Methods, architectures, apparatuses and systems for WTRU-to-network relay discovery and selection in multi-hop connection

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products comprising a first device to device relay wireless transmit / receive unit (WTRU), wherein the first device to device relay WTRU is configured for a multi-hop communication between a remote WTRU and a device to network relay WTRU, the first device to device relay WTRU being configured for receiving, from any of: (1) the device to network relay WTRU, (2) a second device to device relay WTRU, and (3) the remote WTRU, a first relay discovery message; determining a cumulative propagation delay associated with the multi-hop communication; and broadcasting, based on the first relay discovery message, a second relay discovery message comprising information indicating the cumulative propagation delay.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR WTRU-TO- NETWORK RELAY DISCOVERY AND SELECTION IN MULTI-HOP CONNECTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 615,341 filed December 28, 2023, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems directed to network relay and computing, for example to methods, apparatus and systems using quantum communications and computing to perform network relay link setup in multi-hop connection.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] 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:

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

[0005] 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;

[0006] 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;

[0007] 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;

[0008] FIG. 2 illustrates an architecture model using a proximity services (ProSe) WTRU-to- network (e.g., UE-to-network) relay;

[0009] FIG. 3 is a diagram illustrating a ProSe WTRU-to-network (e.g., UE-to-network) relay;

[0010] FIG. 4 is a diagram illustrating a multi-hop WTRU-to-network / U2N relay discovery architecture according to an embodiment;

[0011] FIG. 5 is a diagram illustrating a multi-hop WTRU-to-network / U2N relay Discovery architecture according to another embodiment;

[0012] FIG. 6 is a diagram illustrating a multi-hop link establishment procedure;

[0013] FIG. 7 is a diagram illustrating a method for WTRU-to-network relay discovery and selection in multi-hop connection according to an embodiment;

[0014] FIG. 8 is a diagram illustrating a method for WTRU-to-network relay discovery and selection in multi-hop connection according to another embodiment;

[0015] FIG. 9 is a diagram illustrating a method for WTRU-to-network relay PC5 link establishment in multi-hop connection according to an embodiment; and

[0016] FIG. 10 is a diagram illustrating a method for WTRU-to-network relay discovery and selection in multi-hop connection according to a further embodimentDETAILED DESCRIPTION

[0017] 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.

[0018] Example Communications System

[0019] 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.

[0020] 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), single-carrier 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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).

[0025] 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).

[0026] 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).

[0027] 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).

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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 Internet110 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 / detectorconfigured 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.

[0037] 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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] 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., basestations 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.

[0042] 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.

[0043] 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)).

[0044] 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.

[0045] 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, forexample, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

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

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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 contiguous20 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.

[0058] Sub 1 GHz modes of operation are supported by 802.1 laf and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those used in802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment,802.1 lah may support meter type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0059] WLAN systems, which may support multiple channels, and channel bandwidths, such as802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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).

[0064] 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 withone 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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 policyenforcement 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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 performing testing using over-the-air wireless communications.

[0073] 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.

[0074] Provided below are acronyms / abbreviations for terms and phrases commonly used in this application:DCR / DCA Direct Connection Request / AcceptLMR / LMA Link Modification Request / AcceptMH U2N RSC Multihop specific RSC offered by U2N relayMH U2U RSC Multihop specific RSC offered by U2U relayRSC Relay Service CodeSource / target End UE UE / WTRU which communicates with U2U relayU2N relay UE-to-network relay / WTRU-to-network relayU2U relay UE-to-UE relay / WTRU-to-WTRU relay

[0075] The ProSe WTRU-to-network (e.g., UE-to-network) relay entity may provide the functionality to support connectivity to the network for remote WTRUs (e.g., UEs) (see FIG. 3).

[0076] If the remote WTRU (e.g., UE) is out of NR coverage and cannot communicate with core network directly (or in NR coverage but prefers to use PC5 for communication), the remote WTRU (e.g., UE) may discover and select a WTRU-to-network (e.g., UE-to-network) relay. The remote WTRU (e.g., UE) may establish PC5 session with WTRU-to-network (e.g., UE-to-network) relay and / or the WTRU-to-network (e.g., UE-to-network) relay may establish a PDU session (or PDN connection in EPC) for the remote WTRU (e.g., UE). After IP address / prefix allocation, the traffic between remote WTRU (e.g., UE) and network may be relayed by WTRU-to-network (e.g., UE- to-network) relay, as shown in FIG. 4.

[0077] For 5G ProSe WTRU-to-network (e.g., UE-to-network) relay discovery, both Model A and Model B discovery are supported: (1) Model A may use a single discovery protocol message (Announcement), and / or (2) Model B may use two discovery protocol messages (Solicitation and Response).

[0078] For relay discovery additional information, (e.g., only) Model A discovery may be used.

[0079] Proposals in 3GPP to study potential enhancements to support multi-hop for U2N andU2U relay in Rel-19 are being discussed.

[0080] Multi-hop for U2N relay may be to enable a remote WTRU (e.g., UE) to discover and communicate with a U2N relay via one or more U2U relays. Multi-hop U2U relay may be to enable End WTRUs (e.g., UEs) to discover and communicate with each via more than one U2U relay. Multi-hop U2U relay procedure may also be used in the context of U2N relay when multiple relays assist to establish the connection between the remote WTRU (e.g., UE) and the U2N relay WTRU (e.g., UE), which may be treated as end WTRUs (e.g., UEs) for a U2U relay.

[0081] The multi-hop capability may be deemed crucial for mission critical communications (e.g., first responders) and in general may be needed to enhance coverage (e.g., indoor).

[0082] A remote WTRU (e.g., UE) may (e.g., use) more than one hops to reach to a U2N relay, when enabled for multi-hop communication. There can be one or more U2U relays that assist in multi-hop connection establishment between the remote WTRU (e.g., UE) and the U2N relay WTRU (e.g., UE). To enable such multi-hop communication between the remote WTRU (e.g., UE) and the U2N relay WTRU (e.g., UE), following questions may be addressed.

[0083] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) relay WTRU (e.g., UE) discovery via multi-hops are provided.

[0084] In a case where (e.g., when) a WTRU (e.g., UE) (Remote UE) wishes to connect to a network via a relay WTRU (e.g., UE) (U2N relay), the current procedure may assume that there is (e.g., always) a U2N relay available in the proximity of the remote WTRU (e.g., UE) to setup a U2N relay connection. In reality it may not be the case and remote WTRU (e.g., UE) may not (e.g., cannot) discover any U2N relay WTRU (e.g., UE) in its proximity. However, U2N relays may be reachable via one or more U2U relay(s). For a multi-hop discovery and selection of U2N relay, methods and apparatus are proposed to allow a remote WTRU (e.g., UE) to discover and select a U2N relay via one or more U2U relay UE(s).

[0085] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) relay WTRU (e.g., UE) PC5 link establishment via multi-hops are provided.

