WO2025240687A1 - Methods, architectures, apparatuses and systems for one to many communication with multihop device-to-device relay - Google Patents

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products using wireless transmit/receive unit (WTRU) configured for receiving, from a first end WTRU, a first solicitation message comprising first information indicating the first end WTRU, a group supporting one-to-many communication; sending, to a second end WTRU, a second solicitation message comprising second information indicating the relay WTRU, the group supporting one-to-many communication, a path from the first end WTRU to the relay WTRU; receiving, from the second end WTRU, a first response message comprising third information indicating the second end WTRU, the group supporting one-to-many communication, a path from the relay WTRU to the second end WTRU; and sending, to the first end WTRU, a second response message comprising fourth information indicating the third WTRU, the group supporting one-to-many communication, a path from the first end WTRU to the second end WTRU.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR ONE TO MANY COMMUNICATION WITH MULTIHOP DEVICE-TO-DEVICE RELAY

INCORPORATION BY REFERENCE

[0001] The content of the following references are incorporated by reference herein in their entirety: 3GPP TS 23.304 vl 8.2.0 (2023-06): “Proximity based Services (ProSe) in the 5G System (5GS) (Release 18)”; 3GPP TR 23.700-03 (2024-03): “Study on system enhancement for Proximity based Services (ProSe) in the 5G System (5GS) Phase 3 (Release 19)”; RFC 7181 : “The Optimized Link State Routing Protocol Version 2”; RFC 6130: “Mobile Ad Hoc Network (MANET) Neighborhood Discovery Protocol (NHDP)”; RFC 5444: “Generalized Mobile Ad Hoc Network (MANET) Packet/Message Format”.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63/648,258 filed 16 May 2024, which is incorporated herein by reference in its entirety.

BACKGROUND

[0003] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems directed to one- to-many communication, for example to methods, apparatus and systems using one-to-many group member discovery.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] 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: [0005] FIG. 1 A is a system diagram illustrating an example communications system;

[0006] 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;

[0007] 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;

[0008] 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; [0009] FIG. 2 illustrates a representative procedure for one-to-many group member discovery with model B discovery;

[0010] FIG. 3 illustrates a representative procedure for one-to-many group member discovery with model A discovery;

[0011] FIG. 4 illustrates a representative procedure for one-to-many communication traffic forwarding via device-to-device relay;

[0012] FIG. 5 is a flow chart of a method according to an exemplary embodiment; and

[0013] FIG. 6 is a flow chart of a method according to an exemplary embodiment.

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] Provided below are acronyms/abbreviations for terms and phrases commonly used in this application:

DCR/DCA Direct Connection Request/ Accept

ID Identifier

L2 ID Layer-2 Identifier (per hop)

LMR/LMA Link Modification Request/ Accept

MANET Mobile Ad hoc Networks

MPR Multi Point Relay

OLSRP Optimized Link State Routing Protocol

PCF Policy Control Function

ProSe Proximity-based Services

RSC E.g., 3GPP TS23.304, Terms and Abbreviations: Relay Service Code is used for the case of UE-to-Network Relay as well as for the case of UE-to-UE Relay. The definition for the case of UE-to-Network Relay is in TS 23.303. For the case of UE-to-UE Relay, the Relay Service Code is used to identify a connectivity service the 5G ProSe UE-to-UE Relay provides, and the authorized users the 5G ProSe UE-to-UE Relay would offer service to. RSC is assigned per application using relay service, and is used to identify the correct relay service associated to the application.

Solicitation Per 3GPP TS23.304 model B discovery, a discovery request is sent, and a

Message response message is received. The discovery request message is also referred to as solicitation message or discovery solicitation message.

U2U Relay UE-to-UE Relay

U2U RSC RSC offered by U2U Relay

User E.g., 3GPP TS23.304, Terms and Abbreviations: User Info ID is configured

Info/Information for Model A or Model B Group Member Discovery and 5G ProSe UE-to-

(ID) Network Relay Discovery either for public safety or commercial applications based on the policy of the HPLMN or via the ProSe application server that allocates it. May also be used to identify users in end-to-end for relay service.

[0016] Hereinafter, 'a' and 'an' and similar phrases are to be interpreted as 'one or more' and 'at least one'. Similarly, any term which ends with the suffix '(s)' is to be interpreted as 'one or more' and 'at least one'. The term 'may' is to be interpreted as 'may, for example'.

[0017] A symbol '/' (e.g., forward slash) may be used herein to represent 'and/or', where for example, 'A/B' may imply 'A and/or B'.

[0018] Herein, the terms “UE-to-UE relay”, “WTRU-to-WTRU relay, “device-to-device relay”, and “U2U relay” may be used interchangeably, but still consistent with the following description. [0019] Herein, the terms “UE-to-Network relay”, “WTRU-to- Network relay, “device-to- network relay”, and “U2N relay” may be used interchangeably, but still consistent with the following description.

[0020] Example Communications System

[0021] 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.

[0022] 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.

[0023] 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 industrial device 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 may be interchangeably referred to as a UE.

[0024] 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.

[0025] 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.

[0026] 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).

[0027] 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).

[0028] 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).

[0029] 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).

[0030] 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). [0031] 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.

[0032] 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 technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In 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.

[0033] 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.

[0034] 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.

[0035] 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 include multiple 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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 two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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)).

[0046] 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.

[0047] 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.

[0048] 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. [0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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. [0054] 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. [0055] In representative embodiments, the other network 112 may be a WLAN.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 in

802.1 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).

[0061] WLAN systems, which may support multiple channels, and channel bandwidths, such as

802.1 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.

[0062] 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. [0063] 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.

[0064] 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).

[0065] 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).

[0066] 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 standalone configuration, 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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. [0075] 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.

[0076] Overview

[0077] For one-to-many communication between a group of devices (‘a group’), the group ID, L2 ID for one-to-many communication and IP multicast address may be provisioned with WTRU- to-WTRU (e.g., U2U) relays.

[0078] For one-to-many communication, Discovery with model B and model A may be performed using L2 ID for one-to-many communication.

[0079] During discovery procedure, path info between End WTRUs (e.g., UEs) via WTRU-to- WTRU (e.g., U2U) relays for one-to-many communication of the group is identified.

[0080] When receiving IP multicast traffic, a WTRU-to-WTRU (e.g., U2U) relay may check whether it is received from next-hop entity based on the stored path info.

