Methods, architectures, devices and systems for utilizing flow control from a relay WTRU in multi-path sidelink operation

Abstract

A process, method, architecture, apparatus, system, apparatus, and computer program product for utilizing flow control from a relay wireless transmit / receive unit (WTRU) in multipath operations including sidelink communication with a remote WTRU. In a representative example, a relay WTRU may provide flow control information to a remote WTRU. The flow control information may be associated with a remote WTRU action. The remote WTRU may perform one or more actions based on receiving the flow control information from the relay WTRU.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 410,302, filed on September 27, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to the fields of communications, software, and coding, including, for example, methods, architectures, devices, systems for multipath sidelink (SL) operations, and more specifically to the utilization of flow control (FC) for remote wireless transmit / receive units (WTRUs) and relay WTRUs operating in a multipath environment. Background Art

[0004] Relaying via ProSe UE-to-network relay was introduced in 3GPP Release 13 to extend network coverage to out-of-coverage UEs by using PC5 communication (otherwise known as device-to-device (D2D) communication) between the out-of-coverage UE and the UE-to-network relay. In addition, 3GPP releases have added additional enhancements for remote and relay WTRU devices. Further enhancements to multipath sidelink operations that take into account the conditions present at the relay WTRU would be beneficial. Summary of the invention

[0005] In a representative embodiment, the remote WTRU may receive configuration information for handling data transmission on a direct link (Uu) and a SL from a base station. For example, the configuration information may include information indicating an association of FC information (e.g., a set of FC information) with a distribution percentage of data on Uu and SL (e.g., a set of distribution percentages). The remote WTRU may receive (e.g., specific) FC information from a relay WTRU. The remote WTRU may transmit data using Uu and SL based on the distribution percentage associated with the received FC information. The remote WTRU may transmit information to the base station indicating that the transmission behavior of the remote WTRU has been modified (e.g., based on the FC information).

[0006] In another representative embodiment, the relay WTRU may determine whether one or more trigger conditions are met. The relay WTRU may transmit FC information to the remote WTRU based on satisfying the one or more trigger conditions. After transmitting the FC information, the relay WTRU may use the SL to relay data received from the remote WTRU to the base station. For example, the remote WTRU may modify its use of the SL based on the FC information transmitted by the relay WTRU. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more detailed understanding may be obtained from the following detailed description given by way of example in conjunction with the accompanying drawings. As with the detailed description, each of the figures in such drawings is an example. Therefore, the drawings (figures) and detailed description should not be considered limiting, and other equally effective examples are possible and possible. In addition, the same reference numerals ("labels") in the various figures indicate the same elements, and wherein:

[0008] Figure 1A is a system diagram illustrating an example communication system;

[0009] Figure 1B It shows that it can be Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within a communication system is shown;

[0010] Figure 1C It shows that it can be Figure 1A A system diagram of an example radio access network (RAN) and an example core network (CN) used within the illustrated communication system;

[0011] Figure 1D It shows that it can be Figure 1A A system diagram of yet another example RAN and yet another example CN used within the communication system shown;

[0012] Figure 2 is a Layer 2 (L2) User Equipment to Network (U2N) relay architecture diagram illustrating an example of a user plane protocol stack;

[0013] Figure 3 is an L2 U2N relay architecture diagram showing an example of a control plane protocol stack;

[0014] Figure 4 is an architectural diagram illustrating an example protocol view of split bearers;

[0015] Figure 5 is an architectural diagram illustrating an example protocol view of splitting bearers in the case of multipath operation;

[0016] Figure 6 is a system diagram illustrating an example multipath scenario;

[0017] Figure 7 is a system diagram illustrating an example of signaling for enabling certain representative embodiments;

[0018] Figure 8 is a process diagram illustrating an example process for flow control at a remote WTRU;

[0019] Fig. 9 is a process diagram illustrating an example process for enabling flow control by a relay WTRU; and

[0020] Fig.10 is a process diagram illustrating another example process for flow control at a remote WTRU. DETAILED DESCRIPTION

[0021] In the following detailed description, many specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples can be practiced without some or all of the specific details set forth herein. In other cases, well-known methods, programs, components and circuits are not described in detail to avoid blurring the following description. In addition, the embodiments and examples not specifically described herein can replace the embodiments and other examples explicitly, implicitly and / or inherently described, disclosed or otherwise provided (collectively referred to as "providing") herein to practice or practice in combination with them. Although various embodiments in which equipment, systems, devices, etc. and / or any of its elements perform operations, processes, algorithms, functions, etc. and / or any part thereof are described and / or claimed herein, it should be understood that any embodiment described and / or claimed herein assumes that any equipment, systems, devices, etc. and / or any of its elements are configured to perform any operations, processes, algorithms, functions, etc. and / or any part thereof.

[0022] Example Communication System

[0023] The methods, devices, and systems provided herein are well suited for communications involving wired and wireless networks. Figures 1A to 1D An overview of various types of wireless devices and infrastructure is provided in which various elements of the network can utilize, perform, be arranged according to, and / or be adapted and / or configured for the methods, devices, and systems provided herein.

[0024] Figure 1A is a system diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content by sharing system resources (including wireless broadband). For example, the communication system 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) discrete Fourier transform (DFT) spread OFDM (ZT UWDTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multi-carrier (FBMC), etc.

[0025] like Figure 1A As shown, the communication 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, but 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 “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 phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated process chain), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, 102d may be interchangeably referred to as a UE.

[0026] The communication system 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, for example, to facilitate access to one or more communication networks such as the CN 106 / 115, the Internet 110, and / or the network 112. By way of example, the base stations 114a, 114b may be 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 NRNode-B (NR NB), a site controller, an access point (AP), a wireless router, etc. 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.

[0027] 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), a relay node, 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 a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area that may be relatively fixed or may vary over time. The cell may also be divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Therefore, in an embodiment, the base station 114a may include three transceivers, i.e., one transceiver 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 a desired spatial direction.

[0028] 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).

[0029] More specifically, as described above, the communication 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, etc. 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 use Wideband CDMA (WCDMA) to establish the air interface 116. 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).

[0030] 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-APro).

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as New Radio (NR) to establish NR radio access over the air interface 116.

[0032] 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 jointly implement LTE radio access and NR radio access, for example using dual connectivity (DC) principles. Thus, the air interface used by the 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., eNBs and gNBs).

[0033] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0034] Figure 1AThe base station 114b in may be, for example, a wireless router, a home Node-B, a home eNode-B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a business location, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, 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, a pico cell, or a femto cell. As Figure 1A As shown, the base station 114b may be directly connected to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0035] 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 different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calls, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although Figure 1A Not shown, but 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 or a different RAT as the RAN 104 / 113. 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) that employs any of GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technologies.

[0036] 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 a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols such as the Transmission Control Protocol (TCP), the 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 communication 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 use the same RAT as the RAN 104 / 114 or a different RAT.

[0037] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c 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.

[0038] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, 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. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0039] 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 associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, such as in an electronic package or chip.

[0040] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) via 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, for example, the transmit / receive element 122 may be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In an embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0041] Although the transmit / receive element 122 is Figure 1B Although depicted as a single element in the figure, 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.

[0042] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described 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 (e.g., such as NR and IEEE 802.11).

[0043] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from: a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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 a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only 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 a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0044] The processor 118 may receive power from the power source 134 and may be configured to distribute the power to and / or control power to 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, etc.

[0045] 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 from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of receiving signals from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0046] The processor 118 may also be coupled to other components / 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 components / peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (e.g., for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, a frequency modulation (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, etc. Components / peripherals 138 may include one or more sensors, which may be gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; geolocation sensors; altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and / or humidity sensors.

[0047] The WTRU 102 may include a full-duplex radio in which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both 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 hardware (e.g., choke) or signal processing via a processor (e.g., a separate processor (not shown) or via the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio in which transmission and reception of some or all of the signals (e.g., associated with specific subframes for both uplink (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0048] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As described 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.

[0049] 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, for example, the eNode-B 160a may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0050] 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, user scheduling in uplink (UL) and / or downlink (DL), etc. Figure 1C As shown, eNode-Bs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0051] Figure 1C The illustrated CN 106 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 is depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0052] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 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 connection of the WTRUs 102a, 102b, 102c, etc. 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.

[0053] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to or from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0054] 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.

[0055] 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) 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 other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0056] Although the WTRU Figures 1A to 1D Although depicted as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may (eg, temporarily or permanently) employ a wired communications interface utilizing a communications network.

[0057] In a representative embodiment, other network 112 may be a WLAN.

[0058] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STA) associated with the AP. The AP may have access or an interface to another type of wired / wireless network that reaches a distribution system (DS) or loads traffic into and / or out of the BSS. Traffic originating from outside the BSS to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA to a destination outside the BSS may be sent to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS may be sent by 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. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be sent between the source STA and the destination STA using a direct link setup (DLS) (e.g., directly sent between them). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0059] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, 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., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by a STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access-collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) including the AP may sense the primary channel. If a primary signal is sensed / detected by a particular STA and / or is determined to be busy, the particular STA may back off. One STA (e.g., only one station) may transmit in a given BSS at any given time.

[0060] A high throughput (HT) STA may communicate using a 40 MHz wide channel, for example, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0061] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two discontinuous 80MHz channels, which can be referred to as 80+80 configuration. For 80+80 configuration, data can be passed through a fragment parser after channel coding, which can divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing can be performed on each stream respectively. The stream can be mapped to two 80MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above-mentioned operation of the 80+80 configuration can be reversed, and the combined data can be sent to the media access control (MAC) layer, entity, etc.

[0062] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz and 20MHz bandwidths in TV white space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah can support meter type control / machine type communication (MTC), such as MTC devices in macro coverage. MTC devices may have certain capabilities, for example, limited capabilities, including support for (e.g., only support for) certain and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0063] A WLAN system that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) includes a channel that can be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by the STA that supports the minimum bandwidth operating mode among all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, due to a STA (which only supports a 1MHz operating mode) transmitting to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0064] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0065] Figure 1D1 is a system diagram showing the RAN 113 and the CN 115 according to an embodiment. As described above, the RAN 113 may employ 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.

[0066] 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, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, for example, the gNB 180a 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 techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be located on an unlicensed spectrum, while the remaining component carriers may be located on a licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and gNB 180b (and / or gNB 180c).