[0086] In a case where (e.g., once) the remote WTRU (e.g., UE) has discovered a U2N relay via one or multiple U2U relay UE(s), the next step may be to establish a PC5 link between the remote WTRU (e.g., UE) and the discovered and selected U2N relay WTRU (e.g., UE). The discovery procedure over multi-hop may involve one or more U2U relay WTRUs (e.g., UEs) and there may exist alternative routes from the remote WTRU (e.g., UE) to the U2N relay WTRU (e.g., UE). Additionally, there can be requirements in terms of end-to-end (E2E) QoS based on the ProSe service, which may (e.g., need to) be taken into account for path selection and connection establishment. In such a scenario, methods and apparatus are proposed to allow a remote WTRU (e.g., UE) to establish a PC5 link to a discovered U2N relay via U2U relay UE(s).

[0087] Remote WTRU (e.g., UE) to establish connection with the network via U2N relay in a singlehop scenario may select a U2N relay WTRU (e.g., UE) that may be in the proximity, meets E2E QoS requirements and supports desired relay services. In a multi-hop scenario, the E2E QoS requirements become more critical in a sense that the connection between the remote WTRU (e.g., UE) and U2N relay may be via multiple-hops, and per hop QoS has an impact on E2E connection. In a case where (e.g., when) multi-hop relays are considered with E2E QoS requirement, methods and apparatus are proposed to determine per hop QoS for initial connection setup and to determine per hop QoS when modifying or updating an existing link.

[0088] Methods and apparatus for U2N relay discovery and connection setup are provided.

[0089] According to some embodiments, upon reception of U2N relay discovery message, if multi-hop indication or multi-hop specific RSC is present, U2U relay may generate a U2U relay discovery message to be broadcasted by the U2U relay.

[0090] According to some embodiments, if multi-hop indication or multi-hop specific RSC is present in the U2N relay discovery message or U2U relay discovery message, U2U relay may perform per-hop QoS determination and may calculate cumulative propagation delay up to that hop.

[0091] According to some embodiments, U2U relay discovery announcement message may include multi-hop propagation delay, i.e., a list with time stamp per hop or measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop. According to some embodiments, the cumulative propagation delay, i.e., sum of per-hop propagation delays or the total multi-hop propagation delay.

[0092] According to some embodiments, U2U relay WTRU (e.g., UE) may send a DCR or LMR message to another U2U relay or to a U2N relay including multi-hop indication, MH_U2N_RSC, MH_U2U_RSC, U2U relay user information [list] of other U2U relays, U2N relay user information, remote WTRU (e.g., UE) user information.

[0093] According to some embodiments, U2U relay at one or more (e.g., each) hop may determine the per-hop QoS or cumulative QoS. For any hop where the U2U relay may estimate cumulative propagation delay to be large, i.e., if exceeded the E2E delay budget up to that hop, it may not send any DCR message further. It may send a direct communication reject message to the remote WTRU (e.g., UE) with a cause value set to "QoS not met" or similar value stating the QoS cannot be fulfilled.

[0094] In this disclosure" U2U relay UE" and "U2U relay" are used interchangeably.

[0095] In this disclosure" U2N relay UE" and "U2N relay" are used interchangeably.

[0096] In this disclosure the following is proposed for multi-hop U2N relay discovery and connection establishment procedure via U2U relay(s). Remote WTRU (e.g., UE) may not be ableto discover any U2N relay WTRU (e.g., UE) in its proximity (e.g., then) U2N relays may be reachable via one or more U2U relay(s). In such a situation, the current U2N relay procedure may be enhanced such that a remote WTRU (e.g., UE) could utilize multi-hop connection to locate a U2N relay WTRU (e.g., UE) via the U2U relay UE(s). One or more (e.g., each) WTRU (e.g., UE) (e.g. remote WTRU (e.g., UE), U2N relay WTRU (e.g., UE), U2U relay UE) involved in the multihop discovery and connection establishment may be either pre-configured or provisioned with multi-hop specific configurations and authorizations, e.g., the authorization based on the capabilities / subscription and multi-hop enable indication for one or more (e.g., each) WTRU (e.g., UE), E2E QoS including max time delay budget, max #hops allowed, multi-hop specific RSC, such as MH U2N RSC, MH U2U RSC, and list of E2E QoS parameters linked to one or more (e.g., each) multi-hop specific RSC.

[0097] For the connection establishment with the network via the U2N relay WTRU (e.g., UE) using multi-hop connection between the remote WTRU (e.g., UE) and the U2N relay, the remote WTRU (e.g., UE) may discover the U2N relay with the help of U2U relay(s) that broadcast discovery messages on behalf of the end WTRUs (e.g., UEs) (e.g., U2U relay WTRU (e.g., UE) facilitating multi-hops or U2N relay UE). The discovery can be done using either the Model A discovery, e.g., announcement messages that may include multi-hop indication, MH U2N RSC, MH_U2U_RSC, E2E QoS, per-hop QoS, cumulative QoS, U2N relay user information, U2U relay user information [list], or Model B discovery, e.g. solicitation request and response messages that include multi-hop indication, MH U2N RSC, MH U2U RSC, E2E QoS, per-hop QoS, cumulative QoS, U2N relay user information, U2U relay user information [list],

[0098] For any hop, the intermediate U2U relay WTRU (e.g., UE) may estimate per-hop QoS, and / or may calculate a cumulative QoS, e.g., propagation delay up to that hop, which may be (e.g., then) compared with the E2E QoS for optimal route selection. The U2U relays assisting per-hop may (e.g., need to) determine per-hop QoS based on the E2E QoS requirements such that the requirement can be met.

[0099] In a case where (e.g., once) the remote WTRU (e.g., UE) has discovered and selected a U2N relay, (e.g., then) the connection may be established via the selected route that may include one or more U2U relay WTRUs (e.g., UEs). The remote WTRU (e.g., UE) may initiate direct link establishment by sending a direct communication request (DCR) that may include multi-hop indication, MH_U2N_RSC, U2U relay user information [list], E2E QoS. A U2U relay WTRU (e.g., UE) further broadcasts this message but it can be either a DCR message or a direct link modification message (LMR) given that a link already exists between the peer WTRUs (e.g., UEs) (U2U relay WTRU (e.g., UE) and U2N relay WTRU (e.g., UE) or between two U2U relay UEs). Content of the message may be the same as the first DCR message from the remote WTRU (e.g.,UE) and additionally MH U2U RSC, per-hop QoS, cumulative QoS, and discovery payload from U2N relay WTRU (e.g., UE).

[0100] According to some embodiments, there may not be standalone discovery, i.e., integrated discovery in a case where (e.g., when) the discovery is not performed and remote WTRU (e.g., UE) has not discovered a U2N relay. In that case the remote WTRU (e.g., UE) may send a DCR message including the information elements as stated above for the DCR message plus the user information of the desired U2N relay. The multi-hop route selection may be performed by the U2N relay or by the remote WTRU (e.g., UE) based on the DCR / DCA messages (or other exchanged messages during link setup e.g., DSMC) and included cumulative QoS in those messages.

[0101] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) Relay Discovery via multi -hops are provided.

[0102] According to some embodiments, one or more (e.g., each) WTRU (e.g., UE), i.e., remote WTRU (e.g., UE), U2U relay and U2N relay, may be either pre-configured or provisioned with multi-hop specific configurations and authorizations such as multi-hop indication to indicate multi-hop is enabled, multi-hop authorization based on the capabilities / subscription and additional parameters as listed in step 1 of FIG.4 and FIG. 5.

