Method and apparatus for sidelink (SL) positioning using multiple reference WTRUs

Abstract

A procedure is provided regarding how a target WTRU and an LMF negotiate a supported WTRU initiated positioning method, as well as how the target WTRU discovers a reference WTRU for SL positioning and a procedure of performing appropriate SL positioning using a plurality of reference WTRUs. A procedure is provided as to how to perform SL positioning between a target WTRU and a reference WTRU in coordination with an LMF. When the number of available reference WTRUs changes, the appropriate SL positioning method can be updated. Each WTRU positioning method requires a different number of reference WTRUs for SL positioning. As the WTRU moves around, there may be no enough reference WTRU available for SL positioning. A positioning method to be employed by negotiation may be considered between the WTRU and the network. When certain WTRU positioning methods are impossible, the requested positioning method may be updated to one or more other available positioning methods.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 410,826, filed on September 28, 2022, and U.S. Provisional Application No. 63 / 526,835, filed on July 14, 2023, which are hereby incorporated by reference herein in their entirety as if fully set forth. Background Art

[0003] Even when a WTRU is within the coverage of a 5G system, there are some situations where the WTRU is not available for Uu - based positioning. This lack of availability may occur, for example, due to a lack of the number of reachable gNBs. In such a case, positioning of the WTRU using the PC5 channel (i.e., SL positioning) is considered to obtain the WTRU location. To perform SL positioning, the WTRU may need to connect multiple WTRUs for a given one or more WTRU positioning methods. Information about the WTRUs involved in SL positioning via PC5 connections at the NW is also required, including, for example, for allocating resources for PC5 connections, sharing assistance information for SL positioning, or for coordination on the WTRU to collect sufficient measurement information to determine the WTRU's location. Summary of the Invention

[0004] According to an example, when selecting an SL positioning method, the target WTRU reports a list of available reference WTRUs, and the LMF considers the reported list of reference WTRUs from the target WTRU.

[0005] According to an example, when the requested SL positioning cannot be satisfied due to a lack of available reference WTRUs, the target WTRU can negotiate the SL positioning method with the LMF.

[0006] When the WTRU is in coverage, the WTRU can initiate a location request with multiple reference WTRUs. The SL - based location request can be initiated by the target WTRU when it is in coverage. An overall process is provided on how the target WTRU and the LMF negotiate the supported WTRU - initiated positioning methods, and how the target WTRU discovers reference WTRUs for SL positioning and performs appropriate SL positioning using multiple reference WTRUs.

[0007] When the WTRU is in coverage, multiple reference WTRUs can be used to support NW - initiated location requests. The SL - based location request can be initiated by the NW. After receiving the location request from the LMF, the target WTRU can be triggered to discover and establish connections with reference WTRUs. With this consideration, an overall process is provided on how to perform SL positioning between the target WTRU and the reference WTRUs in coordination with the LMF.

[0008] When the available number of reference WTRUs changes, the appropriate SL positioning method can be updated. Each WTRU positioning method requires a different number of reference WTRUs for SL positioning. As the WTRU moves around, there may not be enough reference WTRUs available for SL positioning. Negotiation between the WTRU and the network can be considered for the positioning method to be employed. When some WTRU positioning methods are not possible, the requested positioning method can be updated to one or more other available positioning methods. Description of the Drawings

[0009] A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals in the drawings indicate like elements and in which:

[0010] Figure 1A is a system diagram showing an example communication system in which one or more of the disclosed embodiments can be implemented;

[0011] Figure 1B is a system diagram showing an example wireless transmit / receive unit (WTRU) that can be used within the communication system shown in Figure 1A ;

[0012] Figure 1C is a system diagram showing an example radio access network (RAN) and an example core network (CN) that can be used within the communication system shown in Figure 1A ;

[0013] Figure 1D is a system diagram showing another example RAN and another example CN that can be used within the communication system shown in Figure 1A ;

[0014] Figure 2 shows a reference model of the potential architecture of a 5G or NextGen network;

[0015] Figure 3 shows a reference model of a 5G / NextGen network for location services;

[0016] Figure 4 shows an NR positioning CP / UP architecture that can implement multiple positioning techniques and methods using defined protocols;

[0017] Figure 5 shows a 5G MO-LR signaling diagram using multiple reference WTRUs;

[0018] Figure 6 shows a 5G MT-LR signaling diagram using multiple reference WTRUs;

[0019] Figure 7 shows signaling associated with a positioning method update procedure; and

[0020] Figure 8 shows a method for sidelink (SL) positioning in a wireless transmit / receive unit (WTRU). DETAILED DESCRIPTION

[0021] describes systems, methods, and devices for SL positioning using multiple reference WTRUs.

[0022] A method for sidelink (SL) positioning in a wireless transmit / receive unit (WTRU) includes triggering a location request, where the location request includes one or more quality metrics; discovering at least one SL reference WTRU; determining a list of available reference WTRUs, where the list includes at least one SL reference WTRU, and including at least one SL reference WTRU is based on at least one of the one or more quality metrics; sending an SL positioning service request to the network, the SL positioning service request including the list of available reference WTRUs; negotiating SL positioning capabilities with the network in view of the list of available reference WTRUs; receiving assistance information from the network; and performing an SL positioning procedure using the assistance information via the negotiated SL positioning capabilities. The at least one SL reference WTRU discovered may be identified in a mobile originated location request. The method may include, in the absence of a reference WTRU, renegotiating SL positioning capabilities with the network based on the list of available reference WTRUs. The one or more quality metrics may include at least one of a group consisting of accuracy, response time, and LCS QoS class. The assistance information may include information for communicating with at least one WTRU from the list of available reference WTRUs. The assistance information may include obtaining assistance data. The use of the assistance information may include at least one of leveraging accessible positioning sources, measurements, and processing of positioning signals. The method may include calculating the location of the WTRU in two or more dimensions and reporting the location to the network. Negotiating SL positioning capabilities with the network may include sending a request including a list of preferred capabilities and supported capabilities, and receiving a response indicating the SL positioning procedure to the sent request. The method may include indicating one or more priorities associated with the SL positioning procedure, and selecting a procedure to use based on the indicated one or more priorities. The indication and selection may be performed via the network.

[0023] A wireless transmit / receive unit (WTRU) for sidelink (SL) positioning includes a processor and a transceiver communicatively coupled to the processor. The processor and the transceiver operate to trigger a location request, where the location request includes one or more quality metrics; discover at least one SL reference WTRU; determine a list of available reference WTRUs, where the list includes at least one SL reference WTRU, and including the at least one SL reference WTRU is based on at least one of the one or more quality metrics; send an SL positioning service request to a network, the SL positioning service request including the list of available reference WTRUs; negotiate SL positioning capabilities with the network in view of the list of available reference WTRUs; receive assistance information from the network; and use the assistance information to perform an SL positioning process via the negotiated SL positioning capabilities. The at least one SL reference WTRU discovered may be identified in a mobile-originated location request. The processor and the transceiver may also operate to renegotiate SL positioning capabilities with the network based on the list of available reference WTRUs in the absence of a reference WTRU. The one or more quality metrics may be at least one of a group consisting of accuracy, response time, and LCS QoS class. The assistance information may be information for communicating with at least one WTRU from the list of available reference WTRUs. The assistance information may be acquisition assistance data. The processor and the transceiver may also operate to calculate the location of the WTRU in two or more dimensions and report the location to the network. Negotiating SL positioning capabilities with the network may include the processor and the transceiver also operating to send a request including a list of preferred capabilities and supported capabilities, and receive a response indicating an SL positioning process to the sent request. The processor and the transceiver may also operate to indicate one or more priorities associated with the SL positioning process and select a process to use based on the indicated one or more priorities.

