A first apparatus including: a processor; a memory; and communication circuitry. The first apparatus is connected to a communications network via the communication circuitry. The first apparatus further includes computer-executable instructions stored in the memory which, when executed by the processor, causes the first apparatus to: discover a second apparatus that the first apparatus can communicate with; obtain device information related to the second apparatus; and configure a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

FIELD

The present disclosure relates generally to wireless communications, and more particularly to wireless communications systems, devices, methods, and computer readable medium for performing vehicle-to-x communications.

BACKGROUND

Existing vehicle-to-x systems and methods are connectionless, and do not support the higher data rates, higher reliability, and lower latency requirements that are needed in a 5G system. Further, in existing systems, connectionless transmission results in several drawbacks, such as, higher protocol overhead, higher processing overhead, and it is hard to enable physical layer feedback.

SUMMARY

An exemplary embodiment of the present disclosure provides a first apparatus including: a processor; a memory; and communication circuitry. The first apparatus is connected to a communications network via the communication circuitry. The first apparatus further includes computer-executable instructions stored in the memory which, when executed by the processor, causes the first apparatus to: discover a second apparatus that the first apparatus can communicate with; obtain device information related to the second apparatus; and configure a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

An exemplary embodiment of the present disclosure provides a method for direct sidelink communication using a first apparatus that includes a processor, a memory, communication circuitry, and the first apparatus is connected to a communications network via the communication circuitry. The method includes: discovering a second apparatus that the first apparatus can communicate with; obtaining device information related to the second apparatus; and configuring a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

An exemplary embodiment of the present disclosure provides a non-transitory computer readable storage medium having computer-readable instructions tangibly recorded thereon which, when executed by processing circuitry, cause the processing circuitry to perform a method for direct sideling communication using a first apparatus. The method including: discovering a second apparatus that the first apparatus can communicate with; obtaining device information related to the second apparatus; and configuring a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description of exemplary embodiments is intended for illustration purposes only and are, therefore, not intended to necessarily limit the scope of the disclosure.

DETAILED DESCRIPTION

The 3rd Generation Partnership Project (3GPP) develops technical standards for cellular telecommunications network technologies, including radio access, the core transport network, and service capabilities—including work on codecs, security, and quality of service. Recent radio access technology (RAT) standards include WCDMA (commonly referred as 3G), LTE (commonly referred as 4G), LTE-Advanced standards, and New Radio (NR), which is also referred to as “5G.” 3GPP NR standards development is expected to continue and include the definition of next generation radio access technology (new RAT), which is expected to include the provision of new flexible radio access below 7 GHz, and the provision of new ultra-mobile broadband radio access above 7 GHz. The flexible radio access is expected to consist of a new, non-backwards compatible radio access in new spectrum below 7 GHz, and it is expected to include different operating modes that can be multiplexed together in the same spectrum to address a broad set of 3GPP NR use cases with diverging requirements. The ultra-mobile broadband is expected to include cmWave and mmWave spectrum that will provide the opportunity for ultra-mobile broadband access for, e.g., indoor applications and hotspots. In particular, the ultra-mobile broadband is expected to share a common design framework with the flexible radio access below 7 GHz, with cmWave and mmWave specific design optimizations.

3GPP has identified a variety of use cases that NR is expected to support, resulting in a wide variety of user experience requirements for data rate, latency, and mobility. The use cases include the following general categories: enhanced mobile broadband (eMBB) ultra-reliable low-latency Communication (URLLC), massive machine type communications (mMTC), network operation (e.g., network slicing, routing, migration and interworking, energy savings), and enhanced vehicle-to-everything (eV2X) communications, which can include any of Vehicle-to-Vehicle Communication (V2V), Vehicle-to-Infrastructure Communication (V2I), Vehicle-to-Network Communication (V2N), Vehicle-to-Pedestrian Communication (V2P), and vehicle communications with other entities. Specific service and applications in these categories include, e.g., monitoring and sensor networks, device remote controlling, bi-directional remote controlling, personal cloud computing, video streaming, wireless cloud-based office, first responder connectivity, automotive ecall, disaster alerts, real-time gaming, multi-person video calls, autonomous driving, augmented reality, tactile internet, virtual reality, home automation, robotics, and aerial drones to name a few. All of these use cases and others are contemplated herein.

The following is a list of acronyms relating to service level and core network technologies that may appear in the below description. Unless otherwise specified, the acronyms used herein refer to the corresponding term listed below.

ABBREVIATIONS

The following features/procedures/functions will be discussed in this disclosure:NR V2X Sidelink L2 Structure.V2 Connection Configuration procedures including connection V2X upper connection configuration, V2X AS connection configuration, V2X AS support for V2X upper layer connection, covering unicast, groupcast and broadcast transmission mode.Providing for V2X transmitter side and Receiver side.V2X RAT and Interface Selection.V2X Communication Mode Selection.

Specifically, the following concepts and topics will be discussed:1. Layer 2 protocol structure;2. Provisioning of V2X transmitter and Receiver;3. Triggers for V2X Transmission or V2X reception;4. Transmitter side and Receiver Side RAT and Interface selection, who does it and based on what criteria;5. Transmitter side and Receiver side Transmission mode selection and criteria for the selection;6. Unicast Connection Management detail procedures including description of assistance parameters from the UE (e.g., receiver capability), and unicast configuration parameters configured into the UE by the scheduling entity or an assisting UE in coordination with the scheduling entity;7. Different alternatives for connection management;8. Group Connection Configuration and idea of V2X upper layer group mapping to AS layer subgroups, maintenance in AS of mapping table and indication by AS to PHY. Broadcast configuration and various options for broadcast configuration signaling.9. Methods for UE handling of multiple simultaneous sidelink RRC connections.10. Modeling of PC5 Unicast Link granularity, Unicast Link Update and Unicast Link Addition Procedures.

Example Communication System and Networks

FIG.1Aillustrates one embodiment of an example communications system100in which the methods and apparatuses described and claimed herein may be embodied. As shown, the example communications system100can include wireless transmit/receive units (WTRUs)102a,102b,102c,102d,102e,102f, and/or102g(which generally or collectively may be referred to as WTRU102), a radio access network (RAN)103/104/105/103b/104b/105b, a core network106/107/109, a public switched telephone network (PSTN)108, the Internet110, other networks112, and V2X server (or ProSe function and server)113, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs102a,102b,102c,102d,102e,102f,102gcan be any type of apparatus or device configured to operate and/or communicate in a wireless environment. Although each WTRU102a,102b,102c,102d,102e,102f,102gis depicted inFIGS.1A-1Eas a hand-held wireless communications apparatus, it is understood that with the wide variety of use cases contemplated for wireless communications, each WTRU can comprise or be embodied in any type of apparatus or device configured to transmit and/or receive wireless signals, including, by way of example only, user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a tablet, a netbook, a notebook computer, a personal computer, a wireless sensor, consumer electronics, a wearable device such as a smart watch or smart clothing, a medical or eHealth device, a robot, industrial equipment, a drone, a vehicle such as a car, bus or truck, a train, or an airplane, and the like.

The communications system100can also include a base station114aand a base station114b. Base stations114acan be any type of device configured to wirelessly interface with at least one of the WTRUs102a,102b,102cto facilitate access to one or more communication networks, such as the core network106/107/109, the Internet110, Network Services113, and/or the other networks112. Examples of Network Services can include V2X Services, ProSe Services, IoT Services, Video Streaming, Edge Computing, etc. Base stations114bcan be any type of device configured to wiredly and/or wirelessly interface with at least one of the RRHs (Remote Radio Heads)118a,118b, TRPs (Transmission and Reception Points)119a,119b, and/or RSUs (Roadside Units)120aand120bto facilitate access to one or more communication networks, such as the core network106/107/109, the Internet110, other networks112, and/or Network Services113. RRHs118a,118bcan be any type of device configured to wirelessly interface with at least one of the WTRU102c, to facilitate access to one or more communication networks, such as the core network106/107/109, the Internet110, Network Services113, and/or other networks112. TRPs119a,119bcan be any type of device configured to wirelessly interface with at least one of the WTRU102d, to facilitate access to one or more communication networks, such as the core network106/107/109, the Internet110, Network Services113, and/or other networks112. RSUs120aand120bcan be any type of device configured to wirelessly interface with at least one of the WTRU102eor102f, to facilitate access to one or more communication networks, such as the core network106/107/109, the Internet110, other networks112, and/or Network Services113. By way of example, the base stations114a,114bcan be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a next generation node-B (gNode B), a satellite, a site controller, an access point (AP), a wireless router, and the like. While the base stations114a,114bare each depicted as a single element, it will be appreciated that the base stations114a,114bcan include any number of interconnected base stations and/or network elements.

The base station114acan be part of the RAN103/104/105, which can also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station114bcan be part of the RAN103b/104b/105b, which can also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station114acan be configured to transmit and/or receive wireless signals within a particular geographic region, which can be referred to as a cell (not shown). The base station114bcan be configured to transmit and/or receive wired and/or wireless signals within a particular geographic region, which can be referred to as a cell (not shown). The cell can further be divided into cell sectors. For example, the cell associated with the base station114acan be divided into three sectors. Thus, in an embodiment, the base station114acan include three transceivers, e.g., one for each sector of the cell. In an embodiment, the base station114acan employ multiple-input multiple output (MIMO) technology and, therefore, can utilize multiple transceivers for each sector of the cell.

The base stations114acan communicate with one or more of the WTRUs102a,102b,102cover an air interface115/116/117, which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface115/116/117can be established using any suitable radio access technology (RAT).

The base stations114bcan communicate with one or more of the RRHs118a,118b, TRPs119a,119b, and/or RSUs120aand120b, over a wired or air interface115b/116b/117b, which can be any suitable wired (e.g., cable, optical fiber, etc.) or wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface115b/116b/117bcan be established using any suitable radio access technology (RAT).

The RRHs118a,118b, TRPs119a,119band/or RSUs120a,120b, can communicate with one or more of the WTRUs102c,102d,102e,102fover an air interface115c/116c/117c, which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface115c/116c/117ccan be established using any suitable radio access technology (RAT).

The WTRUs102a,102b,102c,102d,102e,102f, and/or102gcan communicate with one another over a direct air interface115d/116d/117d, such as Vehicle-to-Vehicle (V2V) sidelink communication, and WTRUs102a,102b,102c,102d,102e,102f, and/or102gcan communicate with Network Service113over a direct air interface115e/116e/117e, such as Vehicle-to-Infrastructure (V2I) sidelink communication, (not shown in the figures), which can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, cmWave, mmWave, etc.). The air interface115d/116d/117dcan be established using any suitable radio access technology (RAT).

More specifically, as noted above, the communications system100can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station114ain the RAN103/104/105and the WTRUs102a,102b,102c, or RRHs118a,118b, TRPs119a,119band/or RSUs120a,120bin the RAN103b/104b/105band the WTRUs102c,102d,102e,102f, can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish the air interface115/116/117or115c/116c/117crespectively using wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In an embodiment, the base station114ain the RAN103/104/105and the WTRUs102a,102b,102c, or RRHs118a,118b, TRPs119a,119b, and/or RSUs120a,120bin the RAN103b/104b/105band the WTRUs102c,102d, can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface115/116/117or115c/116c/117crespectively using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A). The air interface115/116/117or115c/116c/117ccan implement 3GPP NR technology. The LTE and LTE-A technology includes LTE D2D and V2X technologies and interface (such as Sidelink communications, etc.). The 3GPP NR technology includes NR V2X technologies and interface (such as Sidelink communications, etc.).

In an embodiment, the base station114ain the RAN103/104/105and the WTRUs102a,102b,102c, or RRHs118a,118b, TRPs119a,119band/or RSUs120a,120bin the RAN103b/104b/105band the WTRUs102c,102d,102e,102fcan implement radio technologies such as IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

The base station114cinFIG.1Acan be a wireless router, Home Node B, Home eNode B, or access point, for example, and can utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a train, an aerial, a satellite, a manufactory, a campus, and the like. In an embodiment, the base station114cand the WTRUs102e, can implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station114cand the WTRUs102d, can implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station114cand the WTRUs102e, can utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, NR, etc.) to establish a picocell or femtocell. As shown inFIG.1A, the base station114ccan have a direct connection to the Internet110. Thus, the base station114cmay not be needed to access the Internet110via the core network106/107/109.

The RAN103/104/105and/or RAN103b/104b/105bcan be in communication with the core network106/107/109, which can be any type of network configured to provide voice, data, messaging, authorization and authentication, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs102a,102b,102c,102d, and102f. For example, the core network106/107/109can provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, packet data network connectivity, Ethernet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication.

Although not shown inFIG.1A, it will be appreciated that the RAN103/104/105and/or RAN103b/104b/105band/or the core network106/107/109can be in direct or indirect communication with other RANs that employ the same RAT as the RAN103/104/105and/or RAN103b/104b/105bor a different RAT. For example, in addition to being connected to the RAN103/104/105and/or RAN103b/104b/105b, which can be utilizing an E-UTRA radio technology, the core network106/107/109can also be in communication with another RAN (not shown) employing a GSM or NR radio technology.

The core network106/107/109can also serve as a gateway for the WTRUs102a,102b,102c,102d,102e, and102fto access the PSTN108, the Internet110, and/or other networks112. The PSTN108can include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet110can include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and the internet protocol (IP) in the TCP/IP internet protocol suite. The other networks112can include wired or wireless communications networks owned and/or operated by other service providers. For example, the networks112can include any type of packet data network (i.e., an IEEE 802.3 ethernet network) or another core network connected to one or more RANs, which can employ the same RAT as the RAN103/104/105and/or RAN103b/104b/105bor a different RAT.

Some or all of the WTRUs102a,102b,102c,102d,102e, and102fin the communications system100can include multi-mode capabilities, e.g., the WTRUs102a,102b,102c,102d,102e, and102fcan include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRU102gshown inFIG.1Acan be configured to communicate with the base station114a, which can employ a cellular-based radio technology, and with the base station114c, which can employ an IEEE 802 radio technology.

Although not shown inFIG.1A, it will be appreciated that a User Equipment can make a wired connection to a gateway. The gateway can be a Residential Gateway (RG). The RG can provide connectivity to a Core Network106/107/109. It will be appreciated that many of the ideas contained herein can equally apply to UEs that are WTRUs and UEs that use a wired connection to connect to a network. For example, the ideas that apply to the wireless interfaces115,116,117and115c/116c/117ccan equally apply to a wired connection.

FIG.1Bis a block diagram of an example apparatus or device configured for wireless communications in accordance with the embodiments illustrated herein, such as for example, a WTRU102. As shown inFIG.1B, the example WTRU102can include a processor118, a transceiver120, a transmit/receive element122, a speaker/microphone124, a keypad126, a display/touchpad/indicators128, non-removable memory130, removable memory132, a power source134, a global positioning system (GPS) chipset136, and other peripherals138. It will be appreciated that the WTRU102can include any sub-combination of the foregoing elements while remaining consistent with an embodiment. Also, embodiments contemplate that the base stations114aand114b, and/or the nodes that base stations114aand114bcan represent, such as but not limited to transceiver station (BTS), a Node-B, a site controller, an access point (AP), a home node-B, an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a home evolved node-B gateway, a next generation node-B (gNode-B), and proxy nodes, among others, can include some or all of the elements depicted inFIG.1Band described herein.

The processor118can be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor118can perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU102to operate in a wireless environment. The processor118can be coupled to the transceiver120, which can be coupled to the transmit/receive element122. WhileFIG.1Bdepicts the processor118and the transceiver120as separate components, it will be appreciated that the processor118and the transceiver120can be integrated together in an electronic package or chip.

The transmit/receive element122of a UE can be configured to transmit signals to, or receive signals from, a base station (e.g., the base station114a) over the air interface115/116/117or another UE over the air interface115d/116d/117d. For example, in an embodiment, the transmit/receive element122can be an antenna configured to transmit and/or receive RF signals. In an embodiment, the transmit/receive element122can be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet an embodiment, the transmit/receive element122can be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element122can be configured to transmit and/or receive any combination of wireless or wired signals.

In addition, although the transmit/receive element122is depicted inFIG.1Bas a single element, the WTRU102can include any number of transmit/receive elements122. More specifically, the WTRU102can employ MIMO technology. Thus, in an embodiment, the WTRU102can include two or more transmit/receive elements122(e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface115/116/117.

The transceiver120can be configured to modulate the signals that are to be transmitted by the transmit/receive element122and to demodulate the signals that are received by the transmit/receive element122. As noted above, the WTRU102can have multi-mode capabilities. Thus, the transceiver120can include multiple transceivers for enabling the WTRU102to communicate via multiple RATs, for example, NR and IEEE 802.11 or NR and E-UTRA, or to communicate with the same RAT via multiple beams to different RRHs, TRPs, RSUs, or nodes.

The processor118of the WTRU102can be coupled to, and can receive user input data from, the speaker/microphone124, the keypad126, and/or the display/touchpad/indicators128(e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit. The processor118can also output user data to the speaker/microphone124, the keypad126, and/or the display/touchpad/indicators128. In addition, the processor118can access information from, and store data in, any type of suitable memory, such as the non-removable memory130and/or the removable memory132. The non-removable memory130can include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory132can include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In an embodiment, the processor118can access information from, and store data in, memory that is not physically located on the WTRU102, such as on a server that is hosted in the cloud or in an edge computing platform or in a home computer (not shown).

