Systems and methods for detecting u2u retransmission state during discovery

Description

1 / 35 “SYSTEMS AND METHODS FOR DETECTING U2U RETRANSMISSION STATE DURING DISCOVERY” CROSS-REFERENCE TO RELATED REQUESTS

[001] This application claims the benefit of Provisional Application US No. 63 / 457,586, filed on April 6, 2023, which is incorporated herein by reference in its entirety. FUNDAMENTALS OF THE INVENTION

[002] Security procedures for Direct Discovery and WTRU-to-Network are specified in certain wireless standards. In particular, restricted discovery messages are protected for integrity, confidentiality, and against replay using security material associated with, respectively, a restricted ProSe and RSC code. Protection against replay is done using a UTC-time-based mechanism to ensure the updating of discovery message protection.

[003] For direct discovery, a WTRU can be provided with security material associated with a ProSe restricted code via a Direct Discovery Name Management Function (DDNMF). For Network WTRU Discovery, terminal WTRUs and relay WTRUs can be provided with security material associated with an RSC via a DDNMF, a Policy Control Function (PCF), or a ProSe Key Management Function (PKMF).

[004] For WTRU 5G ProSe to WTRU Relay Discovery, both Model A and Model B discovery are supported. Model A uses a single discovery protocol message (Advertisement) and Model B uses two discovery protocol messages (Request and Response). The procedures for WTRU 5G ProSe to WTRU Relay Discovery with Model A and Model B are defined in the 3GPP wireless standards. Petition 870250087603, dated 09 / 26 / 2025, p. 12 / 66 2 / 35

[005] 5G ProSe communication via a WTRU 5G ProSe to WTRU relay with integrated discovery in the PC5 unicast link establishment procedure is supported. The link establishment procedure using integrated discovery does not require standalone discovery to run. The detailed procedure is defined in the 3GPP wireless standards. SUMMARY OF THE INVENTION

[006] A method executed by a first WTRU may comprise: receiving, from a network, one or more relay service codes (RSCs), wherein each of one or more RSCs includes a network assistance security indicator; selecting, from among one or more RSCs, a first RSC, wherein the selection of the first RSC is based on a first network assistance security indicator associated with the first RSC and on a network coverage state of the first WTRU; under the condition that the network coverage state of the first WTRU is out of coverage, transmitting, to a second WTRU, a discovery message, the discovery message including the first RSC; and receiving, from the second WTRU, a Direct Communication Request (DCR) message, wherein the DCR message includes a second RSC. The first WTRU may be a relay WTRU and the second WTRU may be an originating WTRU. The second RSC may be the same as the first RSC.

[007] A method executed by a first WTRU may comprise: receiving, from a network, one or more relay service codes (RSCs), where each of the one or more RSCs includes a network assistance security indicator; receiving, from a second WTRU, a discovery message, the discovery message including a first RSC; and transmitting, to the second WTRU, a direct communication request (DCR) message, the DCR message including a second RSC. The first WTRU may be an originating WTRU and the second WTRU may be a relaying WTRU. The second Petition 870250087603, dated 09 / 26 / 2025, p. 13 / 66 3 / 35 RSC may be equal to the first RSC. BRIEF DESCRIPTION OF THE DRAWINGS

[008] A more detailed understanding can be obtained from the following description, given by way of example in conjunction with the attached drawings, where similar reference numbers in the figures indicate similar elements, and where:

[009] Figure 1A is a system diagram that illustrates an exemplary communications system in which one or more of the described modalities can be implemented.

[010] Figure 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that can be used within the communications system illustrated in Figure 1A according to one embodiment.

[011] Figure 1C is a system diagram that illustrates an exemplary radio access network (RAN) and an exemplary central network (CN) that can be used within the communications system illustrated in Figure 1A according to a modality.

[012] Figure 1D is a system diagram that illustrates an exemplary additional RAN and an exemplary additional CN that can be used within the communications system illustrated in Figure 1A according to a modality.

[013] Figure 2 illustrates an example of a status indication procedure during discovery.

[014] Figure 3 illustrates an example of a WTRU retransmission state detection procedure without autonomous discovery.

[015] Figure 4 illustrates an example of a security establishment procedure between a destination WTRU and a relay WTRU.

[016] Figure 5 illustrates an example of a procedure performed by a WTRU.

[017] Figure 6 illustrates an example of a procedure performed by a Petition 870250087603, dated 09 / 26 / 2025, p. 14 / 66 4 / 35 WTRU. DETAILED DESCRIPTION

[018] Figure 1A is a diagram illustrating an exemplary 100 communications system, in which one or more described modalities can be implemented. The 100 communications system can be a multiple access system that provides content, such as voice, data, video, messages, transmission, etc., to multiple wireless users. The 100 communications system can allow multiple wireless users to access such content by sharing system resources, including wireless bandwidth.For example, communication systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero-tailed single-word DFT propagation OFDM (ZT UW DTS-s OFDM), single-word OFDM (UWOFDM), feature block filtered OFDM, filter bank multicarrier (FBMC), and the like.