[0024] Figure 1A FIG. is a diagram illustrating an example communication system 100 that may implement one or more of the disclosed embodiments. The communication system 100 may be a multi-access system that provides content such as voice, data, video, messaging, broadcast, etc. to a plurality of wireless users. The communication system 100 may enable the plurality of wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may use 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 discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multicarrier (FBMC), etc.

[0025] AsFigure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, 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. For example, the WTRUs 102a, 102b, 102c, 102d (any one of which may be referred to as a station (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 the context of an industrial and / or automation processing chain), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, and so on. Any one of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0026] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a, 114b may be any type of device configured to facilitate access to one or more communication networks (such as CN 106, the Internet 110, and / or other networks 112) by wirelessly interfacing with at least one of the WTRUs 102a, 102b, 102c, 102d. By way of example, the base stations 114a, 114b may be base transceiver stations (BTSs), Node Bs, evolved Node Bs (eNBs), home Node Bs, home eNBs, next-generation Node Bs (e.g., g Node Bs (gNBs)), New Radio (NR) Node Bs, site controllers, access points (APs), wireless routers, and so on. Although each of the base stations 114a, 114b is described as a single element, it should be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0027] The base station 114a may be part of the RAN 104, 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.). The base station 114a and / or the 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 a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. The cell may provide coverage for wireless services to a specific geographical area, which may be relatively fixed or may change over time. The cell may also be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, that is, each transceiver corresponds to one sector of the cell. In an embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology and may use 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.

[0028] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via an air interface 116, which may be any suitable wireless communication link (such as 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 the air interface 116.

[0029] More specifically, as described above, the communication system 100 may be a multi-access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed Uplink (UL) Packet Access (HSUPA).

[0030] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as evolved UMTS terrestrial radio access (E-UTRA), which may use Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-A Pro (LTE-A Pro) to establish the air interface 116.

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as NR radio access, which may use NR to establish the air interface 116.

[0032] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example using the dual connectivity (DC) principle. Thus, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions to / from multiple types of base stations (e.g., eNBs and gNBs).

[0033] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement the following radio technologies, such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (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), GSM Enhanced Data Rate for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0034] As an example, Figure 1AThe base station 114b therein may be a wireless router, a home Node B, a home eNode B, or an access point, for example, and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a business premise, a residence, a vehicle, a campus, an industrial facility, an air corridor (e.g., for drones), a road, and so on. 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 establish a pico cell or a femto cell by using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). 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.

[0035] The RAN 104 may communicate with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or voice over Internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, location-based services, prepaid calls, Internet connectivity, video distribution, etc., and / or perform advanced security functions such as user authentication. Although not shown in Figure 1A the figure, it should be understood that the RAN 104 and / or the CN 106 may communicate directly or indirectly with other RANs that use the same or different RATs as the RAN 104. For example, in addition to being connected to the RAN 104 that may use NR radio technology, the CN 106 may also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0036] CN 106 can also be used as a gateway for WTRU 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols such as the Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in the TCP / IP protocol suite. The network 112 may include wired and / or wireless communication networks 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 employ the same RAT or a different RAT as the RAN 104.

[0037] Some or all of the WTRU 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRU 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 employ a cellular-based radio technology, and with a base station 114b that may employ IEEE 802 radio technology.

[0038] Figure 1B is a system diagram showing 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 keyboard 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.

[0039] 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), any other type of integrated circuit (IC), a state machine, etc. The processor 118 can perform signal coding, data processing, power control, input / output processing, and / or any other function that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to a transceiver 120, and the transceiver 120 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.

[0040] The transmit / receive element 122 can be configured to transmit or receive signals to or 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 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.

[0041] 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.

[0042] The transceiver 120 can be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described above, the WTRU 102 can have multi-mode capabilities. Thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs (such as NR and IEEE802.11).

[0043] The processor 118 of the WTRU 102 may be coupled to the speaker / microphone 124, the keyboard 126, and / or the display / touchpad 128 (such as a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit), and may receive user input data from these components. The processor 118 may also output user data to the speaker / microphone 124, the keyboard 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from any type of suitable memory (such as the non-removable memory 130 and / or the removable memory 132), and store data in these memories. 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, and so on. In other embodiments, the processor 118 may access information from memories that are not actually located on the WTRU 102 (such as located on a server or a home computer (not shown)), and store data in these memories.

[0044] The processor 118 may receive power from a power supply 134, and may be configured to distribute and / or control the power for 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 batteries (such as nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, and so on.

[0045] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (such as longitude and latitude) about the current location of the WTRU 102. As a supplement or replacement to the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (such as base stations 114a, 114b) via an air interface 116, and / or determine its location based on the signal timing received from two or more nearby base stations. It should be understood that the WTRU 102 may obtain location information by means of any suitable location determination method while remaining consistent with the embodiments.

[0046] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game console module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripherals 138 may include one or more sensors. The sensors may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, etc.

[0047] The WTRU 102 may include a full-duplex radio for which some or all of the transmission and reception of signals (e.g., associated with a particular subframe for both 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 to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing by a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which some or all of the transmission and reception of signals (e.g., associated with a particular subframe for UL (e.g., for transmission) or DL (e.g., for reception)).

[0048] Figure 1C is a system diagram showing the RAN 104 and the CN 106 according to an embodiment. As described above, the RAN 104 may communicate with the WTRU 102a, 102b, 102c via the air interface 116 using E-UTRA radio technology. The RAN 104 may also communicate with the CN 106.

[0049] The RAN 104 may include eNodeBs 160a, 160b, 160c, but it should be understood that the RAN 104 may include any number of eNodeBs while remaining 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.

[0050] 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, user scheduling 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.

[0051] Figure 1C The illustrated CN 106 may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although the foregoing elements are 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.

[0052] 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 handover between the RAN 104 and other RANs (not shown) using other radio technologies such as GSM and / or WCDMA.

[0053] The SGW 164 can be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 can typically 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 eNodeBs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the contexts of the WTRUs 102a, 102b, 102c, and so on.

[0054] The SGW 164 can be connected to the PGW 166, and the PGW 166 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.

[0055] 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 or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. 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.

[0056] Although the WTRU is described as a wireless terminal in Figure 1A - Figure 1D it is contemplated that in certain representative embodiments, such a terminal can use (e.g., temporarily or permanently) a wired communication interface to the communication network.

[0057] In a representative embodiment, the other network 112 can be a WLAN.

[0058] A WLAN in infrastructure basic service set (BSS) mode can have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic destined for an STA from outside the BSS can reach the STA through the AP and can be delivered to the STA. Traffic originating from an STA to a destination outside the BSS can be sent to the AP for delivery to the corresponding destination. Traffic between STAs within the BSS can be sent through the AP. For example, the source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. The traffic volume between STAs within the BSS can be regarded as and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between the source STA and the destination STA (e.g., directly between the source STA and the destination STA) using direct link setup (DLS). In some representative embodiments, DLS can 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) can communicate directly with each other. The IBSS communication mode can sometimes be referred to here as the "ad-hoc" communication mode.