The processor118can receive power from the power source134, and can be configured to distribute and/or control the power to the other components in the WTRU102. The power source134can be any suitable device for powering the WTRU102. For example, the power source134can include one or more dry cell batteries, solar cells, fuel cells, and the like.

The processor118can also be coupled to the GPS chipset136, which can be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU102. In addition to, or in lieu of, the information from the GPS chipset136, the WTRU102can receive location information over the air interface115/116/117from a base station (e.g., base stations114a,114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU102can acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

The processor118can further be coupled to other peripherals138, which can include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals138can include various sensors such as an accelerometer, biometrics (e.g., finger print) sensors, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port or other interconnect interfaces, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.

The WTRU102can be embodied in other apparatuses or devices, such as a sensor, consumer electronics, a wearable device such as a smart watch or smart clothing, a medical or eHealth device, a robot, industrial equipment, a drone, a vehicle such as a car, truck, train, or an airplane. The WTRU102can connect to other components, modules, or systems of such apparatuses or devices via one or more interconnect interfaces, such as an interconnect interface that can comprise one of the peripherals138.

FIG.1Cis a system diagram of the RAN103and the core network106according to an embodiment. As noted above, the RAN103can employ a UTRA radio technology to communicate with the WTRUs102a,102b, and102cover the air interface115. The RAN103can also be in communication with the core network106. As shown inFIG.1C, the RAN103can include Node-Bs140a,140b,140c, which can each include one or more transceivers for communicating with the WTRUs102a,102b,102cover the air interface115. The Node-Bs140a,140b,140ccan each be associated with a particular cell (not shown) within the RAN103. The RAN103can also include RNCs142a,142b. It will be appreciated that the RAN103can include any number of Node-Bs and RNCs while remaining consistent with an embodiment.

As shown inFIG.1C, the Node-Bs140a,140bcan be in communication with the RNC142a. Additionally, the Node-B140ccan be in communication with the RNC142b. The Node-Bs140a,140b,140ccan communicate with the respective RNCs142a,142bvia an Iub interface. The RNCs142a,142bcan be in communication with one another via an Iur interface. Each of the RNCs142a,142bcan be configured to control the respective Node-Bs140a,140b,140cto which it is connected. In addition, each of the RNCs142a,142bcan be configured to carry out or support other functionality, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro-diversity, security functions, data encryption, and the like.

The core network106shown inFIG.1Ccan include a media gateway (MGW)144, a mobile switching center (MSC)146, a serving GPRS support node (SGSN)148, and/or a gateway GPRS support node (GGSN)150. While each of the foregoing elements are depicted as part of the core network106, it will be appreciated that any one of these elements can be owned and/or operated by an entity other than the core network operator.

The RNC142ain the RAN103can be connected to the MSC146in the core network106via an IuCS interface. The MSC146can be connected to the MGW144. The MSC146and the MGW144can provide the WTRUs102a,102b,102cwith access to circuit-switched networks, such as the PSTN108, to facilitate communications between the WTRUs102a,102b,102cand traditional land-line communications devices.

The RNC142ain the RAN103can also be connected to the SGSN148in the core network106via an IuPS interface. The SGSN148can be connected to the GGSN150. The SGSN148and the GGSN150can provide the WTRUs102a,102b,102cwith access to packet-switched networks, such as the Internet110, to facilitate communications between and the WTRUs102a,102b,102cand IP-enabled devices.

As noted above, the core network106can also be connected to the other networks112, which can include other wired or wireless networks that are owned and/or operated by other service providers.

FIG.1Dis a system diagram of the RAN104and the core network107according to an embodiment. As noted above, the RAN104can employ an E-UTRA radio technology to communicate with the WTRUs102a,102b, and102cover the air interface116. The RAN104can also be in communication with the core network107.

The RAN104can include eNode-Bs160a,160b,160c, though it will be appreciated that the RAN104can include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs160a,160b,160ccan each include one or more transceivers for communicating with the WTRUs102a,102b,102cover the air interface116. In an embodiment, the eNode-Bs160a,160b,160ccan implement MIMO technology. Thus, the eNode-B160a, for example, can use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU102a.

Each of the eNode-Bs160a,160b, and160ccan be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown inFIG.1D, the eNode-Bs160a,160b,160ccan communicate with one another over an X2 interface.

The core network107shown inFIG.1Dcan include a mobility management gateway (MME)162, a serving gateway164, and a packet data network (PDN) gateway166. While each of the foregoing elements are depicted as part of the core network107, it will be appreciated that any one of these elements can be owned and/or operated by an entity other than the core network operator.

The MME162can be connected to each of the eNode-Bs160a,160b, and160cin the RAN104via an S1 interface and can serve as a control node. For example, the MME162can be responsible for authenticating users of the WTRUs102a,102b,102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs102a,102b,102c, and the like. The MME162can also provide a control plane function for switching between the RAN104and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

The serving gateway164can be connected to each of the eNode-Bs160a,160b, and160cin the RAN104via the S1 interface. The serving gateway164can generally route and forward user data packets to/from the WTRUs102a,102b,102c. The serving gateway164can also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs102a,102b,102c, managing and storing contexts of the WTRUs102a,102b,102c, and the like.

The serving gateway164can also be connected to the PDN gateway166, which can provide the WTRUs102a,102b,102cwith access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs102a,102b,102cand IP-enabled devices.

The core network107can facilitate communications with other networks. For example, the core network107can provide the WTRUs102a,102b,102cwith access to circuit-switched networks, such as the PSTN108, to facilitate communications between the WTRUs102a,102b,102cand traditional land-line communications devices. For example, the core network107can include, or can communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the core network107and the PSTN108. In addition, the core network107can provide the WTRUs102a,102b,102cwith access to the networks112, which can include other wired or wireless networks that are owned and/or operated by other service providers.

FIG.1Eis a system diagram of the RAN105and the core network109according to an embodiment. The RAN105can employ an NR radio technology to communicate with the WTRUs102aand102bover the air interface117. The RAN105can also be in communication with the core network109. The N3IWF199can employ a non-3GPP radio technology to communicate with the WTRU102cover the air interface198. The N3IWF199can also be in communication with the core network109.

The RAN105can include gNode-Bs180aand180bthough it will be appreciated that the RAN105can include any number of gNode-Bs while remaining consistent with an embodiment. The gNode-Bs180aand180bcan each include one or more transceivers for communicating with the WTRUs102aand102bover the air interface117. In an embodiment that uses an integrated access and backhaul connection, the same air interface can be used between the WTRUs and gNode-Bs which can be the core network109via one or multiple gNBs. In an embodiment, the gNode-Bs180aand180bcan implement MIMO, MU-MIMO, and/or digital beamforming technology. Thus, the gNode-B180a, for example, can use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU102a. It should be appreciated that the RAN105can employ of other types of base stations such as an eNode-B. It should also be appreciated that the RAN105can employ more than one type of base station. For example, the RAN can employ eNode-Bs and gNode-Bs.

The N3IWF199can include a non-3GPP Access Point180cthough it will be appreciated that the N3IWF199can include any number of non-3GPP Access Points while remaining consistent with an embodiment. The non-3GPP Access Point180ccan include one or more transceivers for communicating with the WTRUs102cover the air interface198. In an embodiment, the non-3GPP Access Point180ccan use the 802.11 protocol to communicate with the WTRU102cover the air interface198.

Each of the gNode-Bs180aand180bcan be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown inFIG.1E, the gNode-Bs180aand180bcan communicate with one another over an Xn interface.

The core network109shown inFIG.1Ecan be a 5G core network (5GC) The 5GC can offer numerous communication services to customers who are interconnected by the radio access network. The 5G Core Network109comprises a number of entities that perform the functionality of the core network. As used herein, the term “core network entity” or “network function” refers to any entity that performs one or more functionalities of a core network. It is understood that such core network entities can be logical entities that are implemented in the form of software (i.e., computer-executable instructions) stored in a memory of, and executing on a processor of, an apparatus configured for wireless and/or network communications or a computer system such as those illustrated inFIG.1F.

As shown inFIG.1E, the 5G Core Network109can include an access and mobility management function (AMF)172, a session management function (SMF)174, user plane functions (UPF)176aand176b, a user data management function (UDM)197, an authentication server function (AUSF)190, a Network Exposure Function (NEF)196, a policy control function (PCF)184, a non-3GPP interworking function (N3IWF)199an application function (AF)188, a User Data Repository (UDR)178. While each of the foregoing elements are depicted as part of the 5G core network109, it will be appreciated that any one of these elements can be owned and/or operated by an entity other than the core network operator. It should also be appreciated that a 5G core network may not consist of all of these elements, can consist of additional elements, and can consist of multiple instances of each of these elements.FIG.1Eshows that network functions directly connect to one another, however, it should be appreciated that they can communicate via routing agents such as a diameter routing agent or message buses. AlthoughFIG.1Eshows that connectivity between network functions is achieved via a set of interfaces, or reference points, it should be appreciated that network functions could be modeled, described, or implemented as a set of services that are invoked, or called, by other network functions or services. Invocation of a Network Function service can be achieved via a direct connection between network functions, an exchange of messaging on a message bus, calling a software function, etc.

The AMF172can be connected to the RAN105via an N2 interface and can serve as a control node. For example, the AMF172can be responsible for registration management, connection management, reachability management, access authentication, access authorization. The AMF can be responsible for forwarding user plane tunnel configuration information to the RAN105via the N2 interface. The AMF172can receive the user plane tunnel configuration information from the SMF via an N11 interface. The AMF172can generally route and forward NAS packets to/from the WTRUs102a,102b,102cvia an N1 interface. The N1 interface is not shown inFIG.1E.

The SMF174can be connected to the AMF172via an N11 interface, can be connected to a PCF184via an N7 interface, and can be connected to the UPF176via an N4 interface. The SMF174can serve as a control node. For example, the SMF174can be responsible for Session Management, IP address allocation for the WTRUs102a,102b,102c, management and configuration of traffic steering rules in the UPF176aand UPF176b, and generation of downlink data notifications to the AMF172.

The UPF176aand UPF176bcan provide the WTRUs102a,102b,102cwith access to a packet data network (DN), such as the Internet110, to facilitate communications between the WTRUs102a,102b,102cand other devices. The UPF176aand UPF176bcan also provide the WTRUs102a,102b,102cwith access to other types of packet data networks. For example, Other Networks112can be Ethernet Networks or any type of network that exchanges packets of data. The UPF176aand UPF176bcan receive traffic steering rules from the SMF174via the N4 interface. The UPF176aand UPF176bcan provide access to a packet data network by connecting a packet data network with an N6 interface or by connecting to other UPFs via an N9 interface. In addition to providing access to packet data networks, the UPF176can be responsible for packet routing and forwarding, policy rule enforcement, quality of service handling for user plane traffic, downlink packet buffering.

The AMF172can also be connected to the N3IWF199via an N2 interface. The N3IWF facilities a connection between the WTRU102cand the 5G core network170via radio interface technologies that are not defined by 3GPP. The AMF can interact with the N3IWF199in the same, or similar, manner that it interacts with the RAN105.

The PCF184can be connected to the SMF174via an N7 interface, connected to the AMF172via an N15 interface, and connected to an application function (AF)188via an N5 interface. The N15 and N5 interfaces are not shown inFIG.1E. The PCF184can provide policy rules to control plane nodes such as the AMF172and SMF174, allowing the control plane nodes to enforce these rules. The PCF184, can send policies to the AMF172for the WTRUs102a,102b,102cso that the AMF can deliver the policies to the WTRUs102a,102b,102cvia an N1 interface. Policies can then be enforced, or applied, at the WTRUs102a,102b,102c.

The UDR178acts as a repository for authentication credentials and subscription information. The UDR can connect to Network Functions so that Network Function can add to, read from, and modify the data that is in the repository. For example, the UDR178can connect to the PCF184via an N36 interface, the UDR178can connect to the NEF196via an N37 interface, and the UDR178can connect to the UDM197via an N35 interface.

The UDM197can serve as an interface between the UDR178and other Network Functions. The UDM197can authorize Network Functions access of the UDR178. For example, the UDM197can connect to the AMF172via an N8 interface, the UDM197can connect to the SMF174via an N10 interface, and the UDM197can connect to the AUSF190via an N13 interface. The UDR178and UDM197can be tightly integrated.

The AUSF190performs authentication related operations and connects to the UDM178via an N13 interface and to the AMF172via an N12 interface.

The NEF196exposes capabilities and services in the 5G core network109to Application Functions188. Exposure occurs on the N33 API interface. The NEF can connect to an AF188via an N33 interface and it can connect to other network functions in order to expose the capabilities and services of the 5G core network109.

Application Functions188can interact with network functions in the 5G Core Network109. Interaction between the Application Functions188and network functions can be via a direct interface or can occur via the NEF196. The Application Functions188can be considered part of the 5G Core Network109or can be external to the 5G Core Network109and deployed by enterprises that have a business relationship with the mobile network operator.

Network Slicing is a mechanism that could be used by mobile network operators to support one or more ‘virtual’ core networks behind the operator's air interface. This involves ‘slicing’ the core network into one or more virtual networks to support different RANs or different service types running across a single RAN. Network slicing enables the operator to create networks customized to provide optimized solutions for different market scenarios which demands diverse requirements, e.g. in the areas of functionality, performance and isolation.

3GPP has designed the 5G core network based on the concept of Network Slicing. Network Slicing is a good tool that network operators can use to support the diverse set of 5G use cases (e.g., massive IoT, critical communications, V2X, and enhanced mobile broadband) which demand very diverse and sometimes extreme requirements. Without the use of Network Slicing techniques, it is likely that the network architecture would not be flexible and scalable enough to efficiently support a wider range of use cases need when each use case has its own specific set of performance, scalability and availability requirements. Furthermore, introduction of new network services should be made more efficient.

In a network slicing scenario, a WTRU102a,102b,102ccan connect to an AMF172, via an N1 interface. The AMF can be logically part of one or more slices. The AMF can coordinate the WTRU's connection or communication with one or more UPF(s)176, SMF(s)174, and other Network Functions. Each of the UPF(s)176, SMF(s)174, and other Network Functions can be part of different or the same slices. When they are part of different slices, they can be isolated from each other in the sense that they can utilize different computing resources, security credentials, etc.

The 5G core network109can facilitate communications with other networks. For example, the 5G core network109can include, or can communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the 5G core network109and the PSTN108. For example, the core network109can include, or communicate with a short message service (SMS) service center that facilities communication via the short message service. For example, the 5G core network109can facilitate the exchange of non-IP data packets between the WTRUs102a,102b,102cand servers or applications functions188. In addition, the core network170can provide the WTRUs102a,102b,102cwith access to the networks112, which can include other wired or wireless networks that are owned and/or operated by other service providers.

The core network entities described herein and illustrated inFIGS.1A,1C,1D, and1Eare identified by the names given to those entities in certain existing 3GPP specifications, but it is understood that in the future those entities and functionalities can be identified by other names and certain entities or functions can be combined in future specifications published by 3GPP, including future 3GPP NR specifications. Thus, the particular network entities and functionalities described and illustrated inFIGS.1A,1B,1C,1D, and1Eare provided by way of example only, and it is understood that the subject matter disclosed and claimed herein can be embodied or implemented in any similar communication system, whether presently defined or defined in the future.

FIG.1Fis a block diagram of an exemplary computing system90in which one or more apparatuses of the communications networks illustrated inFIGS.1A,1C,1D and1Ecan be embodied, such as certain nodes or functional entities in the RAN103/104/105, Core Network106/107/109, PSTN108, Internet110, Other Networks112, or Network Services113. Computing system90can comprise a computer or server and can be controlled primarily by computer readable instructions, which can be in the form of software, wherever, or by whatever means such software is stored or accessed. Such computer readable instructions can be executed within a processor91, to cause computing system90to do work. The processor91can be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor91can perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the computing system90to operate in a communications network. Coprocessor81is an optional processor, distinct from main processor91, that can perform additional functions or assist processor91. Processor91and/or coprocessor81can receive, generate, and process data related to the methods and apparatuses disclosed herein.

Memories coupled to system bus80include random access memory (RAM)82and read only memory (ROM)93. Such memories include circuitry that allows information to be stored and retrieved. ROMs93generally contain stored data that cannot easily be modified. Data stored in RAM82can be read or changed by processor91or other hardware devices. Access to RAM82and/or ROM93can be controlled by memory controller92. Memory controller92can provide an address translation function that translates virtual addresses into physical addresses as instructions are executed. Memory controller92can also provide a memory protection function that isolates processes within the system and isolates system processes from user processes. Thus, a program running in a first mode can access only memory mapped by its own process virtual address space; it cannot access memory within another process's virtual address space unless memory sharing between the processes has been set up.

In addition, computing system90can contain peripherals controller83responsible for communicating instructions from processor91to peripherals, such as printer94, keyboard84, mouse95, and disk drive85.

Display86, which is controlled by display controller96, is used to display visual output generated by computing system90. Such visual output can include text, graphics, animated graphics, and video. The visual output can be provided in the form of a graphical user interface (GUI). Display86can be implemented with a CRT-based video display, an LCD-based flat-panel display, gas plasma-based flat-panel display, or a touch-panel. Display controller96includes electronic components required to generate a video signal that is sent to display86.

