Discovery and selection of WTRU located by target WTRU status

Description

1 / 57 “DISCOVERY AND SELECTION OF LOCATED WTRU BY TARGET WTRU STATUS” Reference to related deposit requests

[001] This application claims the benefit of Provisional Patent Application No. 63 / 457,565, filed on April 6, 2023, the contents of which are incorporated herein by reference. FUNDAMENTALS

[002] Mobile communications using wireless communication continue to evolve. A fifth generation of mobile communication radio access technology (RAT) may be referred to as 5G New Radio (NR). A previous (legacy) generation of mobile communication RAT may be, for example, the long-term evolution (LTE) of fourth generation (4G). SUMMARY

[003] Systems, methods, and apparatus are disclosed in this document to provide methods for discovering and / or selecting a localized wireless transmit / receive unit (WTRU) based on a target WTRU status. A target WTRU can send a request message to Model B discovery to discover a localized WTRU for SL positioning service. The request message can include the target WTRU status and / or requested capabilities of the localized WTRU so that the target WTRU can discover and select an appropriate WTRU to perform SL positioning.

[004] A first wireless transmit / receive unit (WTRU) can perform (e.g., be configured to perform) one or more of the following actions. The first WTRU can receive a request message from a second WTRU. The request message can indicate a status of the second WTRU and / or service information associated with a side link positioning (SL) service. The first WTRU can determine that the first WTRU is capable Petition 870250087538, dated 09 / 26 / 2025, p. 11 / 87 2 / 57 to provide the SL positioning service based on the status of the second WTRU and service information. The first WTRU may send a reply message to the second WTRU based on the determination that the first WTRU is capable of providing the SL positioning service. The reply message may indicate that the first WTRU is capable of providing the SL positioning service.

[005] The first WTRU can receive a connection request message from the second WTRU to establish a connection and establish a connection with the second WTRU. The first WTRU can perform an SL placement operation using the connection with the second WTRU. The SL placement operation can be based on the status of the second WTRU. The status of the second WTRU can indicate whether or not the second WTRU has an available non-access stratum (NAS) connection. The SL placement operation can be a synchronization method.

[006] The request message may indicate a connection status associated with the second WTRU, a placement method, and / or a location associated with the second WTRU. The response message may indicate a capability of the first WTRU to perform an SL placement operation associated with the status of the second WTRU. In examples, the response message may not be protected by integrity (e.g., so that the response message may be sent via the connection). In examples, the response message is protected by integrity and protected by confidentiality.

[007] A first wireless transmit / receive unit (WTRU) may perform (e.g., be configured to perform) one or more of the following actions. The first WTRU may receive an advertisement message from a second WTRU. The advertisement message may indicate service information associated with a side link positioning (SL) service, an identity of the second Petition 870250087538, dated 09 / 26 / 2025, p. 12 / 87 3 / 57 The first WTRU, and / or a capability of the second WTRU to support the SL positioning service. The first WTRU can determine that the second WTRU is configured to provide the SL positioning service to the first WTRU based on a status of the first WTRU and the capability of the second WTRU. The first WTRU can establish a connection with the second WTRU based on the determination that the second WTRU is configured to provide the SL positioning service.

[008] In examples, the first WTRU can receive a service message from the second WTRU using a connection. The service message can be associated with the SL positioning service. The SL positioning service can be a round-trip time (RTT) positioning method or a time-difference-at-arrival (TDOA) positioning method.

[009] The status of the first WTRU can indicate whether or not the first WTRU has a non-access stratum (NAS) connection available.

[010] In examples, the first WTRU may receive a second advertisement message from a third WTRU. The determination that the second WTRU should provide the SL positioning service may be based on the second advertisement message. The determination that the second WTRU should provide the SL positioning service may be based on a link quality associated with the first WTRU.

[011] The first WTRU may receive a list of candidates indicating the ability of the second WTRU to support the SL positioning service. The list of candidates may include a first set of WTRUs associated with a first SL positioning service and a second set of WTRUs associated with a second SL positioning service. For example, the first set of WTRUs may include the second WTRU, and the first SL positioning service may be the SL positioning service. Petition 870250087538, dated 09 / 26 / 2025, p. 13 / 87 4 / 57

[012] A first wireless transmit / receive unit (WTRU) can be used to provide an SL positioning service. The first WTRU may comprise a processor. A request message may be received from a second WTRU. The request message may indicate a status of a second WTRU and may indicate service information associated with an SL positioning service. It can be determined that the first WTRU is capable of providing the SL positioning service based on the status of the second WTRU and the service information. A reply message may be sent to the second WTRU when the first WTRU is capable of providing the SL positioning service.

[013] A first wireless transmit / receive unit (WTRU) can be used to receive a service message associated with an SL positioning service. An announcement message can be received from a second WTRU, indicating service information associated with the SL positioning service, the identity of the second WTRU, and the second WTRU's capability to support the SL positioning service. It can be determined that the second WTRU should provide the SL positioning service based on the status of the first WTRU and the capability of the second WTRU. A connection can be established with the second WTRU based on the determination that the second WTRU should provide the SL positioning service. The service message can be received from the second WTRU using the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[014] Figure 1A is a system diagram illustrating an exemplary communication system, in which one or more disclosed modalities can be implemented;

[015] Figure 1B is a system diagram illustrating a unit of Petition 870250087538, dated 09 / 26 / 2025, page 14 / 87 5 / 57 exemplifying wireless transmission / reception (WTRU) that can be used in the communication system illustrated in Figure 1A according to one embodiment.

[016] Figure 1C is a system diagram illustrating an exemplary radio access network (RAN) and an exemplary main network (CN) that can be used in the communication system illustrated in Figure 1A according to one modality.

[017] Figure 1D is a system diagram illustrating an additional example of RAN and an additional example of CN that can be used in the communication system illustrated in Figure 1A according to a modality;

[018] Figure 2 is a system diagram illustrating an exemplary network architecture.

[019] Figure 3 is a system diagram illustrating an exemplary network architecture that can be used for, or provide, location services.

[020] Figure 4 is a system diagram illustrating an exemplary positioning control plane (CP) / user plane (UP) architecture.

[021] Figure 5 is a flowchart illustrating an example method for discovering and selecting a WTRU located with discovery.

[022] Figure 6 is a flowchart illustrating an example method for discovering and selecting a WTRU located with discovery.

[023] Figure 7 is a flowchart illustrating an example method of an SL positioning protocol between a target WTRU and a located WTRU. DETAILED DESCRIPTION

[024] Figure 1A is a diagram illustrating an exemplary communications system 100 in which one or more disclosed modalities can be implemented. The communications system 100 can be an access system. Petition 870250087538, dated 09 / 26 / 2025, p. 15 / 87 A 6 / 57 multiple system that provides content, such as voice, data, video, messaging, broadcasting, etc., to multiple wireless users. A 100 communication system can enable multiple wireless users to access this content through the sharing of system resources, including wireless bandwidth. For example, 100 communication systems may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero-tail single-word DFT spread OFDM (ZT-UW-DTS-S-OFDM), single-word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), and similar methods.

[025] As shown in Figure 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, although it should be recognized that the disclosed embodiments contemplate any number of WTRUs, base stations, networks and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment.By way of example, WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a mobile phone, a personal digital assistant (PDA), a smartphone, a laptop computer, a netbook computer, a personal computer, a wireless sensor, an access point or MiFi device, an Internet of Things (IoT) device, a wristwatch or other. Petition 870250087538, dated 09 / 26 / 2025, page 16 / 87 7 / 57 wearable device, a virtual reality headset (HMD), a vehicle, a drone, a medical device and its applications (e.g., remote surgery), an industrial device and its applications (e.g., a robot and / or other wireless devices operating in the context of an industrial and / or automated processing chain), a consumer electronic device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may interchangeably be referred to as UE.

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

[027] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be called a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a Petition 870250087538, dated 09 / 26 / 2025, p. 17 / 87 8 / 57 Combination of licensed and unlicensed spectrum. A cell can provide coverage for a wireless service to a specific geographic area that may be relatively fixed or that may change over time. The cell may also be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, that is, one for each cell sector. In another embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may use multiple transceivers for each cell sector. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

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

[029] More specifically, as indicated above, communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SCFDMA and the like. For example, base station 114a in RAN 104 / 113 and WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) of the Universal Mobile Telecommunications System (UMTS), which may establish the air interface 116 by using Wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or evolved HSPA (HSPA+). HSPA may include downlink packet access. Petition 870250087538, dated 09 / 26 / 2025, page 18 / 87 9 / 57 (DL) high-speed (HSDPA) and / or high-speed UL packet access (HSUPA).

[030] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement a radio technology, such as evolved UMTS terrestrial radio access (E-UTRA), which may establish the air interface 116 with the use of long-term evolution (LTE) and / or advanced LTE (LTE-A) and / or advanced LTE Pro (LTE-A Pro).