[019] 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 is important to note that the described embodiments consider 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 subscriber unit or Petition 870250087603, dated 09 / 26 / 2025, page 15 / 66 5 / 35 mobile, a subscription-based unit, a pager, a mobile phone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, virtual reality glasses (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in industrial and / or automated processing chain contexts), a consumer electronic device, a device operating on commercial and / or industrial wireless networks and the like. Any of the WTRUs 102a, 102b, 102c, 102d may be interchangeably referred to as a UE.

[020] 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 interact 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 base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR NodeB, a site controller, an access point (AP), a wireless router and the like. Although base stations 114a and 114b are represented as a single element, it is important to note that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[021] 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 Petition 870250087603, dated 09 / 26 / 2025, p. 16 / 66 6 / 35 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 the licensed spectrum, the unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may 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 further be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one for each sector of the cell. In another embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell.For example, beamforming can be used to transmit and / or receive signals in desired spatial directions.

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

[023] More specifically, as noted 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, SC-FDMA 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 Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as Access Petition 870250087603, dated 09 / 26 / 2025, page 17 / 66 7 / 35 in High-Speed ​​Packet Access (HSPA) and / or HSPA Enhanced (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink (UL) Packet Access (HSUPA).

[024] 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 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[025] 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 116 air interface using New Radio (NR).

[026] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using dual connectivity (DC) principles. Thus, the air interface used by WTRUs 102a, 102b, 102c may 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).

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

[028] Base station 114b in Figure 1A could be a wireless router, a Petition 870250087603, dated 09 / 26 / 2025, page 18 / 66 8 / 35 Home NodeB, a Home eNodeB, or an access point, for example, and can utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as a commercial location, a residence, a vehicle, 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 another embodiment, base station 114b and WTRUs 102c, 102d 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 the 110 Internet. Thus, base station 114b may not need to access the 110 Internet via CN 106 / 115.

[029] RAN 104 / 113 may be in communication with CN 106 / 115, which may be any type of network configured to provide voice, data, application 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 requirements for throughput, latency, error tolerance, reliability, data throughput, mobility and the like. CN 106 / 115 may provide call control, billing services, location-based mobile services, prepaid calls, internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in Figure 1A, it is important to note that RAN 104 / 113 and / or CN 106 / 115 may be in direct or indirect communication with other RANs that use the same RAT as RAN 104 / 113 or a different RAT.For example, in addition to being connected to the RAN. Petition 870250087603, dated 09 / 26 / 2025, p. 19 / 66 9 / 35 104 / 113, which may use NR radio technology, CN 106 / 115 may also be in communication with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA or WiFi radio technology.

[030] 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 traditional telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP) and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. Networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, 112 networks may include another NC connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[031] Some or all of the WTRUs 102a, 102b, 102c, 102d in the 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 cellular-based radio technology, and with base station 114b, which may employ IEEE 802 radio technology.

[032] 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 numeric keypad 126, a touchscreen / touch surface 128, non-removable memory 130, removable memory 132, a power supply 134, Petition 870250087603, dated 09 / 26 / 2025, p. 20 / 66 10 / 35 a global positioning system (GPS) chipset 136 and / or other peripherals 138, among others. It should be noted that the WTRU 102 may include any subcombination of the above elements, remaining consistent with a modality.

[033] 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 Arrays (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 allows 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.While Figure 1B depicts processor 118 and transceiver 120 as separate components, it is important to note that processor 118 and transceiver 120 can be integrated into a single electronic package or chip.

[034] The transmit / receive element 122 can be configured to transmit to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In another embodiment, the transmit / receive element 122 can 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 can be configured to transmit and / or receive both RF and light signals. It is important to note that the transmit / receive element 122 Petition 870250087603, dated 09 / 26 / 2025, page 21 / 66 11 / 35 can be configured to transmit and / or receive any combination of wireless signals.

[035] 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.

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

[037] The WTRU 102 processor 118 can be coupled with and receive user input data from the speaker / microphone 124, the numeric keypad 126, and / or the screen / touch surface 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit). The processor 118 can also send user data to the speaker / microphone 124, the numeric keypad 126, and / or the screen / touch surface 128. In addition, the processor 118 can access information and store data in any suitable type of memory, such as non-removable memory 130 and / or removable memory 132. Non-removable memory 130 can 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 SIM card (subscriber identity module), a memory card, a secure digital memory card (SD), and similar items. In other words... Petition 870250087603, dated 09 / 26 / 2025, page 22 / 66 In 12 / 35 modes, the 118 processor can access information 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).

[038] Processor 118 can receive power from power supply 134 and can be configured to distribute and / or control power to the other components in WTRU 102. Power supply 134 can be any device suitable for powering WTRU 102. For example, power supply 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.

[039] Processor 118 can also be coupled to GPS chipset 136, which can be configured to provide location information (e.g., longitude and latitude) pertaining to the current location of WTRU 102. In addition to, or in substitution for, GPS chipset 136 information, WTRU 102 can receive location information via 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 is important to note that WTRU 102 can acquire location information by any suitable location determination method, remaining consistent with a mode.