Further, computing system90can contain communication circuitry, such as, for example, a wireless or wired network adapter97, that can be used to connect computing system90to an external communications network or devices, such as the RAN103/104/105, Core Network106/107/109, PSTN108, Internet110, WTRUs102, or Other Networks112ofFIGS.1A,1B,1C,1D, and1E, to enable the computing system90to communicate with other nodes or functional entities of those networks. The communication circuitry, alone or in combination with the processor91, can be used to perform the transmitting and receiving steps of certain apparatuses, nodes, or functional entities described herein.

FIG.1Gillustrates one embodiment of an example communications system111in which the methods and apparatuses described and claimed herein can be embodied. As shown, the example communications system111can include wireless transmit/receive units (WTRUs) A, B, C, D, E, F, a base station gNB121, a V2X server124, and RSU123aand RSU123b, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base station gNBs, V2X networks, and/or network elements. One or several or all WTRUs A, B, C, D, E can be out of range of the access network coverage122. WTRUs A, B, C form a V2X group, among which WTRU A is the group lead and WTRU B and WTRU C are group members. WTRUs A, B, C, D, E, F can communicate among them over Uu interface129a/129bif under the access network coverage or sidelink (PC5 or NR PC5) interface125aif under or out of the access network coverage. WTRUs A, B, C, D, E, F can communicate to an RSU via a Vehicle-to-Network (V2N) interface126or sidelink interface125b. WTRUs A, B, C, D, E, F can communicate to a V2X Server124via a Vehicle-to-Infrastructure (V2I) interface127. WTRUs A, B, C, D, E, F can communicate to another UE via a Vehicle-to-Person (V2P) interface128.

It is understood that any or all of the apparatuses, systems, methods and processes described herein can be embodied in the form of computer executable instructions (e.g., program code) stored on a computer-readable storage medium which instructions, when executed by a processor, such as processors118or91, cause the processor to perform and/or implement the systems, methods and processes described herein. Specifically, any of the steps, operations or functions described herein can be implemented in the form of such computer executable instructions, executing on the processor of an apparatus or computing system configured for wireless and/or wired network communications. Computer readable storage media includes volatile and nonvolatile, removable and non-removable media implemented in any non-transitory (e.g., tangible or physical) method or technology for storage of information, but such computer readable storage media do not include signals. Computer readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible or physical medium which can be used to store the desired information, and which can be accessed by a computing system.

Connection Management in LTE D2D Sidelink

One-to-Many ProSe Direct Communication

In ProSe and specifically LTE D2D Sidelink communication, One-to-many ProSe Direct Communication has the following characteristics:One-to-many ProSe Direct Communication is connectionless. Thus, there is no signaling over PC5 control plane.The radio layer provides a user plane communication service for transmission of IP packets between UEs engaged in direct communication.Members of a group share a secret from which a group security key can be derived to encrypt all user data for that group.Authorization for one-to-many ProSe Direct Communication is configured in the UE by the ProSe Function using PC3 reference point.ProSe UE configuration parameters (e.g. including ProSe Group IP multicast addresses, ProSe Group IDs, Group security material, radio related parameters for transmission and reception) are configured in the UE.

One-to-One ProSe Direct Communication

One-to-one ProSe Direct Communication is connection oriented and realized by establishing a secure layer-2 link over PC5 between two UEs. The control plane for establishing, maintaining and releasing the logical connection for one-to-one sidelink communication is shown in theFIG.2. Note that throughout this disclosure, PC5 and sidelink interface are used interchangeably.

Each UE (e.g., UE A and UE B inFIG.2) has a Layer-2 ID for unicast communication that is included in the Source Layer-2 ID field of every frame that it sends on the layer-2 link and in the Destination Layer-2 ID of every frame that it receives on the layer-2 link. Conflicts between Destination Layer-2 ID for unicast and one-to-many communication will be resolved by RAN WG2. The UE needs to ensure that the Layer-2 ID for unicast communication is at least locally unique.

The layer-2 link for one-to-one ProSe Direct Communication is identified by the combination of the Layer-2 IDs of the two UEs. This means that the UE can engage in multiple layer-2 links for one-to-one ProSe Direct Communication using the same Layer-2 ID.

In ProSe, the PC5-S signaling is designed for connection management and security management as illustrated inFIG.3. InFIG.3, in step S302, UE-1 sends a direct communication request to UE-2. In step S304, authentication and establishment of security association is performed.

The connection management procedures include PC5 link setup, link maintenance through keep-alive functionality and link release procedures. The security management includes PC5 security mode control procedures and (re)keying procedures.

PC5-S is not capable of AS layer parameter configuration, except for security parameters. It is worth noting that RRC is not currently used for PC5 AS configuration in support of sidelink communication. RRC is only used for broadcasting sidelink generic configuration parameters over sidelink broadcast control channel (SBCCH).

Support for QoS in ProSe

QoS Control is per packet based QoS. When the ProSe upper layer (i.e. above PC5 access stratum) passes a protocol data unit for transmission to the PC5 access stratum, the ProSe upper layer provides a ProSe Per-Packet Priority (PPPP) from a range of 8 possible values, and a ProSe Per-Packet Reliability (PPPR) from a range of 8 possible values. The PPPP and PPPR are independent of the Destination Layer-2 ID and apply to both one-to-one and one-to-many ProSe Direct Communication. The PPPP and PPPR are selected by the application layer. A ProSe Per-Packet Priority value shall be assigned to PC5-S messages. The UE is configured with one ProSe Per-Packet Priority value that is used for transmitting any of the PC5-S messages.

The PPPP and PPPR are neutral to the mode in which the UE accesses the medium i.e. whether scheduled or autonomous transmission modes are used.

The ProSe access stratum uses the ProSe Per-Packet Priority associated with the protocol data unit, as received from the upper layers to prioritize the transmission with respect to other intra-UE transmissions (i.e. protocol data units associated with different priorities awaiting transmission inside the same UE) and inter-UE transmissions (i.e. protocol data units associated with different priorities awaiting transmission inside different UEs).

The ProSe access stratum uses the PPPR associated with the protocol data unit as received from the upper layers to decide and adjust the transmission behavior, or e.g. packet duplication.

PC5 Access Stratum (Radio) Configuration for ProSe

The user plane Access Protocol Stack (AS) in the PC5 interface consists of PDCP, RLC, MAC and PHY as shown in theFIG.4.

As indicated above, the one-to-many ProSe communication over PC5 interface is connectionless and has no intended specific receiver. Consequently, there is no need for receiver side control or capability dependent configuration of the radio protocol stack or the radio resources. One-to-one ProSe communication over PC5 interface is connection oriented however as indicated above, the PC5-S signaling protocol used for the connection establishment is not designed and not capable of AS layer parameters configuration. As a result, for both one-to-many ProSe communication and one-to-one ProSe communication, the RX UE protocol stack configuration is predefined in the specification with all features mandatory for the RX UE. For example, no HARQ feedback for sidelink communication, RLC UM is used for sidelink communication, ROHC Unidirectional Mode is used for header compression in PDCP for sidelink communication, Uplink Data Compression (UDC) is not used for sidelink communication. A receiving UE needs to maintain at least one RLC UM entity per transmitting peer UE. A receiving RLC UM entity used for sidelink communication does not need to be configured prior to reception of the first RLC UMD PDU. For the TX UE, AS parameters are configured or derived from QoS input provided by the upper layer. For example, a UE can establish multiple logical channels based on QoS input from upper layer. LCID included within the MAC subheader uniquely identifies a logical channel within the scope of one Source Layer-2 ID and Destination Layer-2 ID combination. As indicated above, the parameters for logical channel prioritization are not configured. The Access stratum (AS) is provided with the PPPP of a protocol data unit transmitted over PC5 interface by higher layer. There is a PPPP associated with each logical channel. Similarly, the PPPR are not configured. The AS is provided with the PPPR of a protocol data unit transmitted over the PC5 interface by a higher layer. The radio resources used for ProSe direct communication can be autonomously selected by the UE AS when out of coverage, based on the QoS input and radio resource configuration information provided by the upper layer, or can be scheduled by the eNB, e.g., when in coverage or when in out of coverage taking into account QoS input and upper layer resource configuration as reported by the UE to the eNB.

Connection Management in LTE V2X Sidelink

The V2X communication over PC5 reference point is a type of ProSe Direct Communication where the V2X communication over PC5 reference point is connectionless, and there is no signaling over PC5 control plane for connection establishment. V2X messages are exchanged between UEs over PC5 user plane.

There is no support for connection oriented and no support for one-to-one V2X communication in LTE.

Support for QoS in V2X

QoS Control for V2X sidelink communication is per packet based QoS and follows the same principle as that of ProSe sidelink communication as described in section 2.2.3.

The PC5 Assess Stratum configuration is similar to that of PC5 Access stratum configuration for ProSe direct communication.

The one-to-many V2X communication over PC5 interface is connectionless and has no intended specific receiver. Consequently, there is no need for receiver side control or capability dependent configuration of the radio protocol stack or the radio resources. As a result, the RX UE protocol stack configuration is predefined in the specification with all features mandatory for the RX UE. For e.g. no HARQ feedback for sidelink communication, RLC UM is used for sidelink communication, ROHC Unidirectional Mode is used for header compression in PDCP for sidelink communication, Uplink Data Compression (UDC) is not used for sidelink communication. A receiving UE needs to maintain at least one RLC UM entity per transmitting peer UE. A receiving RLC UM entity used for sidelink communication does not need to be configured prior to reception of the first RLC UMD PDU. For the TX UE, AS parameters are configured or derived from QoS input and other configuration parameters such TX profile provided by the upper layer. For example, a UE can establish multiple logical channels based on QoS input from the upper layer. LCID included within the MAC subheader uniquely identifies a logical channel within the scope of one Source Layer-2 ID and Destination Layer-2 ID combination. As indicated above, the parameters for logical channel prioritization are not configured. The Access stratum (AS) is provided with the PPPP of a protocol data unit transmitted over PC5 interface by a higher layer. There is a PPPP associated with each logical channel. Similarly, the PPPR are not configured. The AS is provided with the PPPR of a protocol data unit transmitted over PC5 interface by higher layer. The radio resources used for ProSe direct communication can be autonomously selected by the UE AS when out of coverage, based on the QoS input and radio resource configuration information provided by the upper layer, or can be scheduled by the eNB, e.g., when in coverage or when in out of coverage taking into account QoS input and upper layer resource configuration as reported by the UE to the eNB. The TX profile is used to decide on whether to use Release 14 PHY format or Release 15 PHY format (e.g. 64QAM) for V2X sidelink transmission.

NR V2X Use Cases

SA1has identified four major advanced V2X use case groups [1][2]: vehicles platooning, extended sensors, advanced driving and remote driving as follows:Vehicles Platooning enables the vehicles to dynamically form a group travelling together. All the vehicles in the platoon receive periodic data from the leading vehicle, in order to carry on platoon operations. This information allows the distance between vehicles to become extremely small, i.e., the gap distance translated to time can be very low (sub second). Platooning applications can allow the vehicles following to be autonomously driven.Extended Sensors enables the exchange of raw or processed data gathered through local sensors or live video data among vehicles, RSUs, devices of pedestrians and V2X application servers. The vehicles can enhance the perception of their environment beyond what their own sensors can detect and have a more holistic view of the local situation. High data rate is one of the key characteristics.Advanced Driving enables semi-automated or fully-automated driving. Longer inter-vehicle distance is assumed. Each vehicle and/or RSU shares data obtained from its local sensors with vehicles in proximity, thus allowing vehicles to coordinate their trajectories or maneuvers. In addition, each vehicle shares its driving intention with vehicles in proximity. The benefits of this use case group are safer traveling, collision avoidance, and improved traffic efficiency.Remote Driving enables a remote driver or a V2X application to operate a remote vehicle for those passengers who cannot drive by themselves or remote vehicles located in dangerous environments. For a case where variation is limited and routes are predictable, such as public transportation, driving based on cloud computing can be used. High reliability and low latency are the main requirements.
The NR V2X requirements are much more diverse and stringent than that of LTE V2X as illustrated in theFIG.5.

As discussed earlier, from the AS perspective, ProSe sidelink unicast and groupcast transmission are connectionless. Furthermore, LTE V2X only supports groupcast transmission which is also connectionless. Considering that NR V2X requirements are much more diverse and stringent than that of LTE V2X, the AS connectionless transmission presents a number of challenges and might not be adequate in the context of NR V2X diverse and stringent requirements, for example, in terms of supporting a higher data rate, higher reliability and lower latency requirements. The following are some examples of challenges to meeting NR V2X requirements using AS connectionless transmission for unicast and groupcast. Note that throughout this disclosure, groupcast and multicast are used interchangeably.1. Higher Protocol Overhead: with AS connectionless transmission, in order to allow delivery of the received V2X packets to the correct upper layer service access point (SAP) in the RX UE as well as allowing the SL RX UE to distinguish the different SL TX UEs, each V2X packet must carry the destination ID and the source ID. Furthermore, AS connectionless transmission with multiplexing of traffic in the MAC layer required each transmitted MAC PDU to carry an L2 destination ID and a source L2 ID so as to uniquely identify a logical channel within the context of a source and destination pair. For ProSe sidelink and V2X sidelink, each MAC PDU carry an L2 source ID and an L2 destination ID which are mapped to upper layer source ID and destination ID respectively to limit the overhead, however despite this mapping, each V2X packet transmission still incur an overhead of an L2 source ID and an L2 destination ID. While such protocol overhead was acceptable in the context of LTE V2X transmission with relatively low data rate transmission, such overhead might be excessive in the context of NR V2X.2. Higher Processing overhead: the fact that each sidelink packet carries an L2 source ID and an L2 destination ID also means more packet filtering processing overhead in L2. For example, in LTE V2X, the RX PHY layer passes on to the RX L2 all successfully decoded V2X packets received on the configured RX resource pools, which are then filtered in L2 using the 24 bits long L2 destination ID and the 24 bits long L2 source ID, so only the V2X packet for this RX UE are passed on to the V2X upper layer. Similarly, for ProSe sidelink, the PHY layer must decode all the packets received on the configured RX resources, performs partial filtering based on the 8 LSB bits of the L2 destination ID in the SCI, and then passed on to the L2 the partially filtered packet, which are then further filtered in L2 based on the 16 MSB bits of the L2 destination ID and the 24 bits longs source L2 ID. While such processing overhead was acceptable in the context of LTE V2X transmission with relatively low data rate transmission, such processing overhead might be excessive in the context of NR V2X.3. Hard to enable physical layer feedback: with AS connectionless transmission, there is no support for L2 feedback i.e. there is no support for RLC feedback and there is no support for HARQ feedback in legacy LTE ProSe or legacy V2X sidelink communication. There is no PHY layer UE specific identity (source or destination) such as C-RNTI or communication context dedicated to a specific UE in support of transmission of individualized feedback from RX UEs to TX UEs, which is significantly complicated to implement without connection-oriented transmission.4. Hard to enable Link management to help meet QoS requirement: with AS connectionless transmission, it is impractical or impossible to enable UE specific radio link management functions such as radio link monitoring and radio link recovery, beam management, link adaptation (power control and rate control) and channel dependent scheduling. While the lack of these functions was acceptable for ProSe sidelink or V2X sidelink, NR V2X diverse and stringent requirements such as higher data rate coupled with higher reliability and lower latency require a more efficient radio resource management. In addition, the connection-based SL makes it easier to enable SL QoS control on per-QoS flow basis, and therefore provides the basis for a unified QoS handling over SL and Uu.5. Inability to support differentiated configuration of RX UE: with AS connectionless transmission, it is not possible to configure RX UE with AS configuration that is specific to the RX UE for example, based on the RX UE capability. As a consequence, all ProSe sidelink features or LTE V2X sidelink features for a given release are mandatory for all the RX UE for that release. NR V2X requirements are diverse and it is not practical to impose that all NR V2 feature of any given release be mandatory for all NR V2X UEs of that release. AS layer connection-based SL transmission can enable more flexible SL radio protocol configuration.

In light of the above shortcomings of AS connectionless transmission in the context of NR V2X communication, support for AS connection-oriented transmission is desired for NR V2X unicast and for NR V2X groupcast as well.