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

[032] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, 102c can implement LTE radio access and NR radio access together, for example, using dual connectivity (DC) principles. In this way, the air interface used by WTRUs 102a, 102b, 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[033] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., wireless fidelity (Wi-Fi)), IEEE 802.16 (i.e., worldwide interoperability for microwave access (WiMAX)), CDMA2000, CDMA2000 CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[034] Base station 114b in Figure 1A could be a wireless router, a Petition 870250087538, dated 09 / 26 / 2025, page 19 / 87 10 / 57 originating node B, an originating eNodeB, or an access point, for example, and can use any suitable RAT to facilitate wireless connectivity in a localized area, such as a workplace, a residence, a carrier, a campus, an industrial facility, an air corridor (e.g., for use by drones), a highway, and the like. In one embodiment, base station 114b and WTRUs 102c, 102d can implement a radio technology, such as IEEE 802.11, to establish a wireless local area network (WLAN). In another embodiment, base station 114b and WTRUs 102c, 102d can implement a radio technology, such as IEEE 802.15, to establish a wireless personal area network (WPAN). In yet another mode, the 114b base station and the 102c, 102d WTRUs can use a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell.As shown in Figure 1A, base station 114b can have a direct connection to Internet 110. Therefore, base station 114b may not be necessary to access Internet 110 via CN 106 / 115.

[035] RAN 104 / 113 may be in communication with CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, 102d. The data may have varying Quality of Service (QoS) requirements, such as different processing capacity requirements, latency requirements, error tolerance requirements, reliability requirements, data processing capacity requirements, mobility requirements and the like. CN 106 / 115 may provide call control, billing services, location-based mobile services, prepaid calling, internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown Petition 870250087538, dated 09 / 26 / 2025, page 20 / 87 11 / 57 in Figure 1A, it should be considered that RAN 104 / 113 and / or CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT, such as RAN 104 / 113 or a different RAT. For example, in addition to being connected to RAN 104 / 113, which may use NR radio technology, CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

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

[037] Some or all of the WTRUs 102a, 102b, 102c, 102d in communications system 100 may include multimode capabilities (for example, WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communication with different wireless networks via different wireless links). For example, WTRU 102c shown in Figure 1A may be configured to communicate with base station 114a, which may employ a cellular network-based radio technology, and with base station 114b, which may employ an IEEE 802 radio technology. Petition 870250087538, dated 09 / 26 / 2025, p. 21 / 87 12 / 57

[038] Figure 1B is a system diagram illustrating an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a screen / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136 and / or other peripherals 138, among others. It will be recognized that the WTRU 102 may include any subcombination of the aforementioned elements while remaining consistent with an embodiment.

[039] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, application-specific integrated circuits (ASICs), field-programmable gate array circuits (FPGAs), any other type of integrated circuit (IC), a state machine, and the like. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other functionality that enables WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, which may be coupled to transmit / receive element 122.Although Figure 1B depicts processor 118 and transceiver 120 as separate components, it will be recognized that processor 118 and transceiver 120 can be integrated together in an electronic package or electronic circuit.

[040] The transmit / receive element 122 can be configured to transmit signals to, or receive signals from, a base station (for example, base station 114a) via the air interface 116. For example, in one embodiment, the Petition 870250087538, dated 09 / 26 / 2025, page 22 / 87 13 / 57 transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be a transmitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be recognized that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[041] Although the transmit / receive element 122 is represented in Figure 1B as a single element, 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) to transmit and receive wireless signals over the air interface 116.

[042] Transceiver 120 can be configured to modulate signals intended to be transmitted by transmit / receive element 122, and to demodulate signals received by transmit / receive element 122. As indicated above, WTRU 102 can have multimode capabilities. Thus, transceiver 120 can include multiple transceivers to enable WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[043] The WTRU 102 processor 118 can be coupled to the speaker / microphone 124, the keypad 126 and / or the screen / touchpad 128 (for example, a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) and can receive user input data from these devices. The processor 118 can also output user data to the speaker / microphone 124, the keyboard 126 and / or the Petition 870250087538, dated 09 / 26 / 2025, page 23 / 87 14 / 57 monitor / touchpad 128. In addition, the processor 118 can access information from, and store data in, any suitable type of memory, such as non-removable memory 130 and / or removable memory 132. 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. Removable memory 132 may include a Subscriber Identity Module (SIM) card, a memory card, a Secure Digital Memory (SD) card, and the like. In other embodiments, the processor 118 can access information from, and store data in, memory that is not physically located in the WTRU 102, such as in a server or a home computer (not shown).

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

[045] Processor 118 can also be coupled to GPS chipset 136, which can be configured to provide location information (e.g., longitude and latitude) regarding the current location of WTRU 102. In addition to, or instead of, information from the GPS electronic circuitry 136, WTRU 102 can receive location information via the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of signals received from two or more nearby base stations. It should be considered that WTRU 102 can capture location information by any suitable location determination method and still remain compatible with a mode. Petition 870250087538, dated 09 / 26 / 2025, page 24 / 87 15 / 57

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

[047] The WRTU 102 may include a full-duplex radio for which the transmission and reception of some or all of the signals (e.g., associated with a given UL subframe (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 and substantially reduce or eliminate self-interference through hardware (e.g., a shutter) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of Petition 870250087538, dated 09 / 26 / 2025, page 25 / 87 16 / 57 some or all signals (e.g., associated with specific subframes for the UL (e.g., for transmission) or for the downlink (e.g., for reception)).

[048] Figure 1C is a system diagram illustrating RAN 104 and CN 106, according to one embodiment. As noted above, RAN 104 can employ E-UTRA radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 104 can also be in communication with CN 106.

[049] RAN 104 may include eNodeBs 160a, 160b, 160c, although it should be considered that RAN 104 may include any number of eNodeBs and still remain consistent with a mode. Each of the eNodeBs 160a, 160b, 160c may include one or more transceivers for communication with WTRUs 102a, 102b, 102c via the air interface 116. In a mode, eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, eNodeB 160a, for example, may use multiple antennas to transmit and / or receive wireless signals from WTRU 102a.

[050] Each of the eNodeBs 160a, 160b, 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in the UL and / or DL, and similar tasks. As shown in Figure 1C, the eNodeBs 160a, 160b, 160c can communicate with each other via an X2 interface.

[051] The CN 106 shown in Figure 1C may include a mobility management entity (MME) 162, a server gateway (SGW) 164, and a packet data network gateway (PDN) (or PGW) 166. Although each of the aforementioned elements is shown as part of the CN 106, it will be recognized that any of these elements may belong to, and / or be operated by, a Petition 870250087538, dated 09 / 26 / 2025, page 26 / 87 17 / 57 entity different from the CN operator.

[052] MME 162 can be connected to each of the eNode-Bs 160a, 160b, 160c in RAN 104 via an S1 interface and can serve as a control node. For example, MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, 102c, for carrier activation / deactivation, for selecting a specific server gateway during an initial connection of WTRUs 102a, 102b, 102c and similar. MME 162 can provide a control plane function for switching between RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

[053] SGW 164 can be connected to each of the eNodeBs 160a, 160b, 160c in RAN 104 via the S1 interface. SGW 164 can generally route and forward user data packets destined for / from WTRUs 102a, 102b, 102c. SGW 164 can perform other functions, such as anchoring user planes during handovers between eNodeBs, triggering radio lookup when DL data is available for WTRUs 102a, 102b, 102c, managing and storing contexts of WTRUs 102a, 102b, 102c and similar.

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

[055] CN 106 can facilitate communications with other networks. For example, CN 106 can provide WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as PSTN 108, to facilitate communications between WTRUs 102a, 102b, 102c and traditional terrestrial communications devices. 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 PSTN 108. Furthermore, CN 106 can provide to Petition 870250087538, dated 09 / 26 / 2025, p. 27 / 87 18 / 57 WTRUs 102a, 102b, 102c provide access to other 112 networks, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[056] Although the WTRU is described in Figures 1A to 1D as a wireless terminal, it is contemplated that, in certain representative embodiments, such a terminal may use (for example, temporarily or permanently) wired communication interfaces with the communication network.

[057] In representative modalities, the other 112 network may be a WLAN.

[058] A WLAN in Basic Services Set (BSS) mode may have a connection point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to, or an interface with, a distribution system (DS) or other type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic to STAs originating outside a BSS may arrive through the AP and may be delivered to the STAs. Traffic from STAs to destinations outside the BSS may be sent to the AP to be delivered to the respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the originating STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as point-to-point traffic.Point-to-point traffic can be sent between (e.g., directly between) the source and destination STAs with a Direct Link System (DLS) configuration. In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z Tunneled DLS (TDLS). A WLAN using an independent BSS mode (IBSS) may not have an AP, and the STAs (e.g., all STAs) within or using IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to in this document as a communication mode. Petition 870250087538, dated 09 / 26 / 2025, p. 28 / 87 19 / 57 “ad hoc”.

[059] When using the 802.11ac operating mode or a similar operating mode of 802.11ac infrastructure, the AP can transmit a signal on a fixed channel, such as a primary channel. The primary channel can have a fixed width (e.g., 20 MHz bandwidth) or a dynamically defined width through signaling. The primary channel can be the BSS's operating channel and can be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier-sensing multiple access with collision avoidance (CSMA / CA) can be implemented, for example, in 802.11 systems. For CSMA / CA, STAs (e.g., each STA), including the AP, can sense the primary channel. If the primary channel is sensed and / or determined / detected as being occupied by a particular STA, that specific STA can back off. An STA (e.g., only one station) can transmit at any given time on a given BSS.