[0059] When using 802.11ac infrastructure operation mode or a similar operation mode, the AP can send beacons on a fixed channel, such as the primary channel. The primary channel can be of a fixed width (e.g., 20 MHz bandwidth) or dynamically set width. The primary channel can be the operation channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, carrier sense multiple access with collision avoidance (CSMA / CA) can be implemented, such as in 802.11 systems. For CSMA / CA, the STA (e.g., each STA) (including the AP) can sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that particular STA can back off. Only one STA (e.g., only one station) can transmit at any given time in a given BSS.

[0060] High throughput (HT) STAs can use a channel with a width of 40 MHz for communication, e.g., by combining a 20 MHz primary channel with an adjacent or non-adjacent 20 MHz channel to form a 40 MHz channel.

[0061] A very high throughput (VHT) STA can support channels that are 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide. 40 MHz and / or 80 MHz channels 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, the data after channel coding can pass through a segmentation parser, which can divide the data into two streams. Inverse fast Fourier transform (IFFT) processing and time - domain processing can be performed separately on each stream. The 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 above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the media access control (MAC).

[0062] Sub - 1GHz operation modes are supported by 802.11 af and 802.11 ah. The channel operation bandwidths and carriers in 802.11 af and 802.11 ah are reduced compared to those used in 802.11 n and 802.11 ac. 802.11 af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non - TVWS spectrum. According to a representative embodiment, 802.11 ah can support meter - type control / machine - type communication (MTC), such as MTC devices in a macro - coverage area. MTC devices can have certain capabilities, such as including limited capabilities that support (e.g., only support) certain and / or limited bandwidths. MTC devices can include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0063] WLAN systems (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) that can support multiple channels and channel bandwidths include channels that can be designated as the primary channel. 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 that supports the minimum bandwidth operation mode among all STAs operating in the BSS. In the example of 802.11ah, for an STA that supports (e.g., only supports) the 1MHz mode (e.g., an MTC type device), 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, due to an STA (that only supports the 1MHz operation mode) sending to the AP, the entire available frequency band may be considered busy even if most of the available band remains idle.

[0064] In the United States, the available frequency band that 802.11ah can use is from 902MHz to 928MHz. In Korea, the available frequency band is from 917.5MHz to 923.5MHz. In Japan, the available frequency band is from 916.5MHz to 927.5MHz. Depending on the country code, the total bandwidth available for 802.11ah is from 6MHz to 26MHz.

[0065] Figure 1D FIG. is a system diagram showing RAN 104 and CN 106 according to an embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, 102c via air interface 116 using NR radio technology. RAN 104 can also communicate with CN 106.

[0066] The RAN 104 may include gNBs 180a, 180b, 180c, but it should be understood that the RAN 104 may include any number of gNBs while remaining consistent with the embodiments. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO techniques. For example, the gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers (not shown) to the WTRU 102a. A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and the gNB 180b (and / or gNB 180c).

[0067] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. 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. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing a varying number of OFDM symbols and / or having a continuously varying absolute time length).

[0068] gNBs 180a, 180b, 180c can be configured to communicate with WTRUs 102a, 102b, 102c that employ a stand-alone configuration and / or a non-stand-alone configuration. In a stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c without accessing another RAN (e.g., such as eNodeBs 160a, 160b, 160c). In a stand-alone configuration, WTRUs 102a, 102b, 102c can utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor. In a stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a 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 eNodeBs 160a, 160b, 160c). For example, WTRUs 102a, 102b, 102c can implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-stand-alone configuration, eNodeBs 160a, 160b, 160c can serve 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.

[0069] 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, user scheduling in UL and / or DL, support network slicing, DC, interworking between NR and E-UTRA, routing of user plane data to user plane functions (UPFs) 184a, 184b, routing of control plane information to 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.

[0070] Figure 1DThe CN 106 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 may include data networks (DN) 185a, 185b. Although the foregoing elements are 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.

[0071] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 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, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, managing the registration area, terminating non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize the 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 that rely on ultra-reliable low latency (URLLC) access, services that rely on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 182a, 182b may provide control plane functions for handover between the RAN 104 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0072] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing DL data notifications, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0073] UPF 184a and 184b can be connected to one or more of gNBs 180a, 180b, and 180c in RAN 104 via the N3 interface, and the N3 interface 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, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, etc.).

[0074] CN 106 can facilitate communication with other networks. For example, CN 106 can include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 106 and the PSTN 108. Additionally, CN 106 can provide access to other networks 112 for WTRU 102a, 102b, and 102c, and the other networks 112 can include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU 102a, 102b, and 102c can be connected to local DNs 185a and 185b via the N3 interface to UPF 184a and 184b and the N6 interface between UPF 184a and 184b and DNs 185a and 185b.

[0075] In view of Figure 1A - Figure 1D and with respect to Figure 1A - Figure 1D 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-d, base stations 114a-b, eNode Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DNs 185a-b, and / or any other device(s) described herein. The emulation device(s) can be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device(s) can be used to test other devices and / or simulate network and / or WTRU functionality.

[0076] Emulation devices can be designed to implement one or more tests of other devices in a laboratory environment and / or an operator network environment. For example, one or more emulation devices can perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more emulation devices can perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. An emulation device can be directly coupled to another device to perform tests and / or execute tests using over-the-air wireless communication.

[0077] One or more emulation devices can perform one or more functions, including all functions, without being implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices can be used in a test laboratory and / or a test scenario in a non-deployed (e.g., test) wired and / or wireless communication network to implement tests of one or more components. One or more emulation devices can be test devices. An emulation device can send and / or receive data using direct RF coupling and / or wireless communication via an RF circuit (e.g., which can include one or more antennas).

[0078] Figure 2 Reference model 200 showing a potential architecture for 5G or next-generation networks is presented. The architecture of model 200 specifies discrete interfaces between control plane elements. RAN 210 refers to a radio access network based on 5G RAT or evolved E-UTRA that is connected to a next-generation core network. The Access and Mobility Management Function (AMF) 220 includes at least the following functions: registration management, connection management, reachability management, mobility management, etc. The Session Management Function (SMF) 230 includes at least the following functions: session management (including session establishment, modification, and release), WTRU IP address allocation, selection and control of the UPF function, etc. The User Plane Function (UPF) 240 includes at least the following functions: packet routing and forwarding, packet inspection, traffic usage reporting, etc.

[0079] 5G Location Service (LCS) can provide a function for providing location information of a WTRU 250. The location of the WTRU 250 can be supported by RAT-related location methods. RAT-related location methods can rely on, for example, 3GPP RAT measurements obtained by the target WTRU and / or measurements of 3GPP RAT signals sent by the target WTRU obtained by the access network. RAT-independent location methods can support the location of the WTRU. RAT-independent location methods can rely on non-RAT measurements and / or other information obtained by the WTRU. The location information of one or more target WTRUs can be requested by an LCS client or Application Function (AF) 260 inside or outside the 3GPP operator network or by a control plane NF inside the 3GPP system and reported to them. For a location request from an LCS client or AF 260, privacy verification of the target WTRU can be enabled to check whether it is allowed to obtain WTRU location information.