[0067] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a scalable digital architecture. For example, the OFDM symbol spacing and / or the OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmit spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of various or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time) .

[0068] 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 a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRU 102a, 102b, 102c may communicate / connect with the gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNode-B 160a, 160b, 160c. For example, the WTRU 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-B 160a, 160b, 160c may serve as a mobility anchor for the WTRU 102a, 102b, 102c, and the gNB 180a, 180b, 180c may provide additional coverage and / or throughput to serve the WTRU 102a, 102b, 102c.

[0069] 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, user scheduling in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNB180a, 180b, and 180c can communicate with each other through the Xn interface.

[0070] Figure 1DThe illustrated CN 115 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. Although each of the foregoing elements is described 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.

[0071] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing, for example, to customize CN support for the WTRU 102a, 102b, 102c based on the type of service the WTRU 102a, 102b, 102c is utilizing. 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, etc. 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-APro) and / or non-3GPP access technologies (such as Wi-Fi).

[0072] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the 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 addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0073] The UPF 184a, 184b may be connected via the N3 interface to one or more of the gNBs 180a, 180b, 180c in the RAN 113, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, for example, 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 multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0074] 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) 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 other networks 112, which may include other wired and / or wireless networks 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 via an N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b through the UPF 184a, 184b.

[0075] Given that Figures 1A to 1D and Figures 1A to 1D 102a to 102d, base stations 114a to 114b, eNode-Bs 160a to 160c, MMEs 162, SGWs 164, PGWs 166, gNBs 180a to 180c, AMFs 182a to 182b, UPFs 184a to 184b, SMFs 183a to 183b, DNs 185a to 185b, and / or any other elements / devices described herein. A simulation device may be one or more devices configured to simulate one or more or all of the functions described herein. For example, a simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0076] The simulation device can be designed to implement one or more tests of other devices in a laboratory environment and / or an operator network environment. For example, one or more simulation devices can perform one or more or all functions when fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more or all functions when temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device can be directly connected to another device for testing purposes, and / or can use over-the-air wireless communication to perform testing.

[0077] One or more simulation devices can perform one or more (including all) functions when not implemented / deployed as a part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a wired and / or wireless communication network that is not deployed (e.g., testing) to achieve testing of one or more components. One or more simulation devices can be test equipment. The simulation device can use direct RF connection and / or wireless communication via RF circuits (e.g., which can include one or more antennas) to transmit and / or receive data.

[0078] Sidelink Operation

[0079] WTRU to Network Relay

[0080] Sidelink relay in earlier versions

[0081] Relaying via ProSe WTRU to Network Relay was introduced in 3GPP Release 13 to extend network coverage to out-of-coverage WTRUs by using PC5 (D2D) between the out-of-coverage WTRUs and the WTRU to Network Relay. Specifically, TS 36.300 V15.4.0 states:

[0082] "The ProSe UE to Network Relay provides a generic L3 forwarding functionality that can relay any type of IP traffic between the remote UE and the network. One-to-one and one-to-many sidelink communications are used between the remote UE and the ProSe UE to Network Relay. For both the remote UE and the relay UE, only one single carrier (i.e., the public safety ProSe carrier) operation is supported (i.e., Uu and PC5 should be the same carrier for the relay / remote UE). The remote UE is authorized by upper layers and can be in coverage of the public safety ProSe carrier or out of coverage on any supported carrier (including the public safety ProSe carrier) for UE to Network Relay discovery, (re)selection and communication. The ProSe UE to Network Relay is always in coverage of the EUTRAN."

[0083] For 3GPP Release 16, the first version of NR sidelink has been developed and the sole focus of this version is to support V2X (vehicle-to-everything) related road safety services. The design aims to provide support for broadcast, multicast and unicast communications in both out-of-coverage and in-network coverage scenarios. Additionally, considering a wider range of applications and services, a sidelink-based relay function should be additionally studied to extend the sidelink / network coverage and improve power efficiency.

[0084] It is proposed to further explore coverage extension for sidelink based communications. For example, with respect to WTRU to network coverage extension, Uu coverage reachability is necessary for the WTRU to reach a server in the PDN network or a corresponding WTRU outside the proximity area. However, for both NG-RAN and NR based sidelink communications, the Release 13 solution for WTRU to network relay is limited to EUTRA based technology and may therefore not be applicable to NR based systems. For example, with respect to WTRU to WTRU coverage extension, at Release 16, proximity reachability is limited to a single hop sidelink link, whether via EUTRA based sidelink technology or NR based sidelink technology. However, given the limited single hop sidelink coverage, this is not sufficient in scenarios without Uu coverage.

[0085] Sidelink connections are further extended in the NR framework to support enhanced QoS requirements.

[0086] Sidelink Relay in Release 17

[0087] 3GPP Release 17 introduced single-hop NR sidelink relay with the following main objectives, as discussed in RP-193253.

[0088] Study mechanisms with minimal regulatory impact to support the SA requirements for WTRU-to-network and WTRU-to-WTRU relaying over the sidelink, focusing on the following aspects for Layer 3 relay and Layer 2 relay [RAN2], as applicable:

[0089] - Relay (re)selection criteria and process;

[0090] - Relay / Remote WTRU authorization;

[0091] -QoS for relay functions;

[0092] - Service continuity;

[0093] - the security of relaying the connection after SA3 has provided its conclusion; and

[0094] - Impact on the user plane protocol stack and control plane procedures, e.g. connection management of relay connections.

[0095] Study the mechanisms to support upper layer operation of the discovery model / process for sidelink relay, assuming no new physical layer channels / signals.

[0096] Figure 2 is an L2 U2N relay architecture diagram showing an example of a user plane protocol stack. The remote WTRU 202 may have a protocol stack including a Uu-SDAP sublayer and a Uu-PDCP sublayer, which correspond to the Uu-SDAP sublayer and the Uu-PDCP sublayer of the gNB 180. The protocol stack at the remote WTRU 202 may also include a PC5-SRAP sublayer, a PC5-RLC sublayer, a PC5-MAC sublayer, and a PC5-PHY sublayer, which correspond to the PC5-SRAP sublayer, PC5-RLC sublayer, PC5-MAC sublayer, and PC5-PHY sublayer of the U2N relay WTRU 204. The protocol stack at the U2N relay WTRU 204 may also include a Uu-SRAP sublayer, a Uu-RLC sublayer, a Uu-MAC sublayer, and a Uu-PHY sublayer, which correspond to the Uu-SRAP sublayer, Uu-RLC sublayer, Uu-MAC sublayer, and Uu-PHY sublayer of the gNB 180.

[0097] Figure 3 is an L2 U2N relay architecture diagram showing an example of a control plane protocol stack. The remote WTRU 202 may have a protocol stack including a Uu-RRC sublayer and a Uu-PDCP sublayer, which correspond to the Uu-RRC sublayer and the Uu-PDCP sublayer of the gNB 180. The protocol stack at the remote WTRU 202 may also include a PC5-SRAP sublayer, a PC5-RLC sublayer, a PC5-MAC sublayer, and a PC5-PHY sublayer, which correspond to the PC5-SRAP sublayer, PC5-RLC sublayer, PC5-MAC sublayer, and PC5-PHY sublayer of the U2N relay WTRU 204. The protocol stack at the U2N relay WTRU 204 may also include a Uu-SRAP sublayer, a Uu-RLC sublayer, a Uu-MAC sublayer, and a Uu-PHY sublayer, which correspond to the Uu-SRAP sublayer, Uu-RLC sublayer, Uu-MAC sublayer, and Uu-PHY sublayer of the gNB 180.

[0098] like Figure 2 and Figure 3As shown, the Sidelink Relay Adaptation Protocol (SRAP) sublayer is located above the RLC sublayer for both the CP (control plane) and UP (user plane) at both the PC5 interface and the Uu interface. The Uu SDAP, PDCP, and RRC sublayers terminate between the L2 U2N Remote WTRU 202 and the gNB 180, while the SRAP, RLC, MAC, and PHY sublayers terminate at each hop (i.e., the link between the L2U2N Remote WTRU 202 and the L2 U2N Relay WTRU 204 and the link between the L2 U2N Relay WTRU 204 and the gNB 180).

[0099] For L2 U2N (UE to Network) relay 204, the SRAP sublayer on the PC5 hop is used only for bearer mapping purposes. The SRAP sublayer is not present on the PC5 hop for relaying messages for L2 U2N remote WTRUs on BCCH (Broadcast Control Channel) and PCCH (Paging Control Channel). For messages for L2 U2N remote WTRUs on SRB0 (Signaling Radio Bearer 0), the SRAP sublayer is not present on the PC5 hop, but the SRAP sublayer is present on the Uu hop for both DL and UL.

[0100] For uplink communication at L2 U2N relay 204:

[0101] - The Uu SRAP sublayer supports UL bearer mapping between the ingress PC5 relay RLC channel and the egress Uu relay RLC channel for relaying over the L2 U2N relay WTRU Uu interface. For uplink relay traffic, different end-to-end RBs (SRBs or DRBs) of the same remote WTRU and / or different remote WTRUs 202 may be multiplexed on the same Uu relay RLC channel.

[0102] - The Uu SRAP sublayer supports L2 U2N remote WTRU identification for UL traffic. The identity information of the L2 U2N remote WTRU Uu radio bearer and the local remote UE ID are included in the Uu SRAP header at the UL so that the gNB 180 can associate the received packets for a specific PDCP entity associated with the correct Uu radio bearer of the remote WTRU 202.

[0103] - L2 U2N The PC5 SRAP sublayer at the remote WTRU 204 supports UL bearer mapping between the remote WTRU Uu radio bearers and the egress PC5 relay RLC channels.

[0104] For downlink communication at L2 U2N relay 204:

[0105] - The Uu SRAP sublayer supports DL bearer mapping at the gNB 180 to map the end-to-end radio bearers (SRBs, DRBs) of the remote WTRU 202 into the Uu relay RLC channel on the relay WTRU Uu interface. The Uu SRAP sublayer supports DL bearer mapping and data multiplexing between multiple end-to-end radio bearers (SRBs or DRBs) of a L2 U2N remote WTRU and / or different L2 U2N remote WTRUs 202 and one Uu relay RLC channel on the Uu interface of the relay WTRU.