[060] High-capacity processing (HT) STAs can use a 40 MHz wide channel for communication, for example, by combining the primary 20 MHz channel with an adjacent or non-adjacent 20 MHz channel to form a 40 MHz wide channel.

[061] Very high processing capacity (VHT) STAs can support channels 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 called an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, can be passed through a segment analyzer that can split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and domain processing are possible. Petition 870250087538, dated 09 / 26 / 2025, page 29 / 87 20 / 57 timing can be performed, for example, on each stream separately. The streams can be mapped to the two 80 MHz channels, and the data can be transmitted by a transmit STA. At the receiver of the receive STA, the operation described above for the 80+80 configuration can be reversed, and the combined data can be sent to the medium access control (MAC).

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

[063] WLAN systems, which can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as the primary channel. The primary channel may, for example, have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be defined and / or limited by an STA, among all STAs operating in a BSS, that supports the lowest bandwidth operating mode. In the 802.11ah example, the primary channel may have a 1 MHz bandwidth for STAs (e.g., MTC-type devices) that support (e.g., only support) a mode Petition 870250087538, dated 09 / 26 / 2025, page 30 / 87 21 / 57 of 1 MHz, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sense and / or network allocation vector (NAV) settings may depend on the primary channel state. If the primary channel is busy, for example, due to transmission from an STA (which only supports a 1 MHz operating mode) to the AP, all available frequency bands may be considered busy even if most frequency bands remain idle and could be available.

[064] In the United States, the available frequency bands that can be used by 802.11ah range from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is from 6 MHz to 26 MHz, depending on the country code.

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

[066] RAN 113 may include gNBs 180a, 180b, 180c, although it is recognized that RAN 113 may include any number of gNBs, remaining consistent with a modality. gNBs 180a, 180b, 180c may include one or more transceivers for communication with WTRUs 102a, 102b, 102c via the air interface 116. In some modality, gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may use beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, can use multiple antennas to transmit wireless signals and / or receive wireless signals from the WTRU 102a. In a Petition 870250087538, dated 09 / 26 / 2025, p. 31 / 87 In a 22 / 57 embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multi-component carriers to WTRU 102a (not shown). A subset of these component carriers may be in the unlicensed spectrum while the remaining component carriers may be in the licensed spectrum. In another embodiment, gNBs 180a, 180b, and 180c can implement coordinated multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[067] WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, OFDM symbol spacing and / or OFDM subcarrier spacing can vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using scalable time intervals (TTIs) of various lengths (e.g., containing a variable number of OFDM symbols and / or variable absolute time durations).

[068] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in a standalone and / or non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without also accessing other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In the standalone configuration, WTRUs 102a, 102b, and 102c can use one or more of the gNBs 180a, 180b, and 180c as a mobility docking point. In a standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in an unlicensed band. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate Petition 870250087538, dated 09 / 26 / 2025, page 32 / 87 23 / 57 com / se connect with gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160C. For example, WTRUs 102a, 102b, 102c can implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c in a substantially simultaneous manner. In the non-autonomous configuration, the eNode-Bs 160a, 160b, 160c can serve as a mobility anchor for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c can provide additional coverage and / or processing capacity for maintaining the WTRUs 102a, 102b, 102c.

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

[070] The CN 115 shown in Figure 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b and possibly a data network (DN) 185a, 185b. Although each of the aforementioned elements is shown as part of the CN 115, it will be recognized that any of these elements may belong to, and / or be operated by, an entity other than the CN operator.

[071] AMF 182a, 182b can be connected to one or more of the gNBs 180a, 180b, 180c in RAN 113 via an N2 interface and can serve as a node of Petition 870250087538, dated 09 / 26 / 2025, p. 33 / 87 24 / 57 control. For example, AMF 182a, 182b can be responsible for authenticating users of WTRUs 102a, 102b, 102c, network splitting support (e.g., handling different PDU sessions with different requirements), selection of a specific SMF 183a, 183b, log area management, non-access stratum signaling interruption (NAS), mobility management, and similar. Network splitting can be used by AMF 182a, 182b to customize CN support for WTRUs 102a, 102b, 102c based on the types of services used by WTRUs 102a, 102b, 102c. For example, different network slices can be established for different use cases such as services that rely on ultra-reliable low-latency access (URLLC), services that rely on bulk mobile broadband access (eMBB), services for machine-to-machine communication (MTC) access, and / or similar services.The AMF 182 can provide a control plane function to switch between RAN 113 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro and / or non-3GPP access technologies such as Wi-Fi.

[072] SMF 183a, 183b can be connected to AMF 182a, 182b on CN 115 via an N11 interface. SMF 183a, 183b can also be connected to UPF 184a, 184b on CN 115 via an N4 interface. SMF 183a, 183b can select and control UPF 184a, 184b and configure traffic routing through UPF 184a, 184b. SMF 183a and 183b can perform other functions such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy and QoS enforcement, providing downlink data notifications, and similar functions. A PDU session type can be IP-based, non-IP-based, Ethernet-based, and similar.

[073] UPF 184a, 184b can be connected to one or more of gNBs 180a, 180b, 180c in RAN 113, via an N3 interface, which can provide WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet. Petition 870250087538, dated 09 / 26 / 2025, page 34 / 87 25 / 57 110, for example, in order to facilitate communication between WTRUs 102a, 102b, 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as packet routing and forwarding, application of user plane policies, support for multi-base PDU sessions, user plane QoS handling, temporary storage of DL packets, provision of mobility anchoring, and the like.

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

[075] In view of Figures 1A to 1D and the corresponding description of Figures 1A to 1D, one or more, or all, of the functions described in the present invention in relation to one or more of: WTRU 102a-d, base station 114a-b, eNode B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, UPF 184a-b, SMF 183a-b, DN 185a-b and / or any other devices described in this document may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described in this document. For example, emulation devices can be used to test other devices and / or to simulate network and / or WTRU functions. Petition 870250087538, dated 09 / 26 / 2025, p. 35 / 87 26 / 57

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

[077] One or more emulation devices may perform one or more, including all, of the functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in a test scenario in a test laboratory and / or in a wired and / or wireless communication network (e.g., test) to implement the testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuits (e.g., which may include one or more antennas) may be used by emulation devices to transmit and / or receive data.

[078] The following abbreviations may be used in this document: non-access stratum (NAS), side link-based positioning (SL) (SL positioning), radio access technology (RAT), radio access network (RAN) or proximity-based service (ProSe).

[079] The reference to a timer in this document may refer Petition 870250087538, dated 09 / 26 / 2025, p. 36 / 87 27 / 57 refers to a time, a period of time, a time tracking, a tracking of a period of time, a combination thereof and / or similar. Reference to a timer expiration in this document may refer to the determination that the time has elapsed or that the period of time has expired.

[080] Systems, methods and devices are disclosed in this document to provide methods for discovering and / or selecting a located WTRU, for example, based on a target WTRU status. For example, discovery and / or selection over PC5 based on 5G ProSe can be provided. The SL distance measurement and positioning protocol (RSPP) can be provided for SL positioning operation over a PC5 connection.

[081] Discovery can generally refer to the process by which devices find and connect to other available network devices and / or resources. Discovery may involve procedures such as scanning available networks, identifying suitable access points, and establishing initial communication with the network. In examples, two discovery approaches can be defined. A first discovery approach can be referred to as Model A discovery and may generally incorporate proactive reporting (e.g., by a device). A second discovery approach can be referred to as Model B discovery and may generally incorporate proactive querying / requesting (e.g., by a device). In examples, a device can be configured to employ multiple discovery approaches (e.g., in different scenarios).

[082] Model A discovery (e.g., which may be referred to as I am here discovery) may be a method used by a monitoring WTRU (e.g., a target WTRU) to discover an announcing WTRU (e.g., a located WTRU), for example, by receiving / monitoring an announcement message from the announcing WTRU. Petition 870250087538, dated 09 / 26 / 2025, p. 37 / 87 28 / 57 An announcing WTRU can be a WTRU that announces information (e.g., without receiving an explicit request from a monitoring WTRU). The announced information can be used by WTRUs in the vicinity of the announcing WTRU that are permitted to discover (e.g., monitoring WTRUs). A monitoring WTRU can be a WTRU that monitors information of interest in the vicinity of announcing WTRUs. In model A, the announcing WTRU can transmit discovery messages at predefined discovery intervals, and monitoring WTRUs interested in these messages can receive and process them. The announced information can include, for example, one or more of the following: SL positioning capabilities (e.g., of the announcing WTRU), a location associated with the announcing WTRU, or an indication of the announcing WTRU's ability to support a monitoring WTRU (e.g., depending on a monitoring WTRU status).