[0080] Several different types of location requests can be supported. A Mobile Terminated Location Request (MT-LR) can occur together with a Mobile Terminated Location Request (MT-LR), where the LCS client or AF sends a location request to the 5G network to obtain the location of the target WTRU. A Mobile Originated Location Request (MO-LR) can occur together with a Mobile Originated Location Request (MO-LR), where the WTRU sends a request to the 5G network to obtain location-related information of the WTRU. An Immediate Location Request can occur together with an Immediate Location Request, where the LCS client or AF 260 sends or initiates a location request for the (one or more) target WTRUs and expects to receive a response containing the location information of the (one or more) target WTRUs within a short period of time. The Immediate Location Request can be used for MT-LR or MO-LR. A Delayed Location Request can occur together with a Delayed Location Request, where the LCS client or AF 260 sends a location request for the target WTRU to the 5G network and expects to receive a response when an indicated event occurs for the target WTRU at some future time. It can be used for MT-LR.

[0081] The Authentication Server Function (AUSF) 270 verifies the identity of the user and provides access to network resources based on its security level.

[0082] The Unified Data Management (UDM) 280 stores and manages user data, including its IMSI and authentication data. When requested, the UDM 280 provides user data (e.g., authentication data) to other network functions (i.e., AMF 220, SMF 230).

[0083] The Policy Control Function (PCF) 290 is responsible for implementing policies that manage a user's access to network resources. When requested, the PCF 290 provides policy data of a user, for example, to other network functions (i.e., the AMF 220, the SMF 230). The Data Network (DN) 295 is within the system as shown and is described herein.

[0084] Figure 3 A reference model 300 for 5G / Next Generation Networks for Location Services is shown. The (R)AN 310 represents the NG-RAN, a trusted non-3GPP access, or an untrusted non-3GPP access. The access network is involved in the handling of various positioning procedures, including the positioning of a target WTRU, the provision of location-related information not associated with a particular target WTRU, and the transfer of positioning messages between the AMF 320 or the LMF 305 and the target WTRU. The AF 360 and the NF may access the LCS service from the Gateway Mobile Location Center (GMLC) 315 in the same 3GPP operator network. The LCS client 345 may access the LCS service from the GMLC 315, and the external AF 360 may access the LCS service from the NEF 335. The GMLC 315 processes requests from the external LCS client 345, the AF 360 via the NEF 335 in the case where the AF 360 is an external AF 360, and forwards the location request to the appropriate NF. The Location Retrieval Function (LRF) 325 is responsible for retrieving or validating location information and may be collocated with the GMLC 315 or be separate. The Location Management Function (LMF) 305 manages the overall coordination and scheduling of resources required to register or access the location of the WTRU 350 registered with or accessing the 5GCN. The LMF 305 may calculate or validate the final location-related information and the achieved accuracy.

[0085] The Unified Data Management (UDM) 380 stores and manages user data, including its IMSI and authentication data. When requested, the UDM 380 provides user data, for example, a privacy profile or subscription data for location services, to the AMF 320, the GMLC 315, and the NEF 335.

[0086] Figure 4Figure 400 shows the NR positioning CP / UP architecture, which can implement various positioning technologies and methods (GNSS, sensors, positioning signals, etc.) using defined protocols. Positioning protocols and RAN-based positioning signals have been specified for implementing emergency services and location-based services. The 3GPP NR positioning protocol is supported by the control plane (CP) 415 positioning architecture on the Uu interface (from the NG-RAN node to the WTRU). The NR positioning architecture can also be supported by a Secure User Plane Location (SUPL) server (also known as the SUPL Location Platform (SLP) 425 or Location Server 430) that can utilize any IP bearer. The interworking of the CP 415 and the user plane (UP) 410 provides a positioning solution, and the SUPL 455 can also be used as a tunnel for the CP positioning protocol (e.g., LPP460), as Figure 4 shown.

[0087] The main protocol (LTE Positioning Protocol (LPP) 460) terminates between the WTRU 450 and the Location Management Function (LMF) 405. LPP 460 is a point-to-point LCS and NAS messaging protocol. LPP 460 has been agreed to be reused for NR and will continue to be utilized in the foreseeable future. Radio Resource Control (RRC) is another protocol used to provide transmission for LPP messages and other positioning procedures over the NR-Uu interface, which terminates between the gNB and the WTRU 450. On the network side, the NG Application Protocol (NGAP) terminates between the AMF420 and the NG-RAN node 440 (i.e., gNB / TRP) and is used as the transmission for LPP 460 and NRPPa 445 messages on the NG-C interface. Finally, the NR Positioning Protocol A (NRPPa) 445 carries information between the NG-RAN node 440 and the LMF 405.

[0088] In the NR positioning mode, positioning can be performed as a stand-alone, WTRU-based, or WTRU-assisted mode. In stand-alone positioning, the WTRU 450 handles all aspects of positioning, scans accessible positioning sources, measures, and processes positioning signals / sources. Finally, the WTRU 450 calculates its own position in 2 or 3 dimensions. In stand-alone positioning, the Uu interface affects include WTRU capability exchange and reporting of WTRU positioning. In WTRU-based positioning (WTRU-B), the network provides acquisition of assistance data, and the WTRU 450 scans accessible positioning sources, measures, and processes positioning signals / sources (based on the assistance information from the network). Finally, the WTRU 450 calculates its own position in 2 or 3 dimensions and can report its position to the network.

[0089] In WTRU-assisted positioning (WTRU-A), the network provides acquisition assistance, and the WTRU 450 scans for accessible positioning sources and measures the positioning signals / sources (based on the assistance information from the NW). Finally, the WTRU 450 returns the measurements to the network, and the network calculates the device location (at the location server 430 / LMF 405).

[0090] The following table (Table 1) provides the techniques of the supported WTRU positioning methods.

[0091] Table 1 - Techniques of the Supported WTRU Positioning Methods

[0092] Method WTRU-based WTRU-assisted, LMF-based DL-TDOA Yes Yes DL-AoD Yes Yes Multi-RTT No Yes NR E-CID No Yes UL-TDOA No No UL-AoA No No

[0093] In LPP 460, the LPP messages related to the (one or more) WTRU-assisted position requests at least include the following procedures:

[0094] Request capabilities, such as the LMF 405 requests from the WTRU 450;

[0095] Provide capabilities, such as the WTRU 450 responds to the LMF 405;

[0096] Request assistance data, such as the WTRU 450 requests positioning assistance data / information from the LMF 405;

[0097] Provide assistance data, such as the LMF 405 to the WTRU positioning assistance data information / configuration (additionally, the broadcast of positioning assistance data (AD) is supported via the positioning system information block (posSIB) and carried in the SI message);

[0098] Request location information, such as the LMF 405 requests positioning / measurements from the WTRU 450;

[0099] Provide location information, such as the WTRU 450 to the LMF 405, positioning and / or measurements;

[0100] Abort, such as aborting the LPP session; and

[0101] Error, such as the error associated with the (one or more) positioning processes.

