Methods, architectures, apparatuses and systems for user equipment (UE)-to-UE relay discovery with mobile ad HOC network

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products user equipment (UE)-to-UE relay discovery in a mobile ad hoc network (MANET) are described. One method may include a WTRU-to WTRU relay joining a mobile ad hoc network based on a configured relay service code (RSC), receiving a first relay solicitation message from a first WTRU to discover a second WTRU, sending a second relay solicitation message to one or more WTRUs in proximity of the WTRU-to-WTRU relay, sending, to other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay, information associated with the first relay solicitation message, receiving a first relay response message from the second WTRU, and sending a second relay response message to the first WTRU.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR USER EQUIPMENT (UE)-TO-UE RELAY DISCOVERY WITH MOBILE AD HOC NETWORKCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 574,440, filed April 4, 2024. The contents of this earlier filed application is incorporated herein by reference in its entirety.FIELD

[0002] Example embodiments described in the present disclosure are generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems related to user equipment (UE)-to-UE relay discovery.BACKGROUND

[0003] 5G new radio (NR) proximity services (ProSe) enables communication between user equipment or devices in a certain proximity. 5G ProSe defined several features and / or procedures such as 5G ProSe Direct Discovery, 5G ProSe Direct Communication, 5G ProSe UE-to-Network Relay, and 5G ProSe UE-to-UE Relay.SUMMARY

[0004] An embodiment may be directed to a wireless transmit / receive unit (WTRU), which may be or may be acting as a WTRU-to-WTRU relay. The WTRU may include circuitry, including any of a processor and transceiver. The WTRU and / or circuitry may be configured to receive configuration information indicating a relay service code (RSC) associated with a mobile ad hoc networkjoin or connect to the mobile ad hoc network based on the relay service code (RSC), and receive, from a first WTRU, a first relay solicitation message to discover a second WTRU. The first relay solicitation message comprises any of user information associated with the first WTRU, user information associated with the second WTRU, and the relay service code (RSC). The WTRU-to-WTRU relay is selected as a flooding multi-point relay (MPR). The WTRU and / or circuitry may be configured to send a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and / or other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay. The second relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network and any of user informationassociated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, and / or the relay service code (RSC). The WTRU and / or circuitry may be configured to receive a first relay response message comprising any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC). The WTRU and / or circuitry may be configured to send a second relay response message to the first WTRU. The second relay response message comprises any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0005] An embodiment may be directed to a method implemented by a wireless transmit / receive unit (WTRU) that may be or may be acting as a WTRU-to-WTRU relay. The method may include receiving configuration information indicating a relay service code (RSC) associated with a mobile ad hoc network, joining or connecting to the mobile ad hoc network based on the relay service code (RSC), and receiving, from a first WTRU, a first relay solicitation message to discover a second WTRU. The first relay solicitation message comprises any of user information associated with the first WTRU, user information associated with the second WTRU, and the relay service code (RSC). The WTRU-to-WTRU relay may be selected as a flooding multi-point relay (MPR). The method includes sending a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and / or other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay. The second relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network and any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, and / or the relay service code (RSC). The method includes receiving a first relay response message comprising any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC). The method includes sending a second relay response message to the first WTRU. The second relay response message comprises any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay,user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein:

[0007] FIG. 1 A is a system diagram illustrating an example communications system;

[0008] FIG. IB is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0009] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0010] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;

[0011] FIG. 2 is a signaling diagram of a process for UE-to-UE relay discovery, according to some embodiments;

[0012] FIG. 3 is a signaling diagram of a process for UE-to-UE relay discovery, according to some embodiments; and

[0013] FIG. 4 illustrates an example flow diagram of a method, according to some embodiments.DETAILED DESCRIPTION

[0014] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and / or inherently (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which an apparatus, system, device, etc.and / or any element thereof carries out an operation, process, algorithm, function, etc. and / or any portion thereof, it is to be understood that any embodiments described and / or claimed herein assume that any apparatus, system, device, etc. and / or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and / or any portion thereof.

[0015] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and / or be adapted and / or configured for the methods, apparatuses and systems provided herein.

[0016] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications 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), singlecarrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0017] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and / or a "STA", may be configured to transmit and / or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, 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 (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrialdevice and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d, or any other WTRU mentioned or described herein, may be interchangeably referred to as a UE.

[0018] The communications 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, e.g., to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0019] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical 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 the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0020] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0021] More specifically, as noted above, the 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, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed Uplink Packet Access (HSUPA).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE- Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0024] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized 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).

[0025] In an embodiment, the base station 114a and the 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 IX, 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.

[0026] The base station 114b in FIG. 1 A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technologysuch as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any of a small cell, picocell or femtocell. As shown in FIG. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0027] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1 A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing an NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0028] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 114 or a different RAT.

[0029] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may includemultiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0030] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other elements / peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0031] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip.

[0032] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0033] Although the transmit / receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit / receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include twoor more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0034] The transceiver 120 may be configured to modulate the signals that are 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, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0035] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), readonly memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0036] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0037] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0038] The processor 118 may further be coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functionality and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., 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. The elements / peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0039] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0040] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0041] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an 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 receive wireless signals from, the WTRU 102a.

[0042] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0043] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and / or operated by an entity other than the CN operator.

[0044] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0045] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0046] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0047] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0048] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0049] In representative embodiments, the other network 112 may be a WLAN.

[0050] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802. l ie DLS or an 802.1 Iz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0051] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0052] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0053] Very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse fast fourier transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above-described operation for the 80+80 configuration may be reversed, and the combined data may be sent to a medium access control (MAC) layer, entity, etc.

[0054] Sub 1 GHz modes of operation are supported by 802.1 laf and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those used in802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment,802.1 lah may support meter type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0055] WLAN systems, which may support multiple channels, and channel bandwidths, such as802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may 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 set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 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 sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP,the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0056] In the United States, the available frequency bands, which may be used by 802.1 lah, 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 802.1 lah is 6 MHz to 26 MHz depending on the country code.

[0057] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0058] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0059] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0060] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non- standalone configuration. In the standaloneconfiguration, WTRUs 102a, 102b, 102c may 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 may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non- standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to 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 may 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 the non- standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0061] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0062] The CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0063] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency(URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0064] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP -based, non-IP based, Ethernet-based, and the like.