[040] 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 wired or wireless 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 Petition 870250087603, dated 09 / 26 / 2025, page 23 / 66 13 / 35 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. Sensors may be one or more of a gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor, and / or a humidity sensor.

[041] The WTRU 102 may include a full-duplex radio for which the transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and DL (e.g., for reception) may be simultaneous. The full-duplex radio may include an interference management unit to substantially reduce and / or eliminate self-interference by means of hardware (e.g., an inductor) or signal processing by means of a processor (e.g., a separate processor (not shown) or by means of processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which the transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be simultaneous.

[042] Figure 1C is a system diagram illustrating RAN 104 and CN 106 according to one mode. 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.

[043] RAN 104 may include eNode-Bs 160a, 160b, 160c, although it is important to note that RAN 104 may include any number of eNode-Bs, Petition 870250087603, dated 09 / 26 / 2025, p. 24 / 66 14 / 35 remaining consistent with one embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communication with the WTRUs 102a, 102b, 102c via wireless interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

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

[045] The CN 106 shown in Figure 1C may include a mobility management entity (MME) 162, a service gateway (SGW) 164, and a packet data network gateway (PDN) (PGW) 166. Although the above elements are represented as part of CN 106, it is important to note that any of these elements may be owned and / or operated by an entity other than the CN operator.

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

[047] The SGW 164 can be connected to each of the eNodes B 160a, 160b, 160c in RAN 104 via the S1 interface. The SGW 164 can generally route Petition 870250087603, dated 09 / 26 / 2025, page 25 / 66 15 / 35 and forward user data packets to / from WTRUs 102a, 102b, 102c. SGW 164 can perform other functions, such as anchoring user planes during transfers between B eNodes, triggering paging when DL data is available for WTRUs 102a, 102b, 102c, managing and storing contexts of WTRUs 102a, 102b, 102c and similar.

[048] 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.

[049] 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 fixed-line communication 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. In addition, CN 106 can provide WTRUs 102a, 102b, 102c with access to other 112 networks, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[050] Although the WTRU is described in Figures 1A-1D as a wireless terminal, it is considered that, in certain representative embodiments, such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[051] In representative modalities, the other 112 network can be a WLAN.

[052] A WLAN in Basic Services Infrastructure Set (BSS) mode can have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can have access to, or an interface with, a System of Petition 870250087603, dated 09 / 26 / 2025, p. 26 / 66 16 / 35 Distribution Network (DS) or other type of wired / wireless network that carries inbound and / or outbound traffic from the BSS. Traffic to STAs originating from outside the BSS can arrive via the AP and be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS can be sent to the AP to be delivered to the respective destinations. Traffic between STAs within the BSS can be sent via the AP, for example, where the originating STA can send traffic to the AP and the AP can deliver the traffic to the destination STA. Traffic between STAs within a BSS can be considered and / or termed point-to-point traffic. Point-to-point traffic can be sent between (e.g., directly between) 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 (IBSS) mode may not have an AP, and the STAs (i.e., all STAs) within or using the IBSS can communicate directly with each other. The IBSS communication mode may sometimes be referred to here as an "ad-hoc" communication mode.

[053] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP can transmit a beacon 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. 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 Sense Multiple Access and 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 to be occupied by a specific STA, that specific STA can back off. An STA (e.g., only one station) can transmit at any time on a given BSS. Petition 870250087603, dated 09 / 26 / 2025, page 27 / 66 17 / 35

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

[055] Very High Throughput (VHT) STAs can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 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 8 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 time-domain processing can be performed on each stream separately. Streams can be mapped to the two 80 MHz channels, and data can be transmitted via a STA transmitter.At the receiving 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).

[056] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating 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 (TVWS) spectrum, and 802.11ah supports bandwidths of 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using non-TVWS spectrum. According to a representative embodiment, 802.11ah can support Meter Type Control / Machine Type Communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain features, for example, Petition 870250087603, dated 09 / 26 / 2025, page 28 / 66 18 / 35 limited features, including support for (e.g., support only for) certain bandwidths and / or limited bandwidths. MTC devices may include a battery with a lifespan exceeding a certain limit (e.g., to maintain a very long battery life).

[057] 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 can have a bandwidth equal to the highest common operational bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be defined and / or limited by an STA, among all STAs operating in a BSS that supports the operating mode with the lowest bandwidth. In the 802.11ah example, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only support) the 1 MHz mode, 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 an STA (which only supports 1 MHz operating mode) transmitting to the AP, all available frequency bands can be considered occupied, even if most of them remain idle and could be available.

[058] In the United States, the available frequency bands that can be used by 802.11ah are 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.

[059] Figure 1D is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 can Petition 870250087603, dated 09 / 26 / 2025, p. 29 / 66 19 / 35 employs NR radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 113 can also be in communication with CN 115.