[0103] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a U2N relay discovery announcement message or U2U relay discovery announcement message including multi-hop indication, multi-hop specific relay service code for U2N relay service (MH_U2N_RSC), E2E QoS associated to the MH_U2N_RSC, U2N relay user information.

[0104] According to some embodiments, a U2U relay WTRU (e.g., UE) may perform per-hop QoS determination and may calculate cumulative propagation delay up to that hop, may create a mapping table where it may associate per-hop QoS calculations with the user information of one or more (e.g., each) of the available end WTRU (e.g., UE) in the proximity. For any hop where a cumulative propagation delay up to that hop has exceeded the E2E delay budget, the U2U relay may ignore the discovery message and may not send it further.

[0105] According to some embodiments, a U2U relay WTRU (e.g., UE) may generate a U2U relay discovery announcement message to be broadcasted by the U2U relay. U2U relay discovery announcement message may include multi-hop propagation delay, i.e., a list with time stamp per hop or measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop. According to some embodiments, the cumulative propagation delay, i.e., sum of per- hop propagation delay or the total multi-hop propagation delay.

[0106] According to some embodiments, a remote WTRU (e.g., UE) may perform U2N relay selection and route selection based on the QoS parameters, e.g., by comparing the cumulative propagation delay or so-called multi-hop propagation delay (as explained in step-5 of FIG. 4) vsthe required E2E propagation delay budget, which may be based on the list of QoS parameters associated to one or more (e.g., each) RSC.

[0107] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a U2N relay discovery announcement message from a U2N relay including multi-hop indication, multihop specific relay service code for U2N relay service (MH_U2N_RSC), E2E QoS associated to the MH_U2N_RSC, U2N relay user information. U2U relay may (e.g., locally) save the received information from the U2N relay WTRU (e.g., UE) and its corresponding parameters.

[0108] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a U2N relay discovery solicitation message from the remote WTRU (e.g., UE) including multi-hop indication, multi-hop specific relay service code for U2N relay service (MH_U2N_RSC), E2E QoS associated with the MH_U2N_RSC.

[0109] According to some embodiments, a U2U relay WTRU (e.g., UE) may generate a U2U relay discovery solicitation message to be broadcasted by the U2U relay.

[0110] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a U2U relay discovery response message from a U2N relay WTRU (e.g., UE) or from another U2U relay WTRU (e.g., UE) which may include, e.g., U2N relays user information, multi-hop indication, cumulative propagation delay (a list of time stamp per hop, a list of measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop or a sum of all measured propagation delay), and the list of U2U relay UE(s) as received in the solicitation message.

[0111] According to some embodiments, a U2U relay WTRU (e.g., UE) may perform per-hop QoS determination and calculates cumulative propagation delay up to that hop, may create a mapping table where it associates per-hop QoS calculations with the user information of one or more (e.g., each) of the available end WTRU (e.g., UE) in the proximity.

[0112] According to some embodiments, a remote WTRU (e.g., UE) may perform U2N relay selection and route selection based on the QoS parameters, e.g., by comparing the cumulative propagation delay or so-called multi-hop propagation delay (as explained in FIG. 5) vs the required E2E propagation delay budget, which may be based on the list of QoS parameters associated to one or more (e.g., each) RSC.

[0113] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) relay PC5 link establishment via multi-hops are provided.

[0114] According to some embodiments, a remote WTRU (e.g., UE) may send a DCR / LMR including Route info using U2U relay user information [list], e.g., User information IDs of one or more (e.g., each) selected U2U relay, where the route may be selected based on the prior discovery. It may include multi-hop indication, MH U2N RSC, U2N relay user information, remote WTRU (e.g., UE) user information, list of E2E QoS parameters associated with the RSC.

[0115] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a DCR / LMR message from the remote WTRU (e.g., UE) including Route info using U2U relay user information [list], e.g., User information IDs of one or more (e.g., each) selected U2U relay, where the route may be selected based on the prior discovery. DCR message may include multi-hop indication, MH_U2N_RSC, U2N relay user information, remote WTRU (e.g., UE) user information, list of E2E QoS parameters associated with the RSC.

[0116] According to some embodiments, a U2U relay WTRU (e.g., UE) may Send a DCR or LMR message to another U2U relay or to a U2N relay including multi-hop indication, MH U2N RSC, MH U2U RSC, U2U relay user information [list] of other U2U relays, U2N relay user information, remote WTRU (e.g., UE) user information.

[0117] According to some embodiments, a U2U relay WTRU (e.g., UE) at one or more (e.g., each) hop may determine the per-hop QoS or cumulative QoS. For any hop where the U2U relay may estimate cumulative propagation delay to be large, i.e., if exceeded the E2E delay budget up to that hop, it may not send any DCR message further. It may send a direct communication reject message to the remote WTRU (e.g., UE) with a cause value set to "QoS not met" or similar value stating the QoS cannot be fulfilled.

[0118] According to some embodiments, if no prior discovery is performed, U2U relay WTRU (e.g., UE) or U2N relay WTRU (e.g., UE) may determine per-hop QoS or cumulative QoS based on the DCR or DCA messages or other messages transmitted during link establishment.

[0119] According to some embodiments, a U2U relay WTRU (e.g., UE) may receive a direct communication accept (DCA) or link modification accept (LMA) message from the U2N relay WTRU (e.g., UE) or from another U2U relay WTRU (e.g., UE) including U2U relay user information [list] of selected U2U relays along the route, U2N relay user information, remote WTRU (e.g., UE) user information, list of E2E QoS parameters per RSC.

[0120] According to some embodiments, a U2U relay WTRU (e.g., UE) may, upon reception of DCA / LMA message from U2N relay, may perform per-hop QoS determination, using similar procedure as specified in FIG. 4 step 3 and 5. One or more (e.g., each) U2U relay may perform this step, if multiple U2U relays are involved in multi-hop communication link.

[0121] According to some embodiments, a U2U relay WTRU (e.g., UE) may passes DCA / LMA message further to another U2U relay or to the remote WTRU (e.g., UE). Before sending a DCA / LMA, the U2U relay may calculate the per hop QoS with remote WTRU (e.g., UE) or other U2U relay at the next hop based on E2E QoS and the received calculated per-hop QoS(s) of U2U relays at the earlier hops. If not met it may send a direct communication reject or link modification reject message with a cause value as stated above.

[0122] According to some embodiments, a U2N relay WTRU (e.g., UE) may initiate a new PDU session establishment procedure or PDU session modification procedure upon reception of DCR / LMR message from U2U relay WTRU or from remote WTRU. Based on the DCR message or LMR message the U2N relay may establish a new PDU session or update an existing PDU session. In case of multi-hop communication, the U2N relay may (e.g., need to) manage the mapping of PQI of the remote WTRU (e.g., UE) and not the U2U relay WTRU (e.g., UE), when establishing or modifying a PDU session. In the existing specification for singlehop the U2N relay may consider the remote WTRU (e.g., UE), which is at the first hop, whereas in this case it may (e.g., need to) consider the remote WTRU (e.g., UE) which is at multi-hops hidden behind the U2U relay UE(s).

[0123] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) relay WTRU (e.g., UE) discovery via multi -hops are provided.

[0124] FIG. 4 is a diagram illustrating a multi-hop U2N relay discovery (Model A).