[0102] The QoS requirements of the location request and the LCS QoS class can indicate the accuracy or response time of the location response. Since the QoS requirements and the LCS QoS class can indicate the accuracy requirements, the QoS requirements and the LCS QoS class can be used to determine the procedure to be used for performing the location calculation. Since the QoS requirements and the LCS QoS class can indicate the accuracy requirements, the QoS requirements and the LCS QoS class can be used to determine how many other WTRUs the first WTRU can interact with in order to perform the location calculation. For example, the accuracy of the location calculation can be improved by collecting location information from a larger number of WTRUs and using the location information from other WTRUs, thereby improving the accuracy of the location calculation. Since the QoS requirements and the LCS QoS class can indicate the response time, the QoS requirements and the LCS QoS class can be used to determine the procedure to be used for performing the location calculation. For example, the QoS requirements and the LCS QoS class indicating a relatively short response time can be used to determine to use a location calculation procedure that takes a relatively short amount of time.

[0103] Even when the WTRU is within the coverage of the 5G system, there are some cases where the WTRU is not available for Uu-based positioning, for example, due to the lack of the number of reachable gNBs. For these cases, the positioning of the WTRU considering the use of the PC5 channel, i.e., SL positioning, is considered to obtain the location of the WTRU. To perform SL positioning, the WTRU may need to connect to multiple WTRUs according to each WTRU positioning method. The NW also needs information about the WTRUs that are connected to the WTRU via PC5 and involved in the SL positioning of the WTRU, such as for assigning resources for the PC5 connection, sharing auxiliary information for SL positioning, or coordinating on the WTRU to collect sufficient measurement information to determine the location of the WTRU.

[0104] When the WTRU is in coverage, the WTRU 450 can initiate a location request with multiple reference WTRUs. The SL-based location request can be initiated by the target WTRU when it is in coverage. An overall process is provided on how the target WTRU and the LMF 405 negotiate the supported WTRU-initiated positioning methods, and how the target WTRU discovers the reference WTRUs for SL positioning and performs appropriate SL positioning using multiple reference WTRUs.

[0105] When the WTRU is in coverage, multiple reference WTRUs can be used to support the NW-initiated location request. The SL-based location request can be initiated by the NW. In this case, after receiving the location request from the LMF 405, the target WTRU can be triggered to discover and establish a connection with the reference WTRU. With this consideration, an overall process is provided on how to perform SL positioning between the target WTRU and the reference WTRU in coordination with the LMF 405.

[0106] When the available number of reference WTRUs changes, the appropriate SL positioning method can be updated. Each WTRU positioning method requires a different number of reference WTRUs for SL positioning. As the WTRU 450 moves around, there may not be enough reference WTRUs available for SL positioning. In such cases, it can be considered when negotiating the positioning method between the WTRU 450 and the network. When some WTRU positioning methods are not possible, the requested positioning method can be updated to other available positioning methods.

[0107] The WTRU 450 can support PC5 signaling. For example, the ProSe layer in the WTRU can support PC5 signaling. The WTRU 450 in the described example includes the capabilities of ranging and sidelink positioning. Sidelink positioning generally refers to positioning via the PC5 interface, while ranging refers to determining the distance between two WTRUs or more than two WTRUs and / or the direction and / or relative positioning of one WTRU with respect to another WTRU.

[0108] For a 5G MO-LR request, the target WTRU can check the available reference WTRUs, and the target WTRU can notify the network of the available reference WTRUs. The LMF 405 can determine the SL positioning method considering the available reference WTRUs, the capabilities of the target WTRU, and the QoS requirements. After deciding on the SL positioning method, the LMF 405 can notify the target WTRU and the involved reference WTRUs. The target WTRU and the reference WTRUs perform SL positioning and notify the result to the LMF 405.

[0109] According to a 5G MT-LR request, the target WTRU and the LMF 405 can communicate to negotiate the capabilities for SL positioning. During this period, the target WTRU can notify the LMF 405 of the available reference WTRUs, and the LMF 405 can decide on the SL positioning method based on the list of reference WTRUs, the capabilities of the target WTRU, and the QoS requirements. After the LMF 405 decides on the SL positioning method, the target WTRU and the reference WTRUs perform the SL positioning requested by the LMF 405.

[0110] When the target WTRU cannot perform the SL positioning requested by the LMF 405 due to a lack of available reference WTRUs, the target WTRU can provide this information to the LMF 405. The LMF 405 can perform another SL positioning method for the WTRU 450 considering the available reference WTRUs, the capabilities of the target WTRU, and the QoS requirements. The target WTRU can perform the SL positioning as indicated by the LMF 405 using the available reference WTRUs.

[0111] The NW may provide a list of reference WTRUs and discovery / selection configuration parameters, and the NW may provide a configuration list regarding SL positioning methods with priorities and other details.

[0112] Figure 5 FIG. 500 shows a 5G MO-LR signaling diagram using multiple reference WTRUs. At 502, the WTRU 15501 may be triggered to obtain a location request. The location request may include its destination, such as an LCS client or an AF. The location request may include a certain QoS requirement (e.g., accuracy, response time, LCS QoS class) that is required.

[0113] For example, an application at the WTRU 15501 may trigger a location request to send the location of the WTRU 15501 and some QoS requirements to an AF or an LCS client. For example, an application hosted by the WTRU may determine to trigger a location request when the application starts, when there is a user request input via the GUI, or when a time period expires.

[0114] As another example, the WTRU 15501 may be configured with some trigger conditions so that the 5GC system sends a location report with certain QoS requirements to an AF or an LCS client. For example, the WTRU may be configured to trigger a location request when a time period expires.

[0115] The WTRU 15501 may discover reference WTRUs (i.e., WTRU 25502, WTRU 3, WTRU 4…). Based on the QoS requirements of the location request and the SL positioning capabilities of the WTRU 15501, the WTRU 15501 may select multiple reference WTRUs (depicted as WTRU 25502) required for the SL positioning to meet the QoS requirements, and may establish a PC5 connection with the selected WTRUs at 504. When selecting reference WTRUs, the WTRU 15501 may select as many reference WTRUs as needed to support the SL positioning that meets the highest QoS requirements of the location request. If the available reference WTRUs are not sufficient to perform the SL positioning that meets the highest QoS requirements, the WTRU 15501 may select as many reference WTRUs as possible. Alternatively, the WTRU 15501 may postpone establishing a PC5 connection with the selected WTRUs at a later time, such as after receiving an SL positioning service request from the LMF 505, which may include a list of the selected positioning method and / or the selected reference WTRUs.

[0116] At 506, the WTRU 1 5501 may send a ranging / sidelink positioning service request to the AMF 520, which may include its destination information. The destination information may include, for example, an LCS client or an AF and the required QoS information. The WTRU 1 5501 may include a list of available reference WTRUs in the ranging / sidelink positioning service request. The WTRU 1 5501 may include an indication of preference for the list of reference WTRUs, or may sort the reference WTRUs in the list according to its preference. The preference may be, for example, per signal strength, latency, or PLMN.

[0117] At 508, the AMF 520 may select the LMF 505 to process the location request from the WTRU 1 5501.

[0118] At 512, the AMF 520 may send a ranging / sidelink positioning service request with a list of available reference WTRUs to the selected LMF 505. The AMF 520 may notify the LMF 505 of the capabilities of the WTRU 1 5501 for positioning.