[0065] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0066] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0067] In view of FIGs. 1 A-1D, and the corresponding description of FIGs. 1 A-1D, one or more, or all, of the functions described herein with regard to any of: WTRUs 102a-d, base stations 114a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and / or any other element(s) / device(s) described herein, may be performed by one or more emulation elements / devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein.For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0068] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0069] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0070] Embodiments disclosed herein are representative and do not limit the applicability of the apparatus, procedures, functions and / or methods to any particular wireless technology, any particular communication technology and / or other technologies. The term network in this disclosure may generally refer to one or more base stations or gNBs or other network entity which in turn may be associated with one or more Transmission / Reception Points (TRPs), or to any other node in the radio access network.

[0071] It is noted that, throughout example embodiments described herein, the terms “base station”, “seving base station”, “RAN,” “RAN node,” “Access Network,” “NG-RAN,” “gNodeB,” and / or “gNB” may be used interchangeably to designate any network element such as, e.g., a network element acting as a serving base station. It should be understood that embodiments described herein are not limited to gNBs and are applicable to any other types of base stations.

[0072] 5G proximity services (ProSe) define several features and procedures such as 5G ProSe Direct Discovery, 5G ProSe Direct Communication, 5G ProSe UE-to-Network Relay, and 5G ProSe UE-to-UE Relay.

[0073] 5G ProSe UE-to-UE Relay enables indirect communication between two End UEs. As such, a 5G ProSe UE-to-UE Relay may refer to a 5G ProSe enabled UE that provides functionality to support connectivity between 5G ProSe End UEs. It is noted that an End UE may refer to a 5G ProSe enabled UE that can connect with another 5G ProSe enabled UE(s) via a 5G ProSe UE-to- UE relay. For UE-to-UE Relay, 5G ProSe UE-to-UE Relay Discovery and 5G ProSe Communication via UE-to-UE Relay are defined.

[0074] For 5G ProSe UE-to-UE Relay Discovery, both Model A and Model B discovery are supported. Model Auses a single discovery protocol message (Announcement). Model B uses two discovery protocol messages (Solicitation and Response).

[0075] During 5G ProSe UE-to-UE Relay Discovery, information of two End UEs is shared between two End UEs to identify the discoverer End UE and the discoveree End UE, but the information of the two End UEs is protected between the two End UEs and is transparent to UE- to-UE Relays. Therefore, UE-to-UE Relay cannot acquire and identify information of End UEs and cannot utilize this information for routing discovery or for other signaling message or for other purposes.

[0076] 5G ProSe Communication via UE-to-UE Relay is possible with Layer2 UE-to-UE Relay or Layer3 UE-to-UE Relay. For Layer2 UE-to-UE Relay and Layer3 UE-to-UE Relay, 5G ProSe communication setup with discovery procedures is defined. Also, discovery integrated into PC5 unicast link establishment procedure is defined.

[0077] With Layer2 UE-to-UE Relay, an end-to-end PC5 link is established between the End UEs, via the Relay. PC5-S messages may then be exchanged between End UEs.

[0078] With Layer3 UE-to-UE Relay, each End UE establishes a PC5 link with the Relay and the Relay forwards messages towards End UEs. PC5-S messages are exchanged between End UEs and the Relay.

[0079] With Layer3 UE-to-UE Relay, when internet protocol (IP) based data connection is used, after PC5 link setup with Relay, each End UE can be assigned an IP address by Relay which is based on dynamic host configuration protocol (DHCP) mechanism or each End UE can assign its own IP address, which is based on link local IP address assignment mechanism, and inform it to the Relay. Whether to use DHCP or link local IP address assignment may be determined during security connection setup between end UE and UE-to-UE Relay.

[0080] Proposals in 3GPP to study potential enhancements to support multi-hop for UE-to- Network (U2N) and UE-to-UE (U2U) relay in Rel-19 are being discussed (e.g., See 3GPP TR 23.700-03 v0.2.0 Study on system enhancement for Proximity based Services (ProSe) in the 5GSystem (5GS); Phase 3 (Release 19)). Multi-hop for U2N Relay is to enable a Remote UE to discover and communicate with a U2N Relay via one or more U2U relays. Multi-hop U2U Relay is to enable End UEs to discover and communicate with each via more than one U2U Relay. The multi-hop capability may be important for mission critical communications (e.g., first responders) and in general needed to enhance coverage (e.g., indoor).

[0081] IETF developed technology for supporting mobile ad hoc network (MANET). Each router in MANET can discover other routers by exchanging HELLO messages and each router can determine its 1-hop and 2-hop neighbors based on the exchanged HELLO messages (e.g., See RFC 6130, Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)). Each router may store the list of its 1-hop and 2-hop neighbors so that MANET routing protocol may utilize the information.

[0082] MANET routing is based on Optimized Link State Routing (OLSR) Protocol (e.g., See RFC 7181, The Optimized Link State Routing Protocol Version 2). Each router exchanges their topology information with other routers in the network regularly. Each router may select two sets of multi-point relays (MPRs), each being a set of its neighbor routers that cover all of its connected 2-hop neighbor routers. These two sets are “flooding MPRs” and “routing MPRs”, which are used to achieve flooding reduction and topology reduction, respectively. Flooding reduction is achieved by control traffic being flooded through the network using hop-by-hop forwarding, but with a router only needing to forward control traffic that is first received directly from one of the routers that have selected it as a flooding MPR. Topology reduction is achieved by assigning a special responsibility to routers selected as routing MPRs when declaring link state information. Routers are not selected as routing MPRs need not send any link state information.

[0083] In order to support multi-hop ProSe UE-to-UE relays, a relay (e.g., each relay) supporting multi-hop ProSe UE-to-UE relay functionality may form a collocated MANET router functionality that connect with neighboring MANET routers and establish a mobile ad-hoc network as defined in MANET (e.g., See RFC 5444, Generalized Mobile Ad Hoc Network (MANET) Packet / Message Format). 5G ProSe communication can be used for communication between two UE-to-UE relays acting as MANET routers and all MANET messages exchanged between UE-to-UE relays may be considered as data traffic over PC5 user plane interface.

[0084] Supporting discovery and PC5 connection setup between two End UEs via one or more UE-to-UE relays is the main functionality of multihop UE-to-UE relay. Therefore, it desirable that multihop UE-to-UE relay with MANET also supports the discovery and PC5 connection setup between two End UEs via UE-to-UE relay with MANET. Furthermore, the security level achievedby 5G ProSe UE-to-UE Relay should be maintained at multihop UE-to-UE Relay including multihop UE-to-UE relay with MANET.