Issues Related to Connection Oriented Unicast Transmission

In support of AS Connection oriented unicast transmission, the following issues need to be addressed.1. Overall procedure for unicast connection establishment, connection modification/reconfiguration and connection release2. Authorization and Provisioning of UE in support of connection oriented unicast transmission (in-coverage and out-of-coverage)3. V2X provisioned information shared with gNB by the UE (UE assistance information) in support of unicast connection establishment, modification or release.4. Triggers for unicast connection reconfiguration, connection release & connection relocation5. SL AS protocol configuration including:a. Configuration of MAC, RLC (e.g., UM versus AM decision), PDCP, SDAP, radio resources/radio bearer, PHY configuration (e.g., HARQ including HARQ TX with feedback versus HARQ Tx without feedback, CSI, etc.) assuming one or more of the following: Flow based QoS versus per-packet based QoS, Mode 1 versus Mode 2 resource allocationb. AS-level information required to exchange among UEs via sidelink for SL unicast for e.g. UE ID, UE capability, Radio/Bearer configuration, PHY information/configuration (e.g. HARQ, CSI), Resource information/configuration and QoS info.c. Enhancement to Uu in support of SL connection management and QoS and what AS-level information required to exchange between UEs and gNB for SL unicast communicationd. How is AS-level information exchanged between UEs via sidelink in support of unicast, RRC versus PC5 signaling details to be specified.6. Admission control, how this is done, and which entity perform the admission control7. UE Identifications configuration and coordination between TX UE and RX UE in support of unicast transmission. For example, in LTE ProSe sidelink unicast design, the UE needs to ensure that the Layer-2 ID for unicast communication is at least locally unique. To that effect the UE should be prepared to handle Layer-2 ID conflicts with adjacent UEs using unspecified mechanisms (e.g., self-assign a new Layer-2 ID for unicast communication when a conflict is detected). How to ensure the uniqueness for L2 IDs for unicast connection-oriented communication is an issue that needs to be addressed.8. It is expected that a discovery procedure is used to identify a specific UE in order to initiate one-to-one communication. While the upper layer above the access stratum can indicate to the access stratum QoS related information and whether a communication should be unicasted, group casted or broadcasted, access stratum specific rules and criteria can need to be designed in deciding whether a unicast communication should be carried out connectionlessly or in a connection oriented manner. Furthermore, the issue of interactions between discovery and unicast connection management and how the output for discovery is used in support of unicast connection establishment, connection release or connection relocation decision needs to be addressed.
Issues Related to Connection Oriented Groupcast Transmission

Similarly, the issues described in the section entitled “Issues Related to Connection Oriented Unicast Transmission” above need to be addressed in relation with connection oriented groupcast transmission. Specifically, in support of AS Connection oriented groupcast transmission, the following issues need to be addressed.1. Overall procedure for groupcast connection establishment, connection modification/reconfiguration and connection release2. Authorization and Provisioning of UE in support of connection oriented groupcast transmission (in-coverage and out-of-coverage)3. V2X provisioned information shared with gNB by the UE (e.g., UE assistance information) in support of groupcast connection establishment, modification or release.4. Triggers for groupcast connection establishment for example between a group member and group lead, triggers for groupcast connection reconfiguration, connection release and connection relocation by a group member toward another group lead.5. SL AS protocol configuration including:a. Configuration of MAC, RLC (e.g., UM versus AM decision), PDCP, SDAP, radio resources/radio bearer, PHY configuration (e.g., HARQ including HARQ TX with feedback versus HARQ Tx without feedback, CSI, etc.) assuming one or more of the following: flow based QoS versus per-packet based QoS, Mode 1 versus Mode 2 resource allocation.b. AS-level information required to exchange among UEs via sidelink for SL groupcast for e.g. UE ID, UE capability, radio/bearer configuration, PHY information/configuration (e.g., HARQ, CSI, etc.), resource information/configuration and QoS info.c. Enhancement to Uu in support of SL connection management and QoS and what AS-level information required to exchange between UEs and gNB for SL groupcast communicationd. How is AS-level information exchanged between UEs via sidelink in support of unicast, RRC versus PC5 signaling details to be specified.6. Admission control, how this is done, and which entity perform the admission control.7. UE Identifications configuration and coordination between TX UE and RX UE in support of groupcast transmission. An RX UE can be involved in the reception of more than one groupcast communications. Similarly, a TX UE can be involved in the transmission of more than one groupcast communication. There is a need to ensure that the Layer-2 ID for groupcast communication is at least locally unique. How to ensure the uniqueness for L2 IDs for connection oriented groupcast communication is an issue that needs to be addressed.8. It is expected discovery procedure is used to identify specific UE or group of UEs in order to initiate one-to-many communication. While the upper layer above the access stratum can indicate to the access stratum QoS related information and whether a communication should be unicasted, groupcasted or broadcasted, access stratum specific rules and criteria can need to be designed in deciding whether a groupcast communication should be carried out in connectionless manner or in a connection-oriented manner. Furthermore, the issue of interactions between discovery and groupcast connection management and how the output for discovery is used in support of groupcast connection establishment, connection release or connection relocation decision needs to be addressed. One question in connection to this is whether V2X group management is performed in the V2X upper layer only, or AS layer only or in both layers and if so, what is the relationship between AS group and V2X upper layer group? For example, if the UE members in upper layer group spread in a large geography, perhaps one single AS layer group cannot cover all the UE members and multiple AS layer groups are needed to enable successful communications among all the UEs in the upper layer UE group. For each AS group, member UE(s) could perform AS layer group connection establishment and maintenance with the AS group leader. When member UE(s) move around, release from original AS layer group and re-connection to another AS group is performed. Procedures, configurations and interaction between upper layer and AS layer for establishment and maintenance of AS groupcast connections and mapping to upper layer session/connection need to be designed and specified.
Summary of Proposed Solutions

In this disclosure, the following solutions in support of Unicast connection management are proposed:1. Layer 2 protocol structure including the following:a new proposal to have one SDAP entity per V2X destination, and only QOS flow ID in the SDAP protocol header as no support for reflective QoS feature on the sidelink is required;MAC SDUs subject to connection-oriented transmission are separately multiplexed from MAC SDU subject to connectionless transmission;A MAC PDU subject to connection-oriented transmission doesn't carry source ID or destination ID;Support for sidelink multicast control channel and sidelink multicast transport channel;2. Provisioning of V2X transmitter and Receiver;3. Triggers for V2X Transmission or V2X reception;4. Transmitter side and Receiver Side RAT and Interface selection, which entity performs the selection and based on what criteria;5. Transmitter side and Receiver side Transmission mode selection and criteria for the selection6. Unicast Connection Management detail procedures including description of assistance parameters from the UE (e.g., receiver capability), and unicast configuration parameters configured into the UE by the scheduling entity or an assisting UE in coordination with the scheduling entity.7. Different alternatives of connection management procedure are described including the following options:Use PC5 RRC signaling to jointly carry V2X upper layer connection configuration and AS layer connection configuration, T-UE is configured by a scheduling entity or the I-UE in coordination with the I-UE; seeFIG.16;Use PC5-S signaling to jointly carry V2X upper layer connection configuration and AS layer connection configuration, T-UE is configured by a scheduling entity or the I-UE in coordination with the I-UE; seeFIG.17;Use PC5 RRC signaling to jointly carry V2X upper layer configuration information in support of AS layer connection, and AS layer connection configuration; T-UE is configured by the scheduling entity or the I-UE in coordination with the I-UE; Additionally, the V2X upper layer connection configuration is carried out independently from the AS connection configuration using PC5-S signaling; seeFIG.18;Use PC5-S Signaling to jointly carry V2X upper layer configuration information in support of AS layer connection, and AS layer connection configuration; I-UE is configured by the scheduling entity or the T-UE in coordination with the I-UE; Additionally, the V2X upper layer connection configuration is carried out independently from the AS connection configuration using PC5-S signaling; seeFIG.19;Use PC5-S signaling to jointly carry V2X upper layer connection configuration and AS layer connection configuration, I-UE is configured by a scheduling entity or the T-UE in coordination with the scheduling entity; seeFIG.20;Use PC5 RRC signaling to jointly carry V2X upper layer connection configuration and AS layer connection configuration, I-UE is configured by a scheduling entity or the T-UE in coordination with the scheduling entity; seeFIG.21;8. Group Connection Configuration and idea of V2X upper layer group mapping to AS layer subgroups, maintenance in AS of mapping table and indication by AS to PHY of one or more of the following:The group layer-2 destination ID;List of V2X UE ID (e.g., ProSe UE ID, UE ID or any other identifier that can be used by the UE as a source ID for the member UE) of the group members;The subgroup layer-2 destination ID;List of V2X UE ID (e.g., ProSe UE ID, U ID or any other identifier that can be used by the UE as a source ID for the member UE) of the subgroup members;For each subgroup, an indication requesting that data received for the subgroup is relayed or not relayed.9. Broadcast configuration and various options for broadcast configuration signaling.10. Methods for UE handling of multiple simultaneous sidelink RRC connections.11. Modeling of PC5 Unicast Link granularity, Unicast Link Update and Unicast Link Addition Procedures
UE Operation Before V2X Communication

Layer 2 Protocol Structure

FIG.6provides an illustration of the Service Data Adaptation Protocol (SDAP) sublayer. It is proposed that there is one SDAP entity per V2X destination. In one embodiment, V2X the destination can be a peer V2X UE Destination. In such embodiment, if a UE has concurrent V2X communication with n peer V2X UEs, the UE then maintains n SDAP entities, one per peer V2X destination UE. Each SDAP entity maintains a set of bearers specific to a peer V2X destination UE. As there might be multiple concurrent V2X services between a UE (in this case the source UE) and a peer V2X destination UE, the L2 destination IDs to which those services mapped to and the radio bearers associated with those services are mapped to the same SDAP entity associated with this specific peer V2X destination UE. A V2X packet associated with a given peer V2X destination UE, regardless of the transmission cast type (i.e. unicast, groupcast or broadcast), is mapped to the SDAP entity to which the corresponding bearer or destination Layer-2 ID is mapped to. In the case of broadcast or groupcast, even if the peer V2X destination UE is not explicitly known to the AS, the corresponding bearer and the associated layer-2 destination ID can be mapped to any SDAP entity; or alternatively, there can be one or more SDAP entities dedicated to support broadcast communication, or one or more SDAP entities to support groupcast communication, or one or more to support both groupcast and broadcast communication.

In another embodiment, the services can be arranged in groups which are (pre)configured or provisioned into the UE. In this embodiment, V2X destination inFIG.6refers to one group of V2X services.

In an alternative embodiment, there can be one SDAP entity per UE for V2X sidelink communication. In such a case, V2X communication bearer identity can need to be unique within the UE.

FIG.7depicts the layer-2 structure in support of V2X communication in AS broadcasting configuration as well as mapping of sidelink broadcast control channel (SBCCH) to the transport sidelink broadcast channel (SL-BCH). The multiplexing of sidelink traffic logical channel (STCH) on the transport sidelink shared channel (SL-SCH) assumes each MAC PDU include a source ID and a destination ID, with respect to which a logical channel identification is unique in support of MAC multiplexing. It is also proposed to introduce a sidelink control channel (SCCH) which can be multiplexed with logical STCH on to the SL-SCH. It is also proposed to introduce a sidelink signaling radio bearer (SL-SRB) to which logical channel such as SCCH can be mapped to. The SL-SRB can be used for the signaling of connection management (e.g., connection establishment, connection reconfiguration or connection release) or for configuration and reporting of sidelink measurements.

FIG.8depicts the layer-2 structure in support of V2X communication in AS unicast connection-oriented configuration, with peer V2X receiver configured with dedicated unicast V2X configuration that takes into account, e.g., the peer V2X UE capability. In this case, the multiplexing of sidelink traffic logical channel (STCH) onto the transport sidelink shared channel (SL-SCH) doesn't assume that each MAC PDU includes a source ID and a destination ID, with respect to which a logical channel identification is unique in support of MAC multiplexing. Instead, multiplexing on STCH assumes a separate instance of SL-SCH is configured at the connection establishment and binded to a HARQ entity dedicated to transmitting V2X unicast traffic or SL-RRC signaling in AS connection-oriented manner. At the connection establishment, a MAC service access point (SAP) for each instance of SL-SCH is created and communicated to the PHY, which then creates and maintains the corresponding instance of the PHY channel (e.g., physical sidelink shared channel, PSSCH) associated with the instance of the SL-SCH indicated by MAC. As part of the connection context, for each V2X service or data radio bearer included into the context of the connection, a Layer-2 destination ID mapped to the V2X service is maintained with association to the logical channel and the corresponding radio bearer. In this scheme and in support of PHY layer multiplexing of traffic into shared channel, for each of the two V2X UEs involved in the connection, a physical layer (PHY) unique identifier, e.g., a PC5 sidelink RNTI that identifies both V2X UEs for the purpose of connection-oriented reception can be assigned to each of the peer UEs and configured into both peer UEs. Alternatively, each of the peer UEs can autonomously derive their own PHY identifier and exchange with each other as part of the connection configuration. The TX UE uses the peer RX V2X UE PHY identifier to identify the peer V2X UE the data is destined to. For example, the TX UE can scramble or mask the transmitted data with the peer RX V2X UE PHY identifier. The RX UE uses its PHY identifier that has been used by the transmitter to identify the RX UE of the data. Once decoded, the RX UE is in position to correctly route the received data to the correct MAC SAP based on the association created at the connection establishment between PHY and the MAC SAP. In an alternative option where there is no PHY layer multiplexing, e.g., traffic from a peer V2X UE is carried on dedicated PHY resources (pre)configured or provisioned into the UE, a PHY identifier that uniquely identifies peers UE involved in the connection might not be required. In this case, the RX UE identifies the peer V2X transmitting UE and the correct routing SAP in MAC based on the PHY resources on which the V2X packet is received. The AS can provide to the PHY the peer V2X UE source ID (e.g., in the case of unicast) or the peer V2X UE destination layer-2 ID (e.g., ProSe Layer-2 Group ID like or ProSe Application Layer Group ID) in the case of groupcast. The PHY can use such ID to derive the RNTI used to identify the peer V2X UE the transmission is destined to. Furthermore, as part of the connection configuration, logical channels carrying control information (e.g., SCCH) mapped to sidelink signaling radio bearers (SL-SRB) can be multiplexed with logical channel carrying sidelink traffic (STCH) mapped to sidelink data radio bearer (SL-DRB), onto the SL-SCH transport channel configured for connection-oriented reception. For unicast, it is proposed that a logical SL control channel denoted sidelink control channel (SCCH) be introduced for the configuration and control of unicast traffic. SCCH can be associated with an SL-SRB. The SL-SRB that SBCCH is mapped to can be denoted SL-SRB0. The SL-SRB that SCCH is mapped to and transmitted in broadcasted manner (AS connectionless), can be denoted SL-SRB1. The SL-SRB that SCCH is mapped to, and transmitted in connection-oriented manner can be denoted SL-SRB2.

FIG.9depicts the layer-2 structure in support of V2X communication in AS groupcast connection-oriented configuration, with peer V2X receiver configured with dedicated groupcast V2X configuration that takes into account, e.g., the peer V2X UE capability. In this case, the multiplexing of sidelink traffic logical channel (e.g., SL-MTCH) onto the transport sidelink shared channel (SL-MCH) doesn't assume that each MAC PDU includes a source ID and a destination ID, with respect to which a logical channel identification is unique in support of MAC multiplexing. Instead, multiplexing on SL-MCH assumes a separate instance of SL-MCH configured at the connection establishment and binded to a HARQ entity dedicated to transmitting V2X groupcast traffic or SL-RRC signaling in AS connection-oriented manner. At the connection establishment, a MAC service access point (SAP) for each instance of SL-MCH is created and communicated to the PHY, which then creates and maintains the corresponding instance of the PHY channel (e.g., physical sidelink shared channel, PSMCH) associated with the instance of the SL-MCH indicated by MAC. As part of the connection context, for each V2X service or data radio bearer included into the context of the connection, a Layer-2 destination ID mapped to the V2X service is maintained with association to the logical channel and the corresponding radio bearer. In this scheme and in support of PHY layer multiplexing of traffic into multicast channel, for each of the TX V2X UE and the RX group member UEs involved in the connection, a physical layer (PHY) unique identifier, e.g., a PC5 sidelink RNTI that identifies the TX V2X UE and a physical layer unique identifier that identifies the RX group member UEs for the purpose of connection-oriented reception can be assigned to each of the UEs part of the group and configured into the UEs. Alternatively, each of the peer UEs can autonomously derive their own PHY identifier and exchange with each other as part of the connection configuration. The TX UE uses the peer RX V2X UE PHY group identifier to identify the peer V2X group member-UEs the data is destined to. For example, the TX UE can scramble or mask the transmitted data with the peer RX V2X group member-UEs PHY identifier. The RX UE uses its PHY group identifier that has been used by the transmitter to identify the RX UE of the data. Once decoded, the RX UE is in position to correctly route the received data to the correct MAC SAP based on the association created at the connection establishment between PHY and the MAC SAP. In an alternative option where there is no PHY layer multiplexing for groupcast traffic, e.g., groupcast traffic is transmitted on dedicated PHY resources (pre)configured or provisioned into the UE, a PHY group identifier that uniquely identifies peers UE involved in the connection might not be required. In this case, the RX member-UEs identifies the groupcast traffic the correct routing SAP in MAC based on the PHY resources on which the groupcast traffic is received. The AS can provide to the PHY, the UE own source ID, as well as the peer V2X UE source ID (e.g., in support of unicast) or the peer V2X UE destination layer-2 ID (e.g., ProSe Layer-2 Group ID like or ProSe Application Layer Group ID), for example, in the case of groupcast communication. The PHY can use such an ID to derive the RNTI used to identify the peer V2X UE the transmission is destined to. Furthermore, as part of the connection configuration, logical channels carrying sidelink multicast control information (e.g., SL-MCCH) mapped to sidelink signaling radio bearers (SL-SRB) can be multiplexed with logical channel carrying sidelink multicast traffic (SL-MTCH) mapped to sidelink data radio bearer (SL-DRB), onto the SL-MCH transport channel configured for connection-oriented reception. For groupcast, a logical sidelink control channel denoted sidelink multicast control channel (SL-MCCH) can be introduced for the configuration and control of groupcast traffic. MCCH cancan be associated with a SL-SRB. The SL-SRB that SBCCH is mapped to cancan be denoted SL-SRB0. The SL-SRB that MCCH is mapped to and transmitted in broadcasted manner (AS connectionless), cancan be denoted SL-SRB1. The SL-SRB that MCCH is mapped to and transmitted in connection-oriented manner cancan be denoted SL-SRB2.