[083] For Model A discovery, a localized WTRU can send an advertisement message. The advertisement message can include the supported capabilities of the localized WTRU (e.g., so that it can perform procedures necessary for SL placement with a target WTRU that does not have a NAS connection). Based on the advertised supported capabilities, the target WTRU can discover and select the localized WTRU, for example, to perform SL placement. In examples, the target WTRU can wait for a period of time (e.g., the expiration of a timer) so that the target WTRU can receive advertisement information from multiple localized WTRUs.

[084] The target WTRU can select the located WTRU based on an additional status of the target WTRU. For example, a target WTRU status might indicate the target WTRU's NAS connectivity (e.g., whether or not the target WTRU has a NAS connection). A located WTRU can provide the requested capability (e.g., for SL placement) according to the status of Petition 870250087538, dated 09 / 26 / 2025, p. 38 / 87 29 / 57 Target WTRU. The target WTRU and the selected localized WTRU can establish a PC5 connection and / or perform an SL positioning operation (e.g., based on the status of the target WTRU).

[085] Model B discovery (which may be referred to as who's there or you're there discovery) can be a method used by a discovering WTRU (e.g., a target WTRU) to discover a discovered WTRU (e.g., a located WTRU) by sending a request message and receiving a reply message (e.g., from the discovered WTRU). The discovering WTRU can be the WTRU that transmits a request for information (e.g., an indication of whether the discovered WTRU is capable of providing a service to the discovering WTRU). The discovered WTRU can be the WTRU that receives the request message and can reply with some information related to the discoverer's request.

[086] For Model B discovery, the target WTRU can send a request message to discover a localized WTRU, for example, for the localized WTRU to provide an SL positioning service. The request message can include the status of the target WTRU (e.g., whether or not the target WTRU has a NAS connection) and / or requested capabilities of a localized WTRU. The request message can be configured so that the target WTRU can discover and select a localized WTRU that is configured to provide a service (e.g., an SL positioning procedure) based on the status of the target WTRU. In examples, the target WTRU can wait for a period of time (e.g., the expiration of a timer) so that the target WTRU can receive responses from multiple localized WTRUs before selecting a localized WTRU.In examples, the target WTRU might wait to select a localized WTRU until it has received responses from multiple localized WTRUs (e.g., a number of localized WTRUs or all WTRUs). Petition 870250087538, dated 09 / 26 / 2025, p. 39 / 87 30 / 57 locations to which the request messages were sent).

[087] The target WTRU can select a localized WTRU, for example, based on the localized WTRU's ability to provide the target WTRU with a service according to the target WTRU's status. The target WTRU and a selected localized WTRU can establish (e.g., configure) a PC5 connection. The target WTRU and the selected localized WTRU can perform the SL placement operation (e.g., via the PC5 connection) according to the target WTRU's status.

[088] In one example, for SL positioning operation, a target WTRU and a located WTRU can negotiate the status of the target WTRU. The status of the target WTRU can indicate whether or not the target WTRU can have a NAS connection. A requested localized WTRU capability can be provided according to a target WTRU status so that an SL positioning method (e.g., synchronization method, measurement mechanism, etc.) and / or a role of one or more WTRUs, such as which entity can make the location report, can be determined (e.g., based on the status of the target WTRU and the capability of a located WTRU). For example, the target WTRU can determine that the localized WTRU capability is associated with a particular SL positioning method.

[089] A localized wireless transmit / receive unit (WTRU) (e.g., a first WTRU) may comprise a processor and may (e.g., be configured to) perform one or more of the following actions (e.g., for B-model discovery). The localized WTRU may be configured to provide an SL positioning service. The localized WTRU may receive a request message from a target WTRU (e.g., a second WTRU). The request message may indicate a status of the target WTRU and / or service information associated with an SL positioning service. A Petition 870250087538, dated 09 / 26 / 2025, p. 40 / 87 31 / 57 The localized WTRU can determine that it is capable of providing SL positioning service to the target WTRU, for example, based on the request message. The localized WTRU can send a reply message to the target WTRU, including an indication that it is capable of providing SL positioning service.

[090] In examples, the request message may indicate one or more of the following: a requested capability, a connection status associated with the target WTRU, a placement method, or a location (e.g., associated with the target WTRU). In examples, the response message may include information about one or more of a requested capability or a capability associated with the target WTRU status.

[091] In examples, the localized WTRU may receive a connection request message from the target WTRU. The connection request message may indicate a request to establish a connection (e.g., a PC5 connection) with the localized WTRU. A connection may be established between the localized WTRU and the target WTRU, for example, based on the received connection request message. An SL placement operation may be performed, for example, using the connection between the localized WTRU and the target WTRU. The SL placement operation performed may be based on the status of the target WTRU (e.g., whether the target WTRU has a NAS connection).

[092] A target wireless transmit / receive unit (WTRU) (e.g., a first WTRU) may comprise a processor and may (e.g., be configured to) perform one or more of the following actions (e.g., for Model A discovery). The target WTRU may receive a service message associated with an SL positioning service. The target WTRU may receive an advertisement message from a located WTRU (e.g., a second WTRU). The advertisement message may indicate information Petition 870250087538, dated 09 / 26 / 2025, p. 41 / 87 32 / 57 service associated with the SL positioning service, the identity of the located WTRU, and / or a capability of the located WTRU to support the SL positioning service. The target WTRU can determine that the located WTRU is capable of providing (e.g., configured to provide) SL positioning service. The determination that the located WTRU is capable of providing the SL positioning service can be based on a status of the target WTRU and / or the capability of the located WTRU. The target WTRU can select the located WTRU based on the determination. A connection can be established with the selected located WTRU, for example, based on the determination that the located WTRU should provide SL positioning service. The target WTRU and the selected located WTRU can perform the SL positioning service, for example, over the connection. The SL positioning service performed can be based on the status of the target WTRU.

[093] In examples, the determination that the located WTRU should provide the SL positioning service (e.g., selection of the located WTRU) may be based additionally on a NAS connection status associated with the target WTRU.

[094] In examples, the announcement message may be a first announcement message, and a second announcement message may be received from a third WTRU. The determination that the located WTRU can provide the SL placement service (e.g., selection of the located WTRU) may be based further on the second announcement message.

[095] A localized wireless transmit / receive unit (WTRU) (e.g., a first WTRU) may comprise a processor and may (e.g., be configured to) perform one or more of the following actions (e.g., for the SL positioning protocol). The localized WTRU may be used to perform a positioning-based operation. The localized WTRU Petition 870250087538, dated 09 / 26 / 2025, p. 42 / 87 33 / 57 can receive an initial message from a target WTRU (e.g., a second WTRU) indicating a connection status associated with the target WTRU. A negotiated capability can be determined based on the connection status, a capability of the localized WTRU, and a capability of a third WTRU (e.g., an SL positioning server, a reference SL WTRU). The localized WTRU can determine and / or receive an SL positioning operation. The localized WTRU can perform the SL positioning operation using the negotiated capability. The SL positioning operation can be, for example, a synchronization method or a measurement mechanism.

[096] In examples, the located WTRU may receive a service message, for example, from the target WTRU and / or the third WTRU, which indicates a result of the SL positioning operation.

[097] In examples, a service message may be received from the third WTRU which includes service data associated with the SL positioning method. For example, the service data may be a characteristic and format of a transmitted signal and / or a time interval.

[098] In examples, the located WTRU may send a report message associated with the SL positioning operation performed. The report message may be sent, for example, to the target WTRU and / or to the third WTRU. The report message may include data associated with an SL operation result. For example, the SL positioning operation result may have been received by the located WTRU. For example, the SL positioning operation result may have been determined by the located WTRU (e.g., using data collected from the SL positioning operation performed).

[099] The discovery and / or selection of a WTRU can be provided Petition 870250087538, dated 09 / 26 / 2025, p. 43 / 87 34 / 57 located according to a target WTRU status (e.g., connection status).

[0100] The discovery and / or selection of a localized WTRU through Model B discovery can be performed. For Model B discovery, a target WTRU can send a request message to discover a localized WTRU, for example, that can provide an SL positioning service. The target WTRU can include the target WTRU's status and / or requested capabilities of the localized WTRU in the request message (for example, so that the target WTRU can discover and select the localized WTRU to perform SL positioning according to the target WTRU's status). A target WTRU and a selected localized WTRU can establish a PC5 connection and perform an SL positioning operation based on the target WTRU's status.

[0101] Discovery and / or selection of a localized WTRU can be provided through Model A discovery. For Model A discovery, a localized WTRU can send an announcement message. The announcement message can indicate the capabilities supported by the localized WTRU to perform SL placement procedures with a target WTRU that may not have a NAS connection. Based on the advertised capabilities, the target WTRU can discover the localized WTRU and / or select the localized WTRU to perform an SL placement operation according to the status of the target WTRU (e.g., whether or not the target WTRU can have a NAS connection). A target WTRU and a selected localized WTRU can establish a PC5 connection and can perform the SL placement operation, for example, according to the status of the target WTRU.

[0102] The target WTRU can share its status of whether or not it has a NAS connection available. The target can share its status to select the appropriate SL placement method and / or to decide the role of each Petition 870250087538, dated 09 / 26 / 2025, p. 44 / 87 35 / 57 WTRU in SL positioning operation. For example, the target WTRU can share its status while the target WTRU and the located WTRU perform the SL positioning operation. Based on the target WTRU's status and the determined SL positioning method, it can be decided (e.g., by the target WTRU, the selected located WTRU, or a different WTRU) whether the selected located WTRU or the target WTRU can collect the SL positioning result and report the result to the network.