[0085] Therefore, it would be desirable to address at least the following issues while remaining compatible with UE-to-UE relay security requirement: how an End UE can discover another End UE(s) in MANET based UE-to-UE relay network, and / or how a UE-to-UE relay in MANET can forward signaling messages from an End UE to another End. As such, some example embodiments described herein may address at least the issues noted above, in addition to addressing other problems not explicitly noted above.

[0086] As will be discussed in more detail below, some example embodiments may be directed to UE-to-UE (U2U) relay discovery using MANET topology. In an embodiment, a U2U relay may be configured with a relay service code (RSC) for MANET (e.g., may receive configuration information indicating the RSC for MANET) and may join the MANET based U2U relay networks based on the RSC. After joining MANET, the U2U relay may share (or provide) routing information in MANET to ProSe layer, e.g., so that the U2U relay discovery and PC5 connection setup procedure may utilize the routing information to forward the message to the proper U2U relay. According to an embodiment, the U2U relay may update user information of U2U relay as discoverer End UE’s first hop relay with its own user information when sending a U2U relay solicitation message, e.g., so that the discoverer End UE and discoveree End UE may identify routing information (i.e., user information of discoverer End UE’s first hop relay and user information of discoveree End UE’s first hop relay). When (e.g., only when) MANET_forwarding_indication is included in U2U relay solicitation message, the U2U relay may decide to utilize the received U2U relay solicitation message to send a U2U relay solicitation message to the End UE in proximity. When sending a U2U relay solicitation message, the U2U relay supporting flooding MPR may include the MANET forwarding indication in the U2U relay solicitation message to be sent, e.g., so that the U2U relay at the next hop of flooding MPR can utilize the U2U relay solicitation message from the U2U relay supporting flooding MPR.

[0087] As will be discussed in more detail below, some example embodiments may be directed to UE-to-UE (U2U) relay discovery with dedicated signalling message(s) for exchanging discovery information between U2U relays. In an embodiment, a U2U relay may be configured with RSC for MANET and may join the MANET based U2U Relay networks based on the RSC. The U2U relay may update user information of U2U relay as discoverer End UE’s first hop relay with its own user information when sending a U2U relay solicitation message, e.g., so that discoverer End UE and discoveree End UE may identify routing information (i.e., user info ofdiscoverer End UE’s first hop relay and user info of discoveree End UE’s first hop relay). One or multiple signalling messages may be sent to U2U relays to share (or provide) information associated with a solicitation message (e.g., the information may include RSC, user information of discoverer End UE, user information of discoveree End UE, or the like) which is sent from an End UE and user information of U2U relay as discoverer End UE’s first hop relay, if the sending U2U relay is the U2U relay which received a U2U relay solicitation message from the discoverer End UE or a U2U relay working as flooding MPR. When receiving signalling messages including the information associated with the solicitation message, which is sent from an End UE, the U2U relay may send a U2U relay solicitation message to be received (or intended to be received) by End UEs in proximity.

[0088] As introduced above, some example embodiments may relate to or include UE-to-UE relay discovery using MANET topology information. For example, an embodiment may include UE-to-UE relay discovery with model B using a solicitation and response message between discoverer End UE and discoveree End UE via multihop UE-to-UE relays which form MANET based UE-to-UE Relay networks.

[0089] In certain embodiments, it may be assumed that UE-to-UE relays that support MANET router capability and support one or more common Relay Service Codes (RSCs) can form MANET based UE-to-UE relay networks and can store routing information for traffic exchange with other UE-to-UE relays in the same MANET.

[0090] In another example, RSC for MANET based U2U relay networks may be preconfigured or configured during parameter provisioning after registration and authorization of UE-to-UE relay having MANET functionality.

[0091] When U2U relays receive RSC for MANET based U2U relay, the U2U relays may try to discover other U2U relays supporting the same RSC and may setup PC5 connection(s) with the discovered U2U relay, e.g., so that a U2U relay may try to join MANET based U2U relay network.

[0092] Routing information may include information about how a U2U relay can connect to another U2U relay via other U2U relays, which is derived based on the information exchanged via MANET technology.

[0093] After joining a MANET, when routing information is available in the MANET, the routing information may be shared or otherwise provided. For example, the routing information may be shared at ProSe layer so that 5G ProSe UE-to-UE discovery procedures and PC5 connection setup procedures may utilize the routing information to forward the message to the proper U2U relay.

[0094] In an embodiment, an End UE may send a U2U relay solicitation message to discover another End UE with (e.g., indicating) RSC supporting multihop U2U relay service. When (or after) receiving a U2U relay solicitation message from an End UE, a U2U relay may send a U2U relay solicitation message to be received by the End UEs in proximity and other U2U relays. The U2U relay solicitation message from the U2U relay may include or indicate user information of the U2U relay (as discoverer End UE’s first hop relay) and MANET_forwarding_indication to indicate that other U2U relay may forward this message to the End UEs in proximity.

[0095] In an embodiment, the U2U relay solicitation message from the U2U relay may include or indicate user information of the U2U relay as discoverer End UE’s first hop relay and also as discoveree End UE’s first hop relay.

[0096] In an embodiment, after receiving a U2U relay solicitation message with MANET_forwarding_indication, the receiving U2U relay may send a U2U relay solicitation message to be (or intended to be) received by the End UEs in proximity (of the receiving U2U relay). If the received U2U relay solicitation message does not include user information of a U2U relay (as discoveree End UE’s first hop relay), the sending U2U relay’s user information (as discoveree End UE’s first hop relay) may be added, appended or otherwise included or indicated in the message. If the received U2U relay solicitation message includes user information of a U2U relay (as discoveree End UE’s first hop relay), the sending U2U relay may change or replace the user information to / with its own user Information (as discoveree End UE’s first hop relay) in the message. If a U2U relay receives a U2U relay solicitation message without MANET forwarding indication, it may discard the received message as it is intended to be received by End UE not by U2U relay. If a U2U relay, which works as flooding MPR at MANET, receives a U2U relay solicitation message with a MANET_forwarding_indication, it may send a U2U relay solicitation message with the MANET_forwarding_indication which is to be received by the End UEs in proximity and other U2U relay(s) at the next hop.

