and SL-PRS measurement report 1804 among WTRUs in a group. As Figure 18 shown, the WTRU can be scheduled for SL-PRS resources 1806a - 1806d and SL-PRS measurement report resources 1808a - 1808d for a group of WTRUs. The WTRU can then determine the SL-PRS resources 1806a - 1806d and SL-PRS measurement report resources 1808a - 1808d for each WTRU.

[0469] The WTRU can determine its SL-PRS and / or SL-PRS measurement report resources from the resources for the group. In the example, for the RTT-based method, the WTRU (e.g., the anchor WTRU) can receive (e.g., from the target WTRU) a set of resources for SL-PRS transmission and a set of resources for SL-PRS measurement report. The WTRU can then determine its SL-PRS transmission resources and / or its SL-PRS measurement report resources (e.g., to report the Tx-Rx difference) based on its WTRU ID, the number of WTRUs in the group, the (pre)-configured OCC for the WTRU, and / or the (pre)-configured multiplexing rule.

[0470] For example, to determine its SL-PRS transmission resources and / or its SL-PRS measurement report resources, the WTRU can perform one or any combination of the following: determine the WTRU ID of the WTRU in the group and locate the number of WTRUs in the group, receive a dedicated OCC for SL-PRS transmission (e.g., based on the WTRU ID), receive the SL-PRS resource configuration and / or SL-PRS measurement report configuration from the target WTRU, receive the side-link resources for performing side-link resources for the group of WTRUs and / or the scheduled side-link resources from the target WTRU, determine the SL-PRS and measurement report resources of the WTRU for each anchor WTRU based on the WTRU ID of the WTRU, the number of WTRUs in the group, the configured OCC of the WTRU, the set of side-link resources scheduled for the group, and / or the (pre)-configured multiplexing rule, and / or perform SL-PRS transmission and / or SL-PRS measurement report in the determined resources.

[0471] Figure 19Depicts an example signal flow diagram for covering the internal round-trip time (RTT) positioning. At 1902, the target WTRU may, for example, transmit a positioning request to a network (such as, for example, an LMF or the like). Such a request may include a MO-LR request (transmitted, for example, in an LPP or LCS message), an LPP message (such as, for example, an LPP request for sidelink positioning, an LPP request for auxiliary data, LPP capability information), and / or an AS layer message (such as, for example, an RRC message, a MAC CE).

[0472] At 1904, the anchor WTRU may receive a PRS configuration for the anchor WTRU and / or the target WTRU (such as, for example, PRS parameters such as comb values, number of time slots, bandwidth, and / or positioning method). 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 an SL-PRS configuration.

[0473] At 1910, the target WTRU may receive resource information (such as, for example, the position of the SL-PRS in the time domain and / or frequency domain) from the anchor WTRU. Next, although not shown in Figure 19 the target WTRU may receive a set of resources and / or an SL PRS configuration from the anchor WTRU and / or the gNB. In an example, the target WTRU may receive an indication of the sidelink positioning method (such as, for example, 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 for the target WTRU based on the above set of resources and / or the SL PRS configuration. The target WTRU may receive such information and / or indication in any one of, for example, an SCI, a MAC-CE, a PC5-RRC, and / or an LPP message.

[0474] At 1912, the target WTRU may monitor the SCI from the anchor WTRU and / or receive the SL-PRS from the anchor WTRU at the resources indicated in the SCI. At 1914, the target WTRU may measure the received PRS (such as, for example, reception timing, RSRP, and / or AoA). At 1914, the target WTRU may transmit an SL-PRS to the anchor WTRU.

[0475] 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, an SL MAC CE, and / or an SCI), where the target WTRU Tx-Rx time difference may be the difference between the time the target WTRU receives the SL-PRS from the anchor WTRU and the time the target WTRU transmits 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.

[0476] At 1920, the anchor WTRU may receive the SL-PRS from the target WTRU and / or may make measurements (e.g., reception timing, RSRP, AoA, and / or the anchor WTRU Rx-Tx time difference), where the anchor WTRU Rx-Tx time difference may be the difference between the time the anchor WTRU transmits the SL-PRS and / or the time the anchor WTRU receives the SL-PRS from the target WTRU. In an example, the anchor WTRU may convey the anchor WTRU Rx-Tx time difference to the LMF in an LPP message.