[0106] - The Uu SRAP sublayer supports remote WTRU identification for DL ​​traffic. The identity information of the remote WTRU Uu radio bearer and the local remote WTRU ID are included in the Uu SRAP header by the gNB 180 at the DL so that the relay WTRU 204 can map packets received from the remote WTRU Uu radio bearer to its associated PC5 relay RLC channel.

[0107] - The PC5 SRAP sublayer at the relay WTRU 204 supports DL bearer mapping between the ingress Uu relay RLC channel and the egress PC5 relay RLC channel.

[0108] - The PC5 SRAP sublayer at the remote WTRU 202 associates packets received for a specific PDCP entity associated with the correct Uu radio bearer of the remote WTRU 202 based on the identity information included in the Uu SRAP header.

[0109] The Local Remote UE ID may be included in both the PC5 SRAP header and the Uu SRAP header. The L2U2N relay WTRU 204 is configured by the gNB 180 with the Local Remote UE ID to be used in the SRAP header. The Remote WTRU 202 obtains the Local Remote ID from the gNB 180 via UuRRC messages including RRCSetup, RRCReconfiguration, RRCResume, and RRCReestablishment. The Uu DRBs and Uu SRBs are mapped to different PC5 relay RLC channels and Uu relay RLC channels in both the PC5 hop and the Uu hop.

[0110] It is the responsibility of the gNB to avoid conflicts regarding the use of the Local Remote UE ID. The gNB 180 may update the Local Remote UE ID by sending the updated Local Remote UE ID to the relay WTRU 204 via an RRCReconfiguration message. The serving gNB 180 may perform the Local Remote UE ID update independently of the PC5 unicast link L2 ID update procedure.

[0111] Multipath operation with SL trunking in NR Release 18

[0112] 3GPP has started enhancing the NR SL relay specification in Release 18. One of the features that will be discussed is support for multipath operation with relays, where a remote WTRU is connected to the network via both direct and indirect paths, which has the potential to improve reliability and / or robustness and throughput of the remote WTRU.

[0113] The multipath relay scheme can also be used for WTRU aggregation, where the WTRU is connected to the network via a direct path and via another WTRU using a non-standardized WTRU-WTRU interconnect. WTRU aggregation is intended to provide applications that require high UL bit rates on 5G terminals, especially at the edge of the cell, where the normal WTRU may be too limited by the UL WTRU transmit power to achieve the required bit rate. In addition, WTRU aggregation can also improve the reliability, stability and latency of the service. That is, if the channel conditions of the terminal deteriorate, another terminal can be used to compensate for the unstable traffic performance caused by the changing channel conditions.

[0114] Multipath operation is listed as one of the core goals of Release 18. Specifically, RP-213585 proposes to study the benefits and potential solutions of multipath support to enhance reliability and throughput in the following scenarios where a UE uses one direct path and one indirect path to connect to the same gNB via 1) a Layer 2 UE-to-network relay or 2) via another UE (where UE-UE interconnection is assumed to be ideal) (e.g., by switching between multiple paths or utilizing multiple paths simultaneously). The solution for 1) can be reused for 2), without excluding the possibility of excluding parts of the solution that are not necessary for the operation of 2).

[0115] A study of the benefits and potential solutions will be completed in RAN#98, which will determine whether and / or how normative work should be initiated.

[0116] The UE to network relay in scenario 1) reuses the Release 17 solution as a baseline.

[0117] It is assumed that supporting Layer 3 UE-to-network relay in multipath scenarios will not have an impact on the RAN and that work and solutions adhere to SA2 to make progress.

[0118] Sidelink measurements and scheduling

[0119] In SL operation, the WTRU may configure the associated peer WTRU to perform NR sidelink measurements and reporting on the corresponding PC5-RRC connection according to the NR sidelink measurement configuration to be unicast by the RRCReconfigurationSidelink message.

[0120] The WTRU shall derive NR sidelink measurements by measuring one or more demodulation reference signals (DMRS) associated with each PC5-RRC connection as configured by the associated peer WTRU. For all NR sidelink measurements, the WTRU applies layer 3 filtering before using the measured results to evaluate reporting criteria and measurement reports. In Release 16, only NR sidelink RSRP may be configured as a triggered quantity and a reported quantity.

[0121] The following measurement events are defined for NR sidelink:

[0122] - Event S1: the serving cell becomes better than a threshold;

[0123] - Event S2: The serving cell becomes worse than a threshold.

[0124] Measurement reports based on S1 and S2 are used by the WTRU that receives the reports to adjust the power level when transmitting data.

[0125] NR sidelink transmission has the following two resource allocation modes:

[0126] - Mode 1: Sidelink resources are scheduled by gNB;

[0127] - Mode 2: The WTRU autonomously selects sidelink resources from a (pre-)configured sidelink resource pool based on a channel sensing mechanism.

[0128] For in-coverage WTRUs, the WTRU may be configured to operate in either Mode 1 or Mode 2. For out-of-coverage WTRUs, only Mode 2 may be employed.

[0129] To enhance the QoS of NR sidelink transmissions, congestion control is important (especially in Mode 2) to prevent the transmitting WTRU from occupying too many resources in the sidelink transmission. Two metrics are defined for this purpose:

[0130] - Channel Busy Rate (CBR): the portion of the subchannel whose RSSI exceeds a preconfigured value within a specific duration;

[0131] - Channel Occupancy Ratio (CR): The ratio of the total number of subchannels used by transmissions to the total number of configured (granted) subchannels within a given measurement.

[0132] For congestion control, an upper limit of the CR denoted by CRlimit is imposed on the transmitting WTRU, where CRlimit is a function of the CBR and the priority of the sidelink transmission.The amount of resources occupied by the transmitting WTRU may not exceed CRlimit.

[0133] The CBR report may also be used by the gNB to determine the resource pool to allocate to the sidelink communication (e.g., if the WTRU participating in the sidelink communication is reporting a high CBR, then increase the resource pool, and if the reported CBR is lower, then decrease the resource pool).

[0134] In addition to peer WTRUs participating in sidelink operations configuring each other for measurements (periodic or S1 / S2 events), for in-coverage operation (i.e., the remote WTRU is within the coverage of the gNB), the gNB may configure CBR measurements to the remote WTRU, which may also be periodic or event triggered.

[0135] The following two measurement events can be configured for CBR measurement reporting:

[0136] - Event C1: The CBR of the NR sidelink communication becomes better than the absolute threshold;

[0137] - Event C2: The CBR of the NR sidelink communication becomes worse than the absolute threshold.

[0138] Split bearer in dual connectivity

[0139] In dual connectivity (DC), the WTRU is served by two nodes, each node comprising a set of cells, the set of cells comprising a master cell group (MCG) and a secondary cell group (SCG). A bearer may be associated only with an MCG, only with an SCG, or a bearer may be configured as a split bearer.

[0140] Figure 4 is an architectural diagram illustrating an example protocol view of split bearers.

[0141] As with any bearer, the WTRU 102 will have one PDCP entity associated with it, and the peer PDCP entity on the network side terminates at one of the gNBs 180a, 180b (primary or secondary). In the DL, the CN sends data to the gNB where the PDCP terminates (gNB1 in the figure above), and the sending depends on the network to send the data directly to the WTRU 102 via the link between gNB1 180a and the WTRU 102, or forward the PDCP PDU to gNB2 180b (e.g., via the Xn interface), and gNB2 180b will send the data to the WTRU 102 via the link between itself and the WTRU 102.

[0142] In the UL, the WTRU 102 is configured to use one of the paths as the primary path and the other as the secondary path. A threshold (e.g., UL split buffer threshold) is also configured. If the UL buffer size for the bearer is less than the threshold, the PDCP will only push data to the RLC associated with the primary path. However, if the buffer size becomes greater than the threshold, the WTRU may push data to either path (e.g., left to the WTRU implementation).

[0143] As discussed above, when the UL buffer size for the split bearer becomes larger than the UL split buffer threshold, the WTRU may push data to either the primary path or the secondary path. One of the reasons for leaving it to the WTRU implementation is that the scheduling of the two links is done independently by the two gNBs.

[0144] Figure 5 is an architectural diagram illustrating an example protocol view of splitting bearers in the context of multipath operation.

[0145] In multipath operation, the direct link between the remote WTRU 502 and the gNB 180 (e.g., Uu1) and the backhaul link between the relay WTRU 504 and the gNB 180 may be served by the same gNB 180 or even by the same cell of the same gNB 180. Also, if Mode 1 is chosen to schedule the SL between the remote WTRU 502 and the relay WTRU 504, the scheduling of all links (e.g., Uu1, Uu2, SL) is done by the gNB 180. Even if Mode 2 is used and the resource pools that the remote WTRU 502 can use autonomously are pre-configured by the gNB 180 for the SL, the gNB 180 is still the entity that decides the resource pool configuration and can therefore control the scheduling over the SL (even without a specific grant or indication from the gNB 180 for each individual transmission, as is the case with Mode 1).

[0146] Therefore, in the multipath relay scenario where the same gNB 180 is responsible for scheduling of both links, the traditional behavior of letting the WTRU decide the path selection for the UL traffic of the split bearers once the UL split buffer threshold has been exceeded is not optimal.

[0147] It is proposed to consider Uu and / or SL radio conditions (e.g., SL and / or Uu RSRP, SL CBR, etc.) when deciding whether to push data for a split bearer over Uu and SL, instead of (or in addition to) a split buffer threshold (e.g., a split buffer threshold that is dynamically updated based on Uu and / or SL radio conditions).

[0148] Although this approach works better than the fixed split buffer threshold approach, it does not take into account the conditions at the relay WTRU 504. For example, even if the radio conditions of the SL are excellent (e.g., high RSRP, low CBR, etc.), packets transmitted via the relay path (e.g., for split bearers, for SL-terminated bearers, etc.) may experience significant delays and / or queuing at the relay WTRU 504 due to poor backhaul Uu radio conditions, additional buffering at the relay WTRU 504 due to pending UL data (e.g., the relay WTRU 504 may be relaying several remote WTRUs 502), DL data buffered at the relay WTRU 504 (e.g., for the remote WTRU 502 concerned or for other remote WTRUs 502 for which the WTRU 504 is acting as a relay), which may cause the CBR in the SL path to increase and may degrade performance.