[0097] In an embodiment, if a discoveree End UE receives a U2U relay solicitation message with or without a MANET_forwarding_indication, it may send a response message to the U2U relay based on the user information of the U2U relay as discoveree End UE’s first hop relay UE.

[0098] According to an embodiment, when receiving response message from discoveree end UE, the U2U relay may send a response message to the next-hop U2U relay based on the user information of the U2U relay (as discoverer End UE’s first hop relay) and routing information to the U2U relay (as discoverer End UE’s first hop relay).

[0099] FIG. 2 illustrates an example signaling diagram of a procedure for UE-to-UE relay discovery with MANET forwarding indication, according to an embodiment. In the example of FIG. 2, at step 200a, End UEs and U2U Relays are authorized to use multihop U2U relay service and may be provisioned with parameters to be used for discovery and / or selection of End UE via U2U relay and setup PC5 connection(s) via multihop U2U relays. At step 200b, U2U relays that are capable of MANET router functionality may join the MANET based U2U relay networks. By exchanging information with other MANET routers, a U2U relay (e.g., each U2U relay) may store routing information for communication with other U2U relays capable of MANET router functionality in the same MANET based U2U relay networks. At step 200c, a U2U relay (e.g., each U2U relay) may share routing information in MANET based U2U relay networks at ProSe layer, e.g., so that it is available to be used during ProSe U2U relay discovery and PC5 connection setup procedure.

[0100] In the example of FIG. 2, at step 201, S-End UE (e.g., source End UE or discoverer End UE) may send a U2U relay solicitation message to discover another End UE. The U2U relay solicitation message may include user information of S-End UE, user information of T-End UE (e.g., target End UE or discoveree End UE) and / or RSC supporting multihop U2U relay service.

[0101] As illustrated in the example of FIG. 2, at step 202, when a U2U Relay (U2U Relay l in the example of FIG. 2) receives a U2U Relay Solicitation message from S-End UE, the U2U Relay may send a U2U Relay Solicitation message for End UE(s) in proximity and other U2U Relays in 1-hop connection based on the routing information (here, U2U Relay _2, U2U Relay _3). The U2U Relay Solicitation message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, RSC and / or MANET forwarding indication.

[0102] In the example of FIG. 2, at step 203 a, when a U2U Relay (U2U Relay _2 in the example of FIG. 2) receives a U2U Relay Solicitation message from U2U Relay_l, the U2U Relay may send a U2U Relay Solicitation message for End UE in proximity. The U2U Relay Solicitation message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _2, and / or RSC. In this example, the Solicitation message does not include MANET forwarding indication because U2U Relay _2 is not selected as flooding MPR by U2U Relay l and the solicitation message is for (e.g., only for) End UEs in proximity but not for other U2U relays.

[0103] As shown in the example of FIG. 2, at step 203b, when a U2U Relay (U2U Relay _3 in the example of FIG. 2) receives a U2U Relay Solicitation message from U2U Relay l, the U2U Relay may send a U2U Relay Solicitation message for End UE in proximity and other U2U relays in 1-hop connection. The U2U Relay Solicitation message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _3, RSC, and / or MANET forwarding indication. In this example, the Solicitation message includes MANET_forwarding_indication because U2U Relay _3 is selected as flooding MPR by U2U Relay l and the solicitation message is for End UEs in proximity and for other U2U relays within 1-hop connection.

[0104] In the example of FIG. 2, at step 204, when a U2U Relay (U2U Relay _4 in the example of FIG. 2) receives a U2U Relay Solicitation message, including MANET forwarding indication, from U2U Relay _3, the U2U Relay may send a U2U Relay Solicitation message for End UE in proximity. The U2U Relay Solicitation message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC. In this example, the solicitation message does not include MANET forwarding indication because U2U Relay _4 is not selected as flooding MPR by U2U Relay _3 and the solicitation message is for (e.g., only for) End UEs in proximity but not for other U2U relays.

[0105] In an embodiment, when U2U Relay (e.g., U2U Relay_l, U2U Relay _2, U2U Relay _3, U2U Relay _4 in the example of FIG. 2) receives U2U relay solicitation message without MANET_forwarding_indication from other U2U relay, the U2U Relay may discard the received message as it is intended to be received by End UE not by U2U relay.

[0106] In the example of FIG. 2, at step 205, when T-End UE receives U2U relay solicitation messages via U2U relays which is to discover T-End UE from S-End UE, the T-End UE may select a U2U relay among U2U relays which sent U2U relay solicitation messages from S-End UE (e.g., T-End UE selected U2U Relay _4 in the example of FIG. 2), for example, based on link quality of received messages, etc. In an embodiment, T-End UE may send a U2U relay response message, to the selected U2U relay (e.g., U2U Relay _4 in the example of FIG. 2), which may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC.

[0107] As shown in the example of FIG. 2, at step 206, when receiving a U2U relay response message from T-End UE, U2U Relay _4 may send a response message to the U2U relay l based on routing information to connect between U2U Relay _4 and U2U Relay l . The response message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC.

[0108] In the example of FIG. 2, at step 207, when receiving a U2U relay response message from T-End UE via other U2U relay, U2U Relay l may send a response message to S-End UE. The response message may include user information of S-End UE (e.g., source End UE or discoverer End UE), user information of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC. After receiving a U2U relay response message, the S-End UE may store user information of U2U Relay l, user information of U2U Relay _4 with user information of T-End U,E which indicates the proper (e.g., the appropriate) U2U relays in the path to communicate with T-End UE via U2U relays.

[0109] As introduced above, some example embodiments may be directed to or include UE-to- UE relay discover with dedicated signalling message(s) for exchanging discovery information between UE-to-UE relays. For example, an embodiment may relate to UE-to-UE relay discovery with model B using a solicitation and response message between discoverer End UE and discoveree End UE via multihop UE-to-UE Relays including sharing information for solicitation message between UE-to-UE Relays.

[0110] In certain embodiments, it may be assumed that UE-to-UE Relays which support MANET router capability and support the same RSC can form MANET based UE-to-UE Relay networks and can store routing information for traffic exchange with other UE-to-UE Relays at the same MANET. Routing information may include information on how a U2U relay can connect to another U2U relay via other U2U relays, which is derived based on the information exchanged via MANET technology.[OHl] In an embodiment, End UE may send a U2U relay solicitation message to discover another End UE with RSC supporting multihop U2U relay service.