[060] RAN 113 may include gNBs 180a, 180b, 180c, although it is important to note that RAN 113 may include any number of gNBs, remaining consistent with a modality. gNBs 180a, 180b, 180c may each include one or more transceivers for communication with WTRUs 102a, 102b, 102c via the 116 air interface. In a modality, gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may use beamforming to transmit to and / or receive signals from gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, can use multiple antennas to transmit to and / or receive wireless signals from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, the gNB 180a can transmit multiple component carriers to the WTRU 102a (not shown).A subset of these component carriers may be in unlicensed spectrum, while the remaining component carriers may be in licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c may implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[061] WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the spacing of OFDM symbols and / or the spacing of OFDM subcarriers 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 subframes or transmission time intervals (TTIs) of varying or scalable lengths. Petition 870250087603, dated 09 / 26 / 2025, p. 30 / 66 20 / 35 (for example, containing a variable number of OFDM symbols and / or with a variable absolute time duration).

[062] gNBs 180a, 180b, 180c can be configured to communicate with WTRUs 102a, 102b, 102c in a standalone and / or non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c can use one or more of gNBs 180a, 180b, 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 / connect to gNBs 180a, 180b, and 180c, while also communicating / connecting to other RANs, such as eNode-Bs 160a, 160b, and 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 substantially simultaneously. In a non-standalone configuration, eNode-Bs 160a, 160b, 160c can serve as a mobility anchor for WTRUs 102a, 102b, 102c, and gNBs 180a, 180b, 180c can provide additional coverage and / or throughput to support WTRUs 102a, 102b, 102c.

[063] 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, transfer decisions, user scheduling in the UL and / or DL, network slicing support, DC, interoperability between NR and E-UTRA, user plane data routing to User Plane Function (UPF) 184a, 184b, control plane information routing to Access and Mobility Management Function (AMF) 182a, 182b and similar. Petition 870250087603, dated 09 / 26 / 2025, page 31 / 66 21 / 35 As shown in Figure 1D, gNBs 180a, 180b, and 180c can communicate with each other via an Xn interface.

[064] 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 the above elements are represented as part of the CN 115, it is important to note that any of these elements may be owned and / or operated by an entity other than the CN operator.

[065] AMF 182a, 182b can be connected to one or more of the gNBs 180a, 180b, 180c in RAN 104 via an N2 interface and can serve as a control node. For example, AMF 182a, 182b can be responsible for authenticating users of WTRUs 102a, 102b, 102c, for supporting network slicing (e.g., handling different Protocol Data Unit (PDU) sessions with different requirements), for selecting a specific SMF 183a, 183b, for managing the log area, for terminating non-access stratum signaling (NAS), for mobility management, and the like. Network slicing can be used by AMF 182a, 182b to customize CN support for WTRUs 102a, 102b, 102c based on the types of services used in 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 enhanced massive mobile broadband access (eMBB), services for MTC access, and the like. AMF 182a, 182b 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 WiFi.

[066] The SMF 183a, 183b can be connected to an AMF 182a, 182b on CN 115 via an N11 interface. The SMF 183a, 183b can also be connected Petition 870250087603, dated 09 / 26 / 2025, page 32 / 66 22 / 35 to a 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, 183b can perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy and QoS enforcement, providing DL data notifications, and similar functions. A PDU session type can be IP-based, non-IP-based, Ethernet-based, and similar.

[067] 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 110, to facilitate communications between WTRUs 102a, 102b, 102c and IP-enabled devices. UPF 184, 184b can perform other functions such as packet routing and forwarding, user plane policy enforcement, support for multihomed PDU sessions, user plane QoS handling, temporary packet storage (DL), mobility tethering, and similar functions.

[068] 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 DN 185a, 185b via UPF 184a, 184b, through the N3 interface to UPF 184a, 184b, and through an N6 interface between UPF 184a, 184b and DN 185a, 185b.

[069] Considering Figures 1A-1D and the corresponding description of Figures 1A-1D, one or more, or all of the functions described herein, in relation to one or Petition 870250087603, dated 09 / 26 / 2025, p. 33 / 66 23 / 35 more than: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b / or any other device described herein, they may be performed by one or more emulation devices (not shown). Emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, emulation devices may be used to test other devices and / or simulate network and / or WTRU functions.

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

[071] One or more emulation devices may perform one or more, including all, functions while not 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 an undeployed (e.g., under test) wired and / or wireless communication network to implement the testing of one or more components. The emulation device(s) may be test equipment. Direct RF coupling and / or wireless communications via RF circuit arrays (e.g., which may include one or more antennas) may be used by the emulation devices to Petition 870250087603, dated 09 / 26 / 2025, page 34 / 66 24 / 35 transmit and / or receive data.