[0081] A WTRU-to-WTRU (e.g., U2U) relay may be provisioned with group information for one-to-many communication.

[0082] A WTRU-to-WTRU (e.g., U2U) relay may receive a solicitation message using L2 ID for one-to-many communication, it forwards the solicitation messages.

[0083] A WTRU-to-WTRU (e.g., U2U) relay receiving a response message as response to the solicitation message using L2 ID for one-to-many communication, may forward the response message to the sender of the solicitation messages.

[0084] A WTRU-to-WTRU (e.g., U2U) relay may store the path info between End WTRUs (e.g., UEs) for one-to-many connection of group and source L2 ID of next hop entity at the path info.

[0085] A WTRU-to-WTRU (e.g., U2U) relay may receive IP multicast packet for one-to-many connection of the group and check whether it is from the next hop entity at the path info.

[0086] Based on the path info and stored source L2 ID of next hop entity and source IP address at the received IP multicast packet, a WTRU-to-WTRU (e.g., U2U) relay may detect whether it is from the entity at the stored path info and whether it is duplicated packet which is handled before. [0087] WTRU-to-WTRU (e.g., U2U) Relay Discovery and PC5 setup

[0088] 5G Prose defined several features and procedures such as 5G ProSe Direct Discovery, 5G ProSe Direct Communication, 5G ProSe WTRU-to-Network Relay (e.g., UE-to-Network Relay), and 5G ProSe WTRU-to-WTRU Relay (e.g, UE-to-UE Relay).

[0089] 5G ProSe WTRU-to-WTRU Relay (e g., UE-to-UE Relay) enables indirect communication between two End WTRUs (e.g., UEs). For WTRU-to-WTRU Relay (e.g., UE-to- UE Relay), 5G ProSe WTRU-to-WTRU Relay (e g., UE-to-UE Relay) Discovery and 5G ProSe Communication via WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) are defined.

[0090] For 5G ProSe WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) Discovery, both Model A and Model B discovery are supported: model A uses a single discovery protocol message (Announcement); and model B uses two discovery protocol messages (Solicitation and Response). [0091] During 5G ProSe WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) Discovery, information of two End WTRUs (e.g, UEs) are shared between two End WTRUs (e.g, UEs) to identify the discoverer End WTRU (e.g, UE) and discoveree End WTRU (e.g, UE) but those information of two End WTRUs (e.g, UEs) are protected between two End WTRUs (e.g, UEs) and are transparent to WTRU-to-WTRU Relays (e.g, UE-to-UE Relays). WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) may not acquire and identify information of End WTRUs (e.g, UEs) and may not utilize these information for routing discover or other signalling message or for other purposes.

[0092] 5G ProSe Communication via WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) is possible with Layer2 WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) or Layer3 WTRU-to- WTRU Relay (e.g, UE-to-UE Relay). For Layer2 WTRU-to-WTRU Relay (e.g, UE-to-UE Relay) and Layer3 WTRU-to-WTRU Relay (e.g, UE-to-UE Relay), 5G ProSe communication setup with discovery procedures is defined. Discovery integrated into PC5 unicast link establishment procedure is defined.

[0093] With Layer2 WTRU-to-WTRU Relay (e.g, UE-to-UE Relay), an end-to-end PC5 link is established between the End WTRUs (e.g, UEs), via the Relay. PC5-S messages may then be exchanged between End WTRUs (e.g, UEs).

[0094] With Layer3 WTRU-to-WTRU Relay (e g, UE-to-UE Relay), one or more (e.g, each) End WTRU (e.g, UE) establishes a PC5 link with the Relay and the Relay forwards messages towards End WTRUs (e.g, UEs). PC5-S messages are exchanged between End WTRUs (e.g, UEs) and the Relay.

[0095] With Layer3 WTRU-to-WTRU Relay (e.g, UE-to-UE Relay), when IP based data connection is used, after PC5 link setup with Relay, one or more (e.g, each) End WTRU (e.g, UE) can be assigned an IP address by Relay which is based on DHCP mechanism or each End WTRU (e.g., UE) can assign its own IP address, which is based on link local IP address assignment mechanism, and inform to the Relay. Whether DHCP or link local IP address assignment is determined during security connection setup between end WTRU (e.g., UE) and WTRU-to- WTRU Relay (e.g., UE-to-UE Relay).

[0096] Multi-hop for WTRU-to-Network (e.g., U2N) and WTRU-to-WTRU (e.g., U2U) Relay

[0097] Proposals in 3GPP to study potential enhancements to support multi-hop for WTRU-to- Network (e.g., U2N) and WTRU-to-WTRU (e.g., U2U) relay in Rel-19 are being discussed .

[0098] Multi-hop for WTRU-to-Network (e.g., U2N) Relay is to enable a Remote WTRU (e.g., UE) to discover and communicate with a WTRU-to-Network (e.g., U2N) Relay via one or more WTRU-to-WTRU (e.g., U2U) relays. Multi-hop WTRU-to-WTRU (e.g., U2U) Relay is to enable End WTRUs (e.g., UEs) to discover and communicate with each via more than one WTRU-to- WTRU (e.g., U2U) Relay.

[0099] The multi-hop capability is deemed crucial for mission critical communications (e.g., first responders) and in general needed to enhance coverage (e.g., indoor).

[0100] ProSe One-to-Many Communication for Public Safety Use Case

[0101] Per TS23.379, for Public Safety Use Case, it is desired to support one-to-many direct communication (e.g., for supporting Off-network group calls.)

[0102] Per TS23.303, WTRU (e.g., UE) may be configured with any of the related information for one-to-many ProSe Direct Communication: (1) Application Layer Group ID: Identifies an application layer group that the WTRU (e.g., UE) belongs to; (2) ProSe Layer-2 Group ID (L2 ID); (3) ProSe Group IP multicast address; and (4) indication whether the WTRU (e.g., UE) should use IPv4 or IPv6 for that group.

[0103] A WTRU (e.g., UE) may use link local address as a source address for the Group communication.

[0104] When sending data for one-to-many ProSe Direct Communication, source L2 ID is set to the WTRU (e.g., UE) ID assigned (e.g. by PKMF) or self-selected and destination L2 ID is set to assigned ProSe L2 Group ID.

[0105] The originating WTRU (e.g., UE) sends the IP data to the IP multicast address using the ProSe Layer-2 Group ID as Destination Layer-2 ID and use its link local address as a source address for the Group communication.