[0125] For the WTRU-to-network (e.g., UE-to-network) relay discovery using model A discovery procedure, the U2N relay may periodically broadcast a U2N relay discovery announcement message. For the multi-hop case, the U2U relay WTRU (e.g., UE) upon receiving the U2N relay discovery announcement message, which may include multi-hop indication or multi-hop specific relay service codes, may send a U2U relay discovery message (e.g., U2U relay announcement or U2U relay solicitation message). U2U relay may determine per-hop QoS based on the E2E QoS before sending the U2U relay discovery message and the E2E QoS from the U2N relay may be based on the list of supported QoS parameters per RSC. When the per-hop QoS as determined by the U2U relay meets the E2E QoS requirements, the U2U relay may send a U2U relay discovery message. If the per-hop QoS as determined by the U2U relay cannot satisfy the E2E QoS per RSC, the U2U relay may ignore the U2N relay discovery announcement message received from the U2N relay and do not send a U2U relay discovery message.

[0126] One or more (e.g., each) WTRU (e.g., UE), i.e., remote WTRU (e.g., UE), U2U relay and U2N relay, may be either pre-configured or provisioned with multi-hop specific configurations and authorizations such as; multi-hop indication to indicate multi-hop is enabled, multi-hop authorization based on the capabilities / subscription, multi-hop parameters, for example multi-hop specific RSC, (e.g., MH U2N RSC, MH U2U RSC), and list of supported E2E QoS parameters (e.g., max time delay budget), and allowed max #hops linked to one or more (e.g., each) RSC (step 4.1).

[0127] U2N relay may send a U2N relay discovery announcement message including multi-hop indication, multi-hop specific relay service code (RSC) for U2N relay service (MH_U2N_RSC),timestamp, hop-counter value set to zero initially, E2E QoS associated to the MH U2N RSC, U2N relay user information (step 4.2).

[0128] U2U relay, upon reception of U2N relay discovery announcement message; may perform per-hop QoS determination (step 4.3).

[0129] U2U relay WTRU (e.g., UE) when enabled for multi-hop may create a mapping table where it associates per-hop QoS calculations with the user information of one or more (e.g., each) of the available U2N relay, remote WTRU (e.g., UE) or U2U relay WTRU (e.g., UE) in the proximity.

[0130] For any hop where the U2U relay may estimate a cumulative propagation delay up to that hop has exceeded the E2E delay budget, the U2U relay may ignore the message and not send any discovery message further.

[0131] U2U relay may look at the multi-hop specific relay service code for U2N relay (MH_U2N_RSC) and / or multi-hop indication in the received U2N relay discovery message received from the U2N relay, if present, it may generate a U2U relay announcement message to be broadcasted by the U2U relay (step 4.4).

[0132] According to some embodiments, there may be the case where both alternatives, i.e., U2U relay discovery announcement message and U2U relay discovery solicitation message, are supported but (e.g., only) the U2U relay discovery announcement message is shown in the figure for illustration and discussed below. For the case where discovery solicitation message is used, similar procedure as stated below for Model B may be followed.

[0133] U2U relay may create the announcement message based on the information gathered by the U2U relay, which may include information of the available U2N relay and additionally the discovery payload received from the U2N relay WTRU (e.g., UE), multi-hop indication, MH U2N RSC, MH U2U RSC, E2E QoS associated to the MH U2N RSC. U2U relay discovery message may include information of a single U2N relay or a list of U2N relay UE(s) may be included covering some or all of the available U2N relays in the proximity of the U2U relay.

[0134] Receiving a U2N relay announcement message could be a trigger for U2U relay WTRU (e.g., UE) to send a U2U relay announcement message, or / and U2U relay announcement message may be periodic time-based message. The message may include the information of the U2N relay gathered by the U2U relay. In this step the most important aspect is the definition of the discovery message, i.e., U2U relay may be receiving U2N relay announcement message and based on that it may be sending a U2U relay announcement message.

[0135] U2U relay may send a U2U relay discovery announcement message including some or all of the additional information elements to indicate the available U2N relays via multi-hop, e.g.,U2N relay(s) user information, U2N relay multi-hop indication, time stamp per hop, measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop may be added, cumulative propagation delay i.e., sum of per-hop propagation delay, also called multihop propagation delay.

[0136] According to some embodiments, in case of 2nd or 3rd hop, U2U relay may include a list of user information for all U2U relay UE(s) involved in the previous hops, cumulative propagation delay and / or also per-hop delay info with or without timestamps.

[0137] In the existing procedure for U2U relay discovery using model A, the U2U relay WTRU (e.g., UE) may send an announcement message with the information of end WTRUs (e.g., UEs) in proximity. However in the multi-hop case, the U2U relay WTRU (e.g., UE) in the announcement message may send the information of an end WTRU (e.g., UE), which in the first hop can be set to the U2N relay WTRU (e.g., UE), but in the second or later hops the U2U relay WTRU (e.g., UE) in the announcement message may include end WTRU (e.g., UE) info set to another U2U relay WTRU (e.g., UE) but it may additionally include the initiating U2N relay WTRU (e.g., UE) and multiple U2U relay WTRUs (e.g., UEs) (i.e. a U2U relay announcement message may include information about end WTRU (e.g., UE) (e.g. remote WTRU (e.g., UE) or U2N relay or U2U relay in proximity) and in addition information about other WTRUs (e.g., UEs) (e.g. U2N relay, U2U relay, remote WTRU (e.g., UE) which are not in proximity but are in the received discovery messages).

[0138] The per-hop QoS determination in step 4.5 may be the same as in step 4.3 above. According to some embodiments, the delay calculated in this step 4.5 may not be only per-hop delay between itself and U2U relay at the last hop but also the delay between itself and U2N relay via other U2U relays, i.e., cumulative delay. To support this, a list of time stamp per hop, a list of measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop or a sum of all measured propagation delay may be included.

[0139] Step 4.6 may be the same as step 4.4, with the difference that the U2U relay discovery announcement message may be triggered based on the reception of a U2U relay discovery announcement message from another U2U relay WTRU (e.g., UE), which in step 4.4 may be based on U2N relay discovery message. The IES in the message may remain the same as in step 4.4, i.e., the discovery information received from U2U relay in the previous hop will be included in the U2U relay announcement message plus the user-info of the announcing relay and the cumulative delay value updated to the current hop or list of the per-hop delay value.

[0140] Remote WTRU (e.g., UE) may perform U2N relay selection and route selection based on the QoS parameters, e.g., by comparing the cumulative propagation delay or so called multi-hop propagation delay (a list of time stamp per hop, a list of measured propagation delay value fromone or more (e.g., each) relay for one or more (e.g., each) hop or a sum of all measured propagation delay) versus the required E2E propagation delay budget, which may be based on the list of QoS parameters associated to one or more (e.g., each) RSC (step 4.7).

[0141] Remote WTRU (e.g., UE) may establish connection with the U2N relay WTRU (e.g., UE), via the U2U relay(s). The detailed PC5 link establishment solution is provided in FIG. 6 (step 4.8).

[0142] FIG. 5 is a diagram illustrating a multi-hop U2N relay discovery (Model B).