[072] The following abbreviations and acronyms may be used: CP Control Plan DCR Direct Communication Request DCA Acceptance of Direct Communication DCReject Direct Communication Rejection Direct Discovery Name Management Function (DDNMF) IC Coverage Out of Coverage (OoC) PRUK ID Remote User Key Identification ProSe RSC Relay Service Code Hidden Signature Identifier SUCI UP User Plan EU-to-EU U2U WTRU Wireless Transmission / Reception Unit

[073] Hereafter, the terms L3 U2U relay WTRU, L3 WTRU-to-WTRU relay WTRU, L3 U2U relay WTRU, U2U relay WTRU, relay WTRU, and relay may be used interchangeably. The term “terminal WTRU” may refer to the source WTRU and / or the destination WTRU.

[074] Certain 3GPP wireless standards address the 3GPP system requirements for the security of a relay WTRU, which stipulate that the 3GPP system must be able to protect the security (i.e., integrity and confidentiality) of information between partner WTRUs across the relay WTRU; failure to comply with this may open vulnerabilities in the 5GS and allow various attacks, such as unauthorized disclosure and modification of information. Protecting communications between partner WTRUs presupposes that the WTRU of Petition 870250087603, dated 09 / 26 / 2025, page 35 / 66 25 / 35 retransmission is a reliable node.

[075] When security is established between terminal WTRUs and a relay WTRU with network assistance and the relay WTRU is within 5G network coverage, then the security procedure is the same as the PC5 security procedure for 5G ProSe communication via 5G ProSe L3 WTRU relay to network, as defined in the wireless standards.

[076] There are two security mechanism options for WTRU 5G ProSe-to-Network relay: User Plane (UP) security procedure, as defined in certain 3GPP wireless standards, and Control Plane (CP) security procedure, as defined in certain 3GPP wireless standards. Remote WTRU 5G ProSe and WTRU 5G ProSe-to-Network relay determine the security mechanism based on the Control Plane Security Indicator associated with the RSC; the Control Plane Security Indicator and the associated RSC are specified in certain 3GPP wireless standards.

[077] The 3GPP wireless standards provide that security procedures between terminal WTRUs and a network-assisted and non-network-assisted relay WTRU can be initiated using different parameters in the DCR message sent by a terminal WTRU and, consequently, use different security credentials to establish security (e.g., PRUK ID or SUCI vs. KNRP ID / MSB of KNRP-ID session). Consequently, which parameters and security material to use to establish security between the terminal WTRUs and the relay WTRU must consider the coverage state (i.e., IC or OoC) of the relay WTRU.

[078] A security procedure that uses network assistance may require the relay WTRU to be in coverage. However, the terminal WTRU(s) may not be able to know the coverage status of the WTRU. Petition 870250087603, dated 09 / 26 / 2025, p. 36 / 66 26 / 35 retransmission (i.e., IC or OoC), because the mechanisms for the terminal WTRU to determine the coverage status of the retransmission WTRU are not defined.

[079] Consequently, one problem is how to select the appropriate security procedure between the terminal WTRU(s) and a relay WTRU. More specifically, the problem includes which security procedure should be executed between the source WTRU and the relay WTRU and which security procedure selection between the relay WTRU and the destination WTRU. Another problem may be the procedure to allow the terminal WTRU to detect the coverage status of the relay WTRU.

[080] In one embodiment, to detect the coverage status of the relay WTRU on the source WTRU, the relay WTRU may indicate its coverage status (i.e., IC or OoC and / or support for network-assisted security or network-unassisted security) during a discovery procedure. Based on the coverage status of the relay WTRU and / or the indication of network-assisted support, the source WTRU may select the correct security parameters for establishing security.

[081] In another embodiment, when discovery is integrated into the establishment of the PC5 link (i.e., without standalone discovery), the relay WTRU may send a direct communication rejection message (DCReject) to a terminal WTRU if the received security parameters are not aligned with the current coverage status of the relay WTRU. The DCReject message may include a cause code indicating the coverage status of the relay WTRU.

[082] In another embodiment, once security has been established with the originating WTRU and the relay WTRU, the relay WTRU can send an indication (i.e., coverage status and / or network assistance support) in a DCR message to the destination WTRU. The destination WTRU, based on Petition 870250087603, dated 09 / 26 / 2025, p. 37 / 66 27 / 35 indication, it can initiate a security establishment (e.g., without network assistance) or send a DCReject message indicating that the destination WTRU can initiate PC5 link establishment (e.g., using network assistance) with the relay WTRU.

[083] In one embodiment, the choice of security material may depend on whether the relay WTRU is IC or OoC. The status of the relay WTRU may be indicated to the terminal WTRUs during a discovery procedure. The indication of the coverage state of the relay WTRU (e.g., IC or OoC) is applicable to both Model A and Model B discovery procedures. The selection of security material during discovery may consider the state of the terminal WTRUs and the relay WTRU as being IC or OoC.

[084] In another embodiment, the network may need more control over the WTRUs and may prefer to use the network-assisted security procedure instead of the non-network-assisted security procedure for this set of services. Consequently, a preference associated with the RSC may be indicated by the network to the terminal WTRUs and the relay WTRU, ensuring that the network-assisted security procedure is used whenever the relay WTRU is in the IC state. A flag associated with the RSC may indicate whether security for communication with the relay WTRU is supported with network assistance, without network assistance, or both.