[0106] As a simple solution for one-to-many communication via WTRU-to-WTRU (e.g., U2U) relays, it can be considered that WTRU-to-WTRU (e.g., U2U) relay just forwards any multicast traffic to the other End WTRUs (e.g., UEs) without any other traffic handling. [0107] But in this case, as one messages arrives to multiple WTRU-to-WTRU (e.g., U2U) relays which will forward this to others without understanding the message, messages can be easily flooded in WTRU-to-WTRU (e.g., U2U) relays network, the total communication quality in ProSe WTRU-to-WTRU (e.g., U2U) relays network will be degraded.

[0108] Therefore, there is a problem to solve for handling one-to-many communication via WTRU-to-WTRU (e g., U2U) relays.

[0109] One or more examples described herein may be used separately or in combination for the WTRU to handle one-to-many communication via multihop WTRU-to-WTRU (e.g., U2U) relays in efficient manner so that the ProSe Communication via multihop WTRU-to-WTRU (e.g., U2U) relays network is not hindered by flooded traffic.

[0110] WTRU-to-WTRU Relay (e.g., UE-to-UE Relay) Configuration and Parameter Provisioning for one-to-many communication.

[0111] When a group is defined which utilize one-to-many communication, one or more (e.g., each) WTRU (e.g., UE), which is a member of the group, may be configured with group ID, multicast IP address for IP multicast to group member, and layer2 ID, as destination L2 ID, for used for one-to-many communication.

[0112] When multihop WTRU-to-WTRU (e.g., U2U) relay is supported for the group, one or more (e.g., each) group member may be configured with RSC(s) for multihop WTRU-to-WTRU (e.g., U2U) relay(s).

[0113] When a multihop WTRU-to-WTRU (e.g., U2U) relay supports a one-to-many communication, the WTRU-to-WTRU (e.g., U2U) relay may be provisioned with the range of layer 2 IDs, as destination L2 ID, which are dedicated for one-to-many communication.

[0114] When a multihop WTRU-to-WTRU (e.g., U2U) relay supports a one-to-many communication, the WTRU-to-WTRU (e.g., U2U) relay may be provisioned with the group ID which utilizes the one-to-many communications and associated Layer 2 ID, as destination L2 ID, and IP multicast address which will be used for one-to-many communications of the group members.

[0115] One-to-Many Group member Discovery with model B discovery

[0116] For group member discovery supporting one-to-many communication, group ld may be included in the (solicitation) message.

[0117] When receiving a message (e.g., a solicitation message) comprising a group ID of a group supporting one-to-many communication, the WTRU-to-WTRU relays (e.g., U2U relays) may forward the (solicitation) messages. If WTRU-to-WTRU (e.g., U2U) relays receives response message(s) from one or multiple End WTRUs (e.g., UEs) belonging to the same group, the WTRU- to-WTRU (e.g., U2U) relay may determine (e.g., consider) if it belongs to the group communication of group ID and may store the path information for group ID. If a WTRU-to- WTRU (e.g., U2U) relay does not receive any response message for the group discovery, it may determine (e.g., consider) that it does not belong to the group communication of the group and may discard any one-to-many traffic using L2 ID for one-to-many communication or IP multicast address of the group.

[0118] A source L2 ID which is selected by End WTRU (e.g., UE) and WTRU-to-WTRU (e.g., U2U) Relays during group discovery (e.g., in a solicitation message or in a response message) may be reused for one-to-many communication for a group.

[0119] FIG. 2 illustrates an exemplary procedure for one-to-many group member discovery with model B discovery, according to an embodiment.

[0120] An End WTRU (e.g., UE) (here, End UE1 200) which is a member of Group l with group identifier (here: ‘GR _U or ‘Group 1’) may send a (solicitation) message 2.1 to discover group members of Group l. The (solicitation) message 2.1 may include User Info of End UE1

200 and the Group ID. When the End WTRU desires the discovery of group member via multihop WTRU-to-WTRU (e.g., U2U) Relay, it may include RSC in the message 2.1.

[0121] When sending the (solicitation) message 2.1, as a source L2 ID, the End WTRU (e.g., UE 200) may include a L2 ID which is selected by UE1 200 for one-to-many communication.

[0122] When sending the (solicitation) message 2.1, as a destination L2 ID, the End WTRU (e.g., UE 200) may include a L2 ID which is configured for group communication of Group l or a L2 ID which is configured for sending a discovery message per RSC as destination L2 ID.

[0123] After receiving the (solicitation) message 2.1, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the (solicitation) message, WTRU-to-WTRU (e.g., U2U) relay 1 201 may detect (determine) that the (solicitation) message is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l .

[0124] Following the receipt of (solicitation) message 2.1, U2U Relay 1 201 may send, in turn, one or more (solicitation) messages 2.2 which may include any of: RSC, User Info of End UE1, Group ID (of Group l), and path info (which includes User Info of U2U Relay 1 201).

[0125] When sending the one or more (solicitation) messages 2.2, as a source L2 ID, U2U Relay 1

201 may include a L2 ID which is selected by U2U Relay 1 201 for forwarding one-to-many communication traffic of Group l .

[0126] When sending the one or more (solicitation) messages 2.2, as a destination L2 ID, U2U Relay 1 201 may use a same destination L2 ID which is used as destination L2 ID of the message 2.1 received . [0127] WTRU-to-WTRU relays U2U Relay2 202 and U2U Relay3 205 may receive the (solicitation) message 2.2 from U2U Relay 1 201. End UE5 206 may also receive the (solicitation) message 2.2 from U2U Relay 1, as will be described further on.

[0128] After receiving the (solicitation) message 2.2, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the (solicitation) message 2.2, U2U relay3 205 may detect/determine that the solicitation message 2.2 is for discovery of member WTRUs (e.g., UE) for one-to-many communication of Group l.

[0129] U2U Relay3 205 may then, in turn, send a (solicitation) message 2.3 which may include any of: RSC, User Info of End UE1 200, Group ID (of Group l), and path info (which may include User Info of U2U Relay 1 201 and ofU2U Relay3 205).

[0130] When sending the (solicitation) message 2.3, as a source L2 ID, U2U Relay3 205 may include a L2 ID which is selected by U2U Relay3 205 for forwarding one-to-many communication traffic of Group l .