[0103] Figure 2 is a system diagram that illustrates an exemplary architecture of a 5G or NextGen network.

[0104] As described in this document, a RAN may refer to a radio access network based on the 5G RAT or Evolved E-UTRA that connects to the NextGen main network.

[0105] An access and mobility management (AMF) function may include functionality such as record management, connection management, reachability management, mobility management, etc.

[0106] A session management function (SMF) may include functionality such as session management (e.g., including session establishment, modification and / or release); WTRU IP address allocation; UP function selection and control; etc.

[0107] A User Plane Function (UPF) may include functionality such as packet routing and forwarding; packet inspection; traffic usage reporting; and other functionalities.

[0108] Location services (LCS) may be provided, such as a 5G location service. A location service (e.g., 5G location service) may provide the functionality to provide the positioning information of a WTRU.

[0109] The positioning of a WTRU can be supported by a method Petition 870250087538, dated 09 / 26 / 2025, page 45 / 87 36 / 57 of RAT position, which may depend on measurements. For example, RAT measurements (e.g., 3GPP RAT measurements) obtained by a target WTRU and / or measurements obtained by an access network of RAT signals (e.g., 3GPP RAT signals) transmitted by a target WTRU. The positioning of a WTRU may be supported by RAT-independent position methods, which may depend on non-RAT measurements obtained by a WTRU and / or on other information.

[0110] Location information for one or more target WTRUs can be requested by and reported to an LCS, a client, and / or an application function (AF) within or outside an operational network (e.g., a 3GPP carrier network), or a control plane network function (NF) within a system (e.g., a 3GPP system).

[0111] For location requests from an LCS client or an AF, a privacy check of the target WTRU may be requested to verify whether it is permissible to acquire the WTRU's location information.

[0112] Several different types of location requests can be supported.

[0113] A mobile-terminated location request (MT-LR) can be supported. An LCS or AF client can send an MT-LR to the network (e.g., 5G network) to locate a target WTRU.

[0114] A mobile-originated location request (MO-LR) can be supported. When an MO-LR occurs, the WTRU can send a request to the network (e.g., 5G network) for information related to the WTRU's location.

[0115] An immediate location request can be supported. With an immediate location request, an LCS or AF client can send or initiate a location request for a target WTRU(s) and can receive a response containing location information for the target WTRU(s) within a Petition 870250087538, dated 09 / 26 / 2025, page 46 / 87 37 / 57 short period of time. It can be used for an MT-LR or MO-LR.

[0116] A deferred location request can be supported. With a deferred location request, an LCS or AF client can send a location request to the network (e.g., 5G network) for a target WTRU(s) and can expect to receive a response when a specified event may occur for the potential target WTRU at some future time. It can be used for an MTLR.

[0117] Figure 3 is a system diagram illustrating an exemplary architecture of a 5G or NextGen network that can be used for, or provide, location service. As shown in Figure 3, the (R)AN can represent an NG-RAN, a trusted non-3GPP access, or an unreliable non-3GPP access. The access network may be involved in handling various positioning procedures, including positioning a target WTRU, providing location-related information that may not be associated with a particular target WTRU, and transferring positioning messages between an AMF or LMF and a target WTRU.

[0118] AFs and NFs can access LCS services from a GMLC on the same 3GPP carrier network.

[0119] LCS customers can access LCS services from a GMLC, and external AF can access LCS services from a NEF.

[0120] The Gateway Mobile Location Center (GMLC) can handle requests from external LCS clients, AF, via NEF if the AF can be an external AF, and forward the location request to the appropriate NF.

[0121] A location retrieval function (LRF) may be responsible for retrieving or validating location information. The LRF may be placed with a GMLC (Gateway Mobile Location Center), or the LRF may be located separately. Petition 870250087538, dated 09 / 26 / 2025, page 47 / 87 38 / 57

[0122] A location management function (LMF) can manage the overall coordination and scheduling of requested (e.g., required) resources for the location of a WTRU that may be registered on or accessing a core network (e.g., 5GCN). It can calculate or verify location-related information and achieve accuracy.

[0123] Positioning protocols and signals, such as NR positioning protocols and signals, may be provided. RAN-based positioning protocols and signals may be used to enable location-based and emergency services.

[0124] Positional protocols, such as NR positioning protocols, can be supported by the Control Plane (CP) positioning architecture over the Uu interface (NG-RAN node to WTRU). The positional architecture, such as the NR positioning architecture, can be supported by a User Plane Secure Location (SUPL) server, which can be referred to as a SUPL location platform (SLP) or location server, which can leverage any Internet Protocol carrier. Interoperability for CP and UP positioning solutions can be provided, where the SUPL can be used as a tunnel for CP positioning protocols (e.g., LPP).

[0125] Figure 4 is a system diagram illustrating an exemplary Control Plane (CP) / User Plane (UP) positioning architecture, as a novel radio positioning (NR) CP / UP architecture.

[0126] Various protocols can be used to enable different positioning technologies and methods (GNSS, sensors, positioning signals, etc.). For example, LPP (LTE Positioning Protocol) can be terminated between the WTRU and the LMF (Location Management Function). LPP can be a Point-to-Point LCS (location services) and a Non-Access Stratum Messaging (NAS) protocol. Petition 870250087538, dated 09 / 26 / 2025, page 48 / 87 39 / 57

[0127] Radio Resource Control (RRC) can be a protocol used to provide transport for LPP messages and other positioning procedures over the NR-Uu interface, which can be terminated between the gNB and the WTRU.

[0128] On the network side, the NG Application Protocol (NGAP) can be terminated between the AMF and the NG-RAN node(s) (e.g., gNB / TRP). It can be used as a transport for LPP messages and NR Positioning Protocol A (NRPPa) over the NG-C interface. NRPPa can carry information between the NG-RAN node(s) and the LMF.

[0129] NR positioning modes can be provided. Positioning can be done in autonomous, WTRU-based, or WTRU-assisted modes.

[0130] In autonomous positioning, the WTRU can handle one or more (e.g., all) aspects of positioning, can scan accessible positioning and measurement sources, and / or can process positioning signals / sources. The WTRU can compute its own position in two or more dimensions, such as two or three dimensions. In autonomous positioning, the Uu interface can impact the WTRU's capability exchange and / or the WTRU's position reporting.

[0131] In WTRU-based positioning, which may be referred to as WTRU-based positioning (WTRU-B), the network may provide acquisition assistance data, and the WTRU may scan accessible positioning and measurement sources and may process positioning signals / sources (e.g., based on assistance information from the network). The WTRU may compute its position using two or more dimensions (e.g., in two or three dimensions) and report its position to the network.

[0132] In WTRU-assisted positioning, which may be referred to as WTRU-assisted positioning (WTRU-A), the network can provide assistance to Petition 870250087538, dated 09 / 26 / 2025, page 49 / 87 40 / 57 acquisition, and the WTRU can scan accessible positioning sources and measure positioning signals / sources (e.g., based on NW assistance information). The WTRU can return measurements to the network, and the network can compute the device's position (e.g., on the location server / LMF).

[0133] Table 1 shows WTRU positioning method techniques that can be supported. Table 1: WTRU positioning method techniques WTRU-Based Method Assisted by WTRU, LFM-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

[0134] A time / angle positioning method may refer to one (e.g., any positioning method) that can use reference signals, such as SL-PRS. WTRU may receive multiple reference signals from WTRU(s) and measure RSTD, RSRP, and / or AoA. Examples of angle / time positioning methods are SL-AoD or SL-TDOA positioning. Another example might be the WTRU transmitting SL-PRS to WTRU(s) and the receiver performing measurements (e.g., RSTD, AoA, RSRP) to determine the locations of the WTRU that transmitted the SL-PRS.

[0135] An “RTT placement method” can refer to any placement method where two WTRUs can transmit SL-PRS to each other. In the examples, an anchor WTRU can transmit an SL-PRS to the WTRU Petition 870250087538, dated 09 / 26 / 2025, p. 50 / 87 41 / 57 target. The target WTRU can receive SL-PRS from the anchor WTRU, and the target WTRU can transmit SL-PRS to the anchor WTRU. The target WTRU can measure the Tx-Rx time difference of the WTRU (e.g., which could be the difference between the transmission time of the target WTRU's SL-PRS and the reception time of the SL-PRS transmitted by the anchor WTRU). The target WTRU can report the Tx-Rx time difference of the WTRU to the anchor WTRU, the WTRU server, and / or the network (e.g., gNB, LMF).

[0136] The LTE Positioning Protocol (LPP) can be implemented. LPP messages related to WTRU-assisted location requests can include a number of procedures. Resources can be requested, for example, in an LMF request to a WTRU. Capabilities can be provided, for example, in a WTRU response to the LMF. Assistance data can be requested, for example, in a WTRU request to the LMF for positioning assistance data / information.