[0477] At 1922, the anchor WTRU may convey the measurements made by the anchor WTRU and the target WTRU to the LMF. In an example, the anchor WTRU may determine the relative positioning between the anchor WTRU and the target WTRU and / or the absolute positioning of the target WTRU, and may convey the positioning to the LMF in an LPP message. At 1924, the LMF may then receive the positioning determination and / or determine the location information based on the measurements. At 1926, the target WTRU may receive the location information determined by the LMF based on the measurements.

[0478] Figure 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, the target WTRU may convey a request for location information for the target WTRU to the network (e.g., the LMF and / or the gNB). For example, the WTRU may convey 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 MACCE).

[0479] At 2004, the target WTRU may receive auxiliary information related to the SL-PRS configuration (e.g., comb value, number of time slots, and / or symbols containing the SL-PRS) and the WTRU-based positioning method from the anchor WTRU.

[0480] At 2006, the anchor WTRU may receive SL-PRS resource information (e.g., the position of the SL-PRS in the time domain and / or frequency domain) from the gNB. The target WTRU may then receive an 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 an RSU, for example, via an LPP message including but not limited to LPP assistance data), the target WTRU may receive the anchor WTRU position from the LMF. In an example, if some of the anchor WTRUs are mobile, the target may receive position information from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0481] At 2012, the target WTRU may monitor for an SCI (e.g., received from the gNB and / or the anchor WTRU) for the SL-PRS transmitted from the anchor WTRU. At 2014, the target WTRU may receive the SL-PRS from the anchor WTRU. At 2016, the target WTRU may measure the received SL-PRS (e.g., RSRP and / or RSTD). At 2018, the target WTRU may determine absolute positioning based on the measurement.

[0482] At 2020, the target WTRU may report the absolute positioning to the LMF (e.g., 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.

[0483] Figure 21 An example process of SL positioning is depicted, where WTRU information may be provided by the anchor WTRU and / or multiple WTRUs. For example, if the anchor WTRU is mobile, the target WTRU may receive the anchor WTRU position.

[0484] At 2102, the target WTRU may receive a request for the position information of the target WTRU from the network (e.g., the LMF and / or the gNB). For example, the WTRU may receive a request for position information in an LCS message (e.g., MT-LR), an LPP message (e.g., an LPP request for sidelink positioning, an LPP request for position information, an LPP request for capability information), and / or an AS layer message (e.g., RRC and / or MAC CE).

[0485] At 2104, the target WTRU may receive assistance information related to the SL-PRS configuration (e.g., comb value, number of time slots, and / or symbols containing the SL-PRS) and the WTRU-based positioning method from the anchor WTRU.

[0486] At 2106, the anchor WTRU may receive SL-PRS resource information (e.g., the position 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 position from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0487] At 2110, the target WTRU may monitor for an SCI (e.g., received from the gNB and / or the anchor WTRU) for the SL-PRS transmitted from the anchor WTRU. At 2112, the target WTRU may receive the SL-PRS from the anchor WTRU. At 2114, the target WTRU may measure the received SL-PRS (e.g., RSRP and / or RSTD). At 2116, the target WTRU may determine absolute positioning based on the measurement.

[0488] At 2118, the target WTRU may report the absolute positioning to the LMF (e.g., via an LPP message). In an example, if the WTRU is configured with the WTRU-assisted SL positioning method, the WTRU may return a measurement report to the LMF.

[0489] Figure 22 An example flow chart depicting in-coverage SL positioning (WTRU-based), anchor WTRU information from the LMF, and PRS configuration from the LMF to the target WTRU is shown. At 2202, the target WTRU may transmit a request for SL positioning data to the LMF. At 2204, the target WTRU may receive a PRS configuration from the LMF in an LPP message (e.g., in any one of an LPP assistance data message and / or an LPP request for a position information message). For example, the WTRU may receive a request for position information in an LCS message (e.g., MT-LR), an LPP message (e.g., an LPP request for sidelink positioning, an LPP request for position information, and / or an LPP request for capability information), and / or an AS layer message (e.g., RRC and / or MAC CE).