[0131] When sending the (solicitation) message 2.3, as a destination L2 ID, U2U Relay3 205 may use same destination L2 ID which is used as destination L2 ID of the message 2.2 received . [0132] After sending the (solicitation) message 2.3, U2U Relay3 205 may monitor any response message. If U2U Relay3 205 does not receive any response message (for example, the response message does not include a destination L2 ID that is the same as the source L2 ID of the (solicitation) message 2.3 or the response message does not include Group ID of Group l; or, the U2U Relay3 does not receive any response message at all), U2U Relay 3 205 may determine (e.g., consider) there is no End WTRU that belongs to the one-to-many communication of the group which is represented by the configured L2 ID for one-to-many communication or group ID in the message; here, End UE2 207 did not reply to (solicitation) message 2.3 because End UE2 207 determined from the Group ID included in the (solicitation) message 2.3 that it does not belong to a group with the Group ID included in the (solicitation) message 2.3 (End UE2 207 belongs to a different group with group ID ‘GR_2’).

[0133] After receiving the (solicitation) message 2.2, based on the destination L2 ID which is configured for group communication of Group l or based on the Group ID included in the solicitation message 2.2, U2U relay2 202 may detect/determine that the (solicitation) message 2.2 is for discovery of member WTRUs (e.g., UE) for one-to-many communication of Group l.

[0134] U2U Relay2 202 may send, in turn, a (solicitation) message 2.4 which may include any of: RSC, User Info of End UE1, Group ID (Group l), and path info (which may include User Info U2U Relay 1 201 and of U2U Relay2 202). [0135] When sending the (solicitation) message 2.4, as a source L2 ID, U2U Relay2 202 may include a L2 ID which is selected by U2U Relay2202 for forwarding one-to-many communication traffic of Group l .

[0136] When sending the (solicitation) message 2.4, as a destination L2 ID, U2U Relay2 202 may use a same destination L2 ID which is used as destination L2 ID of the message received 2.2. [0137] End UE3 203 may receive the solicitation message 2.4 from U2U Relay2 202. After receiving the (solicitation) message 2.4, based on the destination L2 ID which is configured for group communication of Group l or based on the Group ID included in the solicitation message, End UE3 203 may detect/determine that the (solicitation) message 2.4 is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l.

[0138] As End UE3 203 is a member of Group l and wants to join the one-to-many communication of Group l, it may send a response message 2.5 which may include any of: RSC, User Info of End UE1, User Info of End UE3, Group ID (of Group l), and path info (which may include User Info of U2U Relay 1 201 and of U2U Relay2 202), for example based on the (solicitation) message 2.4 received .

[0139] When sending the response message 2.5, as a source L2 ID, End UE3 203 may include a L2 ID which is selected by End UE3 203 for forwarding one-to-many communication traffic of Group l .

[0140] When sending the response message 2.5, as a destination L2 ID, End UE3 203 may use the source L2 ID in the (solicitation) message 2.4 received .

[0141] End UE4 204 may receive the (solicitation) message 2.4 from U2U Relay2 202. After receiving the (solicitation) message 2.4, for example, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the (solicitation) message, End UE4 204 may detect/determine that the (solicitation) message 2.4 is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l.

[0142] As End UE4 204 is a member of Group l and wants to join the one-to-many communication of Group l, it may send a response message 2.6 which may include any of: RSC, User Info of End UE1, User Info of End UE4, Group ID(Group l), and path info (which may include User Info of U2U Relayl and of U2U Relay2), for example based on the (solicitation) message 2.4 received .

[0143] When sending the response message 2.6, as a source L2 ID, End UE4 204 may include a L2 ID which is selected by End UE4 204 for forwarding one-to-many communication traffic of Group l .

[0144] When sending the response message 2.6, as a destination L2 ID, End UE4 204 may use the source L2 ID in the (solicitation) message 2.4 received . [0145] U2U Relay2202 may receive the response message(s) 2.5 and 2.6 from End UE(s) of the group (here, UE3 203 and UE4 204). Based on the destination L2 ID of the received response messages 2.5 and 2.6 which may be same as the source L2 ID in the solicitation message 2.4 sent or based on Group ID included in the response messages 2.5/2.6, U2U Relay2 202 may detect the response messages 2.5 and 2.6 are a response to the (solicitation) message 2.4 sent .

[0146] For one or more (e.g., each) of the response messages 2.5 and 2.6 received, U2U Relay2 202 may send a response message 2.7 to U2U Relayl 201.

[0147] For a response message 2.5 received from End UE3 203, U2U Relay2 202 may send a response message 2.7 to U2URelayl 201 which may include any of: RSC, User Info of End UE1 200, User Info of End UE3 203, Group ID(Group l), and path info (which may include User Info of U2U Relayl 201 and of U2U Relay2 202).

[0148] For a response message 2.6 received from End UE4 204, U2U Relay2 202 may send a response message 2.7 to U2U Relay 1 201 which may include RSC, User Info of End UE1 200, User Info of End UE4 204, Group ID (Group l), and path info (which may include User Info of U2U Relayl 201 and U2U Relay2 202).

[0149] When sending the response message(s) 2.7 to U2URelayl 201, as a source L2 ID, U2U Relay2 202 may include a L2 ID which is selected by U2U Relay2 202 for forwarding one-to- many communication traffic of Group l .

[0150] The selected source L2 ID may be reused for another response message in response to (solicitation) message for group discovery of Group l.

[0151] When sending the response message(s) 2.7 to U2U Relayl 201, as a destination L2 ID, U2U Relay2 202 may use the source L2 ID in the (solicitation) message 2.2 received by U2URelay2 202 .

[0152] As another embodiment, U2U Relay2 202 may send a response message 2.7 to U2URelayl 201 which may include discovery results (e.g., user info) from multiple WTRUs (e.g., UEs) that replied to the group discovery (here, UE3 203 and UE4 204).

[0153] U2U Relay2 202 may store the path information for Group l based on the discovery result (for example User Info of [End UE1, U2U Relayl, U2U Relay2, [End UE3, End UE4]] may be stored at U2U Relay2 202 as path info for Group l). If there are multiple group discoveries for the Group l, U2U Relay2 202 may update the path information for Group l based on the discovery results (based on the multiple group discoveries for Group l).

[0154] U2U Relay2 202 may use the source L2 ID used in message 2.7 as source L2 ID when forwarding traffic one-to-many communication.

[0155] End UE5 206 may receive the (solicitation) message 2.2 from U2U Relayl 201. After receiving the (solicitation) message 2.2, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the (solicitation) message 2.2, End UE5 206 may detect/determine that the (solicitation) message 2.2 is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l.