[0137] Assistance data can be provided (e.g., to a WTRU). For example, an LMF can send positioning assistance data information / configuration from the WTRU. Positioning assistance data (AD) can be transmitted via positioning system information blocks (posSIBs) and / or carried in SI messages.

[0138] Location information can be requested and provided. For example, an LMF can send a request to a WTRU for position / measurements. The WTRU can send a response to the LMF with its position and / or measurements.

[0139] A device may be able to abort an LPP session. Errors associated with positioning procedure(s) may be identified and / or addressed.

[0140] An SL positioning service can be provided. The Petition 870250087538, dated 09 / 26 / 2025, page 51 / 87 42 / 57 SL positioning can be used, for example, by a positioning WTRU to obtain absolute position, relative position, or distance measurement information (e.g., via PC5).

[0141] Distance measurement may refer to a determination of the distance between two or more WTRUs and / or the direction of a WTRU (e.g., a target WTRU) from another WTRU (e.g., a reference WTRU) via an interface, such as the PC5 interface.

[0142] A target WTRU, a reference SL WTRU, a client SL positioning WTRU and a localized WTRU can be provided for SL positioning.

[0143] A target WTRU may be provided. A target WTRU may be a WTRU whose distance, direction and / or position may be measured with the support of one or more reference SL WTRUs, for example, using the SL in the SL distance measurement and positioning-based service.

[0144] A localized WTRU can be provided. A localized WTRU can be an SL reference WTRU whose location is known or can be determined, for example, using Uu-based positioning. A localized WTRU can be used to determine the location of a target WTRU using SL positioning.

[0145] An SL reference WTRU can be provided. An SL reference WTRU can support the positioning of a target WTRU, for example, by transmitting and / or receiving reference signals for positioning, providing positioning-related information, etc., using SL.

[0146] An SL positioning client WTRU can be provided. An SL positioning client WTRU can be a third-party WTRU (e.g., different from an SL reference WTRU and a target WTRU) that can initiate a distance measurement / positioning service request. Petition 870250087538, dated 09 / 26 / 2025, page 52 / 87 43 / 57 SL, in the name of the application that resides on it.

[0147] An SL distance measurement / positioning operation can be performed using a network-assisted operation or a WTRU-A operation (e.g., only). In a network-assisted operation, a network function (e.g., NF(s) 5GC) may be involved in handling the service request and / or calculating the result. In a WTRU operation (e.g., WTRU-only operation), the procedures for handling the service request and / or calculating the result may be performed by the WTRU.

[0148] When network-assisted operation is used, an identified (e.g., defined) LMF in the 5G location service can be used to support the triggering of SL positioning, the coordination of the SL positioning operation, and / or the delivery of the result to the client. The SL distance measurement / positioning service request can be initiated by a WTRU (e.g., SL positioning client WTRU, target WTRU, SL reference WTRU), a 5GC NF, an LCS Client, or an AF.

[0149] When the WTRU-A operation (e.g., only) can be used, WTRUs can interact with each other over an interface (e.g., PC5) as needed to perform SL positioning operations. An SL positioning server WTRU can be identified (e.g., defined) to coordinate an SL positioning operation and calculate the positioning result.

[0150] A WTRU SL positioning server can be provided. A WTRU SL positioning server can be a WTRU that offers method determination, assistance data distribution, location calculation functionalities, and / or location calculation functionalities for a distance measurement and SL positioning-based service.

[0151] NW-assisted SL positioning can be provided. Petition 870250087538, dated 09 / 26 / 2025, page 53 / 87 44 / 57 NW-assisted SL positioning can be used to estimate the location of a WTRU with network assistance using the location of one or more located WTRUs and the distance and / or direction between the WTRU and the located WTRU(s).

[0152] The network-assisted SL positioning feature may have a number of cases, such as two cases. For example, one case may be when the WTRU can establish a NAS signaling connection. For example, another case may be when the WTRU cannot establish a NAS signaling connection.

[0153] When a WTRU establishes a NAS connection, the WTRU can enter a connected-CM state by performing a WTRU-triggered service request to 5GC-MO-LR or a network-triggered service request to 5GC-NI-LR or 5GC-MT-LR. When the target WTRU establishes a NAS signaling connection with the AMF, the functionality specified in the 5G location service can be reused, for example, 5GC-MO-LR, 5GC-MT-LR, and 5GCNI-LR. The target WTRU or LMF can determine if network-assisted SL positioning can be applied. The target WTRU can discover located WTRU(s) for network-assisted SL positioning.

[0154] The target WTRU and the located WTRU(s) can perform SL distance measurement / positioning. The target WTRU can include the identity of the located WTRU(s) for the LMF, for example, with the distance measurement data, and / or estimation result. The LMF can interact with the GMLC to obtain the location of the located WTRU.

[0155] LMF can use the location of located WTRUs, distance measurement or SL positioning data, the estimation results reported by the target WTRU, and / or the estimation results reported by the located WTRUs, to estimate the location of the target WTRU. Petition 870250087538, dated 09 / 26 / 2025, p. 54 / 87 45 / 57

[0156] The target WTRU may not establish a NAS connection with the AMF if the target WTRU is out of coverage. In one example, for pending 5GC-MO-LR or 5GCMT-LR (e.g., deferred 5GC-MT-LR), a number of principles may apply. The target WTRU may perform discovery and selection of the located WTRU. The target WTRU may transmit its distance measurement / measurement results to the located WTRU(s). A located WTRU may report the distance measurement or SL positioning result to the LMF. This may include measurements or distance measurement results received from the target WTRU. The endpoints for LPP messages may be the LMF and the located WTRU(s). The LMF may use the received information to calculate the location of the target WTRU. The LMF may provide the resulting location of the target WTRU, for example, via the located WTRU, to the target WTRU.The LMF can provide the resulting location of the target WTRU, for example, via a network function (e.g., a 5G NF), to the LCS client or to the AS.

[0157] Exposure of the SL positioning service to a WTRU can be provided. A WTRU (e.g., a WTRU client for SL positioning) can request SL positioning via PC5 or via a NW.

[0158] When an SL positioning client WTRU requests an SL positioning service via a connection (e.g., a PC5 connection), it can discover a reference WTRU and / or a target WTRU, and can invoke the SL distance measurement / positioning service request for the discovered reference WTRU / target WTRU (e.g., to obtain the SL distance measurement and positioning result between the reference WTRU and the target WTRU). This request can include user information from one or more of the following: the SL positioning client WTRU, the reference WTRU, or the target WTRU. Petition 870250087538, dated 09 / 26 / 2025, p. 55 / 87 46 / 57

[0159] In NW-assisted SL placement, there may be various use cases in which localized WTRUs are used (e.g., two possible use cases based on the presence of a NAS connection).

[0160] For example, a use case (e.g., case 1) might be when the target WTRU has a NAS connection. In this case, a localized WTRU can be selected for SL placement, and the location report can be performed by the target WTRU. In this case, the requested capability of a localized WTRU might be the availability of the localized WTRU for Uu placement and / or capability for SL placement with the target WTRU.

[0161] For example, one use case (e.g., case 2) might be when the target WTRU does not have a NAS connection. In this case, a localized WTRU can be selected for SL placement. A location report can be performed by the selected localized WTRU. In this case, the requested capability of a localized WTRU might be the ability of the localized WTRU to perform a location report of a target WTRU, for example, by transporting parameters received from the target WTRU. This capability may be in addition to other requested capabilities, such as capabilities related to other cases (e.g., as described with respect to the previous use case where a NAS connection is present).

[0162] A localized WTRU can be selected based on the status of the target WTRU. The requested capacity of a localized WTRU for case 1 and case 2 may be different and may depend on the state of the target WTRU (e.g., inside or outside coverage). The target WTRU may be able to select the localized WTRU with a requested capacity according to the status of the target WTRU. The localized WTRU can be selected according to the state of the target WTRU.

[0163] An SL placement method can be determined based on a target WTRU status. A role for one or more WTRUs in the method Petition 870250087538, dated 09 / 26 / 2025, p. 56 / 87 47 / 57 SL placement can be determined based on the status of the target WTRU. As shown in case 1 and case 2, depending on the status of the target WTRU, the requested role of a localized WTRU may differ. Based on the mobility of the target WTRU and other circumstances, a target WTRU may gain or lose a connection to a core network (e.g., a NAS connection to the 5GC), and the status of the target WTRU may change. The localized WTRU and the target WTRU may request (e.g., may need) to synchronize the status of the target WTRU with each other so that an SL placement method and a role for each WTRU can be determined (e.g., based on the status of the target WTRU). Examples (e.g., as described in this document) may allow one or more WTRUs to synchronize the status of a target WTRU with each other to determine an SL placement method and / or to determine a role for each WTRU according to the status of the target WTRU.

[0164] In examples, a WTRU may support PC5 signaling. PC5 signaling may be supported by the ProSe layer in WTRUs. In examples, the WTRU may have the capability for distance measurement and SL positioning. SL positioning may refer to positioning via an interface (e.g., the PC5 interface), and distance measurement may refer to determining the distance between two or more WTRUs and / or the direction and / or relative positioning of one WTRU from another WTRU.