[0149] Overview

[0150] Figure 6 is a system diagram showing an example multipath scenario. Certain representative embodiments of the present disclosure are mainly directed to the following and Figure 6 The multipath scenario shown in Figure 6 In the embodiment of the present invention, a remote WTRU 602 (e.g., WTRU 102) is connected to the same gNB 180 via a direct link and via a relay link of a SL relay WTRU 604 (e.g., another WTRU 102). However, without loss of generality, certain representative embodiments described below are applicable to other scenarios, such as (1) a WTRU in dual connectivity with two different gNBs, where one of the links is a direct link and the other is a relay link, (2) a remote WTRU 602 is connected via two or more relays, or (3) a multi-hop scenario (e.g., where the relay WTRU 604 is further connected to a parent relay WTRU, which is connected to the gNB). Figure 6 , the direct link 606 corresponds to the Uu1 interface between the remote WTRU 602 and the gNB 180. The relay link corresponds to the SL link 608 between the remote WTRU 602 and the relay WTRU 604 and the Uu2 link 610 between the relay WTRU 604 and the gNB 180.

[0151] In all representative embodiments described below, it is assumed that the split bearer can be configured with a primary path (Uu1 link 606 or SL link 608) and a secondary path (SL link 608 or Uu1 link 606) as in conventional NR. A UL split buffer threshold can be configured, where setting the threshold to zero means there is no primary path, and setting the threshold to infinity means that only the primary path is used regardless of the UL buffer size.

[0152] Flow control information from the relay WTRU to the remote WTRU

[0153] In certain representative embodiments, the relay WTRU 604 may be configured by the gNB 180 to provide flow control (FC) information to the remote WTRU 602. For example, the FC information may include any of a DL buffer status, a UL buffer status, a DL buffer level, a DL buffer status change rate, a UL buffer status change rate, a latency on backhaul Uu, radio link information on backhaul Uu, and / or availability of UL resources on Uu.

[0154] In certain representative embodiments, the DL buffer status may be related to pending data to be transmitted from the relay WTRU 604 to any remote WTRU 602. For example, the DL buffer status may refer to a total DL buffer level at the relay WTRU 604 for the remote WTRU 602 in question. For example, the DL buffer status may refer to a total DL buffer level at the relay WTRU 604 for any (e.g., all) remote WTRUs 602 served by the relay WTRU 604. For example, the DL buffer status may refer to a DL buffer level at the relay WTRU 604 for the remote WTRU 602 in question, for any of certain bearers, logical channels (e.g., LCIDs), radio link control (RLC) channels, and the like. For example, the DL buffer status may refer to a DL buffer level at the relay WTRU 604 for all remote WTRUs 602, for any of certain bearers, LCIDs, RLC channels, and the like.

[0155] In certain representative embodiments, the UL buffer status may be related to pending data to be transmitted from the relay WTRU 604 to the gNB 180. For example, the UL buffer status may refer to the total UL buffer level at the relay WTRU 604 for the associated remote WTRU 602. For example, the UL buffer status may refer to the total UL buffer level at the relay WTRU 604 for any (e.g., all) remote WTRUs 602 served by the relay WTRU 604. For example, the UL buffer status may refer to the DL buffer level at the relay WTRU 604 for the associated remote WTRU 602, for certain bearers, LCIDs, RLC channels, etc.

[0156] In certain representative embodiments, the DL buffer level at the relay WTRU 604 may be relevant to any (eg, all) remote WTRUs 602 for certain bearers, LCIDs, RLC channels, etc.

[0157] In certain representative embodiments, a DL buffer status change rate may be provided similar to the DL buffer status, but taking into account the rate of change, such as within a given configured time.

[0158] In certain representative embodiments, a UL buffer status change rate may be provided similar to the UL buffer status, but taking into account the rate of change, such as within a given configured time.

[0159] In certain representative embodiments, the latency on the backhaul Uu may be related to the amount of time it takes for a packet to traverse the backhaul Uu link. For example, the latency may be configured to include buffering time at the relay WTRU 604, such as the time from receiving a packet from Uu at the relay WTRU 604 to receiving an ACK (e.g., a HARQ ACK for all transport blocks containing data for the packet) from the gNB 180. For example, the latency may be (e.g., only) the transmit time on Uu, such as without taking into account the buffering time at the relay WTRU 604. For example, the latency may be any of an average / mean, a maximum, a minimum, a standard deviation, and / or a moving average filtered value with some coefficient favoring older or more recent latency values, and the like. For example, the latency may be calculated per LCID, per bearer, per remote WTRU 602, and the like.

[0160] In certain representative embodiments, the radio link information about the backhaul Uu may refer to any of RSRP, RSRQ, SINR, etc. of the backhaul Uu. For example, the radio link information may be any of an average value / mean, a maximum value, a minimum value, a standard deviation, and / or a moving average filtered value with some coefficients favoring older or more recent radio link signal levels, etc.

[0161] In certain representative embodiments, the availability of UL resources on Uu may refer to the presence of a UL configuration grant on Uu for the relay WTRU 604. For example, the availability of UL resources may include details such as size, duration, and / or periodicity.

[0162] In certain representative embodiments, the FC information may (e.g., additionally) include information such as a DL data rate between the gNB 180 and the relay WTRU 604, a DL data rate between the relay WTRU 604 and a remote WTRU 602 other than the associated WTRU, a UL data rate between the gNB 180 and the relay WTRU 604, etc. Each such piece of information may have an associated granularity, such as at a bearer and / or LCID level, for example.

[0163] In certain representative embodiments, the FC information may (e.g., additionally) include any of an RRC state change of the relay WTRU 604, fault-related information (e.g., a handover failure or a radio link failure experienced at the relay WTRU 604), and the mobility of the relay WTRU 604 (e.g., the relay WTRU 604 is handed over from one cell of the same gNB 180 to another cell, the relay WTRU 604 is handed over to another gNB 180, etc.).

[0164] Triggering of flow control reports / information from the relay WTRU to the remote WTRU

[0165] In certain representative embodiments, the relay WTRU 604 may be configured to provide FC information and / or reports to the remote WTRU 602 periodically (eg, every X ms).

[0166] In certain representative embodiments, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 based on trigger conditions, which may include, for example, any of the following:

[0167] -DL buffer level is above / below / within a certain threshold;

[0168] -UL buffer level is above / below / within a certain threshold;

[0169] -DL buffer change rate is above / below / within a certain threshold;

[0170] -UL buffer change rate is above / below / within a certain threshold; and / or

[0171] -The latency on the backhaul Uu is above / below / within a certain threshold.

[0172] For example, any of the above thresholds may be specified at different levels of granularity (eg, pertaining to all remote WTRUs, pertaining to remote WTRUs 602 providing FC, pertaining to only specific bearers / LCIDs / RLC channels, etc.).

[0173] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 when its RRC state changes.

[0174] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 when it performs a handover (HO) or cell reselection.

[0175] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 upon encountering a failure (eg, HO failure, RLF, etc.).

[0176] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 based on a request by the remote WTRU 602. This may be performed in a one-time request-response manner. Alternatively, the remote WTRU 602 may agree to receive the information (e.g., periodically, or specifying trigger conditions similar to those discussed above and related to the trigger conditions specified by the gNB). The remote WTRU 602 may also indicate the information it is interested in (e.g., UL buffer level or / and DL buffer level and / or latency, etc.).

[0177] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 via dedicated signaling (eg, PC5-RRC, MAC CE, etc.).

[0178] For example, the relay WTRU 604 may be configured to provide FC information / reports to the remote WTRU 602 via broadcast / multicast signaling through PC5.

[0179] Remote WTRU actions based on flow control information received from the relay WTRU

[0180] In certain representative embodiments, the remote WTRU 602 may be configured to modify the UL split buffer threshold used by the split bearer based on the FC received from the relay WTRU 604 (eg, taking into account one or more values ​​of the indicated flow control element).

[0181] For example, the WTRU may be configured with multiple split buffer thresholds. Each value may correspond to a specific value or value range of one or more of the elements in the FC information / report (e.g., threshold 1 when the UL buffer level indicated in the FC is below level 1, threshold 2 when the UL buffer level indicated in the FC is below level 2, etc.)

[0182] For example, the WTRU may be configured with a baseline separation buffer threshold and a scaling factor that depends on a specific value or value range of one or more of the elements in the FC information / report. For example, the WTRU may be configured to use the baseline separation buffer threshold when the UL buffer level indicated in the FC is below level 1, and for values ​​above level 1, increase / decrease the separation buffer threshold by the percentage difference between the indicated value and level 1. For example, the percentage difference may be determined based on the scaling factor. For example, the increase (or decrease) may be based on a function of any one of the scaling factor, the baseline separation buffer threshold, the percentage difference, and / or level 1.

[0183] For example, the WTRU may be configured with a baseline buffer threshold and an incremental value applied that depends on a specific value or value range of one or more of the elements in the FC information / report (e.g., when the UL buffer level indicated in the FC is below level 1, a baseline buffer threshold is used, and for values ​​above level 1, an increase / decrease of a certain amount / percentage is applied for each buffer level increase of a certain amount / percentage, etc.).

[0184] In certain representative embodiments, the remote WTRU 602 may be configured to distribute UL data between Uu and SL based on a dynamic distribution percentage (e.g., 20% on Uu and 80% on SL), where the percentage depends on the value of one or more of the elements included in the received FC.

[0185] For example, the WTRU may be configured with multiple distribution percentage values, each value corresponding to a specific value or value range of one or more of the elements in the FC information / report (e.g., if the UL buffer level indicated in the FC information is below level 1, then percentage 1 of the UL data is placed on the SL, if the UL buffer level indicated in the FC information is between level 1 and level 2, then percentage 2 of the UL data is placed on the SL, and if the UL buffer level indicated in the FC information is above level 3, then percentage 3 of the UL data is placed on the SL).

[0186] For example, the WTRU may be configured with a baseline distribution percentage value and a scaling factor that depends on a specific value or value range of one or more of the elements in the FC information / report. For example, the WTRU may be configured to use the baseline distribution percentage if the UL buffer level indicated in the FC is below level 1, otherwise reduce the threshold by the percentage difference between the currently indicated UL buffer level and level 1. For example, the percentage difference may be determined based on the scaling factor. For example, the reduction may be based on a function of any one of the scaling factor, the baseline separation buffer threshold, the percentage difference, and / or level 1.