[0112] According to an embodiment, when receiving (or after receiving) a U2U relay solicitation message from an End UE, a U2U relay may forward or send U2U relay solicitation message including or indicating user information of the U2U relay (as discoverer End UE’s first hop relay) to End UEs in proximity. The U2U relay may send message(s) including information relating to the solicitation message to the other U2U relays in 1-hop connection.

[0113] In an embodiment, when receiving (or after receiving) the information of solicitation message from a U2U relay, the receiving U2U relay may send U2U relay solicitation message which includes user information of discoverer End UE, user information of discoveree End UE, user information of the U2U relay (as discoverer End UE’ s first hop relay), and its user information (as discoveree End UE’s first hop relay) to End UEs in proximity.

[0114] According to an embodiment, if a U2U relay, which works as flooding MPR at MANET, receives the information of solicitation message from a U2U relay, it may send message(s) including the information of solicitation message to the other U2U relays within 1-hop connection.

[0115] In an embodiment, if Discoveree End UE receives a U2U relay solicitation message from a U2U relay, it may send a Response message to the U2U relay based on the user information of the U2U relay as discoveree End UE’s first hop relay.

[0116] According to an embodiment, when receiving (or after receiving) a response message from the discoveree end UE, the U2U relay may send a response message to the U2U relay based on the user information of the U2U relay (as discoverer End UE’s first hop relay) by utilizing routing information.

[0117] FIG. 3 illustrates an example signaling diagram of a procedure for UE-to-UE Relay discovery with MANET message, according to some example embodiments. In the example of FIG. 3, at 300a, End UEs and U2U Relays are authorized to use multihop U2U reay service and may be provisioned with parameters to be used for discovery and / or selection of End UE via U2U relay and setup PC5 connect! on(s) via multihop U2U relays. At 300b, U2U relays that are capable of MANET router functionality may join the MANET based U2U relay networks. By exchanging information with other MANET routers, U2U relays (e.g., each U2U relay) may store routing information for communication with other U2U relays capable of MANET router functionality in the same MANET based U2U relay networks.

[0118] As shown in the example of FIG. 3, at 301, S-End UE (e.g., source End UE or discoverer End UE) may send a U2U relay solicitation message to discover another End UE. The U2U relay solicitation message may include user information of S-End UE, user information of T-End UE (e.g., target End UE or discoveree End UE) and / or RSC supporting multihop U2U relay service.

[0119] In the example of FIG. 3, at 302, when a U2U Relay (U2U Relay l in the example of FIG. 3) receives a U2U Relay Solicitation message from S-End UE, it may send a U2U Relay Solicitation message for End UE(s) in proximity. The U2U Relay Solicitation message may include user information of S-End UE (e.g., source End UE or discoverer End UE), userinformation of T-End UE (e.g., target End UE or discoveree End UE), user information of U2U Relay l and / or RSC.

[0120] As illustrated in the example of FIG. 3, at 303, U2U Relay l may send a message (e.g., new MANET message) to U2U relays at 1-hop connection (e.g., U2U Relay _2, U2U Relay _3 in FIG. 3) for sharing information for the solicitation message from S-End UE. The message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l and / or RSC.

[0121] In the example of FIG. 3, at 304a, when a U2U Relay (e.g., U2U Relay _2) receives a signalling message from U2U Relay l for sharing the information for the solicitation message from End UE, it may send a U2U Relay Solicitation message for End UE(s) in proximity. The U2U Relay Solicitation message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _2, and / or RSC.

[0122] As illustrated in the example of FIG. 3, at 304b, when a U2U Relay (e.g., U2U Relay _3) receives (or after it receives) a signalling message from U2U Relay l for sharing information solicitation message from End UE, it may send a U2U Relay Solicitation message for End UE(s) in proximity. The U2U Relay Solicitation message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _3, and / or RSC.

[0123] In the example of FIG. 3, at 305, as U2U Relay _3 is selected as flooding MPR by U2U Relay_l, U2U Relay _3 may forward the message (e.g., MANET message) from U2U Relay_l for sharing information of solicitation message from end UE to the other U2U relays within 1-hop connection. The signalling message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l and / or RSC.

[0124] As illustrated in the example of FIG. 3, at 306, when a U2U Relay (e.g., U2U Relay _4) receives a signalling message from U2U Relay _3 for sharing information of the solicitation message from End UE, it may send a U2U Relay Solicitation message for End UE in proximity. The U2U Relay Solicitation message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC.

[0125] In the example of FIG. 3, at 307, when T-End UE receives U2U relay solicitation messages via U2U relays which is to discover T-End UE from S-End UE, it may select a U2U relay among U2U relays which sent U2U relay solicitation messages from S-End UE (e.g., T-End UE selected U2U Relay _4 in the example of FIG. 3), for example, based on link quality of received message, etc. T-End UE may send a U2U relay response message to the selected U2U relay (e.g., U2U Relay _4) which includes user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay_l, user information of U2U Relay _4, and / or RSC.

[0126] As illustrated in the example of FIG. 3, at 308, when receiving a U2U relay response message from T-End UE, U2U Relay _4 may send a response message to the U2U relay l based on routing information to connect between U2U Relay _4 and U2U Relay l . The response message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay l, user information of U2U Relay _4, and / or RSC.

[0127] In the example of FIG. 3, at 309, when receiving (or after receiving) a U2U relay response message from T-End UE via other U2U relay, U2U Relay l may send a response message to S- End UE. The response message may include user information of S-End UE (source End UE or discoverer End UE), user information of T-End UE (target End UE or discoveree End UE), user information of U2U Relay_l, user information of U2U Relay _4, and / or RSC. After receiving U2U relay response message, S-End UE may store user information of U2U Relay l, user information of U2U Relay _4 with user information of T-End UE, which indicates proper U2U relays in the path to communicate with T-End UE via U2U relays.

[0128] Some example embodiments may relate to or include U2U relay discovery with model A for sharing End UEs in proximity. In an embodiment, a U2U relay may send an announcement message with (e.g., indicating or including) a list of direct discovery set including user information of End UEs based on the received information from other U2U relays. According to an embodiment, when including the list of direct discovery set received from other U2U relay, the user information of the U2U relay may be included to indicate the End UEs in the direct discovery set are in proximity of the U2U relay. In an embodiment, when receiving an announcement message from U2U relay, a source End UE may store the U2U relay information together with the list of direct discovery set. According to an embodiment, when sending a direct communication request (DCR) to the target End UE, the U2U relay may include the user information of the U2U relays as received in the announcement message or response message for model B discovery.