FIG.10provides a functional view of SDAP sublayer. It is proposed that reflective QoS is not supported in V2X sidelink. As illustrated inFIG.11, it is therefore proposed to simplify the SDAP header and made the header identical between downlink and uplink. The QoS Flow Identifier (QFI) can be 6 bits or less, while the remaining bit of the header can be reserved bits or can be used to carry data thereby minimizing overhead of support for QoS Flow over V2X sidelink.

Transmitter Operation

An exemplary Transmitter side high level illustration of UE operation, including intermediate procedures in the UE leading to the decision for V2X communication either by AS broadcast, AS unicast or AS groupcast is provided inFIG.12.

In step S1200, the UE is either pre-configured (in SIM or ME), or provisioned by the V2X control function located in the core network with information in support of V2X operation, i.e., discovery procedure whereby the UE discovers other devices for V2X communication, and for V2X communication whereby the UE engages in communication with other V2X devices as required by V2X applications running on the V2X devices. Communication between the UE and the V2X Control function for provisioning of V2X operation parameters can be through user plane or through control plane. Provisioning parameters for NR V2X operation and particularly in support of unicast communication or groupcast communication are described in the section below entitled “Provisioning for Transmitter Side V2X Communication.” With V2X communication triggered in step S1202, the UE can perform synchronization if not already synchronized in step S1204. The UE furthermore can perform discovery in order to identify a peer UE or group of UEs it can communicate with as dictated by the triggering condition of the communication for e.g., an application in the application layer can trigger the V2X upper layer to discover a peer UE or group of UEs if not discovered yet and initiate V2X communication toward such UE or group of UEs. The output from the discovery procedures, e.g., the Layer-2 link ID(s) of the discovered UE or group of UEs can be used by the UE in subsequent procedure(s) of the V2X operation, such as connection establishment toward specific UE or group of UEs or configuration of broadcast resource for V2X transmission. In steps S1206and S1208, the UE performs RAT selection and interface (e.g., sidelink versus Uu interface) selection. While step S1206and step S1208are listed as separate steps, the two steps can be performed concurrently, as described below in the section entitled “Transmitter Side RAT Selection and Interface Selection.” In step S1210, it is determined whether the SL interface is selected. If yes, it is determined what the SL transmission mode is (step S1212). If the SL transmission mode is a broadcast mode, AS configuration for broadcast transmission is performed in step S1218. If the SL transmission mode is a unicast mode, Layer-2 link configuration for unicast transmission is performed in step S1214. If the SL transmission mode is a multicast mode, Layer-2 link configuration for multicast reception is performed in step S1216. In step S1210, if the SL interface is not selected, transmission over Uu interface is initiated (step S1220).

Provisioning for Transmitter Side V2X Communication

In support of unicast transmission, groupcast transmission, broadcast transmission, or flow based QoS, the NR V2X UE can be pre-configured or provisioned with the following system parameters; the configuration can be on per-interface basis, e.g., NR sidelink interface, NR Uu interface, LTE sidelink interface, LTE Uu interface, WLAN sidelink interface or WLAN to network interface:List of authorized V2X Services and for each service, the transmission mode (transmission cast type), i.e., whether the service is broadcast based transmission, groupcast based transmission or unicast based transmission; the transmission mode of a service can be defined on PLMN or group of PLMNs basis, or on cell or group of cells basis or on geographical area or group of geographical areas basis.List of authorized V2X Services and for each service, whether the transmission is V2X upper layer connectionless or V2X upper layer connection oriented. For example, a broadcast transmission can be a connectionless transmission while a unicast transmission or groupcast transmission can be connection-oriented transmission, or connectionless transmission at the V2X upper layer.List of authorized V2X Services and for each service, whether the transmission is AS layer connectionless or V2X AS layer connection oriented. For example, a broadcast transmission can be a connectionless transmission while a unicast transmission or groupcast transmission can be connection-oriented transmission, or connectionless transmission at the AS layer.Authorization to act as a scheduler or scheduling entity for other UEs, or local controller or a scheduler node. Such authorization can be defined on PLMN basis or group of PLMNs basis, on a cell basis, on a group of cells basis or on a geographical area basis or a group of geographical area basis. In this disclosure, the terms local controller, scheduling entity or scheduler entity will be used interchangeably. For example, a platoon lead can be provisioned with the authorization to act as a scheduling entity. Such authorization can also be defined on a service basis or group of services basis.Authorization to act as assisting UE to a scheduling entity. Such authorization can be defined on PLMN basis or group of PLMNs basis, on a cell basis, or on a group of cells basis, on a geographical area basis or group of geographical area basis.Authorization for duplication across radio interface, i.e., transmission of the same data across two or more radio interfaces, e.g., across two or more of the following radio interfaces: NR sidelink interface, NR Uu interface, LTE sidelink interface, LTE Uu interface, WLAN sidelink interface or WLAN to network interface. Such duplication can be defined based on a reliability requirement, e.g., ProSe Per-Packet Reliability value in the case of per-packet based QoS model or Packet Error Rate or QoS Identifier value in the case of QoS Flow or bearer based QoS model. Such authorization can be defined on per service basis. Furthermore, such authorization can be defined on cell or group of cells basis, or per geographical area or group of geographical areas basis, or on per PLMN or group of PLMNs basis. In the context of V2X we will denote QoS Identifier V2X QoS Identifier (VQI).List of V2X QoS Identifiers. For each VQI, the corresponding QoS profile parameters can be configured. The QoS profile can include one or more of the following: priority level (i.e., scheduling priority level), payload, transmission rate, maximum end-to-end latency, reliability, data rates, minimum required communication range, pre-emption priority level (i.e., admission pre-emption priority level). In another alternative, the QoS profile can include one or more of the following: priority level (i.e., scheduling priority level), resource type (e.g., GBR, Delay critical GBR or Non-GBR), packet delay budget, packet error rate, averaging window, maximum data burst volume. This configuration can be defined on per PLMN or group of PLMNs basis, on a cell or group of cells basis, on per geographical area or group of geographical areas basis.List of QoS Flow Identifiers (QFI). For each QFI, the mapping between QFI and VQI. A QoS Flow is the finest granularity of QoS differentiation. This configuration can be defined on per PLMN or group of PLMNs basis, on a cell or group of cells basis, on per geographical area or group of geographical areas basis.Resource pool configuration for connection-oriented transmission and signaling in support of those connections.Resource pool configuration for PC5 signaling or SL RRC signaling in support of connection establishment and maintenance of that connection. Such a resource pool can be a shared resource pool that is also used for connectionless PC5 data transmission.

Each of the provisioning parameters defined above can be defined on the basis of whether or not the UE is served by a radio access network or not served by a radio access network. Furthermore, when not served by a radio access network, the provisioning parameters can be configured on the basis of whether the carrier frequency for V2X communication is operator managed, or non-operator managed.

The UE can also be preconfigured (e.g., on the SIM or Mobile Equipment (ME)) with the following capability parameters:Support of AS based unicast transmissionSupport of AS based groupcast transmissionSupport for V2X UpL based unicast transmissionSupport for V2X UpL based groupcast transmissionSupport for AS connectionless transmissionSupport for AS connection-oriented transmissionSupport of cross radio interface packet duplicationSupport of capability to act as a scheduling entity.Support of capability to act as an assisting UE to a scheduler entitySupport for QoS flow based QoS Model, e.g., the capability to support a QoS model where QoS requirement for packets transferred from V2X upper layer to V2X AS is indicated using QoS Flow.Support for Per-Packet QoS mode, e.g., the capability to support a QoS model where each packet transferred from V2X upper layer to V2X AS carried its QoS requirement, e.g. PPPP or PPPR.

Transmitter Side Triggers for V2X Communication

In the context of the high-level illustration of V2X operation described inFIG.12, one or more of the following events can trigger V2X communication procedure including connection establishment procedure in the UE:Submission of V2X packet by a V2X application for transmission. In this case, the procedure is triggered as the result of an event originating from the application layer;Trigger of discovery by the application layer;Communication quality of current/existing V2X communication no longer meets quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.). In this case, the V2X upper layer of V2X UE can initiate communication toward another UE or group of UEs in order to continue the V2X communication initiated by the application layer;Radio link Failure or beam failure or failure of beam failure recovery. In this case, the V2X upper layer of V2X AS can initiate communication toward another UE or group of UEs in order to continue the V2X communication initiated by the application layer;Radio Link quality no longer meets quality threshold;Congestion is above threshold;Transmit Power is above threshold or pathloss is above threshold;Mobility events in which case the V2X upper layer of V2X AS can initiate communication toward another UE or group of UEs in order to continue the V2X communication initiated by the application layer. The mobility events can be related to the UE own mobility or can be related to peer UE mobility;Reception of connection release for example from a peer UE or from a scheduling entity controlling resource allocation to the UE;Reception of connection establishment request from a peer UE or from a scheduling entity controlling resource allocation to the UE;Reception of handover request from a peer UE or from a scheduling entity controlling resource allocation to the UE;Failure of connection reconfiguration.

The V2X upper layer can trigger the V2X Communication operation described inFIG.12. Similarly, the V2X AS layer can trigger the V2X Communication operation described inFIG.12.

Transmitter Side RAT Selection and Interface Selection

The V2X upper layer can perform RAT selection or interface selection. The V2X upper layer can perform sequentially or concurrently, RAT selection and interface selection. The V2X AS can provide assistance information such as availability information to the V2X upper layer for the selection of the RAT or the interface. For example, the AS of a RAT can determine the availability of that RAT. Furthermore, the AS can determine the availability of the interface in connection with a particular RAT. In an exemplary embodiment, the RAT can be one or more of the following: NR RAT, LTE RAT, Wi-Fi or WLAN RAT. Similarly, the interface can be one or more of the following: sidelink NR RAT, Uu RAT, sidelink LTE RAT, Uu LTE RAT, sidelink Wi-Fi or WLAN RAT, and the radio interface between WLAN and the network. The AS can determine the availability of a RAT or of an interface associated with a particular RAT, based on one or more of the following:Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.);Radio link quality threshold;Congestion threshold. The congestion threshold can be related, for example, to channel busy ratio (CBR) and/or channel occupancy ratio (CR);Radio link Failure or beam failure or failure of beam failure recovery.Out-of-coverage or partially out of coverage detection;Anticipated transmit power threshold or pathloss threshold;UE capability.
The availability information can include one or more of the following information:Available or not available;Communication quality thresholdRadio link quality thresholdCongestion thresholdOut-of-coverage or partially out of coverage detectionUE Capability

Transmitter Side Communication Mode Selection

The V2X upper layer can perform transmission cast type selection, i.e., broadcast versus groupcast versus unicast and indicate the selected transmission cast type to the V2X AS layer. The V2X upper layer can indicate to the V2X AS layer, the transmission cast type of each packet submitted to the AS layer. Such approach can be considered per-packet transmission cast type indication to the V2X AS layer by the V2X upper layer. The V2X upper layer can use the per-packet transmission cast type indication, e.g., in association with the per-Packet QoS specification. In an alternative embodiment, the V2X upper layer and the AS layer can specify service access point (SAPs) for each transmission cast type. For each example, for each transmission cast type (i.e., unicast, groupcast or broadcast), the AS layer exposes to the V2X upper layer, one or more transmission cast type specific SAP. The V2X upper layer, submit to the AS layer SAPs, packets according to the transmission cast type. The AS derives the transmission cast type of a packet from the SAP through which the packet is submitted to the AS. The V2X AS layer transmits packets received through a specific V2X upper layer SAP according to the transmission cast type associated with that SAP through which the packet is received from the upper layer.

The V2X upper layer can establish connection in support of a secure Layer-2 link and create a V2X upper layer context for such a connection with an association (including security association) between a source ID and destination ID. From the V2X upper layer perspective, transmission can therefore be connection oriented in which case a Layer-2 link connection context is maintained by the V2X upper layer, or the transmission can be connectionless with no context created and associated between the source and the destination before transmission begins. The V2X upper layer can indicate to the V2X AS, when a Layer-2 link connection exists. The AS layer can decide to create an AS level connection and associate the context of such connection with an upper layer connection context in the UE. The AS context of AS connection can include connection-oriented AS protocol stack configuration, and security association between the source and the destination. Alternatively, the AS may not create an AS level connection for a specific V2X upper layer connection. In such a case, the upper layer packets submitted to the AS from upper layer connection-oriented SAP for transmission, can be transmitted in a connectionless manner at the AS level for example through broadcast transmission at the AS layer level.

Mechanism that the V2X Upper Layer Decides to Use Unicast Versus Groupcast Versus Broadcast Transmission

The V2X upper layer can decide to use a transmission cast type based on one or more of the following:Indication from Application layer;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, scheduling priority, pre-emption priority, etc.);Service type or Traffic Type for e.g. signaling versus application data;Service Authorization configuration;Capability;Destination ID, or number of destination UEs;Configuration into the UE, including pre-configuration (e.g., ME, SIM), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type.Link Quality

Mechanism that the AS Layer Decides to Use Unicast Versus Groupcast Versus Broadcast Transmission

The V2X AS layer can decide to use a transmission cast type based on one or more of the following:Indication from V2X Upper layer;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.);Service type or Traffic Type (e.g., signaling versus application data);Service Authorization configuration;Capability, (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.);Destination ID or number of destination UEs;Configuration into the UE, including pre-configuration (e.g., ME, SIM), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type;Radio Link quality.

Mechanism that V2X Upper Layer Decides to Use Connection Oriented Versus Connectionless

The V2X upper layer can decide to use connection-oriented transmission or connectionless transmission based on one or more of the following:Indication from Application layer;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.);Service type or Traffic Type (e.g., signaling versus application data);Service Authorization configuration;Capability, e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network;Destination ID, or number of destination UEs;Configuration into the UE, including pre-configuration (e.g., ME, SIM, etc.), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type.Link QualitySecurity requirement (e.g., security thresholds). The security requirement can be authentication, integrity or ciphering related requirement.

Next, it will be described how the AS layer decides to use connection oriented versus connectionless. The V2X AS layer can decide to use a transmission cast type based on one or more of the following:Indication from V2X Upper layer;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.);Service type or Traffic Type (e.g., signaling versus application data);Service Authorization configuration;Capability (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.);Destination ID or number of destination UE;Configuration into the UE, including pre-configuration (e.g., ME, SIM, etc.), provisioning into the UE by the network (e.g., V2X control function or configuration into the UE by the scheduling entity). The configuration can include a mapping of a service to a transmission cast type;Radio Link quality;Security requirement (e.g., security thresholds). The security requirement can be integrity or a ciphering related requirement.

Receiver Operation

An exemplary receiver side high level illustration of UE operation, including intermediate procedures in the UE leading to the decision for V2X communication either by AS broadcast, AS unicast or AS groupcast is provided inFIG.13.

In step S1300, the UE is either pre-configured (in SIM or ME) or provisioned by the V2X control function located in the core network with information in support of V2X operation i.e. discovery procedure whereby the UE discover other devices for V2X communication, and for V2X communication whereby the UE engages in communication with other V2X devices. Communication between the UE and the V2X Control function for provisioning of V2X operation parameters can be through user plane or through control plane. Provisioning parameters for NR V2X operation and particularly in support of reception of unicast communication or groupcast communication are described below in the section entitled “Provisioning for Receiver side V2X Communication.” With V2X communication triggered in step S1302, the UE can perform synchronization if not already synchronized in step S1304. The UE furthermore can perform discovery in order to identify peer UE or group of UEs from which it can receive V2X communication. The output from the discovery procedures, e.g., the Layer-2 link ID(s) of the discovered UE or group of UEs can be used by the UE in subsequent procedure(s) of the V2X operation such as monitoring for reception of V2X communications, or connection establishment toward specific UE or group of UEs, or configuration of broadcast resources for reception of V2X communications. In steps S1306and S1308, the UE performs RAT selection and interface (e.g., sidelink versus Uu interface) selection. While step S1306and step S1308are listed as separate steps, the two steps can be performed concurrently, as described in the section below entitled “Receiver Side RAT Selection and Interface Selection.” In step S1310, it is determined whether the SL interface is selected. If yes, it is determined what the SL reception mode is (step S1312). If the SL reception mode is a broadcast mode, AS configuration for broadcast reception is performed in step S1318. If the SL reception mode is a unicast mode, Layer-2 link configuration for unicast reception is performed in step S1314. If the SL reception mode is a multicast mode, Layer-2 link configuration for groupcast reception is performed in step S1316. In step S1310, if the SL interface is not selected, configuration for reception over Uu interface is initiated (step S1320).