[0490] At 2206, the target WTRU may receive assistance information related to the SL-PRS configuration (e.g., comb value, number of time slots, and / or symbols containing the 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 value, number of time slots, and / or symbols containing the SL-PRS) and the WTRU-based positioning method from the LMF.

[0491] At 2210, the anchor WTRU may receive SL-PRS resource information (e.g., the position 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 position from the LMF. In an example, if some of the anchor WTRUs are mobile, the target may receive position information from the anchor WTRU (e.g., via any one of an LPP message, PC5-RRC, MAC CE, and / or SCI).

[0492] At 2214, the target WTRU may monitor for an 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 measure the received SL-PRS (e.g., RSRP and / or RSTD). At 2220, the target WTRU may determine absolute positioning based on the measurement.

[0493] At 2222, the target WTRU may report the absolute positioning to the LMF (e.g., 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.

[0494] Figure 23 An example process for bilateral RTT SL positioning is depicted. At 2302, the target WTRU may convey a request for positioning to the LMF in an LPP message. 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 convey a request for the 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 the 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 one of LPP, PC5-RRC, MAC CE, and / or SCI). At 2312, the target WTRU may monitor for an SCI (e.g., received from the gNB and / or the anchor WTRU) for the sent SL-PRS.

[0495] At 2314, the target WTRU may receive the SL-PRS sent by the anchor WTRU, where the resources for the SL-PRS are indicated in the SCI. At 2316, the target WTRU may measure the SL-PRS (e.g., RSRP and / or ToA). At 2318, the target WTRU may perform resource selection based on the measurement. At 2320, the target WTRU may send the SL-PRS based on the resources determined by the target WTRU to be used. At 2322, the target WTRU may transmit a first measurement report to the LMF in an LPP message, where the report includes, for example, the target WTRU Tx-Rx time, the RSRP per SL-PRS resource, and / or the associated AoA measurement.

[0496] At 2324, the anchor WTRU may measure the SL-PRS sent by the target WTRU. At 2326, the target WTRU may monitor the SCI (received, for example, from the gNB and / or the anchor WTRU) for the sent SL-PRS. At 2328, the anchor WTRU may transmit a measurement report (e.g., the anchor WTRU Rx-Tx time, AoA, and / or RSRP). At 2330, the target WTRU may receive a second SL-PRS from the anchor WTRU, where the resource information of the second SL-PRS is indicated in the SCI. At 2332, the target WTRU may measure 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, where the report may include, for example, the target WTRU Rx-Tx time, the RSRP per SL-PRS resource, and / or the associated AoA measurement.

[0497] 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.

[0498] 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.

[0499] The sidelink positioning method described herein may support the SL-TDOA method and / or the RTT method. 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 independently request its sidelink Tx resources. This may result in uncoordinated SL-PRS transmissions in SL-TDOA and / or an extended time gap between SL-PRS Tx and / or Rx in RTT.

[0500] In an example, a WTRU (e.g., a target WTRU) may request resources (e.g., SL-PRS Tx resources) for a group of WTRUs. Figure 24 An example diagram depicting a WTRU obtaining and providing sidelink resources associated with a group of WTRUs is depicted. Figure 25 Another example diagram depicting a WTRU obtaining and providing sidelink resources associated with a group of WTRUs is depicted.

[0501] As Figure 24 Depicted, the WTRU 2402 (e.g., the depicted target WTRU) may request sidelink positioning reference signal (SL-PRS) transmission (Tx) resources for a group of WTRUs 2404a - 2404d (e.g., the depicted anchor WTRUs). The target WTRU 2402 may indicate the quantity of resources required for itself and the anchor WTRUs 2404a - 2404d in the request. The target WTRU 2402 may receive an indication of the requested resources and forward the scheduled SL-PRS resources to the group (e.g., the anchor WTRUs 2404a - 2404d). The target WTRU 2402 may request a change in the SL-PRS configuration based on the measurement report status of the other WTRUs 2404a - 2404d in the group. For network-assisted positioning, the target WTRU 2402 may determine a set of received measurements and / or a set of WTRUs to report to the network based on one or more (pre)-configured conditions.