[0143] For the WTRU-to-network (e.g., UE-to-network) relay discovery using Model B discovery procedure, the remote WTRU (e.g., UE) may trigger the discovery procedure by sending a U2N relay discovery solicitation message including multi-hop indication. The U2U relay WTRU (e.g., UE) upon reception of U2N relay discovery solicitation message from the remote WTRU (e.g., UE) that may include the multi-hop indication and / or the MH U2N RSC, may generate a U2U relay discovery solicitation message including the parameters as listed in the detailed solution below.

[0144] There could be a situation where the U2U relay has previously received a U2N relay discovery announcement from the U2N relay WTRU (e.g., UE)., In that case, the U2U relay WTRU (e.g., UE) may save the information (e.g., locally) and may use it when U2N relay discovery using Model B may be triggered by a remote WTRU (e.g., UE), i.e. the U2U relay may send a response message to the remote WTRU (e.g., UE) (or to another U2U relay if the Solicitation message is received from another U2U relay), including the saved information, instead of sending the Solicitation message towards the U2N relay.

[0145] In step 5.1, one or more (e.g., each) WTRU (e.g., UE), i.e., remote WTRU (e.g., UE), U2U relay and U2N relay, may be either pre-configured or provisioned with multi-hop specific configurations and authorizations such as; indication if multi-hop is enabled / disabled, multi-hop authorization to act as a remote UE / U2U relay WTRU (e.g., UE) or U2N relay, E2E QoS including max time delay budget, max #hops, multi-hop specific RSC, e.g., MH_U2N_RSC, MH U2U RSC and list of E2E QoS parameters linked to one or more (e.g., each) multi-hop specific RSC.

[0146] In step 5.2, U2U relay may receive a discovery announcement message from a U2N relay including multi-hop indication, multi-hop specific relay service code for U2N relay service (MH U2N RSC), E2E QoS associated to the MH U2N RSC.

[0147] In step 5.3, if step 5.2 takes place, (e.g., then), U2U relay (e.g., locally) may save the information about the U2N relay WTRU (e.g., UE) and its corresponding parameters.

[0148] Remote WTRU (e.g., UE) may send a U2N relay discovery solicitation message including multi-hop indication, multi-hop specific relay service code for U2N relay service(MH U2N RSC), timestamp, hop-counter value set to zero initially, E2E QoS associated to the MH U2N RSC (step 5.4).

[0149] In step 5.5a (discovery solicitation message from U2U relay to another U2U relay) - U2U relay 1 may look at the multi-hop specific relay service code for U2N relay (MH_U2N_RSC) and / or multi-hop indication in the received U2N relay discovery solicitation message received from the remote WTRU (e.g., UE), if present, (e.g., then) it will use it as a trigger to generate a U2U relay discovery solicitation message to be broadcasted by the U2U relay.

[0150] U2U relay discovery solicitation message may include information of the remote WTRU (e.g., UE), multi-hop indication, MH U2N RSC, MH U2U RSC, E2E QoS associated to the MH U2N RSC, discovery payload received from the remote WTRU (e.g., UE) and the user information of the U2U relay WTRU (e.g., UE) itself. In this step, an aspect may be the definition of the discovery message, i.e., U2U relay may be receiving U2N relay discovery solicitation message (from Remote UE) and based on that it may be sending a U2U relay discovery solicitation message. U2U relay may forward U2U relay discovery solicitation message to another U2U relay WTRU (e.g., UE) or to the U2N relay WTRU (e.g., UE). One or more (e.g., each) solicitation message may include user information of a single U2U relay WTRU (e.g., UE), or a list of user information of U2U relay UE(s).

[0151] In step 5.5b, the U2U relay 2 may forward the discovery solicitation message from U2U relay 1 to a U2N relay WTRU (e.g., UE). The discovery solicitation message may include all the IES as received in 5a, and additionally it may include a list of U2U relay UE(s) involved in the previous hop including itself.

[0152] In step 5.6, U2N relay (e.g., then) may send U2U relay discovery response message to the U2U relay 2 from where the U2U relay discovery solicitation message was received. The U2U relay discovery response message may include, e.g., U2N relays user information, multi-hop indication, cumulative propagation delay if calculated by the U2N relay WTRU (e.g., UE) (a list of time stamp per hop, a list of measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop or a sum of all measured propagation delay) and may return the list of U2U relay UE(s) as received in the solicitation message.

[0153] In step 5.7, based on the received discovery response message, the U2U relay 2 may determine per-hop QoS between itself and the U2N relay WTRU (e.g., UE). U2U relay WTRU (e.g., UE) when enabled for multi-hop may create a mapping table where it associates per-hop QoS calculations with the user information of one or more (e.g., each) of the available U2N relay WTRU (e.g., UE) in proximity.

[0154] According to some embodiments, assuming the step 5.2 and 5.3 happened before step 5.4, in that case step 5.5b and 5.6 may be skipped. The U2U relay 2 in that case may utilize the (e.g.,locally) saved information as in step 5.2, may determine available U2N relay WTRUs (e.g., UEs) in the proximity, may calculate the per-QoS and also the cumulative delay. It may compare the results with the E2E QoS info received from the U2N relay and send a U2U relay discovery response message as a reply to the U2U relay solicitation message.

[0155] In step 5.8(a), U2U relay 2 (e.g., then) may send U2U relay discovery response message toU2U relay 1, from which the solicitation message has been received. In the response message it may include the available U2N relays, e.g., U2N relays user information, multi-hop indication, MH U2N RSC and cumulative propagation delay as calculated at one or more (e.g., each) hop by one or more (e.g., each) U2U relay WTRU (e.g., UE).

[0156] In step 5.8(b), U2U relay 1 (e.g., then) may send U2N relay discovery response message to remote WTRU (e.g., UE), from which the solicitation message has been received. In the response message may include the available U2N relay, e.g., U2N relays user information, multihop indication, MH U2N RSC and cumulative propagation delay as calculated at one or more (e.g., each) hop by one or more (e.g., each) U2U relay WTRU (e.g., UE).

[0157] In step 5.8(a / b), the U2U relays may send the info of U2N relays individually in separate solicitation response messages or may send one solicitation response message including a list with the info of all U2N relays for all receives solicitation response messages.

[0158] In step 5.9, remote WTRU (e.g., UE) may perform U2N relay selection and route selection based on the QoS parameters, e.g., by comparing the cumulative propagation delay or so called multi-hop propagation delay (a list of time stamp per hop, a list of measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop or a sum of all measured propagation delay) versus the required E2E propagation delay budget, which may be based on the list of QoS parameters associated to one or more (e.g., each) RSC.

[0159] In step 5.10, remote WTRU (e.g., UE) may establish connection with the U2N relay WTRU (e.g., UE). The detailed solution is provided in FIG.6.

[0160] Methods and apparatus for WTRU-to-network (e.g., UE-to-network) relay WTRU (e.g., UE) PC5 link establishment via multi-hops are provided.

[0161] FIG. 6 is a diagram illustrating a multi-hop link establishment.