[0165] A procedure for discovering and selecting a localized WTRU in Model B discovery can be provided. For Model B discovery, the target WTRU can send a request message to discover a localized WTRU for an SL positioning service. The target WTRU can include the target WTRU's status or requested localized WTRU capabilities so that the target WTRU can discover and select the localized WTRU, which can be used to perform SL positioning according to the target WTRU's status. A Petition 870250087538, dated 09 / 26 / 2025, p. 57 / 87 48 / 57 The target WTRU and the selected localized WTRU can establish a connection, such as a PC5 connection, and can perform the SL positioning operation according to the target WTRU's status.

[0166] Figure 5 is a flowchart illustrating an exemplary method for discovering and selecting a localized WTRU (e.g., which may be discovery of model B). To discover a localized WTRU, in 1, a target WTRU can send a request message. The request message can include ProSe service information indicating the SL positioning service and a requested WTRU type that can be specified for a localized WTRU. The request message can include target WTRU status information (e.g., whether the target WTRU has a network connection, such as a NAS connection) and / or a requested capability of the localized WTRU. The requested capability of the localized WTRU can be, for example, a capability to support an SL positioning operation when the target WTRU may not have a network connection (e.g., it may not have a NAS connection).

[0167] In one example, the request message may include the placement method (e.g., RTT, TDOA, AoA, AoD) that the target WTRU may wish to use.

[0168] In another example, the request message may include the location of the target WTRU determined based on a positioning method (e.g., a RAT-independent positioning method, such as GNSS). The target WTRU may indicate the positioning method (e.g., the RAT-independent positioning method) used to determine its location.

[0169] With continued reference to Figure 5, in 1, the message (e.g., the target WTRU status IE) can be protected by integrity. In examples, the message may have confidentiality protection. If the association of Petition 870250087538, dated 09 / 26 / 2025, pp. 58 / 87 49 / 57 safety is established in 1, the parameters exchanged in 1-3 can be analyzed (e.g., verified) in 4.

[0170] In 2, a located WTRU can receive a request message to discover a located WTRU for SL positioning service. The located WTRU can check if it has the capability to support the SL positioning operation included in the request message. The capability of the located WTRU may vary based on, for example, the status of the target WTRU.

[0171] In 3, if the located WTRU supports the requested capacity, the located WTRU can respond to the target WTRU with a response message. The response message can include an indication of the capacity supported by the target WTRU's status. For example, the response message can indicate whether the located WTRU can support the requested capacity based on the target WTRU's status or based on the requested capacity itself (e.g., as included in the request message in 1).

[0172] After sending a request message, the target WTRU may wait for some time to receive responses from multiple localized WTRUs.

[0173] In 3, the message, or at least the indication of capability that supports the target WTRU status IE, can be (i.e., must be) at least protected by integrity, for example, with optional confidentiality protection. If this is not possible (e.g., due to a lack of security association in 1), the parameters exchanged in 1-3 can be parsed (e.g., verified) in 4.

[0174] In 4, after receiving reply message(s), the target WTRU can select a localized WTRU for an SL placement based on the capabilities of a localized WTRU and other conditions (e.g., Petition 870250087538, dated 09 / 26 / 2025, page 59 / 87 50 / 57 link quality). The target WTRU can perform a connection configuration (for example, it can perform a PC5 connection configuration).

[0175] If security for a connection, such as a PC5 connection, can be established during connection setup (e.g., PC5 configuration), the parameters exchanged in 1-3 can be verified. In one example, verification of the parameters exchanged in 1-3 can be performed after the connection is configured.

[0176] In 5, the target WTRU and the located WTRU can perform an SL positioning operation. The SL positioning operation may depend on the status of the target WTRU.

[0177] A procedure for discovering and selecting WTRU located in the discovery of model A can be provided.

[0178] For Model A discovery, a located WTRU can send an advertisement message including its supported capabilities (e.g., so that it can perform requested procedures for SL placement with the target WTRU, which may not have a connection (e.g., may not have a NAS connection)). Based on the advertised capabilities, the target WTRU can discover and select the located WTRU, which can be used to perform SL placement according to the target WTRU's status, which may indicate whether or not the target WTRU can have a connection (e.g., may or may not have a NAS connection). The target WTRU and the selected located WTRU can set up a connection (e.g., they can set up a PC5 connection) and can perform the SL placement operation according to the target WTRU's status.

[0179] Figure 6 is a flowchart illustrating an example procedure for discovering and selecting a localized WTRU with discovery (e.g., which could be the discovery of model A). In 1, a localized WTRU Petition 870250087538, dated 09 / 26 / 2025, pp. 60 / 87 51 / 57 can send an announcement message to indicate that it can support an SL positioning service and can indicate its supported WTRU type (e.g., it can be a localized WTRU type). The localized WTRU can indicate its capability, for example, to support SL positioning operation when the target WTRU may not have a connection (e.g., it may not have a NAS connection). In one example, the localized WTRU can indicate positioning methods (e.g., RTT, TDOA, AoA, AoD) that the localized WTRU supports in the announcement message.

[0180] In 2, when a target WTRU determines to perform SL placement, it can discover and select an appropriate localized WTRU based on the advertisement message(s) received from the localized WTRU(s). The target WTRU can receive multiple advertisement messages from localized WTRUs, and the target WTRU can select an appropriate localized WTRU that can advertise its capability for SL placement operation to be compatible with the requested capability according to the target WTRU's status. The target WTRU's status may indicate that the target WTRU may not have a connection (e.g., it may not have a NAS connection). The target WTRU can select the appropriate localized WTRU based on one or more conditions, such as link quality.

[0181] In 3, the target WTRU and the selected localized WTRU can establish a connection, which can be a PC5 connection. Verification of the parameters exchanged in 1 (e.g., an advertisement) can be done after 3 or in 3 when the connection security is established (e.g., PC5 connection security).

[0182] In 4, the target WTRU and the located WTRU can perform an SL positioning operation. The SL positioning operation may differ depending on the status of the target WTRU.

[0183] A list of localized WTRUs may be provided. Petition 870250087538, dated 09 / 26 / 2025, pp. 61 / 87 52 / 57 candidates with the necessary skills.

[0184] A core network, such as a 5GC, can provide a list of candidate localized WTRUs for NW-assisted SL placement of the target WTRU via control plane NAS signaling (registration, WTRU configuration update command, WTRU parameter update, SoR, etc.).

[0185] The candidate list may include the capacity of each located WTRU so that the located WTRU can perform a requested SL placement operation with a target WTRU that does not have a NAS connection.

[0186] In one example, if the main network (e.g., the 5GC) provides the list of candidate localized WTRUs with capabilities, the target WTRU can attempt to discover the localized WTRU in the list that has the appropriate capability according to the target WTRU's status.

[0187] In one example, the list provided by the main network (e.g., 5GC) may comprise one or more sets of localized WTRUs, where each set may be associated with a different placement method. For example, one set of localized WTRUs may consist of localized WTRUs that may support a round-trip time (RTT) placement method. In another example, another set of localized WTRUs (e.g., another set of localized WTRUs) may consist of localized WTRUs that may support a time-of-arrival difference (TDOA) placement method.

[0188] If a target WTRU attempts to discover the WTRU located in the list with capabilities, it can perform discovery of model A or model B without indicating the target WTRU's status and the WTRU's localized capability in the related messages. The target WTRU can select an appropriate localized WTRU from among the discovered localized WTRUs by referring to the WTRU's localized capability. Petition 870250087538, dated 09 / 26 / 2025, p. 62 / 87 53 / 57 discovered in the candidate list information.

[0189] A localized WTRU SL placement protocol procedure can be selected based on the status of the target WTRU. While a target WTRU and a localized WTRU perform SL placement, to select an appropriate SL placement method and to decide the role of each WTRU in the SL placement operation, the target WTRU can share its status. For example, the target WTRU can indicate whether it has a connection (e.g., a NAS connection) available or not. Based on the status of the target WTRU and the determined SL placement method, it can be decided (e.g., by the target WTRU) whether the localized WTRU or the target WTRU can collect an SL placement result and report it to the network.

[0190] Figure 7 is a flowchart illustrating an example SL positioning protocol procedure between the target WTRU and the localized WTRU. In 1, a target WTRU, a localized WTRU, an SL reference WTRU, and an SL positioning server or LMF WTRU can communicate for an SL positioning capacity negotiation. During the capacity negotiation, the status of the target WTRU denoting that the target WTRU may not have network connectivity (e.g., NAS connectivity) and the requested capacity of the localized WTRU according to the status of the target WTRU can be negotiated.

[0191] In one example, the target WTRU status can be shared separately from the capacity negotiation via signaling, or pre-configured or pre-acquired target WTRU status information during discovery or a connection configuration (e.g., PC5 connection configuration) can be reused. In this case, the capacity negotiation may not include the target WTRU status.

[0192] In one example, a capacity negotiation of a target WTRU, Petition 870250087538, dated 09 / 26 / 2025, pp. 63 / 87 54 / 57 a localized WTRU, and one or more SL reference WTRUs may occur between the target WTRU, the localized WTRU, and one or more SL reference WTRUs. The SL positioning server WTRU and / or the LMF may be informed of the negotiated capacity for the SL positioning decision in 2.