Provisioning for Receiver Side V2X Communication

In support of unicast reception, groupcast reception, broadcast reception, connection-oriented reception or flow based QoS, the NR V2X UE can be pre-configured or provisioned with the following system parameters; the configuration can be on per-interface basis, e.g., NR sidelink interface, NR Uu interface, LTE sidelink interface, LTE Uu interface, WLAN sidelink interface or WLAN to network interface:List of authorized V2X Services and for each service, the reception mode (reception cast type), i.e., whether the service is broadcast based reception, groupcast based reception or unicast based reception; The reception mode of a service can be defined on PLMN or group of PLMNs basis, or on cell or group of cells basis or on geographical area or group of geographical areas basis.List of authorized V2X Services and for each service, whether the reception is V2X upper layer connectionless or V2X upper layer connection oriented. For example, a broadcast reception can be a connectionless reception while a unicast reception or groupcast reception can be connection-oriented reception, or connectionless reception at the V2X upper layer.List of authorized V2X Services and for each service, whether the reception is AS layer connectionless or V2X AS layer connection oriented. For example, a broadcast reception can be a connectionless reception while a unicast reception or groupcast reception can be connection-oriented reception, or connectionless reception at the V2X AS layer.Authorization to act as a scheduler or scheduling entity for other UEs, or local controller or a scheduler node. Such authorization can be defined on PLMN basis or group of PLMNs basis, on a cell basis, on a group of cells basis or on a geographical area basis or a group of geographical area basis. In this disclosure, the terms local controller, scheduling entity or scheduler entity will be used interchangeably. For example, a platoon lead can be provisioned with the authorization to act as a scheduling entity. Such authorization can also be defined on service basis or group of services basis.Authorization to act as assisting UE to a scheduling entity. Such authorization can be defined on PLMN basis or group of PLMNs basis, on a cell basis, or on a group of cells basis, on a geographical area basis or group of geographical area basis.Authorization for duplicated reception across radio interface, i.e., reception of the same data across two or more radio interfaces, e.g., across two or more of the following radio interfaces: NR sidelink interface, NR Uu interface, LTE sidelink interface, LTE Uu interface, WLAN sidelink interface or WLAN to network interface. Such duplication can be defined based on a reliability requirement, e.g., ProSe Per-Packet Reliability value in the case of per-packet based QoS model or Packet Error Rate or QoS Identifier value in the case of QoS Flow or bearer based QoS model. Such authorization can be defined on per service basis. Furthermore, such authorization can be defined on cell or group of cells basis, or per geographical area or group of geographical areas basis, or on per PLMN or group of PLMNs basis. In the context of V2X, we will denote QoS Identifier as V2X QoS Identifier (VQI).List of V2X QoS Identifiers. For each VQI, the corresponding QoS profile parameters can be configured. The QoS profile can include one or more of the following: priority level, i.e., scheduling priority level, payload, transmission rate, maximum end-to-end latency, reliability, data rates, minimum required communication range, pre-emption priority level (i.e., admission pre-emption priority level). In another alternative, the QoS profile can include one or more of the following: priority level (i.e., scheduling priority level), resource type (e.g. GBR, Delay critical GBR or Non-GBR, etc.), packet delay budget, packet error rate, averaging window, maximum data burst volume. This configuration can be defined on per PLMN or group of PLMNs basis, on a cell or group of cells basis, on per geographical area or group of geographical areas basis.List of QoS Flow Identifiers (QFI). For each QFI, there is a mapping between QFI and VQI. A QoS Flow is the finest granularity of QoS differentiation. This configuration can be defined on per PLMN or group of PLMNs basis, on a cell or group of cells basis, on per geographical area or group of geographical areas basis.Resource pool configuration for connection-oriented reception and signaling in support of the maintenance of those connections.Resource pool configuration for PC5 signaling or SL RRC signaling in support of reception of signaling for connection establishment and maintenance of that connection. Such a resource pool can be a shared resource pool that is also used for connectionless PC5 data transmission.

Each of the provisioning parameters defined above can be defined on the basis of whether or not the UE is served by a radio access network or not served by a radio access network. Furthermore, when not served by a radio access network, the provisioning parameters can be configured on the basis of whether the carrier frequency for V2X communication is operator managed or non-operator managed.

The UE can also be preconfigured (e.g., on the SIM or Mobile Equipment (ME)) with the following capability parameters:Support of AS based unicast reception;Support of AS based groupcast reception;Support for V2X UpL based unicast reception;Support for V2X UpL based groupcast reception;Support for AS connectionless reception;Support for AS connection-oriented reception;Support of cross radio interface packet duplication receptionSupport of capability to act as a scheduling entity.Support of capability to act as an assisting UE to a scheduler entitySupport for QoS flow based QoS specification, e.g. the capability to support a QoS model where V2X AS layer supports mappings of packets from radio bearers to QoS flows SAPs as it delivers the received packets to V2X upper layer.Support for Per-Packet QoS mode, e.g., the capability to support a QoS model where each packet delivered to V2X upper layer from V2X AS carried its QoS requirement (e.g., PPPP or PPPR).

Receiver Side Triggers for V2X Reception

In the context of the high-level illustration of V2X reception operation described inFIG.13, one or more of the following events can trigger V2X reception procedure including monitoring for connection management related messages including, e.g., reception of connection establishment messages:Trigger from V2X application for transmission. In this case, the procedure is triggered as the result of an event originating from the application layer;Trigger of discovery by the application layer;Periodic monitoring of reception on V2X reception resource poolsCommunication quality of current/existing V2X communication no longer meets quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.). In this case, the V2X upper layer of V2X AS can initiate communication toward another UE or group of UEs in order to continue reception of the V2X communication initiated by the application layer. For example, if a UE is a platoon group, upon detecting V2X reception quality no longer meeting quality threshold, the UE can initiate communication toward another platoon lead UE.Radio link Failure or beam failure or failure of beam failure recovery. In this case, the V2X upper layer of V2X AS can initiate reception of communication toward another UE or group of UEs in order to continue the V2X communication initiated by the application layer;Radio Link quality of current/existing V2X communication no longer meets quality threshold;Congestion of current/existing V2X communication is above threshold;Transmit Power of current/existing V2X communication is above threshold or pathloss is above threshold.Mobility events in which case the V2X upper layer of V2X AS can initiate reception of V2X communication toward another UE or group of UEs in order to continue the V2X communication initiated by the application layer. The mobility events can be related to the UE own mobility or can be related to peer UE mobility;Reception of connection release, for example, from a peer UE or from a scheduling entity controlling resource allocation to the UE;Reception of connection establishment request from a peer UE or from a scheduling entity controlling resource allocation to the UE;Reception of handover request from a peer UE or from a scheduling entity controlling resource allocation to the UE;Failure of connection reconfiguration of current/existing V2X communication.

The V2X upper layer can trigger reception of V2X Communication operation described inFIG.13. Similarly, the V2X AS layer can trigger reception of V2X Communication operation illustrated inFIG.13.

Receiver Side RAT Selection and Interface Selection

Similar to the transmitter side operation described above, the V2X upper layer can perform RAT selection or interface selection. In one embodiment, the receiver side RAT of a given UE can be same as the transmitter side RAT, i.e., is set to be the same as the transmitter side RAT. Similarly, the receiver side interface can be the same as the transmitter side interface, i.e., is set to be the same as the transmitter interface. In another embodiment, the receiver side RAT can be different from the transmitter side RAT. Similarly, the receiver side interface can be different from the transmitter side interface. The V2X upper layer can perform sequentially or concurrently, RAT selection and interface selection. The V2X AS can provide assistance information such as availability information to the V2X upper layer for the selection of the RAT or the interface. For example, the AS of a RAT can determine the availability of that RAT. Furthermore, the AS can determine the availability of the interface in connection with a particular RAT. In an exemplary embodiment, the RAT can be one or more of the following: NR RAT, LTE RAT, Wi-Fi RAT, etc. Similarly, the interface can be one or more of the following: sidelink NR RAT, Uu RAT, sidelink LTE RAT, Uu LTE RAT, sidelink Wi-Fi RAT, and the radio interface between Wi-Fi and the network. The AS can determine the availability of a RAT or of an interface associated with a particular RAT for V2X reception, based on one or more of the following:Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.);Radio link quality threshold;Congestion threshold. The congestion threshold can be related, for example, to channel busy ratio (CBR), channel occupancy ratio (CR), etc.;Radio link Failure or beam failure or failure of beam failure recovery.Out-of-coverage or partially out of coverage detection;Anticipated received power threshold or pathloss threshold;Capability (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.).
The availability information can include one or more of the following information:Available or not available;Communication quality thresholdRadio link quality thresholdCongestion thresholdOut-of-coverage or partially out of coverage detectionCapability (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.)

Receiver Side Sidelink Communication Mode Selection

This section describes how the V2X upper layer decides to use unicast versus groupcast versus broadcast for V2X reception. The V2X upper layer can decide to use a reception cast type based on one or more of the following:Indication from Application layer;Indication from the peer V2X UE transmitter, e.g., as part of connection establishment procedures or other connection management procedures such as connection reconfiguration procedure;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.). For example, a platoon group member UE can, for example, decide to request a switch from groupcast communication to unicast communication based on communication reception quality threshold or can decide to switch to receiving the communication from another member UE acting as a relay UE, on a unicast basis.Service type or Traffic Type, e.g., signaling versus application data;Service Authorization configuration;Capability, e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.;Configuration into the UE, including preconfiguration (e.g., ME, SIM, etc.), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type.Link Quality

Mechanism that the AS Layer Decides to Use Unicast Versus Groupcast Versus Broadcast Transmission

The V2X AS layer can decide to use a reception cast type based on one or more of the following:Indication from V2X Upper layer;Indication from the peer V2X UE transmitter, e.g., as part of connection establishment procedures or other connection management procedures such as connection reconfiguration procedure;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.). For example, a platoon group member UE can, for example, decide to request a switch from groupcast communication to unicast communication based on communication reception quality threshold or can decide to switch to receiving the communication from another member UE acting as a relay UE, on a unicast basis.Service type or Traffic Type, e.g., signaling versus application data;Service Authorization configuration;Capability (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.);Configuration into the UE, including pre-configuration (e.g. ME, SIM, etc.), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type;Radio Link quality;

Mechanism that V2X Upper Layer Decides to Use Connection Oriented Versus Connectionless Reception

The V2X upper layer can decide to use connection-oriented reception or connectionless reception based on one or more of the following:Indication from Application layer;Indication from the peer V2X UE transmitter, e.g., as part of connection establishment procedures or other connection management procedures such as connection reconfiguration procedure;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g. packet error rate, latency, reliability, communication range, etc.); For example, a platoon group member UE can, e.g., decide to request a switch from connectionless reception to a connection oriented reception quality threshold, or can decide to switch to receiving the communication from another member UE acting as a relay UE, on a connection oriented basis.Service type or Traffic Type, e.g., signaling versus application data;Service Authorization configuration;Capability (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.);Configuration into the UE, including pre-configuration (e.g. ME, SIM, etc.), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type.Link QualitySecurity requirement, e.g., security thresholds. The security requirement can be authentication, integrity or ciphering related requirement.

Mechanism that AS Layer Decides to Use Connection Oriented Versus Connectionless

The V2X AS layer can decide to use a transmission cast type based on one or more of the following:Indication from V2X Upper layer;Indication from the peer V2X UE transmitter, e.g., as part of connection establishment procedures or other connection management procedures such as a connection reconfiguration procedure;Communication quality threshold. The quality threshold can be related to one or more QoS profile metrics (e.g., packet error rate, latency, reliability, communication range, etc.). For example, a platoon group member UE can, e.g., decide to request a switch from connectionless reception to a connection oriented reception quality threshold, or can decide to switch to receiving the communication from another member UE acting as a relay UE, on a connection oriented basis.Service type or Traffic Type, e.g., signaling versus application data;Service Authorization configuration;Capability, (e.g., capability of the UE, capability of peer V2X UE, capability of scheduling entity, capability of gNB or the network, etc.);Configuration into the UE, including pre-configuration (e.g., ME, SIM, etc.), provisioning into the UE by the network, e.g., V2X control function or configuration into the UE by the scheduling entity. The configuration can include mapping of service to transmission cast type;Radio Link quality;Security requirement, e.g., security thresholds. The security requirement can be integrity or ciphering related requirement.
Unicast Connection Management

High Level Unicast Connection Management Procedure

FIG.14is a high-level illustration of transmitter side operation for unicast layer-2 link management including connection establishment. In step S1400, it is determined whether AS is connection oriented. Step S1402and Step S1410refer to unicast connection establishment and connection context associations in V2X upper layer (V2X UpL) between peer V2X UEs. A unicast connection can also be established in the AS layer, with connection establishment signaling between peer V2X UEs for configuration and associations of AS contexts between peer V2X UEs, before transfer of unicast packets as depicted in step S1404. In this case, the receiver of peer V2X UE is configured with a dedicated configuration possibly including a dedicated radio resource configuration for unicast reception taking into account the UE capability of the receiver UE. As part of the unicast connection establishment procedure, the UE can associate the unicast AS context with the corresponding V2X upper layer unicast context. In an alternative embodiment illustrated in step S1410, the AS can support the V2X upper layer unicast connection with an AS connectionless configuration. In this case, the AS is configured in AS connectionless manner where AS resources are configured in connectionless manner without taking into account for example the UE capability of the receiver UE for the receiver UE AS configuration. In this case, there is no signaling for the receiver UE configuration required before reception of V2X packet. The receiver AS is configured to common default parameters for V2X packet receptions, and the transmitter transmit packet in broadcast manner from AS MAC perspective, where filtering of received packet is performed based on source ID and destination ID encapsulated in the received MAC PDU. For connection-oriented AS resource configuration depicted in step S1404, PHY, MAC, RLC, PDCP and SDAP (when applicable) are configured for this specific connection in the receiver UE and transmitter UE before transfer of data packets takes place. An AS context consisting of configuration such as PHY channel configuration possibly including radio resource configuration, transport channel configuration, HARQ entity configuration, logical channel configuration, bearer configuration possibly including security configuration, QoS flow configuration and association of these configurations across the AS protocol sublayers are created in both the transmitter UE and the receiver UE before transfer of data packet. Once step S1402and step S1404or step S1410and step S1412are completed, the transmitter UE and the receiver UE can exchange packet (data or signaling) in a connection-oriented communication manner.

Step S1406refers to link monitoring in the case of AS connection oriented. The link monitoring can be realized in the AS, for example, based on radio link monitoring and beam management procedures. The link monitoring can trigger the execution of connection maintenance procedures such as connection reconfiguration, beam recovery, connection relocation or connection release. Link maintenance procedure can be triggered by the transmitter UE, the receiver UE or a third entity such as the scheduling entity. In the case of AS connectionless communication, the link monitoring referred to in step S1414can be realized in the V2X upper layer, for example based on link keep-alive procedure carried out by V2X upper layer. In this case, the link monitoring can trigger the execution of the transmitter side reconfiguration, connection relocation, or connection release. Also, in this case, link maintenance procedure can be triggered by the transmitter UE, the receiver UE or a third entity such as the scheduling entity. In step S1408, the link is released. Also, in step S1416, the link is released.

FIG.15provides a high-level illustration of the receiver side operation for layer-2 link management including connection establishment. In step S1500, it is determined whether AS connection is oriented. If yes, in step S1502, V2X upper layer configuration for Layer-2 unicast link connection establishment is performed. If no, in step S1510, V2X upper layer configuration for Layer-2 unicast link connection establishment is performed. In step S1512, V2X SL RX AS configuration-preconfiguration of common signaling or no signaling based SL RXs AS configuration for Layer-2 unicast link connection establishment is performed. In step S1514, link monitoring and maintenance in V2X upper layer is performed. In step S1516, link release is performed. In step S1504, V2X SL RX AS configuration-dedicated signaling based SL RX AS configuration for Layer-2 for unicast link connection establishment is performed. In step S1506, link monitoring and maintenance in AS is performed. In step S1508, link release is performed.

Unicast Connection Establishment Detail Procedure

FIG.16,FIG.17,FIG.18,FIG.19,FIG.20andFIG.21provide different alternative embodiments for detailed procedural steps in support of unicast connection establishment and follow-up data transfer. They provide further detailed embodiments of the high-level procedures illustrated inFIG.14andFIG.15. The procedures are structured around three entities. The initiating UE (I-UE) which is the UE initiating the connection establishment procedure, the target UE (T-UE) which is the end receiver UE of the connection establishment request, and the scheduling entity, which is the entity that provides resource configuration or resource scheduling function. The scheduling entity can be a gNB, a UE that controls resource configuration for other UEs or assists resource configuration for other UEs, an RSU-UE (i.e. a road side unit (RSU) acting as a UE), an RSU-gNB (i.e., an RSU acting as a gNB), a UE-to-network relay (i.e., an entity acting as a relay node toward other UEs (e.g., an IAB node)) or any other local controller that provides resource configuration to UEs under its control. In the remainder of this disclosure, we will further extend the I-UE and T-UE definition as follows: the T-UE with respect to a configuration procedure over an interface (e.g., PC5 interface or Uu interface) is the UE that is the receiving UE of the configuration request. The I-UE with respect to a configuration procedure over an interface (e.g., PC5 interface or Uu interface) is the UE that transmits the configuration request. A configuration request can be one or more of the following: a connection establishment request, a connection reconfiguration or modification, a connection relocation, or a connection release.

These figures also assume one or more of the steps described inFIG.12andFIG.13are already performed. With respect to resource allocation, each of the figures also proposes that after both the T-UE and I-UE are configured with radio resource configuration through RRC signaling or PC5-S signaling, the T-UE can use autonomous resource selection for transmission, or can be dynamically scheduled by the scheduling entity or the I-UE. Similarly, the I-UE can use autonomous resource selection for transmission or can be dynamically scheduled by the scheduling entity or the T-UE.