[0119] At 514, the LMF 505 and the WTRU 1 5501 may communicate to exchange SL positioning capability negotiation. This communication may be used to transfer the sidelink positioning capabilities of the WTRU from the WTRU 1 5501 to the LMF 505. For example, the LMF 505 may send a capabilities REQ to the WTRU 1 5501 to query the SL positioning capabilities of the WTRU 1 5501 (e.g., supported positioning methods), and the WTRU 1 5501 may respond to the LMF 505 with a capabilities response that includes the SL positioning capabilities of the WTRU 1 5501 (e.g., supported positioning methods, such as DL-TDOA, DL-AOA, etc.).

[0120] Alternatively, the WTRU 1 5501 may perform a discovery process of available reference WTRUs (i.e., WTRU 2 5502, WTRU 3, WTRU 4 …), and notify the list of available reference WTRUs during the SL positioning capability negotiation or as a separate signaling process.

[0121] The LMF 505 can select a positioning method based on the QoS information included in the location request, the negotiated SL positioning capabilities of the WTRU 1 5501, and a list of available reference WTRUs from the WTRU 1 5501. The LMF 505 can select a list of reference WTRUs from the list of reference WTRUs to participate in the SL positioning of the WTRU 1 5501. When the LMF 505 selects a list of reference WTRUs, the LMF 505 can select as many reference WTRUs as the selected QoS requires, more reference WTRUs than the selected QoS requires, or all WTRUs in the list with or without a prioritization order. After selecting the positioning method, the LMF 505 can send assistance information to the selected reference WTRUs at 516 for the SL positioning of the WTRU 15501. For example, the assistance information at 516 can include information about the selected reference signal, which will be used for positioning using the selected positioning method (such as DL-TDOA, DL-AOA, etc.). For example, the assistance information at 516 can include information used by the WTRU to communicate with at least one WTRU selected from the list. Communicating with at least one WTRU selected from the list can include performing a side-link positioning procedure with at least one WTRU selected from the list. For example, the assistance information at 516 can include information used by the WTRU to receive a reference signal from the WTRU selected from the list and information about the use of the reference signal in the position calculation. When the LMF 505 makes a selection from the list of reference WTRUs, the LMF 505 can consider an indication of the preference from the WTRU 1 5501 to the reference WTRU (if available).

[0122] At 518, the LMF 505 can send assistance information to the NG-RAN 540. The assistance information at 518 can indicate the WTRU 1 5501 and the list of selected reference WTRUs, for example, when resource allocation for SL positioning is required. At 522, the NG-RAN 540 can perform resource allocation for the reference WTRUs for SL positioning.

[0123] Some of the above signaling can occur when the reference WTRU does not belong to the same PLMN as the target WTRU.

[0124] At 524, the LMF 505 may send a ranging / SL positioning service request to the WTRU 1 5501. The LMF 505 may indicate the selected positioning method. The LMF 505 may include a list of the selected reference WTRUs. If the list of the selected reference WTRUs is not included in the request from the LMF 505, the WTRU 1 5501 may consider each reference WTRU included in the request (ranging / sidelink positioning service request) to participate in the SL positioning.

[0125] At 526, the WTRU 1 5501 and the selected reference WTRU (described as the WTRU 2 5502) may perform a ranging / SL positioning process. The location information of the reference WTRU may be shared with the WTRU 1 5501. Before performing the ranging / SL positioning process at 526, if there is no PC5 connection already available for SL positioning, the WTRU 1 5501 and the selected reference WTRU(s) may establish one or more PC5 connections.

[0126] At 528, the WTRU 1 5501 may send the SL positioning result to the LMF 505.

[0127] The LMF 505 may determine the location of the WTRU 1 5501 based on the received SL positioning result and the known locations of the reference WTRUs. If needed, if the reference WTRU is available for Uu positioning by the LMF 505, the LMF 505 may perform Uu positioning with the reference WTRU. The LMF 505 may send the location of the WTRU 1 5501 to the AMF 520 at 532 as requested above.

[0128] At 534, the AMF 520 may send the location of the WTRU 1 5501 to the indicated destination as provided above.

[0129] As an alternative or addition to the discovery of the above reference WTRUs, the AMF 520 or the LMF 505 may provide a list of reference WTRUs according to the known locations of the WTRUs, and the WTRU may provide a list of available reference WTRUs as a response after performing the discovery or PC5 connection establishment process. In this case, the selection of the positioning method may be performed after receiving the list of reference WTRUs and may be shared.

[0130] Alternatively, or in addition, determining the location of the target WTRU may be performed by the LMF 505, the target WTRU, or another location server (in the WTRU or NW entity). When the target WTRU performs the location determination, the WTRU 1 5501 may send the determined location information to the LMF 505. If the LMF 505 or the WTRU 1 5501 is used to exchange further information to determine the exact WTRU location, further signaling exchanges may occur. When another location server performs the location determination, the WTRU 15501 or the LMF 505 may send the SL positioning result and other information, such as the location information of the reference WTRU, to the location server respectively. After the location server determines the location information of the WTRU 1 5501, the location server may send the location information to the LMF 505.

[0131] Figure 6 A 5G MT-LR signaling diagram 600 using multiple reference WTRUs is shown. At 602, the AMF 620 may receive a location request for the location information of the WTRU 1 6501 from an LCS client or AF via the GMLC and / or NEF. The location request may include some QoS requirements to be satisfied (e.g., accuracy, response time, LCS QoS class).

[0132] At 604, the AMF 620 may select the LMF 605 to handle the location service of the WTRU 1 6501.

[0133] At 606, the AMF 620 may forward the LMF 605 location request for positioning the WTRU 1 6501, which may include the received QoS requirements.

[0134] At 608, the LMF 605 may communicate with the WTRU 1 6501 to determine the capabilities of the WTRU 1 6501 for Uu or SL-based positioning methods. The LMF 605 may provide a list of potential reference WTRUs and the information required to discover and set up the PC5 connection for each WTRU's location.

[0135] After receiving a positioning capability request 608 from the LMF 605, the WTRU 1 6501 may check whether Uu-based positioning is available or SL-based positioning is available, e.g., based on the channel monitoring results of the available number of cells, based on the number of discovered reference WTRUs, or based on the registered PLMN information. At 612, the WTRU 1 6501 may discover reference WTRUs for SL positioning (i.e., WTRU 2 6502, WTRU 3, WTRU 4…). When provided with a list of potential reference WTRUs, the WTRU 1 6501 may attempt to discover a reference WTRU among those reference WTRUs in the list.

[0136] Based on the capabilities of the WTRU 1 6501 regarding SL positioning, i.e., the supported SL positioning methods, the WTRU 1 6501 may select the number of reference WTRUs and may establish a PC5 connection with the selected WTRUs. If QoS requirements are notified from the LMF 605, then when selecting reference WTRUs, the WTRU 1 6501 may select as many reference WTRUs as required to support SL positioning that meets the highest QoS requirements for the location request. If the available reference WTRUs are not sufficient to perform SL positioning by meeting the highest QoS requirements, or if no QoS requirements are notified, then the WTRU 1 6501 may select as many reference WTRUs as possible. Alternatively, the WTRU 1 6501 may defer establishing a PC5 connection with the selected WTRUs at a later time, e.g., after receiving an SL positioning service request from the LMF 605, which may include a list of the selected positioning method and / or the selected reference WTRUs.