[0156] As End UE5 206 is a member of Group l and wants to join the one-to-many communication of Group l, it may send a response message 2.8 to U2U Relayl 201 which may include any of: RSC, User Info of End UE1, User Info of End UE5, Group ID(Group l), and path info (which may include User Info of U2U Relayl 201) based on the (solicitation) message 2.2 that was received .

[0157] When sending the response message 2.8, as a source L2 ID, End UE5 206 may include a L2 ID which is selected by End UE5 206 for forwarding one-to-many communication traffic of Group l .

[0158] When sending the response message 2.8, as a destination L2 ID, End UE5 206 may use the source L2 ID in the received (solicitation) message 2.2 .

[0159] U2U Relayl 201 may receive the response messages 2.8 from End UE5 206 and 2.7 from U2U Relay2 202. Based on the destination L2 ID of the received response messages 2.7 and 2.8 which is the same as the source L2 ID in the (solicitation) message 2.2 or based on Group ID included in the response messages 2.7 and 2.8, U2U Relayl 201 may detect/determine that the response messages 2.7 and 2.8 are replies to the (solicitation) messages 2.2 .

[0160] For one or more (e.g., each) response messages 2.7 and 2.8 received, U2U Relayl 201 may send a response message 2.9 to End UE1 200.

[0161] For the response message 2.8 received from End UE5 206, U2U Relayl may send a response message 2.9 to End UE1 200 which may include any of: RSC, User Info of End UE1, User Info of End UE5, Group ID (of Group l), and path info (which may include User Info of U2U Relayl 201).

[0162] For one or more (e.g., each) response messages 2.7 received from End UE3 203, End UE4 204 via U2U Relay2 202, U2U Relayl 201 may send a response message 2.9 to End UE1 200 which may include any of: RSC, User Info of End UE1, User Info of End UE3 or User Info of End UE4, Group ID(Group l), and path info (which includes User Info of U2U Relayl 201 and of U2U Relay 2 202).

[0163] When sending a response message 2.9, as a source L2 ID, U2U Relayl 201 may include a L2 ID which is selected by U2U Relayl 201 for forwarding one-to-many communication traffic of Group l .

[0164] The selected source L2 ID may be reused for another response message in response to (solicitation) message for group discovery of Group l. [0165] As another embodiment, the source L2 ID which is used in message 2.2 may be used in response message 2.9.

[0166] When sending a response message 2.9 to End UE1 200, as a destination L2 ID, U2U Relay 1 201 may use the source L2 ID in the (solicitation) message 2.1 received .

[0167] As another embodiment, U2U Relayl 201 may send a response message 2.9 to the (solicitation) message received in step 2.1 which includes user information from multiple WTRUs (e.g., UEs) that replied within the context of the group discovery (here, UE3 203, UE4 204, and UE5 206).

[0168] U2U Relayl may store the path information for Group l based on the discovery result, (for example, [[End UE1, U2U Relayl, U2U Relay2, [End UE3, End UE4]], [End UE1,U2U Relayl, End UE5]] may be stored at U2U Relayl as path info for Group l). If there are multiple group discoveries for the Group l, U2U Relay2 may update the path information for Group l based on the discovery results.

[0169] After receiving response message(s) 2.9 from U2U Relayl, End UE1 may store the information of discovered End WTRUs (e.g., UEs) (UE3, UE4, and UE5) with U2U Relayl or with path info.

[0170] One-to-Many Group member Discovery with model A discovery

[0171] For group member discovery supporting one-to-many communication, group ld may be included in the announcement message.

[0172] When receiving an announcement message with group ID supporting one-to-many communication, U2U relays may forward the announcement messages with path information which may include User Info of U2U relays.

[0173] If U2U relays receives announcement message with group ID supporting one-to-many communication, U2U relay may determine (e.g., consider) it is belonging to the group communication of group ID and may store the path information for group ID.

[0174] When receiving a message for one-to-many communication for the group, U2U relays may forward the message to the stored path.

[0175] If there is any stored End WTRU’s (e.g., UE) information for the Group ID with path info in the U2U relay, the U2U Relay may include this information in the announcement message from U2U relays. For example, [End UE1, U2U Relayl, U2U Relay2, [End UE3, End UE4]] is available in U2U Relayl, it may include [[UE1, U2U Relayl], [[End UE3, End UE4]], U2U Relay2, U2U Relayl]]. As another embodiment, it may include list of End WTRUs (e.g., UEs) (e.g., [End UE1, End UE3, End UE4]).

[0176] FIG. 3 illustrates an example embodiment of a representative procedure for one-to-many group member discovery with model A discovery. [0177] An End WTRU (e.g., UE) (here, UE1 300) which is a member of Group l may send an announcement message 3.1 for a group (here Group l). The announcement message 3.1 may include User Info of End UE1 300 and Group ID (here, Group l). When the End WTRU 300 wants to discover group members via multihop U2U Relay, it may include RSC.

[0178] When UE1 300 has discovered other End WTRUs (e.g., UEs) for the group, it may include the discovered End WTRUs (e.g., UEs) information with path info in the announcement message (for example, [[End UE3, End UE4, End UE5], U2U Relay5]).

[0179] When sending an announcement message 3.1, as a source L2 ID, the End WTRU (e.g., UE 300) may include a L2 ID which is selected by UE1 300 for one-to-many communication.

[0180] When sending an announcement message 3.1, as a destination L2 ID, the End WTRU (e.g., UE 300) may include a L2 ID which is configured for group communication of Group l or a L2 ID which is configured for sending announcement message per RSC as destination L2 ID.

[0181] Ater receiving announcement message 3.1, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the announcement message, U2U relayl 301 may detect the announcement message 3.1 is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l.

[0182] U2U Relayl 301 may send an announcement message 3.2 which may include any of: RSC, User Info of End UE1, Group ID (Group l), and path info (which may include User Info of U2U Relayl).

[0183] When sending an announcement message 3.2, as a source L2 ID, U2U Relayl 301 may include a L2 ID which is selected by U2U Relayl 301 for forwarding one-to-many communication traffic of Group l .

[0184] When sending an announcement message 3.2, as a destination L2 ID, U2U Relayl 301 may use a same destination L2 ID which is used as destination L2 ID of message 3.1 .