FIGS.16A-Cillustrate the steps for connection establishment where the T-UE is configured by the I-UE or by the I-UE in coordination with the scheduling entity. Furthermore, in this embodiment of a connection establishment procedure, the V2X upper layer configuration of the T-UE is carried jointly with the AS layer configuration of the T-UE using SL RRC signaling from the I-UE to the T-UE.

FIGS.16A-Cinclude a Target UE/RSU UP Stack1602, Target UE/RSU RRC1604, Target UE/RSU-V2X Higher Layer Functions1606, Initiating UE/RSU RRC1608, Initiating UE/RSU UP Stack1610, Initiating UE/RSU-V2X Higher Layer Functions1612, and gNB/RSU/Scheduling Entity1614. In step S1600, a direct communication is sent from the UE/RSU-V2X Higher Layer Functions1612. In step S1602, a SL RRC signaling-target device info request is sent from the Initiating UE/RSU RRC1608. In step S1604, an upper layer info request is sent from the Target UE/RSU RRC1604. In step S1606, an upper layer info response is sent from the Target UE/RSU-V2X Higher Layer Functions1606. In step S1608, an SL RRC signaling-target device info response is sent from the Target UE/RSU RRC1604. In step S1610, a RRC signaling—direct security mode command is sent from the Initiating UE/RSU RRC1608. In step S1612, resource allocation can be performed. In an optional step, S1614, criteria for connection establishment can be verified and a connection can be established as needed, otherwise resource allocation is performed. In step S1610a, a security procedure is performed.

In step S1616, a RRC signaling V2X connection configuration info request is sent from the Initiating UE/RSU RRC1608. In step S1618, admission control and decision for SL transmission configuration parameters is performed. In step S1620, a RRC signaling V2X signaling info response is sent from the gNB/RSU/Scheduling Entity1614. In step S1622, a RRC signaling—direct security mode completion message is sent from the Target UE/RSU RRC1604. In step S1624, a SL RRC signaling—direct communication request is sent from the Initiating UE/RSU RRC1608.

In step S1628, upper layer configuration information is sent. In step S1630, the T-UE protocol stack is configured. In step S1632, a SL RRC signaling-direct communication accept message is sent. In step S1634, a SR/BSR message is sent. In step S1636, SL resource grant DCI information is sent from the gNB/RSU/Scheduling Entity1614. In optional step S1638, the Initiating UE/RSU UP Stack1610can send the SL resource grant DCI information to the Target UE/RSU UP Stack1602. In an alternative embodiment, steps S1640and S1642are performed.

In step S1640, SR/BSR is sent from the Target UE/RSU UP Stack1602to the Initiating UE/RSU UP Stack1610, and in step S1642, the Initiating UE/RSU UP Stack1610sends the SL resource grant DCI information to the Target UE/RSU UP Stack1602. In another alternative embodiment, steps S1644and S1646are performed. In step S1644, SR/BSR is sent from the Target UE/RSU UP Stack1602to the gNB/RSU/Scheduling Entity1614, and in step S1646, the gNB/RSU/Scheduling Entity1614sends the SL resource grant DCI information to the Target UE/RSU UP Stack1602. In step S1648, SL data reception or transmission can be performed. In step S1650, reception or transmission can be performed. In step S1652, radio link monitoring can be performed. In step S1654, release of the radio link can be performed.

FIGS.17A-Cillustrate the steps for connection establishment where the T-UE is configured by the I-UE or by the I-UE in coordination with the scheduling entity. Furthermore, in this embodiment of connection establishment procedure, the V2X upper layer configuration of the T-UE is carried jointly with the AS layer configuration of the T-UE using PC5-signaling from the I-UE to the T-UE. InFIGS.17A-C, steps S1600, S1602, S1604, S1606, S1608, S1610, S1610a, S1612, S1614, S1616, S1618, S1620, and S1622are the same as inFIGS.16A-C. In step S1656, AS SL configuration information is transferred. In step S1658, a PC5 signaling-direct communication request is performed. In step S1660, an AS SL configuration information transfer is performed. In step S1662, the I-UE protocol stack is configured. In step S1664, the T-UE protocol stack is configured. In step S1666, PC5 signaling—direct communication acceptance is performed. In step S1668, which can be optional, e.g., in support of mode 2-d or mode 2-b resource allocation, SR/BSR can be sent to the gNB/RSU/Scheduling Entity1614. In step S1670, which can also be optional, a SL resource grant DCI can be sent from the gNB/RSU/Scheduling Entity1614. In step S1672, which can be optional, a SL resource grant DCI is sent from the Initiating UE/RSU UP Stack1610. Steps S1674and S1676are Alternative 1, and Steps S1678and S1680are Alternative 2. In step S1674, SR/BSR is sent from the Target UE/RSU UP Stack1602. In step S1676, SL resource grant SCI is sent from the Initiating UE/RSU UP Stack1610. In step S1678, SR/BSR is sent from the Target UE/RSU UP Stack1602to the gNB/RSU/Scheduling Entity1614. In step S1680, SL resource grant SCI is sent from the gNB/RSU/Scheduling Entity1614to the Target UE/RSU UP Stack1602. In step S1682, SL data reception or transmission is performed. In step S1684, SL data reception or transmission is performed. In step S1686, radio link monitoring is performed. In step S1688, radio link release is performed.

FIGS.18A-Cillustrate the steps for connection establishment where the T-UE is configured by the I-UE or by the I-UE in coordination with the scheduling entity. Furthermore, in this embodiment of connection establishment procedure, the V2X upper layer configuration of the T-UE is carried jointly with the AS layer configuration of the T-UE using RRC signaling from the I-UE to the T-UE. Additionally, the V2X upper layer connection establishment procedure is carried out independently from V2X AS layer connection establishment procedure. In step S1800, a PC5 signaling-direct communication request is sent from the Initiating UE/RSU-V2X Higher Layer Functions1612. In step S1802, a PC5 signaling-direct security mode command is sent from the Target UE/RSU-V2X Higher Layer Functions1606. In step S1806, PC5 signaling-direct communication acceptance information is sent from the Target UE/RSU-V2X Higher Layer Functions1606. In step S1808, direct communication is established. Steps S1810, S1812, S1814, and S1816can be optional steps. In step S1810, a SL RRC signaling-target device information request is sent from the Initiating UE/RSU RRC1608. In step S1812, an upper layer information request is sent from the Target UE/RSU RRC1604. In step S1814, an upper layer information response is sent from the Target UE/RSU-V2X Higher Layer Functions1606. In step S1816, a SL RRC signaling—target device information response is sent from the Target UE/RSU RRC1604. In step S1818, resource allocation can be performed (Alternative 1). Steps S1820, S1822, S1824, and S1826are Alternative 2. In step S1820, which can be optional, criteria for connection establishment is verified and a connection is established as needed, otherwise, resource allocation is performed. In step S1822, a RRC signaling V2X connection configuration information request is sent from the Initiating UE/RSU RRC1608. In step S1824, admission control and a decision for SL transmission configuration parameters is performed. In step S1826, RRC signaling V2X signaling configuration information response is sent from the gNB/RSU/Scheduling Entity1614.

In step S1828, a SL RRC signaling—direct AS connection request is sent from the Initiating UE/RSU RRC1608. In step S1830, the I-UE protocol stack is configured. In step S1832, upper layer configuration is performed. In step S1834, the T-UE protocol stack is configured. In step S1836, an SL RRC signaling-direct AS connection accept signal is sent. Steps S1838and S1840are optional. In step S1838, SR/BSR is sent from the Initiating UE/RSU UP Stack1610. In step S1840, the Initiating UE/RSU UP Stack1610receives a SL resource grant DCI. Alternative 1 includes optional steps S1842, S1844, and S1846. In step S1842, the Target UE/RSU UP Stack1602receives a SLresource grant DCI. In step S1844, the Target UE/RSU UP Stack1602sends an SR/BSR. In step S1846, the Target UE/RSU UP Stack1602receives a SL resource grant SCI. Alternative 2 includes optional steps S1848and S1850. In step S1848, the Target UE/RSU UP Stack1602sends an SR/BSR to gNB/RSU/Scheduling Entity1614. In step S1850, the Target UE/RSU UP Stack1602receives an SL resource grant DCI. In step S1852, SL data reception or transmission is performed by the Target UE/RSU UP Stack1602. In step S1854, SL data reception or transmission is performed by the Initiating UE/RSU UP Stack1610. In step S1856, radio link monitoring is performed. In step S1858, radio link release is performed.

FIGS.19A-Cillustrate the steps for connection establishment where the I-UE is configured by the T-UE or by the T-UE in coordination with the scheduling entity. Furthermore, in this embodiment of connection establishment procedure, the V2X upper layer configuration of the I-UE is carried jointly with the AS layer configuration of the I-UE using PC5-S signaling from the T-UE to the I-UE. Additionally, the V2X upper layer connection establishment procedure is carried out independently from the V2X AS layer connection establishment procedure.

FIGS.19A-Cshow Initiating/RSU UP Stack1902, Initiating UE/RSU RRC1904, Initiating UE/RSU-V2X Higher Layer Functions1906, Target UE/RSU RRC1908, Target UE/RSU UP Stack1910, Target UE/RSU-V2X Higher Layer Functions1912, and gNB/RSU/Scheduling Entity1614. In step S1900, a PC5 signaling—direct communication request is sent. In step S1902, PC5 signaling—direct security mode command is sent. In step S1904, a PC5 signaling—direct mode response complete message is sent. In step S1906, a PC5 signaling—direct communication accept message is sent. In step S1908, direct communication is established. In step S1910, a direct AS connection request is sent. In step S1912, a PC5 signaling—direct AS connection request is sent from the Initiating UE/RSU-V2X Higher Layer Functions1906to the Target UE/RSU-V2X Higher Layer Functions1912. In step S1914, a Direct AS connection resource request is sent. In step S1916(Alternative 1), resource allocation is performed. Alternative 2 can include steps S1918, S1920, S1922, and S1924. In step S1918(optional), verification of criteria for connection establishment and a connection is established as needed, otherwise, resource allocation is performed. In step S1920, a RRC signaling V2X connection configuration information request is sent. In step S1922, admission control and decision for SL transmission configuration parameters is performed. In step S1924, a RRC signaling V2X signaling configuration information response is sent. In step S1926, a Direct AS connection resource response is sent.

In step S1928, a PC5 signaling—direct AS connection accept message is sent. In step S1930, a Direct AS connection accept message is sent. In step S1932, a T-UE protocol stack is configured. In step S1934, an I-UE protocol stack is configured. Steps S1936and S1938are optional. In step S1936, SR/BSR is sent from the Target UE/RSU RRC1908to the gNB/RSU/Scheduling Entity1614. In step S1938, a SL resource grant DCI is sent from the gNB/RSU/Scheduling Entity1614to the Target UE/RSU UP Stack1910. Steps S1940, S1942, and S1944are also optional steps as Alternative 1, and steps S1946and S1948are optional steps as Alternative 2. In step S1940, a SL resource grant DCI message is sent. In step S1942, a SR/BSR is sent. In step S1944, an SL resource grant SCI is sent. In Alternative 2, in step S1946, the SR/BSR is sent from the Initiating/RSU UP Stack1902to the gNB/RSU/Scheduling Entity1614. In step S1948, a SL resource grant DCI is sent from the gNB/RSU/Scheduling Entity1614to the Initiating/RSU UP Stack1902. In step S1950, SL data reception or transmission is performed by the Initiating/RSU UP Stack1902. In step S1952, SL data reception or transmission is performed by the Target UE/RSU UP Stack1910. In step S1954, radio link monitoring is performed. In step S1956, radio link release is performed.

FIGS.20A-Cillustrate the steps for connection establishment where the I-UE is configured by the T-UE or by the T-UE in coordination with the scheduling entity. Furthermore, in this embodiment of a connection establishment procedure, the V2X upper layer configuration of the I-UE is carried jointly with the AS layer configuration of the I-UE using PC5-S signaling from the T-UE to the I-UE.

FIGS.20A-Cshow Initiating UE/RSU UP Stack2002, Initiating UE/RSU RRC1904, Initiating UE/RSU-V2X Higher Layer Functions1906, Target UE/RSU RRC1908, Target UE/RSU UP Stack1910, Target UE/RSU-V2X Higher Layer Functions1912, and gNB/RSU/Scheduling Entity1614. In step S2000, a direct communication AS information request is sent from the Initiating UE/RSU-V2X Higher Layer Functions1906to the Initiating UE/RSU RRC1904. In step S2002, direct communication AS information response is sent from the Initiating UE/RSU RRC1904to the Initiating UE/RSU-V2X Higher Layer Functions1906. In step S2004, an SL PC5 signaling-direct communication request is sent from the Initiating UE/RSU-V2X Higher Layer Functions1906to the Target UE/RSU-V2X Higher Layer Functions1912. In step S2006, a direct communication AS information request is sent from the Target UE/RSU-V2X Higher Layer Functions1912to the Target UE/RSU RRC1908.

Steps S2008, S2010, S2012, S2014, and S2016can be optional steps. In step S2008(Alternative 1) resource allocation can be performed. Alternative 2 is steps S2010, S2012, S2014, and S2016. In step S2010, criteria for connection establishment is verified and connection is established as needed, otherwise, resource allocation is performed. In step S2012, a RRC signaling V2X connection configuration information request is sent from the Target UE/RSU RRC1908. In step S2014, admission control and decision for SL transmission configuration parameters is performed. In step S2016, a RRC signaling V2X signaling configuration information response is sent from the gNB/RSU/Scheduling Entity1614to the Target UE/RSU RRC1908. In step S2018, a RRC signaling—direct security mode command is sent from the Target UE/RSU RRC1908to the Initiating UE/RSU RRC1904. In step S2018a, a security procedure can be performed. In step S2020, a RRC signaling-direct security mode complete message is sent from the Initiating UE/RSU RRC1904to the Target UE/RSU RRC1908. In step S2022, a direct communication AS information response is sent from the Target UE/RSU RRC1908to the Target UE/RSU-V2X Higher Layer Functions1912.

In step S2024, configuring of the T-UE protocol stack is performed. In step S2026, an SL PC5 signaling—direct communication accept message is sent from the Target UE/RSU-V2X Higher Layer Functions1912to the Initiating UE/RSU-V2X Higher Layer Functions1906. In step S2028, an AS layer configuration information transfer message is sent from the Initiating UE/RSU-V2X Higher Layer Functions1906to the Initiating UE/RSU RRC1904. In step S2030, configuration of the I-UE protocol stack is performed. Steps S2032and S2034are optional. In step S2032, SR/BSR is sent from the Target UE/RSU UP Stack1910to the gNB/RSU/Scheduling Entity1614. In step S2034, an SL resource grant DCI is sent from the gNB/RSU/Scheduling Entity1614to the Target UE/RSU UP Stack1910.

In step S2036(an optional step), the SL resource grant DCI can be sent from the Target UE/RSU UP Stack1910to the Initiating UE/RSU UP Stack2002. Steps S2038and S2040are optional steps and are Alternative 1. In step S2038, a SR/BSR is sent from the Initiating UE/RSU UP Stack2002to the Target UE/RSU UP Stack1910. In step S2040, a SL resource grant SCI is sent from the Target UE/RSU UP Stack1910to the Initiating UE/RSU UP Stack2002. In Alternative 2, in step S2042, the SR/BSR is sent from the Initiating UE/RSU UP Stack2002to the gNB/RSU/Scheduling Entity1614. In step S2044, the gNB/RSU/Scheduling Entity1614sends the SL resource grant DCI to the Initiating UE/RSU UP Stack2002. In step S2046, sidelink data transmission or reception is performed. In step S2048, sidelink data transmission or reception is performed. In step S2050, radio link monitoring is performed. In step S2052, radio link release is performed.

FIGS.21A-Cillustrate the steps for connection establishment where the I-UE is configured by the T-UE or by the T-UE in coordination with the scheduling entity. Furthermore, in this embodiment of a connection establishment procedure, the V2X upper layer configuration of the I-UE is carried jointly with the AS layer configuration of the I-UE using RRC signaling from the T-UE to the I-UE.

In step S2100, a direct communication request is sent from the Initiating UE/RSU-V2X Higher Layer Functions1906to the Initiating UE/RSU RRC1904. In step S2102, a SL RRC signaling-direct communication request is sent from the Initiating UE/RSU RRC1904to the Target UE/RSU RRC1908. In step S2104, a direct communication V2X UPL information request is sent from the Target UE/RSU RRC1908to the Target UE/RSU-V2X Higher Layer Functions1912. In step S2106, a direct communication V2X UPL information response is sent from the Target UE/RSU-V2X Higher Layer Functions1912to the Target UE/RSU RRC1908. In step S2108(Alternative 1), resource allocation is performed. Alternative 2 includes steps S2110, S2112, S2114, and S2116. In step S2110, an optional step, criteria is verified for connection establishment and connection is established as needed, otherwise, resource allocation is performed. In step S2112, a RRC signaling V2X connection configuration information request is sent from the Target UE/RSU RRC1908to the gNB/RSU/Scheduling Entity1614. In step S2114, admission control and a decision for SL transmission configuration parameters can be performed. In step S2116, the gNB/RSU/Scheduling Entity1614sends a RRC signaling V2X signaling configuration information response to the Target UE/RSU RRC1908. In step S2118, a RRC signaling—direct security mode command is sent from the Target UE/RSU RRC1908to the initiating UE/RSU UP Stack2002. In step S2118a, a security procedure is performed. In step S2120, a RRC signaling—direct security mode complete message is sent from the Initiating UE/RSU RRC1904to the Target UE/RSU RRC1908.