[0187] In some embodiments, the WTRU may be configured to switch the primary path of a split bearer based on the received FC.

[0188] For example, if the FC indicates that the UL buffer level at the relay WTRU 604 is below level 1, the WTRU may be configured to switch the primary path to the SL.

[0189] For example, if the FC indicates that the UL buffer level at the relay WTRU 604 is above level 2, the WTRU may be configured to switch the primary path to Uu.

[0190] For example, the WTRU may select the primary path for the case of two paths via relays based on the path with the lowest UL buffer level.

[0191] In certain representative embodiments, the WTRU may be configured to suspend or stop using the SL for UL data transmission based on received FC information. For example, if the FC indicates that the UL buffer level at the relay WTRU 604 is above level 1, the WTRU may be configured to suspend / stop using the SL. This behavior may be used for any bearer (e.g., split bearer, SL bearer, etc.), or it may be configured separately for split bearers and SL bearers (e.g., setting a lower UL buffer level threshold for stopping transmitting UL data via the SL for the split bearer, and setting a higher UL buffer level threshold for stopping transmitting UL data via the SL for the SL bearer, etc.).

[0192] In certain representative embodiments, the WTRU may be configured to resume using the SL for UL data transmission based on a received FC. For example, if the FC indicates that the UL buffer level at the relay WTRU 604 is below level 2, the WTRU may be configured to resume using the SL. This behavior may be used for any bearer (e.g., split bearer, SL bearer, etc.), or it may be configured separately for split bearers and SL bearers (e.g., setting a lower UL buffer level threshold for resuming UL data transmission via SL for SL bearers, and setting a higher UL buffer level threshold for resuming UL data transmission via SL for split bearers, etc.).

[0193] In certain representative embodiments, the remote WTRU 602 may perform any of the above actions based on a single FC report.

[0194] In certain representative embodiments, the remote WTRU 602 may perform any of the above actions based on a specific number of consecutive FC reports (e.g., such as a specific number of consecutive FC reports received within a specific time that indicate the UL buffer level is greater than the configured level for changing the path selection behavior).

[0195] In certain representative embodiments, the remote WTRU 602 may perform any of the above actions based on a difference or rate of change in reported values ​​of one or more elements in two or more consecutive FC reports (e.g., the UL buffer level indicated in the current FC report has increased by x% compared to the amount reported in the previous FC report).

[0196] Consideration of Uu and SL service cells

[0197] The application of the above embodiments may further depend on whether the SL and Uu paths are associated with the same cell or different cells.

[0198] In certain representative embodiments, the remote WTRU 602 may apply any of the embodiments discussed above only when the SL is also served by the same cell as the Uu link (or vice versa). Alternatively, the remote WTRU 602 may apply different embodiments or different behaviors when the SL and Uu are served by different cells. Alternatively, the remote WTRU 602 may not consider flow control for the case of different cells.

[0199] In certain representative embodiments, the remote WTRU 602 may be configured to apply different configurations depending on whether the SL is served by a cell different from the cell serving the Uu link. For example, the WTRU may be configured with two sets of configurations, one set applicable to the same cell scenario and the other set applicable to the different cell scenario. Alternatively, instead of two sets of configurations, the WTRU may be configured with configurations related to the same cell scenario and information on how to convert the separation buffer threshold or distribution factor to different cell scenarios (e.g., the incremental value or scaling factor to be applied)

[0200] In certain representative embodiments, the remote WTRU 602 may be configured to apply different configurations depending on whether the SL is served by a different gNB than the gNB 180 serving the Uu link (e.g., the WTRU is in DC operation and the WTRU is able to identify the gNB ID from the cell identity). For example, the WTRU may be configured with two sets of configurations, one set applicable to the same gNB case and the other set applicable to the different gNB case. Alternatively, instead of two sets of configurations, the WTRU may be configured with configurations related to the same gNB scenario and information on how to translate the buffer threshold or distribution factor to the different gNB scenario (e.g., the increment value or scaling factor to apply)

[0201] Considerations for Resource Allocation Patterns at Remote WTRUs

[0202] The application of the above embodiments may further depend on the resource allocation mode of the remote WTRU 602 on the SL.

[0203] In certain representative embodiments, the remote WTRU 602 may apply any of the embodiments discussed above only when the remote WTRU 602 is configured with Mode 2 resource allocation. Otherwise, when the remote WTRU 602 is configured with Mode 1 resource allocation, it will apply different embodiments or not consider flow control.

[0204] Applicability to a specific bearer or set of bearers

[0205] In certain representative embodiments, the split bearer configuration according to any of the above embodiments may be applicable to all bearers. For example, each split bearer has its own split buffer configuration, which may include a set of split buffer thresholds corresponding to a specific range of UL buffer levels reported by FC information / reports, or a baseline threshold and a scaling factor or increment value, and how to apply the scaling / increment when the UL buffer level is above / below the baseline threshold.

[0206] In certain representative embodiments, the split bearer configuration according to any of the above solutions may be configured per split bearer.

[0207] In certain representative embodiments, the split bearer configuration according to any of the above embodiments may be applicable to all split bearers using Uu as the primary path.

[0208] In certain representative embodiments, the split bearer configuration according to any of the above solutions may be applicable to all split bearers using SL as the primary path.

[0209] In certain representative embodiments, a split bearer configuration according to any of the above solutions may be applicable to a collection of split bearers (e.g., bearers belonging to a list of bearers (such as bearer IDs), bearers with a specific QoS type, logical channels with a priority higher than a threshold, etc.).

[0210] In certain representative embodiments, the split bearers may share a portion of the split bearer configuration and have other portions that are bearer specific (e.g., per bearer, for a subset of bearers). For example, each split bearer may have its own baseline split buffer threshold, and all bearers or a subset of bearers (e.g., specified in a list of bearer IDs or QoS types) share a scaling factor or delta value to apply when the UL buffer level reported in the FC information is above a certain value.

[0211] Instructions for network behavior changes

[0212] In certain representative embodiments, the remote WTRU 602 may be configured to send an indication to the network whenever the behavior regarding the split bearer operation is updated. For example, the WTRU may send an indication to the network when the WTRU performs one or more of the following actions as a result of the received FC report / information:

[0213] - Update the split bearer buffer threshold;

[0214] - Update the distribution percentage between Uu and SL;

[0215] - Switch the primary path of the split bearer to Uu

[0216] -Switch the primary path of the split bearer to the SL;

[0217] - suspend any data transmission via the SL; and / or

[0218] -Resume data transmission via SL.

[0219] In certain representative embodiments, any changes are indicated by the remote WTRU 602.

[0220] In certain representative embodiments, the change must be significant, according to some pre-configuration, to trigger an indication to the network. For example, the remote WTRU 602 may be configured to send an indication to the network when the split buffer threshold has changed by a certain amount (e.g., an absolute value, a percentage value, etc.).

[0221] In certain representative embodiments, the indication to the network may be sent via a dedicated message (eg, RRC, MAC CE, etc.).

[0222] In certain representative embodiments, the indication may be included in another message (e.g., in a measurement report, in a SL or Uu Buffer Status Report (BSR) sent to the gNB, etc.).

[0223] In certain representative embodiments, the WTRU may maintain a log of the history of changes in its behavior (eg, split bearer changes).

[0224] In certain representative embodiments, the network may request this information (eg, in a WTRU Assistance Information message).

[0225] In certain representative embodiments, the indication sent to the network may include information about the flow control information received from the relay WTRU 604 (e.g., detailed information, summary information within a certain configured time period, information about abnormal flow control information, such as the indicated value being greater than or less than a certain configured value, etc.).

[0226] Figure 7 is a system diagram showing an example of signaling for enabling certain representative embodiments discussed above. Figure 7 In the embodiment, the relay WTRU 701, the remote WTRU 703 and the gNB 705 are in communication. As in the conventional system, the remote WTRU 703 is provided with bearer configuration information and / or SL flow control usage configuration information. The bearer configuration information and / or SL flow control usage configuration information may be received via the SL or Uu1 link, but in Figure 7 , shown at 710 as being received via the Uu1 link from the gNB 705. In addition, the relay WTRU 701 may receive flow control related configuration information 712 from the gNB 705 via the Uu2 link, such as which triggers are used to send flow control information 714 to the remote WTRU and which specific flow control information 714 is sent.

[0227] As shown, the relay WTRU 701 may transmit flow control information 714 to the relay WTRU 703. The flow control information 714 may include any of DL transmission status (e.g., level / status for remote UEs to let the remote UE know how much data is pending in DL via SL), UL transmission status (e.g., buffer level / status to let the remote UE know how much data is pending in UL via backhaul Uu2), latency on Uu, radio link quality of backhaul Uu2, RRC state change of the relay UE 701, failure indication (RLF, HOF), etc. The relay WTRU 701 may periodically and / or based on a buffer level threshold, latency threshold, Uu quality threshold, a request from a remote UE (e.g., such as Figure 7 ), RRC state changes and / or detection of failures (e.g., RLF, HOF, etc.) to send flow control information to the remote UE 703. Figure 7 As described in the flow control related configuration information 712, both the trigger item for transmitting the flow control information 714 and the type of the transmitted flow control information 714 can be configured by the gNB 705 in the relay WTRU 701.

[0228] The remote WTRU 703 is configured to change its behavior based on the flow control information 714 from the relay WTRU 701. These changes may include one or more of the following: how much data is transmitted over the SL for split bearers, suspending / resuming the SL path for some bearers (e.g., suspending for a given time when a bad FC is received, suspending until a good FC is received indicating better conditions at the relay WTRU 701, etc.), different behaviors for different bearers (depending on the QoS profile of the bearers), and sending indications to the gNB 705 about the changed behavior (e.g., SL path suspension, split bearer threshold modification, etc.).

[0229] Despite Figure 7 Not depicted, but as previously mentioned, the remote WTRU 703 may report (eg, indicate) information about flow control changes that have been made at the remote WTRU 703 to the network via the Uu1 or SL link.