[0193] In one example, the functionality of a WTRU SL positioning server can place with the target WTRU, the located WTRU, or one or more reference WTRUs of SL.

[0194] In 2, an SL placement method can be determined, for example, by a WTRU SL placement server or an LMF based on negotiated capacity (for example, which may include a target WTRU status, capabilities of the located WTRU according to the target WTRU status, and one or more available SL reference WTRUs and their capabilities). Based on the determined SL placement method, the role of the target WTRU and the role of the located WTRU can be decided in 2.

[0195] In one example, an SL placement method may be determined between a target WTRU and a localized WTRU or between a target WTRU, a localized WTRU, and one or more SL reference WTRUs. The determination may be based on a negotiated capability that may include a target WTRU status, localized WTRU capabilities according to the target WTRU status, and / or one or more SL reference WTRUs and their capabilities.

[0196] In 3, assistance data for performing SL positioning can be shared. Service data may include transmitted signal features and formatting, time intervals, etc. Assistance data may be provided by an SL positioning server WTRU or an LMF, to the target WTRU, the located WTRU, and / or one or more involved SL reference WTRUs. This may be based on the positioning method. Petition 870250087538, dated 09 / 26 / 2025, pp. 64 / 87 55 / 57 of SL determined.

[0197] In one example, assistance data can be shared within the target WTRU, the located WTRU, and one or more involved SL reference WTRUs. (Pre-)configured information in the located WTRU, the target WTRU, and / or one or more SL reference WTRUs can be used as assistance data to perform SL placement.

[0198] In one example, the placement method can be determined based on (for example, by) the number of located WTRUs that have established connections with the target WTRU.

[0199] In 4, a located WTRU, a target WTRU, and one or more SL reference WTRUs can perform the determined SL positioning operation.

[0200] In 5, the results of the SL positioning operation can be collected at the located WTRU and / or the target WTRU. Based on the SL positioning method and the status of the target WTRU, it can be decided whether the located WTRU or the target WTRU can collect the result.

[0201] In 6, the location report may include the result of the SL positioning operation, and information about the located WTRU may be reported to the LMF or to the SL positioning server. Based on the status of the target WTRU, it can be determined whether the located WTRU or the target WTRU can transmit the location report.

[0202] In one example, if the localized WTRU cannot report the result of the SL placement operation to the LMF, the target WTRU may receive a message from the localized WTRU indicating that the report could not be sent to the LMF. Based on the message, the target WTRU may send a request to the localized WTRU at a configured frequency to send the report to the LMF until the target WTRU receives the message from the localized WTRU. Petition 870250087538, dated 09 / 26 / 2025, pp. 65 / 87 56 / 57 that the transmission of the report to the LMF was successful.

[0203] Handling of an updated target WTRU status can be provided during an SL positioning operation.

[0204] After capacity negotiation, the status of the target WTRU and / or the located WTRU may change. For example, the target WTRU may have lost a connection (e.g., a NAS connection), the target WTRU may have regained a connection (e.g., a NAS connection), and the located WTRU may have lost a connection (e.g., a NAS connection). A target WTRU or located WTRU may inform the other WTRU of the updated status so that it can be determined whether the SL placement operation can continue or restart.

[0205] When the target WTRU status changes after capacity negotiation, the target WTRU or the located WTRU can decide whether the current session of an SL placement operation can continue or whether the current SLPP session can be updated according to the target WTRU status in consideration of the resource allocation method, synchronization methods, etc.

[0206] If the target WTRU decides that the current session can continue regardless of the target WTRU's status change, the target WTRU may not share the updated target WTRU status with the localized WTRU until the end of the session.

[0207] Although the resources and elements described in this document are described in specific combinations, each resource or element can be used alone, without the other resources and elements of the preferred modalities, or in various combinations with or without other resources and elements.

[0208] Although the implementations described in this document may consider specific 3GPP protocols, it is understood that the implementations described in this document are not restricted to this scenario. Petition 870250087538, dated 09 / 26 / 2025, pp. 66 / 87 57 / 57 and may be applicable to other wireless systems. For example, although the solutions described in this document consider specific LTE, LTE-A, New Radio (NR) or 5G protocols, it is understood that the solutions described in this document are not restricted to this scenario and are applicable to other wireless systems as well.

[0209] The processes described above can be implemented in a computer program, software, and / or firmware embedded in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), a register, a cache memory, semiconductor memory devices, magnetic media such as, without limitation, internal hard disks and removable disks, magneto-optical media and / or optical media such as compact disc (CD)-ROM disks and / or digital versatile disks (DVDs).A processor, in conjunction with software, can be used to implement a radio frequency transceiver for use in a WTRU, a terminal, a base station, an RNC, and / or any central computer. Petition 870250087538, dated 09 / 26 / 2025, pp. 67 / 87

Claims

1 / 4 CLAIM 1. Wireless transmit / receive unit (WTRU) CHARACTERIZED in that it comprises: a processor configured to: receive a request message from a second WTRU, wherein the request message indicates a status of the second WTRU and service information associated with a side link (SL) positioning service; determine that the first WTRU is capable of providing the SL positioning service based on the status of the second WTRU and the service information; and send, based on the determination that the first WTRU is capable of providing the SL positioning service, a response message to the second WTRU, wherein the response message indicates that the first WTRU is capable of providing the SL positioning service.

2. First WTRU, according to claim 1, CHARACTERIZED in that the request message also indicates a connection status associated with the second WTRU, a placement method, and a location associated with the second WTRU.

3. First WTRU, according to claim 1, CHARACTERIZED in that the response message also indicates a capability of the first WTRU to perform an SL positioning operation associated with the status of the second WTRU.

4. First WTRU, according to claim 1, CHARACTERIZED in that the processor is further configured to: receive a connection request message from the second WTRU to establish a connection; and establish a connection to the second WTRU.

5. First WTRU, according to claim 4, CHARACTERIZED Petition 870250087538, dated 09 / 26 / 2025, pp. 84 / 87 2 / 4 by the fact that the processor is further configured to: perform an SL positioning operation using the connection to the second WTRU, wherein the SL positioning operation is based on the status of the second WTRU.

6. First WTRU, according to claim 5, CHARACTERIZED in that the SL positioning operation is a synchronization method.

7. First WTRU, according to claim 4, CHARACTERIZED in that the reply message is not protected by integrity, and the reply message is sent over the connection.

8. First WTRU, according to claim 1, CHARACTERIZED in that the response message is protected by integrity and protected by confidentiality.

9. First WTRU, according to claim 1, CHARACTERIZED in that the status of the second WTRU indicates that the second WTRU has an available non-access stratum (NAS) connection.

10. First WTRU, according to claim 1, CHARACTERIZED in that the status of the second WTRU indicates that the second WTRU does not have a non-access stratum (NAS) connection available.

11. First wireless transmit / receive unit (WTRU), the first WTRU being CHARACTERIZED in that it comprises: a processor configured to: receive an advertisement message from a second WTRU, the advertisement message indicating service information associated with a side link (SL) positioning service, an identity of the second WTRU and a capability of the second WTRU to support the SL positioning service; determine that the second WTRU is configured to provide the SL positioning service to the first WTRU based on a status of the first WTRU and the capability of the second WTRU; establish a connection to the second WTRU based on the determination that the second WTRU is configured to provide the SL positioning service; and receive a service message from the second WTRU using the connection, the service message being associated with the SL positioning service.

12. First WTRU, according to claim 11, CHARACTERIZED in that the status of the first WTRU indicates that the first WTRU has an available non-access stratum (NAS) connection.

13. First WTRU, according to claim 11, CHARACTERIZED in that the status of the first WTRU indicates that the first WTRU does not have a non-access stratum (NAS) connection available.

14. First WTRU, according to claim 11, CHARACTERIZED in that the announcement message is a first announcement message, and the processor is further configured to: receive a second announcement message from a third WTRU.

15. First WTRU, according to claim 14, CHARACTERIZED in that the determination that the second WTRU serves to provide the SL positioning service is based, further, on the second advertisement message.

16. First WTRU, according to claim 15, CHARACTERIZED in that the determination that the second WTRU serves to provide the SL positioning service is further based on a link quality associated with the first WTRU.

17. First WTRU, according to claim 11, CHARACTERIZED Petition 870250087538, dated 09 / 26 / 2025, p. 86 / 87 4 / 4 by the fact that the processor is further configured to: receive a candidate list indicating the ability of the second WTRU to support the SL positioning service.

18. First WTRU, according to claim 17, CHARACTERIZED in that the candidate list comprises a first set of WTRUs associated with a first SL positioning service and a second set of WTRUs associated with a second SL positioning service, wherein the first set of WTRUs includes the second WTRU, and the first SL positioning service is the SL positioning service.

19. First WTRU, according to claim 11, CHARACTERIZED in that the SL positioning service is a round-trip time (RTT) positioning method.

20. First WTRU, according to claim 11, CHARACTERIZED by the fact that the SL positioning service is a time-of-arrival difference (TDOA) positioning method. Petition 870250087538, dated 09 / 26 / 2025, pp. 87 / 87

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