[085] In another embodiment, the selection of the relay WTRU may be based on the coverage state of the relay WTRU (for example, for the RSC where network-assisted security is preferred, the relay WTRU is chosen by the originating WTRU only when the coverage state of the relay WTRU is indicated as IC). If there is no preference associated with the RSC for network-assisted security, the originating WTRU may learn the status of Petition 870250087603, dated 09 / 26 / 2025, p. 38 / 66 28 / 35 coverage of the relay WTRU during discovery and use this information to select appropriate parameters for establishing security with the relay WTRU.

[086] Figure 2 illustrates an example of a status indication procedure 200 during discovery.

[087] In 210, the source WTRU 202, the relay WTRU 204, and the destination WTRU 206 can be provided with one or more RSCs that include a network assistance security indicator that indicates whether a network assistance security procedure should be used or a non-network assistance security procedure should be used. The source WTRU 202, the relay WTRU 204, and the destination WTRU 206 can be provided with the security materials to support IC and OoC scenarios.

[088] In 212, relay WTRU 204, as part of a discovery procedure, may transmit its status indication (e.g., IC or OoC and / or with network assistance indicator or without network assistance indicator) to source WTRU 202. If model A is implemented, the relay WTRU's status indication may be sent via a discovery announcement message. If model B is implemented, the relay WTRU's status indication may be sent via a request reply message sent in response to the request received by the relay WTRU from source WTRU 202.

[089] In 214, the originating WTRU 202 can learn or monitor the state of the relay WTRU, including its coverage state, and can use the relay state to determine whether to connect to the relay WTRU 204 and what security procedure to execute if it connects to the relay WTRU 204.

[090] For example, if the WTRU of relay 204 is IC, the WTRU of Petition 870250087603, dated 09 / 26 / 2025, p. 39 / 66 29 / 35 Origin 202 can initiate a network-assisted security procedure. If relay WTRU 204 is OoC, origin WTRU 202 can initiate OoC security procedures by transmitting a PRUK ID or a SUCI (i.e., using PRUK as a credential), a KNRP ID (if available), or a KNRP ID / MSB session KNRP-ID (e.g., using long-term provided credentials). For example, origin WTRU 202 might decide to select a different relay based on the preference associated with the RSC and the relay selection state of relay WTRU 204. For example, if the relay is OoC and the RSC prefers network assistance, then origin WTRU 202 might not select that relay and instead might select and / or search for a relay WTRU that is IC.In another example, relay WTRU 204 may decide to stop advertising and / or responding to request messages for an RSC that only supports network assistance when relay WTRU 204 is out of service (OoC).

[091] In 216, the originating WTRU 202 can transmit a DCR message to the relaying WTRU 204. The DCR message can include an RSC. The RSC can be the same RSC that the originating WTRU 202 received from the relaying WTRU in 212. The DCR message can also, based on a prior security procedure determination, include security parameters for network assistance and / or security parameters for non-network assistance. Upon receiving the DCR message, the relaying WTRU 204 can transmit a DCReject message if the status of the relaying WTRU 204 has changed (e.g., from IC to OoC at the time the DCR message is sent by the originating WTRU 202 and received by the relaying WTRU 204, and the DCR includes parameters for network assistance). A WTRU originating from 202 can transmit a new DCR message with the correct security parameters (e.g., without network assistance), unless there is a preference associated with the RSC. Petition 870250087603, dated 09 / 26 / 2025, p. 40 / 66 30 / 35

[092] After the DCR message, the PC5 link and security between the source WTRU 202 and the relay WTRU 204 can be established as defined in various 3GPP wireless standards.

[093] If discovery is integrated into the establishment of a PC5 link (i.e., without standalone discovery), an originating WTRU can know the status of a relay WTRU and, if the originating WTRU includes incorrect security parameters in the DCR message, the relay WTRU can send a DCReject message with a cause code indicating the coverage status of the relay WTRU and / or an indication of whether network-assisted or non-network-assisted security parameters are expected. Based on the cause code and / or RSC flag, the originating WTRU can transmit a new DCR message that includes appropriate parameters for the same relay.

[094] Figure 3 illustrates an example of a state detection procedure for a relay WTRU without autonomous discovery.

[095] In 310, the source WTRU 302, the relay WTRU 304, and the destination WTRU 306 can be provided with one or more RSCs that include a network assistance security indicator that indicates whether a network assistance security procedure should be used or a non-network assistance security procedure should be used. The source WTRU 302, the relay WTRU 304, and the destination WTRU 306 can be provided with the security materials to support IC and OoC scenarios.

[096] In 312, the originating WTRU 302 can transmit, to the relaying WTRU 304, a first DCR message. The first DCR message can be based on an RSC with a safety indicator with or without a network assistance indicator (for example, using parameters for network assistance, such as SUCI).