[0230] Figure 8 6 is a process diagram illustrating an example process for flow control at a remote WTRU 602. In certain representative embodiments, the remote WTRU 602 may operate in a multipath setting using a direct link (e.g., Uu) with a base station (e.g., gNB 180) and a sidelink (SL) with a relay WTRU 604. For example, the relay WTRU 604 may use a backhaul direct link (Uu) with the same or a different base station (e.g., gNB 180) than the remote WTRU 602. For example, the remote WTRU 602 and / or the relay WTRU 604 may be provided as the corresponding WTRU 102.

[0231] like Figure 8 As shown, at 802, the remote WTRU 602 may receive configuration information for handling data transmission on Uu and SL from a base station (e.g., gNB 180). For example, the configuration information may include: information indicating an association of FC information with a data distribution percentage on Uu and SL. For example, the configuration information received at 802 may be provided as the SL FC usage configuration at 710. At 804, the remote WTRU 602 may receive FC information from the relay WTRU 604. For example, the FC information received at 804 may be provided as the FC information at 714. At 806, the remote WTRU 602 may transmit data using Uu and SL based on the distribution percentage associated with the received FC information. At 808, the remote WTRU 602 may transmit information to the base station indicating that the transmission behavior of the remote WTRU has been modified.

[0232] In certain representative embodiments, the configuration information (e.g., received at 802) may include information indicating an association of a set of FC information with a set of distribution percentages. For example, the set of FC information may include the FC information (e.g., which will be received at 804). For example, the set of distribution percentages may include the distribution percentages.

[0233] In certain representative embodiments, the remote WTRU 602 may determine a distribution percentage from a set of distribution percentages based on an association with received FC information.

[0234] In certain representative embodiments, the configuration information may also include information indicating a scaling factor and / or a threshold. For example, the remote WTRU 602 may transmit data using Uu and SL at 808 based on (i) the received FC information being above a threshold, (ii) a distribution percentage associated with the received FC information, and / or (iii) a distribution percentage modified using a scaling factor.

[0235] In certain representative embodiments, the configuration information may also include information indicating a threshold. For example, the remote WTRU 602 may transmit data using Uu and SL at 808 based on (i) a distribution percentage associated with the received FC information and (ii) a difference between the received FC information and the threshold.

[0236] In certain representative embodiments, the received FC information may include any of the following: a downlink buffer status of data to be transmitted by the relay WTRU, a rate of change of the downlink buffer status, a downlink data rate at the relay WTRU, an uplink buffer status of data to be transmitted by the relay WTRU, a rate of change of the uplink buffer status, an uplink data rate at the relay WTRU, a latency of the backhaul Uu between the relay WTRU and the base station, radio link information of the backhaul Uu, resource availability of the backhaul Uu, and / or a connection status of the backhaul Uu. For example, the downlink buffer status may be associated with data to be transmitted by the relay WTRU 604 to the remote WTRU 602 using the SL. For example, the uplink buffer status may be associated with data to be transmitted by the relay WTRU 604 using the backhaul Uu.

[0237] In certain representative embodiments, configuration information may be associated with cells serving remote WTRUs and relay WTRUs.

[0238] In certain representative embodiments, the configuration information may be associated with a first cell serving a remote WTRU. For example, the first cell may be different from a second cell serving a relay WTRU.

[0239] In certain representative embodiments, Uu and SL may be associated with a split bearer. For example, a split bearer may be configured to use Uu and SL as a primary path and a secondary path, or vice versa.

[0240] In certain representative embodiments, Uu may be set as the primary path for the split bearer, such as based on received FC information.

[0241] In certain representative embodiments, the SL may be set as the primary path for the split bearer, such as based on received FC information.

[0242] In certain representative embodiments, information indicating that the transmission behavior of the remote WTRU has been modified may be included in any of a radio resource control (RRC) message, a medium access control (MAC) control element, a measurement report, and / or a buffer status report (BSR).

[0243] Fig. 9 6 is a process diagram illustrating an example process for enabling flow control by a relay WTRU 604. In certain representative embodiments, the remote WTRU 604 may be operable to provide a multipath setup for the remote WTRU 602 using a direct link (e.g., Uu) with a base station (e.g., gNB 180) and a sidelink (SL) with the relay WTRU 604. For example, the relay WTRU 604 may use a backhaul direct link (Uu) with the same base station or a different base station (e.g., gNB 180) than the remote WTRU 602. For example, the remote WTRU 602 and / or the relay WTRU 604 may be provided as the corresponding WTRU 102.

[0244] like Fig. 9 As shown, at 902, the relay WTRU 604 may determine whether one or more trigger conditions are satisfied. At 904, the relay WTRU 604 may transmit FC information to the remote WTRU based on satisfying the one or more trigger conditions. For example, the FC information transmitted at 904 may be provided as the FC information at 714. At 906, after transmitting the FC information at 904, the relay WTRU 604 may use the SL to relay data received from the remote WTRU 602 to the base station. For example, the remote WTRU 602 may modify its use of the SL based on the FC information transmitted by the relay WTRU 604 at 904.

[0245] In certain representative embodiments, the FC information transmitted at 904 may be associated with a distribution percentage of data to be transmitted by the remote WTRU 602 using Uu between the remote WTRU 602 and the base station and SL between the remote WTRU 602 and the relay WTRU 604 .

[0246] In certain representative embodiments, the relay WTRU 604 may receive configuration information indicating one or more trigger conditions from the base station. For example, the configuration information indicating one or more trigger conditions may be provided to the relay WTRU 604 as (eg, a portion of) the FC-related configuration information at 712.

[0247] In certain representative embodiments, the relay WTRU 604 may receive one or more types of configuration information associated with one or more trigger conditions indicating FC information from the base station. For example, various trigger conditions for providing FC information to the remote WTRU 602 are described herein, such as trigger items related to the UL buffer and / or DL ​​buffer of the relay WTRU 604.

[0248] In certain representative embodiments, the FC information transmitted at 904 may include any of the following: a downlink buffer status of data to be transmitted by the relay WTRU, a rate of change of the downlink buffer status, a downlink data rate at the relay WTRU, an uplink buffer status of data to be transmitted by the relay WTRU, a rate of change of the uplink buffer status, an uplink data rate at the relay WTRU, a latency of the backhaul Uu between the relay WTRU and the base station, radio link information of the backhaul Uu, resource availability of the backhaul Uu and / or a change in the connection of the backhaul Uu.

[0249] In certain representative embodiments, one or more trigger conditions may include any of the following: a configured time period, a downlink buffer status of data to be transmitted by the relay WTRU 604 is above (or below a threshold), a rate of change of the downlink buffer status is above (or below a threshold), an uplink buffer status of data to be transmitted by the relay WTRU 604 is above (or below a threshold), a rate of change of the uplink buffer status is above (or below a threshold), a latency of the backhaul direct link (Uu) between the relay WTRU and the base station is above (or below a threshold), a change in the connection of the backhaul Uu, and / or receiving a request for FC information from the remote WTRU 602.

[0250] In certain representative embodiments, one or more trigger conditions may be associated with one or more separate bearers, one or more logical channels, one or more radio link control channels, a remote WTRU and / or a group of remote WTRUs (e.g., associated with data to be transmitted using them).

[0251] In certain representative embodiments, the FC information at 904 may be included in any of a radio resource control (RRC) message and / or a medium access control (MAC) control element.

[0252] In certain representative embodiments, the FC information at 904 may be transmitted via broadcast or multicast signaling using the SL.

[0253] Fig.10 6 is a process diagram illustrating another example process for flow control at a remote WTRU 602. In certain representative embodiments, the remote WTRU 602 may operate in a multipath setting using a direct link (e.g., Uu) with a base station (e.g., gNB 180) and a sidelink (SL) with a relay WTRU 604. For example, the relay WTRU 604 may use a backhaul direct link (Uu) with the same base station or a different base station (e.g., gNB 180) than the remote WTRU 602. For example, the remote WTRU 602 and / or the relay WTRU 604 may be provided as the corresponding WTRU 102.

[0254] like Fig.10 As shown, at 1002, the remote WTRU 602 may receive configuration information for handling data transmission on Uu and SL from a base station. For example, the configuration information may include: information indicating an association of flow control (FC) information with a data transmission behavior of the remote WTRU 602. For example, the configuration information received at 1002 may be provided as the SL FC usage configuration at 710. At 1004, the remote WTRU 602 may receive FC information from the relay WTRU 604. For example, the FC information received at 804 may be provided as the FC information at 714. At 1006, the remote WTRU 602 may transmit data using Uu and SL using the data transmission behavior associated with the received FC information.

[0255] In certain representative embodiments, the configuration information received at 1002 may include information indicating an association of a set of FC information with a set of data transmission behaviors for the remote WTRU 602. For example, various data transmission behaviors (eg, remote WTRU actions) are described herein.

[0256] In certain representative embodiments, the remote WTRU 602 may determine the data transmission behavior from a set of data transmission behaviors based on an association with the received FC information.

[0257] In certain representative embodiments, the data transmission behavior may include an uplink split buffer threshold (or a modification thereof). For example, the remote WTRU 602 may transmit data using Uu and SL at 1006 (e.g., transmit data distributed over Uu and SL) based on the amount of data to be transmitted at 1006 and the uplink split buffer threshold.

[0258] In certain representative embodiments, the data transmission behavior may include a distribution percentage between Uu and SL. For example, the remote WTRU 602 may transmit data at 1006 using Uu and SL (eg, transmit data distributed on Uu and SL) based on the distribution percentage.

[0259] In certain representative embodiments, the data transmission behavior may include setting one of Uu and SL as the primary path. For example, the remote WTRU 602 may transmit data using Uu and SL at 1006 (e.g., transmit data distributed over Uu and SL) based on the primary path and / or the uplink buffer level.

[0260] In certain representative embodiments, the data transmission behavior may include resuming (or suspending) the use of one of Uu and SL. For example, the remote WTRU 602 may transmit data including resuming the use of Uu or SL at 1006. For example, the remote WTRU 602 may transmit data including suspending the use of SL or SL at 1006.

[0261] In certain representative embodiments, the received FC information may include any of the following: a downlink buffer status of data to be transmitted by the relay WTRU 604, a rate of change of the downlink buffer status, a downlink data rate at the relay WTRU 604, an uplink buffer status of data to be transmitted by the relay WTRU 604, a rate of change of the uplink buffer status, an uplink data rate at the relay WTRU, a latency of the backhaul Uu between the relay WTRU 604 and a base station (e.g., gNB 180), radio link information of the backhaul Uu, resource availability of the backhaul Uu, and / or a connection status of the backhaul Uu.