[0129] Some example embodiments may relate to or include an initial connection setup procedure with MANET based U2U relay network. In an embodiment, when S-End UE sends a DCR message for communication with T-End UE, it may include user information of a first U2U Relay (as U2U relay at discoverer UE, e.g., U2U Relay l in FIG. 3) and user information of a second U2U Relay (as U2U relay at discoveree UE, e.g., U2U Relay _4 in FIG. 3) which are used to route the DCR message to T-End UE via U2U relays. According to an embodiment, when receiving a DCR message from S-End UE, U2U Relay l may forward the DCR to U2U Relay _4 based on routing information. In an embodiment, when T-End UE sends a direct communication accept (DC A) message as a response to the DCR from S-End UE, it may include user information of U2U Relay l and user information of U2U Relay _4, which can be used to route DC A message to S-End UE via U2U relays. According to an embodiment, when receiving a DCA message from T-End UE, U2U Relay _4 may forward the DCA to U2U Relay l based on routing information.

[0130] FIG. 4 illustrates an example flow diagram of a method 400 for or relating to relay discovery in a mobile ad hoc network (MANET), according to some embodiments. The example method 400 of FIG. 4 and accompanying disclosures herein may include, may be based on, or may be a synthesization of various embodiments or elements discussed in detail above.

[0131] For convenience and simplicity of exposition, the example of FIG. 4 may be described with reference to the architecture or system described above with respect to FIGs. 1A-1D, for instance. However, the example method 400 depicted in FIG. 4 may be carried out using different architectures as well. According to some embodiments, the method 400 of FIG. 4 may be performed or implemented by a UE or WTRU, such as the WTRU 102 described in the foregoing or a WTRU (i.e., U2U relay) illustrated in the examples of FIGs. 2-3.

[0132] It is noted that the method 400 of FIG. 4 may include further steps, procedures or details as discussed in detail elsewhere in this disclosure. As such, the method 400 of FIG. 4 may be modified to include any of the steps, procedures, elements and / or details illustrated and / or discussed in the foregoing or the following. For example, additional details regarding the information, parameters, messages, signaling, configurations, etc. described in FIG. 4 have been discussed in detail above.

[0133] Moreover, it is noted that the method and / or blocks of FIG. 4 may be modified to include, or to be replaced by, any one or more of the procedures, elements or blocks discussed elsewhere herein. As such, one of ordinary skill in the art would understand that FIG. 4 is provided as one example and modifications thereto are possible while remaining within the scope of certain example embodiments.

[0134] As illustrated in the example of FIG. 4, the method 400 may include, at 410, receiving configuration information indicating a relay service code (RSC) associated with a mobile ad hoc network. At 420, the method 400 may include joining or connecting to the mobile ad hoc network based on the relay service code (RSC). The method 400 may include, at 430, receiving, from a first WTRU, a first relay solicitation message to discover a second WTRU. The first relay solicitation message may include any one or more of user information associated with the first WTRU, user information associated with the second WTRU, and / or the relay service code (RSC). In certain embodiments, the WTRU-to-WTRU relay performing the method 400 may be selected as a flooding multi-point relay (MPR).

[0135] In the example of FIG. 4, the method may include, at 440, sending a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and / or other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay. The second relay solicitation message may include a forwarding indication associated with the mobile ad hoc network and any one or more of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to- WTRU relay, and / or the relay service code (RSC).

[0136] As illustrated in the example of FIG. 4, the method 400 may include, at 450, receiving a first relay response message. The first relay response message may include any one or more of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0137] In the example of FIG. 4, the method 400 may include, at 460, sending a second relay response message to the first WTRU. The second relay response message may include any one or more of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0138] In an embodiment, if the first relay solicitation message does not include user information associated with another WTRU-to-WTRU relay, the method 400 may include adding the user information associated with the WTRU-to-WTRU relay to the second relay solicitation message.

[0139] In an embodiment, if the first relay solicitation message includes user information associated with another WTRU-to-WTRU relay, the method may include replacing the userinformation associated with the another WTRU-to-WTRU relay with the user information associated with the WTRU-to-WTRU relay in the second relay solicitation message.

[0140] In an embodiment, if the WTRU-to-WTRU relay is a flooding multi-point relay (MPR), the first relay solicitation message may include a forwarding indication associated with the mobile ad hoc network to indicate that the WTRU-to-WTRU relay is to send the second relay solicitation message to any one or more of the WTRUs in proximity of the WTRU-to-WTRU relay and / or other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay.

[0141] In an embodiment, if the first relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network, the forwarding indication associated with the mobile ad hoc network may be included in the second relay solicitation message.

[0142] In an embodiment, if the first relay solicitation message does not include a forwarding indication associated with the mobile ad hoc network, the method 400 may include discarding the first relay solicitation message.

[0143] In an embodiment, the method 400 may include providing routing information associated with the WTRU-to-WTRU relay in the mobile ad hoc network. The routing information may include information indicating how other WTRU-to-WTRU relays can connect to the WTRU-to- WTRU relay.

[0144] In an embodiment, the first WTRU may be a source WTRU, discoverer WTRU, or another WTRU-to-WTRU relay. In an embodiment, the second WTRU may be a target WTRU, discoveree WTRU, or discovered WTRU.

[0145] Certain example embodiments may include a method of relay discovery using MANET topology information, which may be implemented in a wireless transmit / receive unit (WTRU)-to- WTRU relay. In some embodiments, the method may include one or more of the steps performed by or associated with a UE-to-UE relay as discussed elsewhere herein, such as described in or illustrated with respect to FIG. 2 and / or FIG. 3. For example, the WTRU-to-WTRU relay implementing the method may be or may include one or more of U2U Relay l, U2U Relay _2, U2U Relay _3, and / or U2U Relay _4. It should also be understood that one or more of the steps of the method may be optional, may be omitted, and / or may be performed in a different order.

[0146] In an embodiment, the method may include receiving configuration information indicating a relay service code (RSC) associated with a mobile ad hoc network (MANET), and joining the MANET based on the relay service code (RSC). The method may include receiving, from a first WTRU, a first relay solicitation message to discover a second WTRU. The first relay solicitation message may include or indicate any of user information associated with the firstWTRU, user information associated with the second WTRU, and / or the relay service code (RSC). In some examples, the first WTRU may be a source WTRU, discoverer WTRU, or another WTRU- to-WTRU relay. In some examples, the second WTRU may be a target WTRU, discoveree WTRU, or discovered WTRU.