[0502] 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., the RTT method, the SL-TDOA method, and / or any suitable combination thereof). The target WTRU 2402 may indicate sidelink positioning group information, such as a group identifier (ID) and / or WTRU numbers, etc., to a network entity.

[0503] The network entity may include any network entity, e.g., gNB1 2406a and / or gNB2 2406b. The target WTRU2402 may request SL-PRS resources for a group of WTRUs from a network entity (e.g., gNB1 2406a and / or gNB2 2406b). The request may include a group ID, the number of resources for SL-PRS Tx for the target WTRU 2402, the number of resources for SL-PRS Tx for the anchor WTRUs2404a-2404d, and / or any combination thereof.

[0504] As Figure 24 Depicted, the target WTRU 2402 may provide the request 2408 directly to gNB1 2406a. The target WTRU2042 may go to gNB2 2406b indirectly 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 the SL-PRS resources for the group from gNB1 2406a. The resources may be received via DCI.

[0505] The target WTRU 2402 may provide and / or forward the resources for the scheduling of SL-PRS to the group. The scheduled resources may be provided and / or forwarded via any mechanism (e.g., PC5-RRC interface).

[0506] As Figure 25 Depicted, the WTRU 2502 (e.g., the depicted target WTRU) may request side link positioning reference signal (SL-PRS) transmission (Tx)2504 resources for a group of WTRUs 2504 (e.g., the depicted anchor WTRUs). The target WTRU2502 may indicate in the request the number 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., the anchor WTRUs 2504a-2504d). The target WTRU 2402 may request a change in the SL-PRS configuration based on the measurement report status of the other WTRUs 2504a-2504d in the group. For network-assisted positioning, the target WTRU 2502 may determine the set of received measurements and / or the set of WTRUs to be reported to the network based on one or more (pre)-configured conditions.

[0507] As Figure 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, an 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, etc., to a network entity.

[0508] The network entity may include any network entity, e.g., gNB1 2506. The target WTRU 2502 may request SL-PRS resources for the group of WTRUs from a network entity (e.g., gNB1 2506a). The request may include a group ID, the number of resources for the SL-PRS Tx 2508 for the target WTRU 2502, the number of resources for the SL-PRS Tx 2510a - 2510d for the anchor WTRUs 2504a - 2504d, and / or any combination thereof.

[0509] Figure 25 An RTT-based positioning method is depicted, where 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 at all the anchor WTRUs 2504a - 2504d. Each anchor WTRU 2504a - 2504d may then use a unicast-based transmission to send back the SL-PRS 2510a - 2510d.

[0510] Although the features and elements are provided above in a specific combination, those of ordinary skill in the art will understand 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 spirit and scope of the invention, as will be apparent to those skilled in the art. Unless explicitly provided otherwise, any element, act, or statement used in the specification of this application should not be construed as essential or necessary to the invention. Based on the foregoing description, methods, devices, and articles that are functionally equivalent to those described herein will be apparent to those skilled in the art within the scope of the present disclosure, in addition to those enumerated herein. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents of such claimed claims. It should be understood that the present disclosure is not limited to a particular method or system.

[0511] Although, for simplicity, the foregoing embodiments may be discussed with respect to specific terms and structures (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.), the embodiments discussed are not limited thereto and may be applied to other systems using other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0512] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the term "video" or the term "image" may mean any one of, or any suitable combination of, a snapshot, a single image, and / or multiple images displayed on a time basis, etc. Also, as 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 embodiment of the plurality of embodiments of the WTRU; (iii) a device having wireless functionality and / or having wired functionality (e.g., tetherable) configured with some or all of the structures and functionality of the WTRU, in particular; (iii) a device having wireless functionality and / or having wired functionality configured with less than all of the structures and functionality of the WTRU; or (iv) etc. Details of an exemplary WTRU that may represent any WTRU described herein are provided herein. Also, various disclosed embodiments herein above and below are described as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than a head-mounted display may be utilized and some or all of the present disclosure and the 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 augmented reality experience. Figures 1A to 1D Furthermore, 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 a processor. Examples of computer-readable media include electronic signals (sent via a wired or wireless connection) and computer-readable storage media. Different from 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 internal 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]