[0185] U2U Relayl 300 may detect/determine (e.g., may become aware) that it is involved in the one-to-many communication of the group Group l and U2U Relayl 300 may store the End UE1 information (i.e., User Info of End UE1 for Group l). If there is a stored path info for Group l, it may update the information.

[0186] When the announcement message 3.1 from End UE1 300 includes other End WTRUs (e.g., UEs) (User Info) information with path info, it may update the information.

[0187] Here, U2U Relay2 302 and End UE2 304 may receive the announcement message 3.2 from U2U Relayl 301.

[0188] When receiving an announcement message 3.2, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the announcement message 3.2, End UE2 304 may detect/determine that the announcement message 3.2 is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l and End UE2 304 may store the End UE1 (User Info) information with path info (i.e., [End UE1, U2U Relayl] for Group l).

[0189] After receiving announcement message 3.2, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the announcement message, U2U relay2 302 may detect/determine that the announcement message is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l.

[0190] U2U Relay2 302 may, in turn, send an announcement message 3.3 which may include any of: RSC, User Info of End UE1, Group ID (Group l), and path info (which may include User Info of U2U Relayl and of U2U Relay2).

[0191] When sending an announcement message 3.3, as a source L2 ID, U2U Relay2 302 may include a L2 ID which is selected by U2U Relay2302 for forwarding one-to-many communication traffic of Group l .

[0192] When sending an announcement message 3.3, as a destination L2 ID, U2U Relay2 302 may use a same destination L2 ID as the one which is used as destination L2 ID of the message 3.2 received.

[0193] U2U Relay2 302 may detect/determine (e.g., be(come) aware) that it is involved in the one-to-many communication of the group Group l and it may store the path info (i.e., [End UE1, U2U Relayl] for Group l).

[0194] Here, End UE3 303 may receive the announcement message 3.3 from U2U Relay2 302.

[0195] When receiving an announcement message 3.3, based on the destination L2 ID which is configured for group communication of Group l or based on Group ID included in the announcement message, End UE3 303 may detect the announcement message is for discovery of member WTRUs (e.g., UEs) for one-to-many communication of Group l and End UE3 303 may store the End UE1 300 (User Info) information with path info (i.e., [End UE1, U2U Relayl, U2U Relay2] for Group l).

[0196] As a result of discovery with model A, End UE2 304 and End UE3 303 may detect/determine (e.g., be(come) aware) that there is an End UE1 300 available for one-to-many communication for Group l with path info and U2U Relayl 301 and U2U Relay2 302 may detect/determine (e.g., be(come) aware) that it is involved in the one-to-many communication for Group l with path info.

[0197] One-to-Many Group member Discovery with Model A by WTRU-to-WTRU Relay (e.g., UE-to-UE Relay)

[0198] When there is End WTRU’s (e.g., UE) information for the Group ID with path info in the U2U relay, the U2U Relay may send an announcement message for Group ID with path information. The announcement message from U2U relay may include RSC, Group ID, and path info.

[0199] For example, [End UE1, U2U Relay 1, U2U Relay2, [End UE3, End UE4]] is available in U2U Relayl, it may include [[UE1, U2U Relayl], [[End UE3, End UE4]], U2U Relay2, U2U Relay 1]] as path info in the announcement message from U2U relayl for group discovery of Group ID.

[0200] As another embodiment, it may include a list of End WTRUs (e.g., UEs) (e.g., [End UE1, End UE3, End UE4]) without path info (i.e. without other U2U Relays info).

[0201] One-to-Many Communication Traffic Forwarding via WTRU-to-WTRU Relay (e.g., UE-to-UE Relay)

[0202] After successful discovery of End WTRUs (e.g., UEs) for one-to-many communication of a group, End WTRU (e.g., UE) may send a multicast (i.e., one-to-many) traffic using the source L2 ID which is used as source L2 ID during discovery procedure by End WTRU (e.g., UE) and destination L2 ID which is provisioned for one-to-many communication of the group.

[0203] When receiving multicast traffic for the group (identified based on the destination L2 ID), U2U relay may check whether it is from an End WTRU (e.g., UE) or an U2U Relay which are identified as an WTRU (e.g., UE) at the next hop of the U2U relay during the discovery procedure based on path info (for example, [End UE1, U2U Relayl, U2U Relay2, [End UE3, End UE4]] shows that End UE1 is not at next hop of U2U Relay2 but U2U Relayl, End UE3 and End UE4 is at next hop of U2U Relay2). It is determined by checking source L2 of the packet whether the traffic is from an End WTRU (e.g., UE) or an U2U Relay.

[0204] If the traffic is not from an End WTRU (e.g., UE) or an U2U Relay at the next hop, it may be discarded.

[0205] When an IP packet for one-to-many communication is received, the U2U Relay may check whether there is any mapping between the source IP Address of the IP packet and an source L2 ID of an End WTRU (e.g., UE) or an U2U Relay. If there is no mapping, the U2U relay may map the source IP Address is from the source L2 ID of an End WTRU (e.g., UE) or an U2U Relay which is indicated at the received IP packet. If there is a mapping between source IP Address and an source L2 ID of an End WTRU (e.g., UE) or an U2U Relay, it may check the source L2 ID of the received IP packet is the same as the one at the (stored) mapping. If it is different from the stored mapping, it may be discarded (as it may be a duplicated packet from other U2U relay while forwarding).

[0206] FIG. 4 illustrates an embodiment of a procedure for one-to-many communication traffic forwarding via device-to-device (e.g., WTRU to WTRU) relays. [0207] When End UE1 400 sends a multicast IP packet 4.1, it may use a source IP address (e.g., based on link local address or self-selected address) and use an assigned multicast IP address as a destination IP address. The source L2 ID of the IP packet is based on the source L2 ID of End UE1 which is used during discovery procedure. The destination L2 ID of the IP packet is based on the configured L2 ID for one-to-many communication.

[0208] When receiving an IP packet 4.1, U2U Relay 1 401 may check whether the destination L2 ID is the configured L2 ID for one-to-many communication and whether the source L2 ID is the one of End WTRU (e.g., UE) or U2U Relay at the next hop of U2U Relay 1 401 based on path info acquired during the discovery procedure for one-to-many communication of the group.

[0209] Based on the received source L2 ID, it is identified as that of End UE1 400 based on the stored path info.

[0210] When there is no mapping between source IP address of the received IP packet and source L2 ID, U2U relay 1 401 may make a mapping between source IP address and source L2 ID (here is source L2 ID of End UE1 400).