[0147] In an embodiment, the method may include sending a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and / or other WTRU-to- WTRU relays that are, for example, within one hop (or next hop) of the WTRU-to-WTRU relay. The second relay solicitation message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay(s), and / or the relay service code (RSC).

[0148] In an embodiment, the method may include receiving a first relay response message including or indicating any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0149] In an embodiment, the method may include sending a second relay response message to the first WTRU. For example, the second relay response message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0150] In an embodiment, on condition that the first relay solicitation message does not include user information associated with another WTRU-to-WTRU relay, the method may include adding (or otherwise including, indicating or incorporating) the user information associated with the WTRU-to-WTRU relay to the second relay solicitation message.

[0151] In an embodiment, on condition that the first relay solicitation message includes user information associated with another WTRU-to-WTRU relay (e.g., a second, third, and / or fourth WTRU-to-WTRU relay), the method may include replacing the user information associated with the another WTRU-to-WTRU relay with the user information associated with the WTRU-to- WTRU relay in the second relay solicitation message.

[0152] In an embodiment, the first relay solicitation message may further include or indicate a forwarding indication associated with the mobile ad hoc network (e.g.,MANET forwarding indication), on condition that the WTRU-to-WTRU relay is selected as a flooding multi-point relay (MPR).

[0153] In an embodiment, on condition that the first relay solicitation message includes or indicates the forwarding indication associated with the mobile ad hoc network (e.g., MANET forwarding indication), the method may include incorporating or including the forwarding indication associated with the mobile ad hoc network in the second relay solicitation message.

[0154] In an embodiment, on condition that the first relay solicitation message does not include a forwarding indication associated with the mobile ad hoc network (e.g., MANET forwarding indication), the method may include discarding the first relay solicitation message.

[0155] In an embodiment, the method may include providing routing information associated with the WTRU-to-WTRU relay in / to the mobile ad hoc network (e.g., sharing the routing information associated with the WTRU-to-WTRU relay with other WTRUs associated with the MANET). For example, the routing information may include or indicate information indicating how other WTRU-to-WTRU relays can connect to the WTRU-to-WTRU relay.

[0156] Certain example embodiments may include a method of relay discovery with dedicated signalling messages for exchanging discovery information between WTRU-to-WTRU relays, which may be implemented in a wireless transmit / receive unit (WTRU)-to-WTRU relay. In some embodiments, the method may include one or more of the steps performed by or associated with a UE-to-UE relay as discussed elsewhere herein, such as described in or illustrated with respect to FIG. 2 and / or FIG. 3. For example, the WTRU-to-WTRU relay implementing the method may be or may include one or more of U2U Relay_l, U2U Relay _2, U2U Relay _3, and / or U2U Relay _4. It should also be understood that one or more of the steps of the method may be optional, may be omitted, and / or may be performed in a different order.

[0157] In an embodiment, the method may include joining a mobile ad hoc network (MANET) based on a configured relay service code (RSC). According to certain embodiments, the WTRU- to-WTRU relay may be a flooding multi-point relay (MPR).

[0158] In an embodiment, the method may include receiving, from a first WTRU, first information indicating a first relay solicitation message to discover a second WTRU. In some examples, the first relay solicitation message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, and / or the relay service code (RSC). In some examples, the first WTRU may be a source WTRU, discovererWTRU, or another WTRU-to-WTRU relay. In some examples, the second WTRU may be a target WTRU, discoveree WTRU, or discovered WTRU.

[0159] In an embodiment, the method may include sending second information indicating a second relay solicitation message to one or more WTRUs in proximity of the WTRU-to-WTRU relay. According to some examples, the second relay solicitation message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, and / or the relay service code (RSC).

[0160] In an embodiment, the method may include sending, to other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay, third information indicating information associated with the first relay solicitation message. According to some examples, the third information may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to- WTRU relay, and / or the relay service code (RSC).

[0161] In an embodiment, the method may include receiving, based on the user information associated with the WTRU-to-WTRU relay, a first relay response message from the second WTRU. According to some examples, the first relay response message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with at least one WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0162] In an embodiment, the method may include sending a second relay response message to the first WTRU. According to some examples, the second relay response message may include or indicate any of user information associated with the first WTRU, user information associated with the second WTRU, user information associated with the WTRU-to-WTRU relay, user information associated with at least one WTRU-to-WTRU relay from which the relay response message is received, and / or the relay service code (RSC).

[0163] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, orinstruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0164] In some example embodiments described herein, (e.g., configuration) information may be described as received by a WTRU from the network, for example, through system information or via any kind of protocol message. Although not explicitly mentioned throughout embodiments described herein, the same (e.g., configuration) information may be pre-configured in the WTRU (e.g., via any kind of pre-configuration methods such as e.g., via factory settings), such that this (e.g., configuration) information may be used by the WTRU without being received from the network.

[0165] Any characteristic, variant or embodiment described for a method is compatible with an apparatus device comprising means for processing the disclosed method, such as with a device comprising a processor configured to process the disclosed method, a computer program product comprising program code instructions and a non-transitory computer-readable storage medium storing program instructions.

[0166] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of infrared capable devices, i.e., infrared emitters and receivers. However, the embodiments discussed are not limited to these systems but may be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0167] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, single image and / or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE", the term "remote" and / or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and / or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and / or wired-capable device configured with less than all structures andfunctionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1 A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0168] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated 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, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0169] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage.

[0170] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed."

[0171] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electricalsystem represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

[0172] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0173] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0174] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and / or systems and / or other technologies described herein may be effected (e.g., hardware, software, and / or firmware), and the preferred vehicle may vary with the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and / or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and / or firmware.

[0175] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, it will beunderstood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples may be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and / or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

[0176] Those skilled in the art will recognize that it is common within the art to describe devices and / or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and / or control systems including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system may be implemented utilizingany suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0177] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0178] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity.

[0179] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and / or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includesthe introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of' followed by a listing of a plurality of items and / or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and / or "any combination of multiples of the items and / or the categories of items, individually or in conjunction with other items and / or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0180] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0181] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized assufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[0182] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

[0183] Although various embodiments have been described in terms of communication systems, it is contemplated that the systems may be implemented in software on microprocessors / general purpose computers (not shown). In certain embodiments, one or more of the functions of the various components may be implemented in software that controls a general-purpose computer.