[0137] Alternatively, the WTRU 1 6501 may notify a list of available reference WTRUs during SL positioning capability negotiation or as a separate signaling procedure.

[0138] At 614, the WTRU 1 6501 may send a positioning capability response to the LMF 605, which includes the positioning capabilities of the WTRU 1 6501 (e.g., supported positioning methods such as DL-TDOA, DL-AOA, etc.). The WTRU 1 6501 may indicate whether Uu positioning is available and / or whether SL positioning is available. The WTRU 1 6501 may include information about the list of available cells for Uu positioning and / or the list of available reference WTRUs for SL positioning. The WTRU 1 6501 may include an indication of the preference for the list of reference WTRUs, or may sort the reference WTRUs in the list according to its preference. The preference may be, for example, each ProSe App code, ProSe App ID, PLMN, or the monitored signal quality (e.g., average SINR) between the WTRU 1 6501 and the reference WTRU.

[0139] The LMF 605 may select a positioning method based on the QoS information included in the location request, the negotiated capabilities of the WTRU 1 6501 regarding SL positioning, and the list of available reference WTRUs from the WTRU 1 6501. When selecting the SL positioning method, the LMF 605 may select a list of reference WTRUs from the reference WTRUs in the list to participate in the SL positioning of the WTRU 1 6501. When the LMF 605 selects the list of reference WTRUs, the LMF 605 may select the number of reference WTRUs required for the selected QoS, more reference WTRUs than required for the selected QoS, or even all the reference WTRUs in the list. After selecting the positioning method, the LMF 605 may send auxiliary information to the selected reference WTRUs at 616 for the SL positioning of the WTRU 1 6501. For example, the auxiliary information at 616 may include information about the selected reference signal, which will be used for positioning using the selected positioning method (such as DL-TDOA, DL-AOA, etc.). For example, the auxiliary information at 616 may include information used by the WTRU to communicate with at least one WTRU selected from the list. Communicating with at least one WTRU selected from the list may include performing a sidelink positioning procedure with at least one WTRU selected from the list. For example, the auxiliary information at 616 may include information used by the WTRU to receive the reference signal from the WTRU selected from the list and information about the use of the reference signal in the position calculation. When the LMF 605 selects the list of reference WTRUs, the LMF 605 may consider the indication of the preference from the WTRU 1 6501 to the reference WTRU (if available).

[0140] At 618, the LMF 605 may send assistance information to the NG-RAN 640. For example, when resource allocation for SL positioning is required, the assistance information at 618 may indicate a list of the WTRU 1 6501 and the selected reference WTRUs.

[0141] At 622, the NG-RAN 640 may perform resource allocation for the reference WTRUs for SL positioning.

[0142] When the reference WTRU does not belong to the same PLMN as the target WTRU, the above signaling may be omitted.

[0143] At 624, the LMF 605 may send a ranging / SL positioning service request to the WTRU 1 6501. The LMF 605 may indicate the selected positioning method. The LMF 605 may include a list of the selected reference WTRUs. If the list of the selected reference WTRUs is not included in the request from the LMF 605, the WTRU 1 6501 may assume that each reference WTRU included in the request may be involved in SL positioning.

[0144] The WTRU 1 6501 and the selected reference WTRUs may perform a ranging / SL positioning procedure at 626. The location information of the reference WTRUs may be shared with the WTRU 1 6501. Before performing the ranging / SL positioning procedure at 626, if there is currently no PC5 connection available for SL positioning, the WTRU 1 6501 and the selected reference WTRU(s) may establish the PC5 connection(s).

[0145] At 628, the WTRU 1 6501 may send the SL positioning result to the LMF 605.

[0146] The LMF 605 may determine the location of the WTRU 1 6501 based on the received SL positioning result and the known locations of the reference WTRUs. If necessary, if the reference WTRU is available for Uu positioning of the LMF 605, the LMF 605 may perform Uu positioning of the reference WTRU. At 632, the LMF 605 may send the location of the WTRU 1 6501 to the AMF 620 according to the request.

[0147] At 634, the AMF 620 may send the location of the WTRU 1 6501 to the destination indicated in the received location request.

[0148] Alternatively or additionally, the determination of the location of the target WTRU can be performed by the LMF 605, the target WTRU, or another location server (in the WTRU or NW entity). When the location determination is performed by the target WTRU, the WTRU 1 6501 can send the determined location information to the LMF605. If the LMF 605 or the WTRU 1 6501 requests further information to more precisely determine the location of the WTRU 1 6501, further signaling exchanges can take place. When the location determination is performed by another location server(s), the WTRU 1 6501 or the LMF 605 can send the SL positioning result and other information (such as the location information of the reference WTRU) to the location server. After the location server determines the location information of the WTRU 1 6501, the location server can send the location information to the LMF 605.

[0149] Figure 7 A signaling 700 associated with the positioning method update process is shown. The LMF 705 can send a ranging / SL positioning service request to the WTRU 17501 at 702. The LMF can indicate the selected positioning method based on the known capabilities of the WTRU 1 7501 (e.g., supported positioning methods such as DL-TDOA, DL-AOA, etc.) and the requested QoS requirements (if available). The LMF 705 can include the QoS requirements in the ranging / SL positioning service request. The LMF 705 can provide a list of potential reference WTRUs and the information required to discover and set up the PC5 connection according to the location of each WTRU.

[0150] To perform the SL positioning requested by the LMF 705, the WTRU 1 7501 can attempt to discover the reference WTRU and perform PC5 connection establishment at 704. When provided with a list of potential reference WTRUs, the WTRU 1 7501 attempts to discover those reference WTRUs. Alternatively, the WTRU 1 7501 can later postpone establishing the PC5 connection with the discovered WTRU, for example, after receiving the SL positioning service request from the LMF 705, which can include the selected positioning method and / or a list of the selected reference WTRUs.

[0151] When the discovered reference WTRUs are not sufficient to perform the requested SL positioning, the WTRU 1 7501 can indicate that it cannot perform the requested SL positioning. At 706, the WTRU 1 7501 can include the identification of the list of available reference WTRUs. When determining whether the SL positioning will be successful, if the QoS requirements are available, for example, by sharing, configuration, or by other means, the discovered reference WTRUs can be considered to meet the requested QoS requirements.

[0152] When the LMF 705 receives a response at 706, which includes that the WTRU 1 7501 cannot perform SL positioning according to the request, the LMF 705 may select another positioning method based on the QoS requirements, the ability of the WTRU 1 7501 regarding SL positioning, and a list of available reference WTRUs (if provided from the WTRU 1 7501). The LMF 705 may select a list of reference WTRUs from the reference WTRUs in the list to participate in the SL positioning of the WTRU 1 7501. When the LMF 705 selects a list of reference WTRUs, the LMF 705 may select the reference WTRUs required for the selected QoS, more reference WTRUs than required for the selected QoS, or all the reference WTRUs on the list. After selecting the positioning method, the LMF 705 may send assistance information to the selected reference WTRUs for the SL positioning of the WTRU 1 7501. The LMF 705 may send a ranging / SL positioning service request to the WTRU 1 7501. At 708, the LMF 705 may indicate the selected positioning method. The LMF 705 may include a list of the selected reference WTRUs. If the list of the selected reference WTRUs is not included in the request from the LMF 705, the WTRU 1 7501 may consider that each reference WTRU included in the request will be involved in the SL positioning. For example, the assistance information may include information about the selected reference signal, which will be used for positioning using the selected positioning method (such as DL-TDOA, DL-AOA, etc.). For example, the assistance information may include information used by the WTRU to communicate with at least one WTRU selected from the list. Communicating with at least one WTRU selected from the list may include performing a side link positioning process with at least one WTRU selected from the list. For example, the assistance information may include information about the reference signal received by the WTRU from the WTRU selected from the list and information about the use of the reference signal in the position calculation.