[097] In 314, the 304 relay WTRU may determine to proceed with Petition 870250087603, dated 09 / 26 / 2025, page 41 / 66 31 / 35 the next steps for establishing security based on its coverage status and an RSC network assistance support configuration. For example, if the received security parameter is compatible with the relay WTRU's coverage status and the relay's RSC configuration (e.g., the RSC supports network assistance while the relay is in coverage), then the 304 relay WTRU can proceed with conventional security establishment. Otherwise, the 304 relay WTRU can proceed according to the procedure described below.

[098] In 316, the originating WTRU 302 may receive a DCReject message from the relay WTRU 304. The DCReject message may include a cause code indicating the coverage status of the relay WTRU 304 and / or what security parameters with or without network assistance are expected (e.g., “relay status is OoC” when network assistance support is expected).

[099] In 318, the originating WTRU 302 can transmit a second DCR message using security parameters with or without network assistance, based on the DCReject message and cause code.

[0100] Alternatively, if there is more than one relay WTRU available within range of source WTRU 302, source WTRU 302, after sending an initial DCR message, may wait for a period of time before sending a new DCR message with different security parameters. For example, source WTRU 302 may start a timer called the DCR retransmission timer. While the timer is running, source WTRU 302 may receive a DCA message or a DCReject message from one or more relay WTRUs that are in IC. If source WTRU 302 receives a DCA message from a relay WTRU, source WTRU 302 may stop the timer and not send another DCR message. If Petition 870250087603, dated 09 / 26 / 2025, p. 42 / 66 32 / 35 If the source WTRU 302 receives a DCReject message from a relay WTRU, the source WTRU 302 may resend, when the timer expires, a DCR message with safety parameters based on the OoC indication from the relay WTRU.

[0101] In 320, after the second DCR message, the PC5 link and security between the source WTRU 302 and the relay WTRU 304 can be established as defined in various 3GPP wireless standards.

[0102] In one embodiment, network assistance can be used using the control plane (CP) safety procedure between the source WTRU and the relay WTRU. For example, in 316, if the procedure fails because the CP procedure is not supported by the service network, relay WTRU 304 can send a DCReject message indicating that source WTRU 302 will transmit a second DCR message to relay WTRU 304 using safety parameters not supported by the network, instead of seeking another relay.

[0103] Figure 4 illustrates an example of a security establishment procedure between a destination WTRU and a relay WTRU.

[0104] In 410, the source WTRU 402, the relay WTRU 404, and the destination WTRU 406 can be provided with one or more RSCs that include a network-assisted security indicator that indicates whether a network-assisted security procedure should be used or a non-network-assisted security procedure should be used. The source WTRU 402, the relay WTRU 404, and the destination WTRU 406 can be provided with the security materials to support CI and OoC scenarios. Alternatively, the list of RSCs can include all RSCs with a preference order and associated states (e.g., CI, OoC, or any other states).

[0105] In 412, the originating WTRU 402 and the relay WTRU 404 Petition 870250087603, dated 09 / 26 / 2025, p. 43 / 66 33 / 35 can select a security procedure (for example, both are IC and there is an indication of network assistance preference for the RSC).

[0106] In 414, relay WTRU 404 (which is in IC) can transmit a DCR message to destination WTRU 406. The DCR message can trigger an IC safety procedure selection and can include an indication that relay WTRU 404 is in coverage and / or with a network assisted or network unassisted indicator.

[0107] In 416, destination WTRU 406 can send a DCReject message in response to the DCR message from relay WTRU 404 with a cause code indicating that destination WTRU 406 can initiate a DCR. Relay WTRU 404 can start a timer for receiving the expected new DCR from destination WTRU 406.

[0108] In 418, the destination WTRU 406 can transmit a DCR message and includes the security parameters relevant to establishing network-assisted security.

[0109] In 420, after the DCR message, security between destination WTRU 406 and relay WTRU 404 can be established as described in various 3GPP wireless standards.

[0110] Figure 5 illustrates an example of a procedure for a status indication during discovery. In 502, a first WTRU can receive one or more RSCs from a network, where each of the one or more RSCs includes a network assistance security indicator. In 504, the first WTRU can select, from among one or more RSCs, a first RSC, where the selection of the first RSC is based on a first network assistance security indicator associated with the first RSC and on a network coverage state of the first WTRU. In 506, under the condition that the network coverage state of the first WTRU is out of coverage, the first WTRU can transmit, to a second WTRU, a Petition 870250087603, dated 09 / 26 / 2025, p. 44 / 66 34 / 35 discovery message. The discovery message may include the first RSC. In 508, the first WTRU may receive a DCR message from the second WTRU. The DCR message may include a second RSC, where the second RSC may be the same as the first RSC. The first WTRU may be a relay WTRU and the second WTRU may be an originating WTRU.

[0111] Figure 6 illustrates an example of a procedure for indicating status during discovery. In 602, the first WTRU can receive one or more relay service codes (RSCs) from a network, where each of the one or more RSCs includes a network assistance security indicator. In 604, the first WTRU can receive a discovery message from a second WTRU, the discovery message including a first RSC. In 606, the first WTRU can transmit a Direct Communication Request (DCR) message to the second WTRU, the DCR message including the first RSC and security parameters, where the security parameters are based on the network assistance security indicator. The first WTRU can be a source WTRU and the second WTRU can be a destination WTRU.