[0514] ​Variations of the methods, apparatuses, articles, and systems provided above are possible without departing from the scope of the present invention. Given the various implementations that are applicable, it should be understood that the illustrated implementations are merely examples and should not be considered as limiting the scope of the following claims. For example, the implementations provided herein include handheld devices, which may include or utilize any suitable voltage source (such as a battery, etc.) that provides any suitable voltage.

[0515] In addition, in the implementations provided herein, processing platforms, computing systems, controllers, and other devices that include a processor are pointed out. These devices may include at least one central processing unit (“CPU”) and a memory. In accordance with the practice of those skilled in the art of computer programming, references to symbolic representations of actions and operations or instructions may be executed by various CPUs and memories. Such actions and operations or instructions may be considered to be “executed,” “computer-executed,” or “CPU-executed.”

[0516] Those of ordinary skill in the art will understand that actions and symbolic representations of operations or instructions include the manipulation of electrical signals by a CPU. The electrical system represents data bits, which may result in the ultimate transformation or reduction of electrical signals and the retention of data bits at memory locations in a memory system, thereby reconfiguring or otherwise altering the operation of the CPU and performing other processing of the signals. A memory location that retains data bits is a physical location that has a particular electrical, magnetic, optical, or organic property corresponding to or representing the data bits. It should be understood that the implementations are not limited to the above platforms or CPUs, and other platforms and CPUs may also support the provided methods.

[0517] Data bits may also be retained on a computer-readable medium, which includes 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 systems readable by a CPU. The computer-readable medium may include cooperative or interconnected computer-readable media that exist uniquely on a processing system or are distributed among multiple interconnected processing systems, which may be local or remote to the processing system. It should be understood that the implementations are not limited to the above memories, and other platforms and memories may also support the provided methods.

[0518] In an illustrative implementation, any one 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.

[0519] The foregoing detailed description has set forth various embodiments of devices and / or processes using block diagrams, flowcharts, and / or examples. Where such block diagrams, flowcharts, and / or examples contain one or more functions and / or operations, those skilled in the art will understand that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented, individually and / or jointly, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an example embodiment, several portions of the subject matter described herein may 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 ...

Claims

1. A first wireless transmit / receive unit (WTRU), the WTRU comprising: A transceiver and a processor, the processor being configured to: Receive a sidelink positioning reference signal (SL-PRS) transmission request from a second WTRU; In response to the SL-PRS transmission request from the second WTRU, transmit, via the transceiver, a request for allocation of SL-PRS resources, a priority associated with the SL-PRS transmission request, and a bandwidth associated with the SL-PRS transmission request to a network; and Receive, via the transceiver, the allocation of the SL-PRS resources for SL-PRS transmission associated with the first WTRU from the network.

2. The first WTRU according to claim 1, wherein the processor is further configured to: Receive an indication from the second WTRU, the indication including information associated with the priority associated with the SL-PRS and the bandwidth associated with the SL-PRS.

3. The first WTRU according to claim 2, wherein the processor is further configured to: Based on the indication, determine the priority associated with the SL-PRS and the bandwidth associated with the SL-PRS.

4. The first WTRU according to claim 2, wherein the indication further includes information associated with one or more of the latency associated with the SL-PRS or the periodicity associated with the SL-PRS.

5. The first WTRU according to claim 4, wherein the processor is configured to: In response to a request to transmit the SL-PRS from the second WTRU, transmit, via the transceiver, the latency associated with the SL-PRS or the periodicity associated with the SL-PRS.

6. The first WTRU according to claim 1, wherein the request for the allocation of SL-PRS resources to the network is transmitted via one or more of a scheduling request (SR), a media access control (MAC) control element (CE) transmission, a radio resource control (RRC) transmission, or a location positioning protocol (LPP) transmission.