[0184] In addition, although some example embodiments are illustrated and described herein, the invention is not intended to just be limited to the details shown. Rather, various modifications and variations may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit or scope invention.

Claims

CLAIMSWhat is claimed is:

1. A method, implemented in a wireless transmit / receive unit (WTRU)-to-WTRU relay, the method comprising: receiving configuration information indicating a relay service code (RSC) associated with a mobile ad hoc network; connecting to the mobile ad hoc network based on the relay service code (RSC); receiving, from a first WTRU, a first relay solicitation message to discover a second WTRU, wherein the first relay solicitation message comprises any of first user information associated with the first WTRU, second user information associated with the second WTRU, and the relay service code (RSC), wherein the WTRU-to-WTRU relay is selected as a flooding multi-point relay (MPR); sending a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay, wherein the second relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network and any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, third user information associated with the WTRU-to-WTRU relay, and the relay service code (RSC); receiving a first relay response message comprising any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, the third user information associated with the WTRU-to-WTRU relay, fourth user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and the relay service code (RSC); and sending a second relay response message to the first WTRU, wherein the second relay response message comprises any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, the third user information associated with the WTRU-to-WTRU relay, the fourth user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and the relay service code (RSC).

2. The method of claim 1, wherein, on condition that the first relay solicitation message does not include user information associated with another WTRU-to-WTRU relay, the method comprises adding the third user information associated with the WTRU-to-WTRU relay to the second relay solicitation message.

3. The method of claim 1, wherein, on condition that the first relay solicitation message includes user information associated with another WTRU-to-WTRU relay, the method comprises replacing the user information associated with the another WTRU-to-WTRU relay with the third user information associated with the WTRU-to-WTRU relay in the second relay solicitation message.

4. The method of any of claims 1-3, wherein, on condition that the WTRU-to-WTRU relay is a flooding multi-point relay (MPR), the first relay solicitation message further comprises a forwarding indication associated with the mobile ad hoc network to indicate that the WTRU-to- WTRU relay is to send the second relay solicitation message to any of the WTRUs in proximity of the WTRU-to-WTRU relay and other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay.

5. The method of any of claims 1-4, wherein, on condition that the first relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network, the method comprises including the forwarding indication associated with the mobile ad hoc network in the second relay solicitation message.

6. The method of any of claims 1-4, wherein, on condition that the first relay solicitation message does not include a forwarding indication associated with the mobile ad hoc network, the method comprises discarding the first relay solicitation message.

7. The method of any of claims 1-6, comprising providing routing information associated with the WTRU-to-WTRU relay in the mobile ad hoc network.

8. The method of claim 7, wherein the routing information comprises information indicating how other WTRU-to-WTRU relays can connect to the WTRU-to-WTRU relay.

9. The method of any of claims 1-8, wherein the first WTRU comprises a source WTRU, discoverer WTRU, or another WTRU-to-WTRU relay, and wherein the second WTRU comprises a target WTRU, discoveree WTRU, or discovered WTRU.

10. A wireless transmit / receive unit (WTRU)-to-WTRU relay, comprising: circuitry, including any of a processor, memory, transmitter and receiver, the circuitry configured to receive configuration information indicating a relay service code (RSC) associated with a mobile ad hoc network; connect to the mobile ad hoc network based on the relay service code (RSC); receive, from a first WTRU, a first relay solicitation message to discover a second WTRU, wherein the first relay solicitation message comprises any of first user information associated with the first WTRU, second user information associated with the second WTRU, and the relay service code (RSC), wherein the WTRU-to-WTRU relay is selected as a flooding multi-point relay (MPR); send a second relay solicitation message intended for any of WTRUs in proximity of the WTRU-to-WTRU relay and other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay, wherein the second relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network and any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, third user information associated with the WTRU-to-WTRU relay, and the relay service code (RSC); receive a first relay response message comprising any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, the third user information associated with the WTRU-to-WTRU relay, fourth user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and the relay service code (RSC); and send a second relay response message to the first WTRU, wherein the second relay response message comprises any of the first user information associated with the first WTRU, the second user information associated with the second WTRU, the third user information associated with the WTRU-to-WTRU relay, the fourth user information associated with a WTRU-to-WTRU relay from which the relay response message is received, and the relay service code (RSC).

11. The WTRU of claim 10, configured to, on condition that the first relay solicitation message does not include user information associated with another WTRU-to-WTRU relay, add the third user information associated with the WTRU-to-WTRU relay to the second relay solicitation message.

12. The WTRU of claim 10, configured to, on condition that the first relay solicitation message includes user information associated with another WTRU-to-WTRU relay, replace the user information associated with the another WTRU-to-WTRU relay with the third user information associated with the WTRU-to-WTRU relay in the second relay solicitation message.

13. The WTRU of any of claims 10-12, wherein, on condition that the WTRU-to-WTRU relay is a flooding multi-point relay (MPR), the first relay solicitation message further comprises a forwarding indication associated with the mobile ad hoc network to indicate that the WTRU-to- WTRU relay is to send the second relay solicitation message to any of the WTRUs in proximity of the WTRU-to-WTRU relay and other WTRU-to-WTRU relays that are within one hop of the WTRU-to-WTRU relay.

14. The WTRU of any of claims 10-13, configured to, on condition that the first relay solicitation message comprises a forwarding indication associated with the mobile ad hoc network, include the forwarding indication associated with the mobile ad hoc network in the second relay solicitation message.

15. The WTRU of any of claims 10-13, configured to, on condition that the first relay solicitation message does not include a forwarding indication associated with the mobile ad hoc network, discard the first relay solicitation message.

16. The WTRU of any of claims 10-15, configured to provide routing information associated with the WTRU-to-WTRU relay in the mobile ad hoc network.

17. The WTRU of claim 16, wherein the routing information comprises information indicating how other WTRU-to-WTRU relays can connect to the WTRU-to-WTRU relay.

18. The WTRU of any of claims 10-17, wherein the first WTRU comprises a source WTRU, discoverer WTRU, or another WTRU-to-WTRU relay, and wherein the second WTRU comprises a target WTRU, discoveree WTRU, or discovered WTRU.

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