[0211] U2U Relayl 401 may forward the received IP packet 4. 1 after checking L2 ID and mapping between source L2 ID and source IP address. When forwarding the received IP packet 4.1, source L2 ID of the forwarded IP packet 4. 2 is based on the source L2 ID of U2U Relayl 401 which is used during the discovery procedure. The destination L2 ID of IP packet 4.2 is based on the configured L2 ID for one-to-many communication.

[0212] U2U Relay2 402, U2U Relay3 405, and End UE5 406 received the IP packet 4.2 from U2U Relayl 401.

[0213] When End UE1 400 receives an IP packet 4.2 from U2U Relayl 401, End UE1 400 discards the received IP packet 4.2 as it has same source IP address as the one of End UE1 400.

[0214] U2U Relay3 405 may discard the multicast IP packet 4.2 based on the destination L2 ID, as it is identified that the U2U Relay3 405 is not involved for one-to-many communication of the group during discovery procedure (for example, it did not receive/does not receive any response of the solicitation message for the group, including no response from End UE2 407 that belongs to another group with group ID ‘GR_2’).

[0215] U2U Relay2 402 may check whether IP packet 4.2 is received from U2U Relayl 401 which is at next hop from U2U Relay2 402.

[0216] U2U Relay2 402 may check the mapping between source IP address of the received IP packet 4.2 and source L2 ID. If there is no mapping, U2U Relay2 402 may make a mapping between source IP address (here, it is selected by End UE1) and source L2 ID (here, it is selected by U2U Relayl 401). [0217] U2U Relay2 402 may forward the received IP packet 4.2 after checking L2 ID and mapping between source L2 ID and source IP address. When forwarding the received IP packet 4.2, the source L2 ID of the forwarded IP packet 4.3 may be based on the source L2 ID of U2U Relay2 402 which is used during the discovery procedure. The destination L2 ID of the IP packet 4.3 may be based on the configured L2 ID for one-to-many communication.

[0218] As the forwarded IP packet 4.3 from U2U Relay2 402 may be based on destination L2 ID for multicast. U2U Relayl 401 may also receive IP packet 4.3 from U2U Relay2 402 (e.g., which is identified based on source L2 ID) and may check the mapping between source IP address and source L2 ID. U2U Relay 1 401 may find that the source IP address is already mapped to source L2 ID of End UE1 400 and the received packet is from the different source L2 ID, and may therefore discard it.

[0219] FIG. 5 is a flowchart illustrating an embodiment of a method 500, implemented by a relay WTRU such as U2U Relayl 201.

[0220] Referring to FIG. 5, the method 500 may include, at block 510, receiving, from a first end WTRU, a first solicitation message comprising first information indicating the first end WTRU, a group supporting one-to-many communication.

[0221] At block 520, the representative method 500 may include sending, to a second end WTRU, a second solicitation message comprising second information indicating the relay WTRU, the group supporting one-to-many communication, a path from the first end WTRU to the relay WTRU.

[0222] At block 530, the representative method 500 may include receiving, from the second end WTRU, a first response message comprising third information indicating the second end WTRU, the group supporting one-to-many communication, a path from the relay WTRU to the second end WTRU.

[0223] At block 540, the representative method 500 may include sending, to the first end WTRU, a second response message comprising fourth information indicating the third WTRU, the group supporting one-to-many communication, a path from the first end WTRU to the second end WTRU.

[0224] According to certain embodiments, sending the second response message may be based on the group ID.

[0225] According to certain embodiments, the first solicitation message and/or the first response message comprise information indicating a layer-2 ID and sending the second response message may be based on the layer-2 ID.

[0226] According to certain embodiments, the first response message may be received via a second relay WTRU. According to certain embodiments, the representative method 500 may include any of the following steps: receiving, from the first end WTRU, an IP packet; sending, to the second end WTRU, the IP packet based on IP address associated with the IP packet, and a layer-2 ID associated with the second end WTRU.

[0227] FIG. 6 is a flow chart of a method 600 implemented by a first relay wireless transmit/receive unit, WTRU (201). The method may comprise:

[0228] Receiving (610), from a first WTRU (200), a first message (2.1) for discovery of members of a group of WTRUs supporting one-to-many communication, the first message (2.1) comprising user information of the first WTRU (200), and a group identifier of the group of WTRUs;

[0229] Following receipt of the first message (2.1), sending (620), to a second relay WTRU (202), a second message (2.2) comprising the user information of the first WTRU (200), the group identifier, and first path information;

[0230] Receiving (630), from the second relay WTRU (202), in reply to the second message (2.2), a first response message (2.7) comprising the user information of the first WTRU (200), user information of at least a second WTRU (203, 204) associated with the group identifier, the group identifier, and second path information; and

[0231] Sending (640), to the first WTRU (200), subsequently to receiving the reply to the second message (2.2) from the second relay WTRU (202) and in reply to the first message, a second response message (2.9) comprising the user information of the first WTRU (200), the user information of the at least a second WTRU (203, 204), the group identifier, and the second path information.

[0232] According to an embodiment, the first path information may comprise user information of the first relay WTRU, and the second path information may comprise user information of the first relay WTRU and of the second relay WTRU.

[0233] According to an embodiment, the user information of the first WTRU may comprise a source L2 identifier selected by the first WTRU for one-to-many communication.

[0234] According to an embodiment, the user information of the first WTRU may comprise a destination L2 identifier configured for group communication.

[0235] According to an embodiment, the first relay WTRU, after having received the first message from the first WTRU, may determine from the destination L2 identifier configured for group communication that the first message is for discovery of members of the group of WTRUs identified by the destination L2 identifier comprised in the first message.

[0236] According to an embodiment, the first relay WTRU may include, in the second message, a source L2 identifier selected by the first relay WTRU for forwarding one-to-many communication traffic of the group identified by the group identifier comprised in the first message.

[0237] According to an embodiment, the first relay WTRU may include, in the second message, the destination L2 identifier configured for group communication that is comprised in the user information of the first WTRU which is comprised in the first message.