[0162] For the WTRU-to-network (e.g., UE-to-network) PC5 link establishment via multi-hops it may be assumed that the remote WTRU (e.g., UE) has discovered a U2N relay WTRU (e.g., UE) via multi-hops utilizing one or more U2U relay UE(s). The discovery may be performed as discussed above in solution of FIG. 4 and FIG.5. Once the remote WTRU (e.g., UE) has discovered a U2N relay (e.g., then) the connection may be established via the selected route that may include one or more U2U relay WTRUs (e.g., UEs). The remote WTRU (e.g., UE) may initiate direct link establishment by sending a direct communication request (DCR). A U2U relay WTRU (e.g., UE)further broadcasts this message but it can be either a DCR message or a direct link modification message (LMR) given that a link already exists between the peer WTRUs (e.g., UEs) (U2U relay WTRU (e.g., UE) and U2N relay WTRU (e.g., UE) or between two U2U relay UEs).

[0163] According to some embodiments, there may not be a standalone discovery, i.e., integrated discovery when the discovery is not performed and remote WTRU (e.g., UE) has not discovered a U2N relay. In that case the remote WTRU (e.g., UE) may send a DCR message including the information elements as stated above for the DCR message plus the user information of the desired U2N relay (if available either by configuration or due to prior communication). The multi-hop route selection may be performed based on the DCR / DCA messages by the U2N relay or by the remote WTRU (e.g., UE), by calculating the cumulative QoS. For example, the U2N relay may receive from a U2U relay a DCR message that may include cumulative QoS information. The U2N relay may further compute the total multi-hop QoS (E2E from remote WTRU (e.g., UE) to U2N relay). The U2N decides whether to reply to the remote WTRU (e.g., UE) request based on multihop QoS determination.

[0164] Based on the DCR message or LMR message the U2N relay may establish a new PDU session or update an existing PDU session.

[0165] In step 6.0a: Authorization and provisioning of parameters for multi-hop relay as stated in solution 1.

[0166] In step 6.0b: Discovery procedure as previously described, for example in FIG.4 or FIG. 5.

[0167] Link Establishments procedure may comprise any of the following steps.

[0168] In step 6.1, remote WTRU (e.g., UE) may select a path based on step 6.0b and may send a DCR (or LMR) including route info using U2U relay user information [list], e.g., user information IDs of one or more (e.g., each) selected U2U relay, it may include multi-hop indication, MH_U2N_RSC, U2N relay user information, remote WTRU (e.g., UE) user information, list of E2E QoS parameters information associated with the RSC.

[0169] In step 6.2, if no PC5 link exists between U2U relay and the next U2U relay in the user information list or with the U2N relay is the user information list is empty - U2U relay may send a DCR message to the next U2U relay in the list (i.e. user information list) or to the U2N relay including multi-hop indication, MH U2N RSC, MH U2U RSC, U2U relay user information [list] of other U2U relays, U2N relay user information, remote WTRU (e.g., UE) user information.

[0170] In step 6.2, if a PC5 link exists between U2U relay and the next U2U relay in the user information list or with the U2N relay is the user information list is empty - U2U relay may send a LMR message to the next U2U relay in the list (i.e. user information list) or to the U2N relayincluding multi-hop indication, MH U2N RSC, MH U2U RSC, U2U relay user information [list] of other U2U relays, U2N relay user information, remote WTRU (e.g., UE) user information.

[0171] LMR may be the new message as compared to the current procedure specified for U2N relay. U2N relay may (e.g., need to) identify the remote WTRU (e.g., UE) behind the U2U relay. This means U2N relay may (e.g., need to) consider not (e.g., only) the U2U relay info but remote WTRU (e.g., UE) info. U2N relay may receive DCR or LMR, which may include a list of U2U relay UE(s) user information that implies that the U2N relay WTRU (e.g., UE) keeps track of this info per remote WTRU (e.g., UE).

[0172] Existing procedure for DCR and LMR can be used, but now U2N relay may (e.g., need to) consider not only remote WTRU (e.g., UE) information but also U2U relays information.

[0173] According to some embodiments, U2U relay at one or more (e.g., each) hop may determine the per-hop QoS or cumulative QoS. For any hop where the U2U relay may estimate cumulative propagation delay to be large, i.e., if exceeded the E2E delay budget up to that hop, it may not send any DCR message further. It may send a direct communication reject message to the remote WTRU (e.g., UE) with a cause value set to "QoS not met" or similar value stating the QoS cannot be fulfilled. It will not send direct communication request message any further.

[0174] In step 6.3, U2N relay may initiate a new PDU session establishment procedure or PDU session modification procedure based on the step 6.2. Based on the DCR message or LMR message the U2N relay may establish a new PDU session or update an existing PDU session. In case of multi-hop communication, the U2N relay may (e.g., need to) manage the mapping of PQI of the remote WTRU (e.g., UE) and not the U2U relay WTRU (e.g., UE), when establishing or modifying a PDU session. In the existing specification for singlehop the U2N relay considers the remote WTRU (e.g., UE), which may be at the first hop, whereas in this case it may (e.g., need to) consider the remote WTRU (e.g., UE) which may be at multi-hops hidden behind the U2U relay UE(s). In other words, for multi-hop relay case, 5GC may accept the PDU session establishment or modification based on the authorization result of remote WTRU (e.g., UE) and involved U2U relays.

[0175] In step 6.4, U2N relay upon reception of DCR / LMR message from U2U relay may accept DCR / LMR message and may send a DCA / LMA message to the U2U relay WTRU (e.g., UE) including U2U relay user information [list] of selected U2U relays along the route, U2N relay user information, remote WTRU (e.g., UE) user information, E2E QoS.

[0176] In step 6.5, U2U relay upon reception of DCA / LMA message from U2N relay may perform per-hop QoS determination, using similar procedure as specified in FIG. 4 step 4.3. One or more (e.g., each) U2U relay may perform this step, if multiple U2U relays are involved in multihop communication link.

[0177] When the U2N relay may send a DCA / LMA to U2U relay, it may include an E2E QoS in the DCA / LMA message. U2U relay may (e.g., need to) determine per-hop QoS between the U2N relay and U2U relay.

[0178] In step 6.6, U2U relay may passe DCA / LMA message further to another U2U relay or to the remote WTRU (e.g., UE) including U2N relay user information, remote WTRU (e.g., UE) user information, E2E QoS. DCA message or LMA message (e.g., then) include per-hop QoS as calculated by the U2U relay. Before sending a DCA / LMA, the U2U relay may calculate the per hop QoS with remote WTRU (e.g., UE) or other U2U relay at the next hop based on E2E QoS and the received calculated per-hop QoS(s) of U2U relays at the earlier hops.

[0179] FIG. 7 is a flowchart illustrating a representative method 700 implemented by a first device / WTRU to device / WTRU (U2U) relay WTRU 102. Referring to FIG. 7, the representative method 700 may include, at block 710, receiving, from a device / WTRU to network (U2N) relay WTRU or from a second device to device relay WTRU, a first relay discovery announcement message. At block 720, the representative method 700 may include broadcasting, a second relay discovery announcement message. At block 730, the representative method 700 may include receiving, from a third device to device relay WTRU, a first DCR message DCR or a first link modification request (LMR) message. At block 740, the representative method 700 may include sending, to the device to network relay WTRU or to the second device to device relay WTRU, a second DCR message or a second LMR message. At block 750, the representative method 700 may include receiving, from the device to network relay WTRU or from the second device to device relay WTRU, a DCA message or LMA message. At block 760, the representative method 700 may include sending, to the third device to device relay WTRU, the DCA / LMA message.