[0112] Although the resources and elements are described above in specific combinations, one skilled in the art will understand that each resource or element can be used in isolation or in any combination with the other resources and elements. Furthermore, the methods described herein can be implemented in a computer program, software, or firmware embedded in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), a register, cache memory, semiconductor memory devices, Petition 870250087603, dated 09 / 26 / 2025, pp. 45 / 66 35 / 35 magnetic media such as internal and removable hard disks, magneto-optical media and optical media such as CD-ROMs and digital versatile discs (DVDs). A processor in conjunction with software can be used to implement a radio frequency transceiver for use in a WTRU, WTRU terminal, base station, RNC or any host computer. Petition 870250087603, dated 09 / 26 / 2025, pages 46 / 66

Claims

1 / 4 CLAIMS 1. A method implemented by a first wireless receiving / transmitting unit (WTRU), CHARACTERIZED in that it comprises: receiving one or more relay service codes (RSCs), wherein each of one or more RSCs includes a network assistance security indicator; selecting, from among one or more RSCs, a first RSC, wherein the selection of the first RSC is based on: (i) a first network assistance security indicator associated with the first RSC and (ii) a network coverage state of the first WTRU; transmitting, to a second WTRU, a discovery message including the first RSC, wherein, if the network coverage state of the first WTRU is out of coverage, the first network assistance security indicator is associated with a security procedure without network assistance; and receiving, in response to the discovery message, from the second WTRU, a Direct Communication Request (DCR) message.

2. Method according to claim 1, CHARACTERIZED in that the first WTRU is a relay WTRU.

3. Method according to claim 1, CHARACTERIZED in that the second WTRU is an originating WTRU.

4. Method according to claim 1, CHARACTERIZED in that it further comprises: based on the first network assistance security indicator and the network coverage status of the first WTRU, accepting the DCR message.

5. Method according to claim 1, characterized in that the DCR message includes a second RSC.

6. Method, according to claim 1, CHARACTERIZED by the fact that Petition 870250087603, dated 09 / 26 / 2025, page 63 / 66 2 / 4, the DCR message includes security parameters for a network-assisted security procedure.

7. Method according to claim 1, CHARACTERIZED in that the DCR message includes security parameters for a network-unassisted security procedure.

8. First Wireless Receive / Transmit Unit (WTRU), CHARACTERIZED in that it comprises: a processor; and a transceiver; wherein the processor and the transceiver are configured to: receive one or more Relay Service Codes (RSCs), wherein each of one or more RSCs includes a network assistance security indicator; select, from among one or more RSCs, a first RSC, wherein the selection of the first RSC is based on: (i) a first network assistance security indicator associated with the first RSC and (ii) a network coverage state of the first WTRU; transmit, to a second WTRU, a discovery message including the first RSC, wherein, if the network coverage state of the first WTRU is out of coverage, the first network assistance security indicator is associated with a security procedure without network assistance;and receive, in response to the discovery message, from the second WTRU, a direct communication request (DCR) message.

9. First WTRU, according to claim 8, CHARACTERIZED in that the first WTRU is a relay WTRU.

10. First WTRU, according to claim 8, CHARACTERIZED by the fact that the second WTRU is a WTRU of origin. Petition 870250087603, dated 09 / 26 / 2025, pp. 64 / 66 3 / 4 11. First WTRU, according to claim 8, CHARACTERIZED in that the processor and transceiver are further configured to: based on the first network assistance security indicator and the network coverage status of the first WTRU, accept the DCR message.

12. First WTRU, according to claim 8, CHARACTERIZED in that the DCR message includes a second RSC.

13. First WTRU, according to claim 8, CHARACTERIZED in that the DCR message includes security parameters for a network-assisted security procedure.

14. First wireless reception / transmission unit (WTRU), CHARACTERIZED in that it comprises: a processor; and a transceiver; wherein the processor and the transceiver are configured to: receive, from a second WTRU, a direct communication request (DCR) message, the DCR message including a retransmission service code (RSC), wherein the RSC includes a network assistance security indicator; and transmit, to a second WTRU, based on the network assistance security indicator and a coverage status of the first WTRU, a direct communication rejection message; wherein the direct communication rejection message includes a cause code.

15. WTRU, according to claim 14, CHARACTERIZED in that the first WTRU is a relay WTRU.

16. WTRU, according to claim 14, CHARACTERIZED by the fact that the second WTRU is a WTRU of origin. Petition 870250087603, dated 09 / 26 / 2025, pp. 65 / 66 4 / 4 17. WTRU, according to claim 14, CHARACTERIZED in that the cover state of the first WTRU is in cover.

18. WTRU, according to claim 14, CHARACTERIZED by the fact that the coverage status of the first WTRU is out of coverage. Petition 870250087603, dated 09 / 26 / 2025, p. 66 / 66

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