[0153] At 712, the WTRU 1 7501 and the selected reference WTRUs may perform a ranging / SL positioning process. The location information of the reference WTRUs may be shared with the WTRU 1 7501. Before performing the ranging / SL positioning process at 712, if there is no PC5 connection currently available for SL positioning, the WTRU 1 7501 and the selected reference WTRU(s) may establish a PC5 connection(s).

[0154] At 714, the WTRU 1 7501 may send the SL positioning result to the LMF 705.

[0155] Alternatively or additionally, for the above, the LMF 705 may send a list of SL positioning methods. The list may refer to a ranking or may have preference values. The LMF 705 may provide the required or recommended number of reference WTRUs for each SL positioning method. Based on the list, the preference of the methods, the number of available reference WTRUs, and the comparison with the required or recommended number of reference WTRUs provided for each method (if available), the target WTRU may determine the SL positioning method that can achieve the best QoS in a given situation. The target WTRU may report the result of the selected or used SL positioning method to the LMF 705.

[0156] Alternatively or additionally, the determination of the location of the target WTRU may be performed by the LMF 705, the target WTRU, or another location server (in the WTRU or NW entity). When the location determination is performed by the target WTRU, the WTRU 1 7501 may send the determined location information to the LMF 705. If the LMF 705 or the WTRU 1 7501 exchanges further information to determine the exact location of the WTRU 17501, further signaling exchanges may occur. For example, when the location determination is performed by another location server, the WTRU 1 7501 or the LMF 705 may send the SL positioning result and other information. The other information may include the location information of the reference WTRU to the location server. After the location server determines the location information of the WTRU 1 7501, the location server may send the location information to the LMF 705.

[0157] Figure 8 A method 800 for sidelink (SL) positioning in a wireless transmit / receive unit (WTRU) is shown. The method 800 includes triggering a location request at 810. The location request may include one or more quality metrics. At 820, the method 800 includes discovering at least one SL reference WTRU. The at least one discovered SL reference WTRU may be identified in a mobile-originated location request. At 830, the method 800 includes determining a list of available reference WTRUs. For example, the list may include at least one SL reference WTRU based on at least one of the one or more quality metrics. At 840, the method 800 includes sending an SL positioning service request to the network, the SL positioning service request including the list of available reference WTRUs. At 850, the method 800 includes negotiating SL positioning capabilities with the network in view of the list of available reference WTRUs. At 860, the method 800 includes receiving assistance information from the network. At 870, the method 800 includes performing an SL positioning procedure using the assistance information via the negotiated SL positioning capabilities. At 880, the method 800 may include re-negotiating the SL positioning capabilities with the network based on the list of available reference WTRUs in the absence of a reference WTRU.

[0158] Although the features and elements have been described above in specific combinations, one of ordinary skill in the art will understand that each feature or element can be used separately or in any combination with other features and elements. Additionally, the methods described herein can be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, buffer memories, semiconductor storage 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 software can be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method for sidelink (SL) positioning in a wireless transmit / receive unit (WTRU), the method comprising: Triggering a location request, wherein the location request includes one or more quality metrics; Discovering at least one SL reference WTRU; Determining a list of available reference WTRUs, wherein the list includes the at least one SL reference WTRU, including the at least one SL reference WTRU is based on at least one of the one or more quality metrics; Sending an SL positioning service request to a network, the SL positioning service request including the list of available reference WTRUs; Negotiating SL positioning capabilities with the network in view of the list of available reference WTRUs; Receiving assistance information from the network; and Using the assistance information to perform an SL positioning procedure via the negotiated SL positioning capabilities.

2. The method according to claim 1, wherein Identifying the at least one SL reference WTRU discovered in a mobile-originated location request.

3. The method according to claim 1, further comprising, under the condition that the reference WTRU is less than a threshold, renegotiating SL positioning capabilities with the network based on the list of available reference WTRUs.

4. The method according to claim 1, wherein The one or more quality metrics include at least one of accuracy, response time, and LCS QoS class.

5. The method according to claim 1, wherein The assistance information includes information for communicating with at least one WTRU from the list of available reference WTRUs.

6. The method according to claim 1, wherein, The assistance information includes obtaining assistance data.

7. The method according to claim 1, wherein The use of the assistance information includes using at least one of an accessible positioning source, measurements, and processing of positioning signals.

8. The method according to claim 1, further comprising calculating the position of the WTRU in two or more dimensions.

9. The method according to claim 8, further comprising reporting the position to the network.

10. The method according to claim 1, wherein The negotiating SL positioning capabilities with the network includes: Sending a request including a list of preferred capabilities and supported capabilities; and Receiving a response indicating an SL positioning procedure to the sent request.

11. The method according to claim 1, further comprising: Receiving a signal indicating one or more priorities associated with an SL positioning procedure; And Selecting an SL positioning procedure based on the indicated one or more priorities.

12. The method according to claim 11, wherein, The indication and selection are performed via the network.

13. A wireless transmit / receive unit (WTRU) for sidelink (SL) positioning, the WTRU comprising: A processor; And A transceiver communicatively coupled to the processor, The processor and transceiver are operative to: Trigger a location request, wherein the location request includes one or more quality metrics; Discover at least one SL reference WTRU; Determine a list of available reference WTRUs, wherein the list includes the at least one SL reference WTRU, including the at least one SL reference WTRU is based on at least one of the one or more quality metrics; Send an SL positioning service request to a network, the SL positioning service request including the list of available reference WTRUs; Negotiate SL positioning capabilities with the network in view of the list of available reference WTRUs; Receive assistance information from the network; and Use the assistance information to perform an SL positioning procedure via the negotiated SL positioning capabilities.

14. The WTRU according to claim 13, wherein The processor and transceiver are further operative to renegotiate the SL positioning capabilities with the network based on the list of available reference WTRUs, under the condition that the reference WTRU is less than a threshold.

15. The WTRU according to claim 13, wherein The one or more quality metrics include at least one of accuracy, response time, and LCS QoS class.

16. The WTRU according to claim 13, wherein, The assistance information includes information for communicating with at least one WTRU from the list of available reference WTRUs.

17. The WTRU according to claim 13, wherein, The assistance information includes obtaining assistance data.

18. The WTRU according to claim 13, wherein The processor and the transceiver are further operative to: Calculate the position of the WTRU in two or more dimensions, and Report the position to the network.

19. The WTRU according to claim 13, wherein negotiating the SL positioning capabilities with the network includes the processor and transceiver further operative to: Send a request including a list of preferred capabilities and supported capabilities; and Receive a response indicating an SL positioning procedure to the sent request.

20. The WTRU according to claim 13, wherein the processor and the transceiver are further operative to: Receive a signal indicating one or more priorities associated with an SL positioning procedure; and Select an SL positioning procedure to use based on the indicated one or more priorities.

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