[0180] According to certain embodiments, the discovery announcement message comprises any of: a multi -hop indication, a multi-hop specific RSC for device to network relay service (MH U2N RSC), a timestamp, a hop-counter value, a E2E QoS associated to the MH U2N RSC, and a U2N relay user information.

[0181] According to certain embodiments, the representative method 700 may further comprise determining per-hop QoS; and determining a mapping table associating per-hop QoS determined with the user information of one or more (e.g., each) of the available end WTRU in the proximity of the first device to device relay WTRU.

[0182] According to certain embodiments, the discovery announcement message comprises any of: a list with time stamp per hop or measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop, and a cumulative propagation delay.

[0183] According to certain embodiments, the second DCR / LMR message comprises any of: a multi-hop indication, a MH U2N RSC, an RSC for device to device relay service(MH U2U RSC, U2U), a user information list of other device to device relays, device to network user information, and a remote WTRU.

[0184] FIG. 8 is a flowchart illustrating a representative method 800 implemented by a first device / WTRU to device / WTRU (U2U) relay WTRU 102. Referring to FIG. 8, the representative method 800 may include, at block 810, receiving, from a device to network relay WTRU, a first relay discovery announcement message. At block 820, the representative method 800 may include receiving, from a remote WTRU, a discovery solicitation message. At block 830, the representative method 800 may include broadcasting, a second relay discovery announcement message. At block 840, the representative method 800 may include receiving a discovery response message from the device to network relay WTRU or from a second device to device relay WTRU. At block 850, the representative method 800 may include receiving, from a third device to device relay WTRU, a first DCR message DCR or a first LMR message. At block 860, the representative method 800 may include sending, to the device to network relay WTRU or to the second device to device relay WTRU, a second DCR message or a second LMR message. At block 870, the representative method 800 may include receiving, from the device to network relay WTRU or from the second device to device relay WTRU, a DCA message or LMA message. At block 880, the representative method 800 may include sending, to the third device to device relay WTRU, the DCA / LMA message.

[0185] According to certain embodiments, the representative method 800 may further comprise determining per-hop QoS; and determining a mapping table associating per-hop QoS determined with the user information of one or more (e.g., each) of the available end WTRU in the proximity of the first device to device relay WTRU.

[0186] According to certain embodiments, the discovery response message comprises any of:

[0187] a list with time stamp per hop or measured propagation delay value from one or more (e.g., each) relay for one or more (e.g., each) hop, and a cumulative propagation delay.

[0188] According to certain embodiments, wherein the second DCR / LMR message comprises any of: a multi-hop indication, a multi-hop specific RSC for device to network relay service (MH_U2N_RSC), an RSC for device to device relay service (MH_U2U_RSC, U2U), a user information list of other device to device relays, device to network user information, and a remote WTRU.

[0189] FIG. 9 is a flowchart illustrating a representative method 900 implemented by a first device / WTRU to device / WTRU (U2U) relay WTRU 102. Referring to FIG. 9, the representative method 900 may include, at block 910, receiving, from a remote WTRU, a first DCR message DCR or a first LMR message. At block 920, the representative method 900 may include sending, to a device to network relay WTRU or to a second device to device relay WTRU, a second DCRmessage or a second LMR message. At block 930, the representative method 900 may include receiving, from the device to network relay WTRU or from the second device to device relay WTRU, a DCA message or LMA message. At block 940, the representative method 900 may include sending, to a third device to device relay WTRU, the DCA / LMA message.

[0190] According to certain embodiments, the first DCR / LMR message comprises any of: route information using device to device user information, user information IDs of one or more (e.g., each) selected device to device relay WTRU along the route, a multi-hop indication, MH U2N RSC, device to network relay user information, remote WTRU user information, and a list of E2E QoS parameters associated to a multi -hop specific RSC.

[0191] According to certain embodiments, the second DCR / LMR message comprises any of: a multi-hop indication, a multi-hop specific RSC for device to network relay service (MH_U2N_RSC), an RSC for device to device relay service (MH_U2U_RSC, U2U), a user information list of other device to device relays, device to network user information, a remote WTRU.

[0192] According to certain embodiments, the DCA / LMA message comprises any of: route information using device to device user information, user information IDs of one or more (e.g., each) selected device to device relay WTRU along the route, a multi-hop indication, MH U2N RSC, device to network relay user information, remote WTRU user information, and a list of E2E QoS parameters associated to a multi -hop specific RSC.

[0193] According to certain embodiments, the representative method 900 may further comprise determining per-hop QoS; and determining a mapping table associating per-hop QoS determined with the user information of one or more (e.g., each) of the available end WTRU in the proximity of the first device to device relay WTRU.

[0194] FIG. 10 is a flowchart illustrating a representative method 1000 implemented by a first device / WTRU to device / WTRU (U2U) relay WTRU 102 configured for a multi-hop communication between a remote WTRU and a device to network relay WTRU

[0195] Referring to FIG. 10, the representative method 1000 may include, at block 1010, receiving, from any of: (1) the device to network relay WTRU, (2) a second device to device relay WTRU, and (3) the remote WTRU, a first relay discovery message.

[0196] At block 1020, the representative method 1000 may include determining a cumulative propagation delay associated with the multi-hop communication.

[0197] At block 1030, the representative method 1000 may include broadcasting, based on the first relay discovery message, a second relay discovery message comprising information indicating the cumulative propagation delay.

[0198] At block 1040, the representative method 1000 may include receiving, from a third device to device relay WTRU, a first direct connection request (DCR) message DCR or a first link modification request (LMR) message.

[0199] At block 1050, the representative method 1000 may include sending, to the device to network relay WTRU or to the second device to device relay WTRU, a second DCR message based on the first DCR message or a second LMR message based on the first LMR message.

[0200] At block 1060, the representative method 1000 may include receiving, from the device to network relay WTRU or from the second device to device relay WTRU, a direct communication accept (DCA) message or link modification accept (LMA) message.

[0201] At block 1070, the representative method 1000 may include sending, to the third device to device relay WTRU, the DCA message or the LMA message.

[0202] According to certain embodiments, the second DCR message or the second LMR message is sent based on the cumulative propagation being less than a threshold value.

[0203] According to certain embodiments, the first relay discovery message is a discovery announcement message, and / or the second relay discovery message is a discovery announcement message.

[0204] According to certain embodiments, the first relay discovery message is a discovery solicitation message, and / or the second relay discovery message is a discovery announcement message.

[0205] According to certain embodiments, the representative method 1000 may include comprising receiving a discovery response message from the device to network relay WTRU or from the second device to device relay WTRU.

[0206] According to certain embodiments, the second relay discovery message may comprise information indicating one or more device to device relay WTRU in a proximity of the first device to device relay WTRU.

[0207] According to certain embodiments, the second relay discovery message may comprise information indicating any of: (1) a multi-hop indication, (2) a multi-hop specific relay service code (RSC) for a device to network relay service (MH_U2N_RSC), (3) a timestamp, (4) a hopcounter value, (5) an end-to-end (E2E) quality of service (QoS) associated to the MH U2N RSC, and (6) a user information associated with the device to network relay.