[0262] In certain representative embodiments, the downlink buffer status may be associated with data to be transmitted by the relay WTRU 604 to the remote WTRU 602 using the SL.

[0263] In certain representative embodiments, the uplink buffer status may be associated with data to be transmitted by the remote WTRU 604 using the backhaul Uu.

[0264] In certain representative embodiments, configuration information may be associated with the cell serving the remote WTRU 602 and the relay WTRU 604 .

[0265] In certain representative embodiments, the configuration information may be associated with a first cell serving the remote WTRU 602. The first cell may be different from a second cell serving the relay WTRU 604.

[0266] In certain representative embodiments, Uu and SL may be associated with a split bearer. For example, a split bearer may be configured to use Uu and SL as a primary path and a secondary path, or vice versa.

[0267] In certain representative embodiments, Uu may be set as the primary path for the split bearer, such as based on received FC information.

[0268] In certain representative embodiments, the SL may be set as the primary path for the split bearer, such as based on received FC information.

[0269] In certain representative embodiments, the remote WTRU 602 may transmit information to the base station indicating that the transmit behavior of the remote WTRU 602 has been modified. For example, the information indicating that the transmit behavior of the remote WTRU has been modified may be included in any of an RRC message, a MAC-CE, a measurement report, or a buffer status report (BSR).

[0270] In certain representative embodiments, the WTRU 102 may function as a relay WTRU 604 for a remote WTRU 602. The WTRU 102 may receive a configuration from a network for transmitting flow control information to the remote WTRU 602. The WTRU 102 may detect a triggering event for transmitting the flow control information to the remote WTRU 602. The WTRU 102 may transmit the flow control information to the remote WTRU 602. The transmission of the flow control information to the remote WTRU 602 may be responsive to the detection of the triggering event.

[0271] In certain representative embodiments, the flow control information may include at least one of a downlink buffer status at the relay WTRU 604, an uplink buffer status at the relay WTRU 604, a latency on the backhaul Uu, a radio link quality of the backhaul Uu, an RRC state change of the relay WTRU 604, an activity level at the relay WTRU 604, and / or a fault indication.

[0272] In certain representative embodiments, triggering events for transmitting FC information to the remote WTRU 602 may include expiration of a predetermined (e.g., time) period since the last transmission of FC information to the remote WTRU 602, satisfying a buffer level threshold, satisfying a latency threshold, satisfying a Uu quality threshold, receiving a request from the remote WTRU 602, an RRC state change, a radio link failure, and / or a handover failure.

[0273] In certain representative embodiments, the WTRU 102 may function as a remote WTRU 602 that communicates with a relay WTRU 604 via SL communications. The remote WTRU 602 may receive FC information from the relay WTRU 604. The remote WTRU 602 may modify a data transmission configuration and / or a data reception configuration at the remote WTRU 602 in response to the FC information.

[0274] In certain representative embodiments, the remote WTRU 602 may receive radio bearer configurations for SL communications and Uu communications from the network (e.g., gNB 180).

[0275] In certain representative embodiments, the FC information may include at least one of a downlink buffer status at the relay WTRU 604, an uplink buffer status at the relay WTRU 604, a latency on the backhaul Uu, a radio link quality of the backhaul Uu, an RRC state change of the relay WTRU 604, an activity level at the relay WTRU 604, and / or a fault indication at the relay WTRU 604.

[0276] In certain representative embodiments, the remote WTRU 602 may transmit to the network an indication of modified behavior of the remote WTRU 602, which may be responsive to the remote WTRU 602 modifying its behavior with respect to transmitting data over the SL (eg, in response to received FC information).

[0277] In certain representative embodiments, the modified behavior may include at least one of the following: the remote WTRU 602 updates the split bearer buffer threshold, the remote WTRU 602 updates the distribution percentage between the Uu link and the SL link for the split bearer, the remote WTRU 602 switches the primary path of the split bearer to the Uu link, the remote WTRU 602 switches the primary path of the split bearer to the SL link, the remote WTRU 602 suspends any data transmission through the SL link and / or the remote WTRU 602 resumes data transmission through the SL link.

[0278] in conclusion

[0279] Although features and elements are provided above in a specific combination, it will be understood by those skilled in the art that each feature or element can be used alone or in any combination with other features and elements. The present disclosure is not limited in terms of the specific embodiments described in the present application, which are intended to be illustrations of various aspects. Without departing from its spirit and scope, many modifications and changes can be made, as will be apparent to those skilled in the art. Any element, action or instruction used in the description of the present application should not be interpreted as being critical or necessary to the present invention, unless explicitly provided as such. In addition to those listed herein, functionally equivalent methods and devices within the scope of the present disclosure will be apparent to those skilled in the art according to the preceding description. Such modifications and changes are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents given by such claims. It should be understood that the present disclosure is not limited to specific methods or systems herein.

[0280] For simplicity, the foregoing embodiments are discussed with respect to the terminology and structure of devices having communication capabilities (i.e., radio wave transmitters and receivers). However, the embodiments discussed are not limited to these systems, but can be applied to other systems using other forms of electromagnetic waves or non-electromagnetic waves (such as sound waves).

[0281] It will also be understood that the terms used herein are used only for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, the term "video" or the term "image" may mean any of a snapshot, a single image, and / or a plurality of images displayed over a certain time basis. As another example, when referred to herein, the term "user equipment" and its abbreviation "UE", the term "remote" and / or the term "head-mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of many embodiments of a WTRU; (iii) a device with wireless capabilities and / or wired capabilities (e.g., wearable) that is configured with some or all of the structure and functionality of a WTRU; (iii) a device with wireless capabilities and / or wired capabilities that is configured with less than all of the structure and functionality of a WTRU; or (iv) a similar device. References herein to Figures 1A to 1D Details of an example WTRU are provided, which may be representative of any WTRU set forth herein. As another example, various disclosed embodiments herein are described above and below as utilizing a head mounted display. Those skilled in the art will recognize that devices other than a head mounted display may be utilized, and some or all of the present disclosure and various disclosed embodiments may be modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an adapted reality experience.

[0282] In addition, the methods provided herein may be implemented in a computer program, software, or firmware that is incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, 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 associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

[0283] Variations of the methods, devices, and systems provided above are possible without departing from the scope of the present invention. In view of the various embodiments that may be applied, it should be understood that the embodiments shown are merely examples and should not be considered to limit the scope of the appended claims. For example, the embodiments provided herein include handheld devices that may include or be used with any suitable voltage source (such as a battery, etc.) that provides any suitable voltage.

[0284] In addition, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices including processors are mentioned. These devices may include at least one central processing unit ("CPU") and memory. According to the practice of those skilled in the art of computer programming, references to actions and symbolic representations of operations or instructions may be performed by various CPUs and memories. Such actions and operations or instructions may be referred to as "execution," "computer execution," or "CPU execution."

[0285] Those of ordinary skill in the art will appreciate that the actions and symbolic representations of operations or instructions include manipulation of electrical signals by the CPU. The electrical system represents data bits, which may cause the final conversion or reduction of electrical signals and maintain the data bits in memory locations in the storage system, thereby reconfiguring or otherwise changing the operation of the CPU and other processing of signals. The memory locations where the data bits are maintained are physical locations having specific electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs, and other platforms and CPUs may support the provided methods.

[0286] The data bits may also be maintained on a computer-readable medium, including a magnetic disk, an optical disk, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read-only memory (ROM)) mass storage system readable by a CPU. The computer-readable medium may include cooperating or interconnected computer-readable media that reside only on a processing system or 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 other platforms and memories may support the provided methods.

[0287] In an illustrative embodiment, any 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.

[0288] There is little difference between hardware and software implementations of various aspects of the system. The use of hardware or software is usually (but not always, as in some cases, the choice of hardware or software may become important) a design choice that represents a cost-efficiency trade-off. There may be various vehicles (e.g., hardware, software, and / or firmware) with which the processes and / or systems and / or other technologies described herein can be implemented, and the preferred vehicle may change with the context in which the processes and / or systems and / or other technologies are deployed. For example, if the implementer determines that speed and accuracy are most important, then the implementer may select a primary hardware and / or firmware vehicle. If flexibility is most important, then the implementer may select a primary software implementation. Alternatively, the implementer may select some combination of hardware, software, and / or firmware.

[0289] The foregoing detailed description has been described various embodiments of the apparatus and / or process by using block diagrams, flow charts and / or examples. Insofar as such block diagrams, flow charts and / or examples include one or more functions and / or operations, it will be understood by those skilled in the art that each function and / or operation within such block diagrams, flow charts or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware or indeed any combination thereof. In an embodiment, several parts of the subject matter described herein may be implemented via an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP) and / or other integrated formats. However, those skilled in the art will recognize that all or part of some aspects of the embodiments disclosed herein may be equivalently implemented in an integrated circuit as one or more computer processes running on one or more computers (e.g., as one or more processes running on one or more computer systems), as one or more processes running on one or more processors (e.g., as one or more processes running on one or more microprocessors), as firmware or almost as any combination thereof, and according to the present disclosure, designing circuit systems and / or writing codes for software and / or firmware will be completely within the skill range of those skilled in the art. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed as a process product in a variety of forms, and that the illustrative examples of the subject matter described herein apply regardless of the specific type of signal-bearing medium used to actually perform the distribution. Examples of signal-bearing media include, but are not limited to, the following: recordable media such as floppy disks, hard drives, CDs, DVDs, digital tapes, computer memory, etc.; and transmission media such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0290] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner 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 can be integrated into a data processing system by a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system can typically include a system unit housing, a video display device, a memory such as volatile and non-volatile memory, a processor such as a microprocessor and a digital signal processor, a computing entity such as an operating system, a driver, a graphical user interface, and an application process, one or more interactive devices such as a touch pad or screen, and / or a control system including a feedback loop and a control motor (e.g., feedback for sensing position and / or velocity; a control motor for moving and / or adjusting components and / or quantity). A typical data processing system can be implemented using any suitable commercially available components, such as components typically found in data computing / communication and / or network computing / communication systems.