7. The first WTRU according to claim 1, wherein the request for the allocation of SL-PRS resources to the network is transmitted via a media access control (MAC) control element (CE), and wherein the request for the allocation of SL-PRS resources to the network includes a request for the transmission of non-periodic SL-PRS resources.

8. The first WTRU according to claim 1, wherein the request for the allocation of SL-PRS resources to the network is transmitted via a radio resource control (RRC) transmission, and wherein the request for the allocation of SL-PRS resources to the network includes a request for the transmission of periodic SL-PRS resources.

9. The first WTRU according to claim 1, wherein the processor is further configured to: In response to the SL-PRS transmission request from the second WTRU, transmit an indication of the availability of sidelink positioning services via the transceiver.

10. The first WTRU according to claim 1, wherein the processor is configured to: In response to the SL-PRS transmission request from the second WTRU, transmit the latency associated with the SL-PRS and the periodicity associated with the SL-PRS via the transceiver.

11. A method implemented by a first wireless transmit / receive unit (WTRU), the method comprising: Receive a sidelink positioning reference signal (SL-PRS) transmission request from a second WTRU; In response to the SL-PRS transmission request from the second WTRU, transmit a request for allocation of SL-PRS resources, a priority associated with the SL-PRS transmission request, and a bandwidth associated with the SL-PRS transmission request to a network; and Receive the allocation of the SL-PRS resources for the SL-PRS transmission associated with the first WTRU from the network.

12. The method according to claim 11, the method further comprising: Receive an indication from the second WTRU, the indication including information associated with the priority associated with the SL-PRS and the bandwidth associated with the SL-PRS.

13. The method according to claim 12, the method further comprising: Based on the indication, determine the priority associated with the SL-PRS and the bandwidth associated with the SL-PRS.

14. The method according to claim 12, wherein the indication further comprises information associated with one or more of the latency associated with the SL-PRS or the periodicity associated with the SL-PRS.

15. The method according to claim 14, the method further comprising: In response to the SL-PRS transmission request from the second WTRU, transmit the latency associated with the SL-PRS or the periodicity associated with the SL-PRS.

16. The method according to claim 11, wherein the request for the allocation of SL-PRS resources to the network is transmitted via one or more of a scheduling request (SR), a medium access control (MAC) control element (CE) transmission, a radio resource control (RRC) transmission, or a location positioning protocol (LPP) transmission.

17. The method according to claim 11, wherein the request for the allocation of SL-PRS resources to the network is transmitted via a medium access control (MAC) control element (CE), and wherein the request for the allocation of SL-PRS resources to the network comprises a request for the transmission of non-periodic SL-PRS resources.

18. The method according to claim 11, wherein the request for the allocation of the SL-PRS resource to the network is transmitted via radio resource control (RRC), and wherein the request for the allocation of the SL-PRS resource to the network includes a request for the transmission of periodic SL-PRS resources.

19. The method according to claim 11, the method further comprising: In response to the SL-PRS transmission request from the second WTRU, transmit an indication of the availability of a sidelink positioning service.

20. The method according to claim 11, the method further comprising: In response to the SL-PRS transmission request from the second WTRU, transmit the latency associated with the SL-PRS and the periodicity associated with the SL-PRS.

21. A wireless transmit / receive unit (WTRU), the WTRU comprising: A transceiver and a processor, the processor being configured to: Configure three SL-PRS modes in one time slot, where each of the three SL-PRS modes corresponds to a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH); Select one of the three SL-PRS modes for transmission; and Determine the position of each PSCCH or PSSCH according to the selected SL-PRS mode.

22. The WTRU according to claim 21, wherein the processor is further configured to: if the WTRU transmits in a first mode of the three SL-PRS modes, transmit a PSCCH or a PSSCH in a first region; if the WTRU transmits in a second mode of the three SL-PRS modes, transmit a PSCCH or a PSSCH in a second region; and if the WTRU transmits in a third mode of the three SL-PRS modes, transmit a PSCCH or a PSSCH in a third region.

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