[0238] There is also disclosed and described a first relay wireless transmit/receive unit, WTRU (201). The first relay WTRU comprises at least one processor, which may be configured to: [0239] Receive (610), from a first WTRU (200), a first message (2.1) for discovery of members of a group of WTRUs supporting one-to-many communication, the first message (2.1) comprising user information of the first WTRU (200), and a group identifier of the group of WTRUs;

[0240] Following receipt of the first message (2.1), send (620), to a second relay WTRU (202), a second message (2.2) comprising the user information of the first WTRU (200), the group identifier, and first path information;

[0241] Receive (630), from the second relay WTRU (202), in reply to the second message (2.2), a first response message (2.7) comprising the user information of the first WTRU (200), user information of at least a second WTRU (203, 204) associated with the group identifier, the group identifier, and second path information; and

[0242] Send (640), to the first WTRU (200), subsequently to receiving the reply to the second message (2.2) from the second relay WTRU (202) and in reply to the first message (2.1), a second response message (2.9) comprising the user information of the first WTRU (200), the user information of the at least a second WTRU (203, 204), the group identifier, and the second path information.

[0243] According to an embodiment, the first path information may comprise user information of the first relay WTRU, and the second path information may comprise user information of the first relay WTRU and of the second relay WTRU.

[0244] According to an embodiment, the user information of the first WTRU may comprise a source L2 identifier selected by the first WTRU for one-to-many communication.

[0245] According to an embodiment, the user information of the first WTRU may comprise a destination L2 identifier configured for group communication.

[0246] According to an embodiment, the at least one processor is configured, after having received the first message from the first WTRU, to determine from the destination L2 identifier configured for group communication that the first message is for discovery of members of the group of WTRUs identified by the destination L2 identifier comprised in the first message.

[0247] According to an embodiment, the at least one processor is configured to include, in the second message, a source L2 identifier selected by the at least one processor for forwarding one- to-many communication traffic of the group identified by the group identifier comprised in the first message.

[0248] According to an embodiment, the at least one processor is configured to include, in the second message, the destination L2 identifier configured for group communication that is comprised in the user information of the first WTRU which is comprised in the first message.

[0249] 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, or instruction 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.

[0250] 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. [0251] 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 and functionality 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.

[0252] 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.

[0253] 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.

[0254] 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."

[0255] 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 electrical system 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.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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 be understood 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.).

[0260] 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 utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems.

[0261] 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.

[0262] 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.

[0263] 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 includes the 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".

[0264] 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.

[0265] 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 as sufficiently 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.

[0266] 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.

Claims

CLAIMS What is claimed is:

1. A method implemented by a first relay wireless transmit/receive unit, WTRU (201), the method comprising: receiving (610), from a first WTRU (200), a first message (2.1) for discovery of members of a group of WTRUs supporting one-to-many communication, the first message (2.1) comprising user information of the first WTRU (200), and a group identifier of the group of WTRUs; following receipt of the first message (2.1), sending (620), to a second relay WTRU (202), a second message (2.2) comprising the user information of the first WTRU (200), the group identifier, and first path information; receiving (630), from the second relay WTRU (202), in reply to the second message (2.2), a first response message (2.7) comprising the user information of the first WTRU (200), user information of at least a second WTRU (203, 204) associated with the group identifier, the group identifier, and second path information; and sending (640), to the first WTRU (200), subsequently to receiving the reply to the second message (2.2) from the second relay WTRU (202) and in reply to the first message, a second response message (2.9) comprising the user information of the first WTRU (200), the user information of the at least a second WTRU (203, 204), the group identifier, and the second path information.

2. The method of claim 1, wherein the first path information comprises user information of the first relay WTRU, and wherein the second path information comprises user information of the first relay WTRU and of the second relay WTRU.

3. The method of claim 1 or 2, wherein the user information of the first WTRU comprises a source L2 identifier selected by the first WTRU for one-to-many communication.

4. The method of any of claims 1 to 3, wherein the user information of the first WTRU comprises a destination L2 identifier configured for group communication.

5. The method of claim 4, further comprising: after having received the first message from the first WTRU, determining from the destination L2 identifier configured for group communication that the first message is for discovery of members of the group of WTRUs identified by the destination L2 identifier comprised in the first message.

6. The method of any of claims 1 to 5, wherein the first relay WTRU includes, in the second message, a source L2 identifier selected by the first relay WTRU for forwarding one-to-many communication traffic of the group identified by the group identifier comprised in the first message.

7. The method of any of claims 1 to 6, wherein the first relay WTRU includes, in the second message, the destination L2 identifier configured for group communication that is comprised in the user information of the first WTRU which is comprised in the first message.

8. A first relay wireless transmit/receive unit, WTRU (201), comprising a transceiver and at least one processor which are configured to: receive (610), from a first WTRU (200), a first message (2.1) for discovery of members of a group of WTRUs supporting one-to-many communication, the first message (2.1) comprising user information of the first WTRU (200), and a group identifier of the group of WTRUs, following receipt of the first message (2.1), send (620), to a second relay WTRU (202), a second message (2.2) comprising the user information of the first WTRU (200), the group identifier, and first path information, receive (630), from the second relay WTRU (202), in reply to the second message (2.2), a first response message (2.7) comprising the user information of the first WTRU (200), user information of at least a second WTRU (203, 204) associated with the group identifier, the group identifier, and second path information, and send (640), to the first WTRU (200), subsequently to receiving the reply to the second message (2.2) from the second relay WTRU (202) and in reply to the first message (2.1), a second response message (2.9) comprising the user information of the first WTRU (200), the user information of the at least a second WTRU (203, 204), the group identifier, and the second path information.

9. The first relay WTRU of claim 8, wherein the first path information comprises user information of the first relay WTRU, and wherein the second path information comprises user information of the first relay WTRU and of the second relay WTRU.

10. The first relay WTRU of claim 8 or 9, wherein the user information of the first WTRU comprises a source L2 identifier selected by the first WTRU for one-to-many communication.

11. The first relay WTRU of any of claims 8 to 10, wherein the user information of the first WTRU comprises a destination L2 identifier configured for group communication.

12. The first relay WTRU of claim 11 , wherein the transceiver and the at least one processor are configured to: after having received the first message from the first WTRU, determine from the destination L2 identifier configured for group communication that the first message is for discovery of members of the group of WTRUs identified by the destination L2 identifier comprised in the first message.

13. The first relay WTRU of any of claims 8 to 12, wherein the second message includes a source L2 identifier selected by the first relay WTRU for forwarding one-to-many communication traffic of the group identified by the group identifier comprised in the first message.

14. The first relay WTRU of any of claims 8 to 13, wherein the second message includes the destination L2 identifier configured for group communication that is comprised in the user information of the first WTRU which is comprised in the first message.