[0291] The subject matter described herein sometimes illustrates different parts that are included in different other parts or connected with different other parts.It should be understood that the architecture of such depiction is only an example, and many other architectures that realize the same function can actually be implemented.In a conceptual sense, any arrangement of parts for realizing the same function is effectively "associated" so that the desired function can be realized.Therefore, any two parts that are combined to realize a specific function in this article can be regarded as "associated" with each other so that the desired function is realized regardless of the architecture or the intermediate parts.Similarly, any two parts that are so associated can also be regarded as "operably connected" or "operably connected" to realize the desired function, and any two parts that can be so associated can also be regarded as "operably connected" to realize the desired function.The specific example of operably connectable includes (but is not limited to) parts that can be matched physically and / or physically interact, and / or parts that can be wirelessly interacted and / or wirelessly interacted, and / or parts that can be logically interacted and / or parts that can be logically interacted.

[0292] With respect to the use of substantially any plural and / or singular terms herein, those skilled in the art may translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. For clarity, the various singular / plural arrangements may be expressly set forth herein.

[0293] Those skilled in the art will understand that, in general, the terms used herein and particularly in the appended claims (e.g., the bodies of the appended claims) are generally intended to be "open" terms (e.g., the term "comprising" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.). Those skilled in the art will further understand that if a specific number of an introduced claim statement is intended, such intent will be expressly stated in the claim, and in the absence of such a statement, such intent is not present. For example, where only one item is intended, the term "single" or similar language may be used. To aid understanding, the following appended claims and / or the description herein may include the use of the introductory phrases "at least one" and "one or more" to introduce multiple claim statements. However, the use of such phrases should not be interpreted as implying that a claim recitation introduced by the indefinite article "a" or "an" will limit any particular claim including such introduced claim recitation to embodiments including only one such recitation, even if the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"). The same is true for the use of definite articles to introduce claim recitations. In addition, even if a specific number of introduced claim recitations is explicitly recited, one skilled in the art will recognize that such recitation should be interpreted as meaning at least the recited number (e.g., merely reciting "two recitations" without other modifiers means at least two recitations or two or more recitations). Furthermore, in those cases where a convention similar to “at least one of A, B, and C, etc.” is used, generally, such construction is intended to represent the convention that one skilled in the art would understand (e.g., “a system having at least one of A, B, and C” would include, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). In those cases where a convention similar to “at least one of A, B, or C, etc.” is used, generally, such meaning is intended in the sense that one skilled in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or both A, B, and C, etc.). One skilled in the art would further understand that any transitional words and / or phrases (whether in the specification, claims, or drawings) that actually give two or more alternatives should be understood to contemplate the possibility of including one of the items, either of the items, or both of the items. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."Furthermore, as used herein, the term "any" followed by a plurality of items and / or a listing of items in a plurality of categories is intended to include "any," "any combination," "any plurality," and / or "any combination of plurality," either alone or in combination with other items and / or items in other categories. Furthermore, 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 as used herein, the term "plurality" is intended to be synonymous with "multiple."

[0294] 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.

[0295] As will be understood by those skilled in the art, for any and all purposes, such as in providing a written description, all ranges disclosed herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed range can be easily identified as fully describing and capable of decomposing the same range into at least equal half, one-third, one-quarter, one-fifth, one-tenth, etc. As a non-limiting example, each range discussed herein can be easily decomposed into a lower third, a middle third, and an upper third, etc. As will be understood by those skilled in the art, all languages ​​such as "at most", "at least", "greater than", "less than", etc. include the enumerated numbers, and refer to the ranges that can be subsequently subdivided into sub-ranges as discussed above. Finally, as will be understood by those skilled in the art, the range includes each individual member. Therefore, for example, a group with 1 to 3 units refers to a group with 1, 2 or 3 units. Similarly, a group with 1 to 5 units refers to a group with 1, 2, 3, 4 or 5 units, and so on.

[0296] Furthermore, the claims should not be read as limited to the order or elements provided unless otherwise stated. In addition, the use of the term "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 term "means for..." is not intended to be so.

Claims

1. A remote WTRU operating in a multipath setting using a direct link (Uu) and a sidelink (SL) via a relay wireless transmit / receive unit (WTRU), the remote WTRU comprising: A processor, a memory, and a transceiver, wherein the transceiver is configured to: receiving configuration information for handling data transmission on the Uu and the SL from a base station, wherein the configuration information comprises: information indicating association of flow control (FC) information with a distribution percentage of data on the Uu and the SL, receiving FC information from the relay WTRU, transmitting data using the Uu and the SL based on the distribution percentage associated with the received FC information, and Information is transmitted to the base station indicating that the transmission behavior of the remote WTRU has been modified.

2. The remote WTRU of claim 1 , wherein the configuration information comprises: information indicating an association of a set of FC information with a set of distribution percentages, and The set of FC information includes the received FC information, and the set of distribution percentages includes the distribution percentage.

3. The remote WTRU of claim 2, wherein the processor, the memory, and the transceiver are configured to determine the distribution percentage from the set of distribution percentages based on the association with the received FC information.

4. The remote WTRU of claim 1 , wherein the configuration information further comprises: information indicating the scaling factor and threshold, and Wherein the processor, the memory and the transceiver are configured to: The data is transmitted using the Uu and the SL based on (i) the received FC information being above the threshold, (ii) the distribution percentage associated with the received FC information, and (iii) the distribution percentage modified using the scaling factor.

5. The remote WTRU of claim 1 , wherein the configuration information further comprises: information indicating the threshold, and Wherein the processor, the memory and the transceiver are configured to: The data is transmitted using the Uu and the SL based on (i) the distribution percentage associated with the received FC information and (ii) a difference between the received FC information and the threshold.

6. A remote WTRU according to any one of claims 1 to 5, wherein the received FC information includes any one of the following: a downlink buffer status of data to be transmitted by the relay WTRU, a rate of change of the downlink buffer status, a downlink data rate at the relay WTRU, an uplink buffer status of data to be transmitted by the relay WTRU, a rate of change of the uplink buffer status, an uplink data rate at the relay WTRU, a latency of the backhaul Uu between the relay WTRU and a base station, radio link information of the backhaul Uu, resource availability of the backhaul Uu and / or a connection status of the backhaul Uu.

7. A remote WTRU according to claim 6, wherein the downlink buffer status is associated with data to be transmitted by the relay WTRU to the remote WTRU using the SL.

8. The remote WTRU of claim 6, wherein the uplink buffer status is associated with data to be transmitted by the remote WTRU using the backhaul Uu.

9. The remote WTRU according to any one of claims 1 to 8, wherein the FC information is associated with a cell serving the remote WTRU and the relay WTRU.

10. The remote WTRU of any one of claims 1 to 8, wherein the FC information is associated with a first cell serving the remote WTRU and a second cell serving the relay WTRU.

11. The remote WTRU of any one of claims 1 to 10, wherein the data to be transmitted is associated with a separate bearer that is using the Uu and the SL.

12. The remote WTRU of claim 11, wherein the Uu is set as a primary path for the split bearer based on the received FC information.

13. The remote WTRU of claim 11, wherein the SL is set as a primary path for the split bearer based on the received FC information.

14. A remote WTRU according to any one of claims 1 to 13, wherein the information indicating that the transmission behavior of the remote WTRU has been modified is included in any one of a radio resource control (RRC) message, a medium access control (MAC) control element, a measurement report or a buffer status report (BSR).

15. A method implemented by a remote WTRU operating in a multipath setting using a direct link (Uu) and a sidelink (SL) via a relay wireless transmit / receive unit (WTRU), the method comprising: receiving, from a base station, configuration information for handling data transmission on the Uu and the SL, wherein the configuration information comprises: information indicating association of flow control (FC) information with a distribution percentage of data on the Uu and the SL; receiving FC information from the relay WTRU; transmitting data using the Uu and the SL based on the distribution percentage associated with the received FC information; and Information is transmitted to the base station indicating that the transmission behavior of the remote WTRU has been modified.

16. The method according to claim 15, wherein the configuration information comprises: information indicating an association of a set of FC information with a set of distribution percentages, and The set of FC information includes the received FC information, and the set of distribution percentages includes the distribution percentage.

17. The method of claim 16, wherein the distribution percentage is determined from a set of the distribution percentages based on the association with the received FC information.

18. The method according to claim 15, wherein the configuration information further comprises: information indicating the scaling factor and threshold, and The data is transmitted using the Uu and the SL based on (i) the received FC information being above the threshold, (ii) the distribution percentage associated with the received FC information, and (iii) the distribution percentage modified using the scaling factor.

19. The method according to claim 15, wherein the configuration information further comprises: information indicating the threshold, and Wherein the data is transmitted using the Uu and the SL based on (i) the distribution percentage associated with the received FC information and (ii) a difference between the received FC information and the threshold.

20. A method according to any one of claims 15 to 19, wherein the received FC information includes any one of the following: a downlink buffer status of data to be transmitted by the relay WTRU, a rate of change of the downlink buffer status, a downlink data rate at the relay WTRU, an uplink buffer status of data to be transmitted by the relay WTRU, a rate of change of the uplink buffer status, an uplink data rate at the relay WTRU, a latency of a backhaul Uu between the relay WTRU and a base station, radio link information of the backhaul Uu, resource availability of the backhaul Uu and / or a connection status of the backhaul Uu.

21. The method of claim 20, wherein the downlink buffer status is associated with data to be transmitted by the relay WTRU to the remote WTRU using the SL.

22. The method of claim 20, wherein the uplink buffer status is associated with data to be transmitted by the relay WTRU using the backhaul Uu.

23. The method of any one of claims 15 to 22, wherein configuration information is associated with a cell serving the remote WTRU and the relay WTRU.

24. The method of any one of claims 15 to 22, wherein the configuration information is associated with a first cell serving the remote WTRU, and the first cell is different from a second cell serving the relay WTRU.

25. The method according to any one of claims 15 to 24, wherein the data to be transmitted is associated with a separate bearer using the Uu and the SL.

26. The method of claim 25, wherein the Uu is set as a primary path for the split bearer based on the received FC information.

27. The method of claim 25, wherein the SL is set as a primary path for the split bearer based on the received FC information.

28. A method according to any one of claims 15 to 27, wherein the information indicating that the transmission behavior of the remote WTRU has been modified is included in any one of a radio resource control (RRC) message, a medium access control (MAC) control element, a measurement report or a buffer status report (BSR).

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