[0208] According to certain embodiments, the representative method 1000 may include determining at least a per-hop QoS; and determining a mapping table associating the at least perhop QoS with user information associated with one or more available end WTRU in a proximity of the first device to device relay WTRU.

[0209] According to certain embodiments, the second relay discovery may comprise information indicating any of: (1) one or more time stamp per hop associated with the multi-hop communication, and (2) a measured propagation delay value from each relay for each hop associated with the multi-hop communication.

[0210] According to certain embodiments, the second DCR message or the second LMR message may comprise information indicating any of: (1) a multi-hop indication, (2) a MH U2N RSC, (3) an RSC for device to device relay service (MH_U2U_RSC, U2U), (4) a user information list of device to device relay WTRUs, (5) device to network relay WTRU user information, and (6) a remote WTRU user information.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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, WTRU (e.g., UE), terminal, base station, RNC, or any host computer.

[0215] 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.

[0216] 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."

[0217] 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 electricalsignals 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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, severalportions 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.).

[0222] 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.

[0223] 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 implementedwhich 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.

[0224] 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.

[0225] 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 oneof 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".

[0226] 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.

[0227] 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, ca

[0228] 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

CLAIMSWhat is claimed is:

1. A method implemented by a first device to device relay wireless transmit / receive unit (WTRU), wherein the first device to device relay WTRU is configured for a multi-hop communication between a remote WTRU and a device to network relay WTRU, the method comprising: receiving, from any of: (1) the device to network relay WTRU, (2) a second device to device relay WTRU, and (3) the remote WTRU, a first relay discovery message; determining a cumulative propagation delay associated with the multi-hop communication; broadcasting, based on the first relay discovery message, a second relay discovery message comprising information indicating the cumulative propagation delay; receiving, from a third device to device relay WTRU, a first direct connection request (DCR) message DCR or a first link modification request (LMR) message; sending, to the device to network relay WTRU or to the second device to device relay WTRU, a second DCR message based on the first DCR message or a second LMR message based on the first LMR message; receiving, from the device to network relay WTRU or from the second device to device relay WTRU, a direct communication accept (DCA) message or link modification accept (LMA) message; and sending, to the third device to device relay WTRU, the DCA message or the LMA message.

2. The method according to claim 1, wherein the second DCR message or the second LMR message is sent based on the cumulative propagation being less than a threshold value.

3. The method according to any of claims 1-2, wherein the first relay discovery message is a discovery announcement message, and / or the second relay discovery message is a discovery announcement message.

4. The method according to any of claims 1-2, wherein the first relay discovery message is a discovery solicitation message, and / or the second relay discovery message is a discovery announcement message; and comprising receiving a discovery response message from the device to network relay WTRU or from the second device to device relay WTRU.

5. The method according to any of claims 1-4, wherein the second relay discovery message comprises information indicating one or more device to device relay WTRU in a proximity of the first device to device relay WTRU.

6. The method according to any of claims 1-5, wherein the second relay discovery message comprises information indicating any of: (1) a multi-hop indication, (2) a multi-hop specific relay service code (RSC) for a device to network relay service (MH_U2N_RSC), (3) a timestamp, (4) a hop-counter value, (5) an end-to-end (E2E) quality of service (QoS) associated to the MH U2N RSC, and (6) a user information associated with the device to network relay.

7. The method according to any of claims 1-6, further comprising: determining at least a per-hop QoS; and determining a mapping table associating the at least per-hop QoS with user information associated with one or more available end WTRU in a proximity of the first device to device relay WTRU.

8. The method according to any of claims 1-7, wherein the second relay discovery comprises information indicating any of: (1) one or more time stamp per hop associated with the multi-hop communication, and (2) a measured propagation delay value from each relay for each hop associated with the multi-hop communication.

9. The method according to any of claims 1-8, wherein the second DCR message or the second LMR message comprises information indicating any of: (1) a multi-hop indication, (2) a MH_U2N_RSC, (3) an RSC for device to device relay service (MH_U2U_RSC, U2U), (4) a user information list of device to device relay WTRUs, (5) device to network relay WTRU user information, and (6) a remote WTRU user information.

10. A first device to device relay wireless transmit / receive unit (WTRU), comprising a processor, a transceiver, and memory, the first device to device relay WTRU being configured for a multi-hop communication between a remote WTRU and a device to network relay WTRU, the processor, the transceiver, and the memory being configured to: receive, from any of: (1) the device to network relay WTRU, (2) a second device to device relay WTRU, and (3) the remote WTRU, a first relay discovery message; determine a cumulative propagation delay associated with the multi-hop communication; broadcast, based on the first relay discovery message, a second relay discovery message comprising information indicating the cumulative propagation delay;receive, from a third device to device relay WTRU, a first direct connection request (DCR) message DCR or a first link modification request (LMR) message; send, to the device to network relay WTRU or to the second device to device relay WTRU, a second DCR message based on the first DCR message or a second LMR message based on the first LMR message; receive, from the device to network relay WTRU or from the second device to device relay WTRU, a direct communication accept (DCA) message or link modification accept (LMA) message; and send, to the third device to device relay WTRU, the DCA message or the LMA message.

11. The first device to device relay WTRU according to claim 10, wherein the second DCR message or the second LMR message is sent based on the cumulative propagation being less than a threshold value.

12. The first device to device relay WTRU according to any of claims 10-11, wherein the first relay discovery message is a discovery announcement message, and / or the second relay discovery message is a discovery announcement message.

13. The first device to device relay WTRU according to any of claims 10-11, wherein the first relay discovery message is a discovery solicitation message, and / or the second relay discovery message is a discovery announcement message; and wherein the first device to device relay WTRU is configured to receive a discovery response message from the device to network relay WTRU or from the second device to device relay WTRU.

14. The first device to device relay WTRU according to any of claims 10-13, wherein the second relay discovery message comprises information indicating one or more device to device relay WTRU in a proximity of the first device to device relay WTRU.

15. The first device to device relay WTRU according to any of claims 10-14, wherein the second relay discovery message comprises information indicating any of: (1) a multi-hop indication, (2) a multi-hop specific relay service code (RSC) for a device to network relay service (MH U2N RSC), (3) a timestamp, (4) a hop-counter value, (5) an end-to-end (E2E) quality of service (QoS) associated to the MH U2N RSC, and (6) a user information associated with the device to network relay.

16. The first device to device relay WTRU according to any of claims 10-15, wherein the processor, the transceiver, and the memory are configured to: determine at least a per-hop QoS; and determine a mapping table associating the at least per-hop QoS with user information associated with one or more available end WTRU in a proximity of the first device to device relay WTRU.

17. The first device to device relay WTRU according to any of claims 10-16, wherein the second relay discovery comprises information indicating any of (1) one or more time stamp per hop associated with the multi-hop communication, and (2) a measured propagation delay value from each relay for each hop associated with the multi -hop communication.

18. The first device to device relay WTRU according to any of claims 10-17, wherein the second DCR message or the second LMR message comprises information indicating any of (1) a multihop indication, (2) a MH_U2N_RSC, (3) an RSC for device to device relay service (MH_U2U_RSC, U2U), (4) a user information list of device to device relay WTRUs, (5) device to network relay WTRU user information, and (6) a remote WTRU user information.

Images