In step S2122, the T-UE protocol stack is configured. In step S2124, a SL RRC signaling—direct communication accept message is sent from the Target UE/RSU RRC1908to the Initiating UE/RSU RRC1904. In step S2126, the I-UE protocol stack is configured. In step S2128, an optional step, a SR/BSR is sent from the Target UE/RSU UP Stack1910to the gNB/RSU/Scheduling Entity1614. In step S2130, the gNB/RSU/Scheduling Entity1614sends a SL resource grant DCI message to the Target UE/RSU UP Stack1910. In step S2132, an optional step, the Target UE/RSU UP Stack1910sends an SL resource grant DCI message to the Initiating UE/RSU UP Stack2002. Steps S2134and S2136are Alternative 1. Steps S2138and S2140are Alternative 2. In step S2134, an SR/BSR message is sent from the Initiating UE/RSU UP Stack2002to the Target UE/RSU UP Stack1910. In step S2136, an SL resource grant SCI message is sent from the Target UE/RSU UP Stack1910to the Initiating UE/RSU UP Stack2002. In step S2138, the SR/BSR message is sent from the Initiating UE/RSU UP Stack2002to the gNB/RSU/Scheduling Entity1614. In step S2142, sidelink data transmission or reception is performed by the Initiating UE/RSU UP Stack2002. In step S2144, sidelink data transmission or reception is performed by the Target UE/RSU UP Stack1910. In step S2146, radio link monitoring is performed. In step S2148, a radio link release is performed.

Unicast Connection Configuration Parameters

UE Assistance Information

In support of a unicast connection configuration or groupcast connection configuration or broadcast connection configuration, a T-UE can provide one or more of the following configuration parameters to the I-UE or to the scheduling entity. Such information can be provided by a T-UE acting as a receiving UE of protocol stack configuration across the PC5 interface, so it can be configured by the scheduling entity, or the J-UE or the J-UE in coordination with the scheduling entity. Examples of related use cases are illustrated inFIG.16,FIG.17orFIG.18. In an alternative embodiment, a J-UE can provide one or more of the following configuration parameters to the T-UE or to the scheduling entity. Such information can be provided by an I-UE acting as a receiving UE of protocol stack configuration across the PC5 interface, so it can be configured by the scheduling entity, or the T-UE or the T-UE in coordination with the scheduling entity. Examples of related use cases are illustrated inFIG.18,FIG.20orFIG.21. One or more of the information below can be provided to the scheduling entity for both the J-UE and the T-UE to assist the scheduling entity for the configuration of I-UE or T-UE.

Information ElementDescriptionCapabilityThe capability information can include theinformationReceiver capability information or the transmittercapability information. The capability informationcan be related to one or more of the following:V2X Upper layer capability (e.g., securitycapability), SDAP capability, PDCP capability,RLC capability, MAC capability, basebandcapability, RF including RF band and subbandcapability or any other specific feature capabilityto assist the scheduling entity or the I-UE in theconfiguration of the T-UE. The information canbe in reference to capability information, e.g.,capability sets provided by the scheduling entityor the I-UE (e.g., FIG. 16, FIG. 17, or FIG. 18),or the T-UE (e.g., FIG. 19, FIG. 20, or FIG. 21),for example, in RRC dedicated signalingover PC5 interface, or in system informationbroadcast signaling over PC5 interface usingPC5-S signaling, or PC5-RRC signaling.V2X ReceptionThe frequency(ies) on which the UE is interestedFrequency listto receive V2X sidelink communication. Thisinformation can also include sub-frequenciesinformation, e.g., specific BWP of the carrierfrequency. The information can be in referenceto V2X reception frequency or sub-frequencylist provided by the scheduling entity or the I-UE(e.g., FIG. 16, FIG. 17, or FIG. 18), or the T-UE(e.g., FIG. 19, 20 or FIG. 21), for example, inRRC dedicated signaling over PC5 interface, orin system information broadcast signaling overPC5 interface using PC5-S signaling, orPC5-RRC signaling.V2X TransmissionThe frequency(ies) on which the UE is interestedFrequency listto Transmit V2X sidelink communication. Thisinformation can also include sub-frequenciesinformation, e.g., specific BWP of the carrierfrequency. The information can be in reference totransmission frequency or sub-frequency listprovided by the scheduling entity or the I-UE(e.g., FIG. 16, FIG. 17, or FIG. 18), or the T-UE(e.g., FIG. 19, FIG. 20, or FIG. 21), for example,in RRC dedicated signaling over PC5 interface,or in system information broadcast signaling overPC5 interface using PC5-S signaling, or PC5-RRCsignaling. The V2X sidelink transmission canbe non-Uu interface relay V2X sidelinktransmission.Destination listThe list of destinations (or destination IDs) forV2X sidelink communication.Source IDThe source ID of the UE providing the assistanceinformationQoS Flow ListList of QoS Flows for the V2X Connection, andthe QoS profile for each QoS Flow in the list.V2X Upper layerInformation specific to V2X upper layer orUser Informationapplication layer. This information can betransferred transparently by the AS layer.SL measurementMeasurements (e.g., RSRP, RSRQ, RSSI, CBR,CR, etc.)RLC ModeIndicate the mode (RLC UJM, RLC AM or RLCindicationTM) for each sidelink radio bearer associatedwith each Layer-2 destination listed herein.Cast TypeIndicate the cast type (unicast, groupcast orbroadcast) for each Layer-2 destination listedherein.

Configuration Parameters of T-UE or the I-UE

One or more of the following parameters can be configured into the T-UE in support of connection configuration by the scheduling entity or the I-UE in coordination with the scheduling entity. Examples of such a connection configuration can be the connection establishment procedure depicted inFIG.16,FIG.17, andFIG.18. Similarly, one or more of the following parameters can be configured into the I-UE in support of connection configuration by the scheduling entity or the T-UE in coordination with the scheduling entity. Examples of such a connection configuration can be the connection establishment procedure depicted inFIG.19,FIG.20, andFIG.21.

Information ElementDescriptionSL RNTI PC5SL Radio bearerList of Radio bearers (data radio bearer orConfigurationsignaling radio bearer) to be added to the UEconnection context. For each radio beareradded, the list of QoS flow mapped to theradio bearer. Each QoS Flow isrepresented by a QFI and radio bearer isrepresented by a radio bearer identity.For each radio bearer to be added, thecorresponding destination ID.List of Radio bearer (data radio bearer orsignaling radio bearer) to be released from theconnection context.Transmission profile for transmission of dataassociated with each radio bearer being added.The transmission profile can be representedby a transmission profile identifier.SDAP configuration for the handling of QoSFlow mapping to bearer for each radio bearerbeing added to the UE context. Each SDAPconfiguration includes the list of flows(represented by a QFI) mapped to the radiobearer and list of flow to be released from aradio bearer. QFI is an integer from 0 to themaximum number of QFI mapped to the radiobearer.PDCP Configuration for each radio bearer beingadded: size of PDCP sequence number of PDCPPDUs transmitted from this UE to destinationUE; size of PDCP sequence number from peerdestination UE to this UE; header compressionprofile choices; whether ciphering is enabledor disabled; whether integrity protection isenabled or disabled; whether PDCP duplicationis supported and number of duplication branches;logical channel identity associated with RLC foreach data branch or path associated with thebearer; t-reordering, specify re-ordering timervalue; Status report required, for AM DRBs,indicates whether the DRB is configured to senda PDCP status report to the peer transmitter;discard timer.RLC Configuration (for each radio bearer beingadded) including configuration of thecorresponding logical channel in MAC,association with a radio bearer and configurationparameters for RLC protocol operation such astimers, RLC mode (i.e., unacknowledgedmode, acknowledge mode, transparent mode,peer RLC polling, sequence number).Specifically, the logical channel configurationcan include the following: the sidelink logicalchannel priority, i.e., the priority associatedwith the sidelink logical channel, where anincreasing priority value indicates a lowerpriority level; the sidelink prioritized bit ratewhich sets the Prioritized Bit Rate (PBR), i.e.,the data rate that must be served on the sidelinklogical channel before a sidelink logical channelof lower priority is served; the sidelink bucketsize duration which set the Bucket Size Duration(BSD) for the sidelink, i.e., the duration to fillup the bucket size at the rate of the prioritizedbit rate. The PBR together with the BSD definedthe size of a prioritized bucket for the sidelinklogical channel. As long as there is data in thesidelink prioritized bucket, and there is a sidelinkgrant that can serve the sidelink logical channel,then the sidelink logical channel is prioritizedfor sidelink resource grant allocation over sidelinklogical channels of lower priority; set of allowedV2X serving cells, which sets the allowed cell(s)for transmission; set of allowed V2X SubCarrierSpacings (SCSs) which sets the allowedSubcarrier Spacing(s) for transmission; set ofallowed V2X Band Width Parts (BWPs) whichsets the allowed bandwidth parts for transmission;Maximum Allowed SL-SCH duration whichsets the maximum SL-SCH duration allowed fortransmission; allowed latency which sets themaximum allowed latency from the time the databecomes available for sidelink transmission tothe time the data transmission ends; allowedSL-SCH K2 duration which sets the maximumallowed latency from the time the SL-SCHgrant becomes available for sidelink transmissionto the time the SL-SCH data transmission begins;allowed RATs which sets the allowed RATs fortransmission; allowed RAT versions which setsthe allowed RAT versions for transmission;allowed transmission profiles which sets theallowed transmission profiles for transmission;configuration parameters for RLC protocoloperation: RLC mode operation either AM,UM or TM. For AM: source-AM-RLC toindicate if transmitted RLC PDU is AM.Destination-AM-RLC to indicate if receivedRLC PDU is AM; For UM: source-UM-RLC toindicate if transmitted RLC PDU is UM.Destination-UM-RLC to indicate if receivedRLC PDU is UM; size of RLC sequencenumber; maximum retransmissionthreshold, pollByte, PollPDU, timer for RLCAM t-Poll retransmit, timer for reassemblyt-Reassembly, timer for status reporting t-StatusProhibitMAC Configuration: DRX Configuration,Scheduling Request Configuration includingscheduling request between V2X UEs; BufferStatus Reporting Configuration, PowerHeadroom Reporting Configuration, datainactivity timer which can be sued for releasingthe sidelink connection upon data inactivity;csi-Mask;The Source ID of the peer V2X UE with whichV2X communication is being established. Forexample, when T-UE is being configured, theSource ID can be the V2X UE ID (e.g., ProSEUE ID) of the I-UE. Similarly, when I-UE isbeing configured, the Source ID can be the V2XUE ID (e.g., ProSE UE ID) of the T-UE.Radio ConfigurationThe radio resource configuration can includeone or more of the following:pool of resources when 5 G RAN schedules TXresources for V2X sidelink communications.pool of resources when a scheduling entity, e.g.,a UE schedules over PC5 interface, TXresources for V2X sidelink communications.Pool of resources when a UE performsautonomously resource allocation for V2Xsidelink communications.Mapping between physical transmissionconfiguration parameters, channel congestionmeasurements such as CBR or CR range andQoS identifier range. Such mapping can be used,for example, in support of autonomous V2Xresource selection or when a schedulingentity, e.g., a UE schedules over PC5 interface,TX resources for V2X sidelink communications.LCG ConfigurationMapping between LCGs and QoS profiles, e.g.,in support of configuration to the UE forconnectionless transmission. QoS profile can berepresented by a QoS profile identifier, e.g., VQIor 5QI. In LTE V2X, the QoS informationmapped to LCG is provided in the form of PPPPor PPPR. In support of bearer-based model, andwith NR V2X having more diverse QoSrequirement, it is proposed to provide QoSmapping to LCG by means of QoS identifiers,where the corresponding QoS profile parametersare preconfigured, provisioned or configuredinto the UE. Each LCG can be configured with alist of associated QoS identifiers.V2X Upper layerInformation specific to V2X upper layer orUser Informationapplication layer of the peer V2X UE withwhich V2X communication is being established.For example, when T-UE is being configured,this IE can be the V2X Upper layer userinformation of the I-UE. Similarly, when I-UE isbeing configured, this IE can be the V2X upperlayer user information of the T-UE. Thisinformation can be transferred transparently bythe AS layer.SL measurementMeasurements (e.g., RSRP, RSRQ, RSSI, CBR,CR, etc.)Preemption PriorityThis parameter can be used to performpreemption, e.g., during carrier sensing forautonomous resource allocation or can be usedto perform preemption when the UE thisinformation is being configured to, act as ascheduling entity for other UEs.
Groupcast Connection Management

High Level Groupcast Connection Management Procedure

FIG.22is a high-level illustration of a transmitter side operation for groupcast layer-2 link management including connection establishment. In step S2200, it is determined whether AS is connection oriented. Step S2202and Step S2210refer to groupcast connection establishment and connection context associations in V2X upper layer (V2X UpL) between peer V2X UEs. A groupcast connection can also be established in the AS layer, with connection establishment signaling between the group lead UE and group member V2X UEs for configuration and associations of AS contexts between the group UE and the group member V2X UEs, before transfer of groupcast packets as depicted in step S2204. In this case, the receiver of group member V2X UEs is configured with dedicated configuration possibly including dedicated radio resource configuration for unicast reception taking into account the group member UEs capability. As part of the groupcast connection establishment procedure, the UE involved in the group cast communication can associate the groupcast AS context with the corresponding V2X upper layer groupcast context. In an alternative embodiment illustrated in step S2210, the AS can support the V2X upper layer groupcast connection with an AS connectionless configuration.

In this case, the AS is configured in an AS connectionless manner where AS resources are configured in a connectionless manner without taking into account, for example, the group members UE capability. In this case, there is no signaling for the receiver group members UE configuration required before reception of a V2X packet. The receiver group member AS is configured to common default parameters for V2X groupcast packet reception, and the transmitter transmit packet in broadcast manner from AS MAC perspective, where filtering of a received packet is performed based on source ID and destination ID encapsulated in the received MAC PDU. For connection-oriented AS resource configuration depicted in step S2204, PHY, MAC, RLC, PDCP and SDAP (when applicable) are configured for this specific groupcast connection in the receiver UE and transmitter UE before transfer of data packets takes place. A groupcast AS context consisting of configuration such as PHY channel configuration possibly including physical layer multicast radio resource configuration, transport channel configuration, HARQ entity configuration, logical channel configuration, bearer configuration possibly including security configuration, QoS flow configuration and association of these configurations across the AS protocol sublayers are created in both the transmitter UE and the receiver UE before transfer of a group cast data packet. Once step S2202and step S2204or step S2210and step S2212are completed, the transmitter UE and the receiver UE can exchange a packet (data or signaling) in a groupcast connection-oriented communication manner.

Step S2206refers to link monitoring in the case of AS groupcast connection-oriented communication. The link monitoring can be realized in the AS, for example, based on radio link monitoring and beam management procedures. The link monitoring can trigger the execution of connection maintenance procedures such as connection reconfiguration, beam recovery, connection relocation or connection release. Link maintenance procedure can be triggered by the transmitter UE, the receiver UE or a third entity such as the scheduling entity. In the case of AS groupcast connectionless communication, the link monitoring referred to in step S2214can be realized in the V2X upper layer, for example, based on a link keep-alive procedure carried out by the V2X upper layer. In this case, the link monitoring can trigger the execution of the transmitter side reconfiguration, connection relocation, connection release, or group reconfiguration including leaving a group and joining a new group. Also, in this case, a link maintenance procedure can be triggered by the transmitter UE, the receiver UE or a third entity such as the scheduling entity. In step S2208, link release is performed. Also, in step S2216, link release is performed.

FIG.23provides a high-level illustration of the receiver side operation for groupcast layer-2 link management including connection establishment. In step S2300, it is determined whether AS is connection oriented. If yes, in step S2302, V2X upper layer configuration is performed for Layer-2 unicast link connection establishment. If no, in step S2310, V2X upper layer configuration is performed for Layer-2 groupcast link connection establishment. In step S2304, V2X SL RX AS configuration—dedicated signaling based SL RX AS configuration for Layer-2 for groupcast link connection establishment is performed. In step S2306, link monitoring and maintenance in AS is performed. In step S2308, link release is performed. In step S2312, V2X SL RX AS configuration—preconfiguration of common signaling or no signaling based SL RXs AS configuration for Layer-2 groupcast link connection establishment is performed. In step S2314, link monitoring and maintenance in V2X upper layer is performed. In step S2316, link release is performed.

The details of the groupcast connection establishment procedure is similar to that of the unicast procedure. The configuration parameters are similar to the ones described above in the sections entitled “Configuration Parameters of T-UE or the I-EU” and “UE Assistance Information.”

In one embodiment, groupcast communication can be configured by configuration individually, the group member UEs using the unicast configuration procedure described in the section entitled “Unicast Connection Management.” Similarly, a connection for a new group member can be added using a unicast connection configuration procedure.

In an alternative embodiment, the groupcast connection is configured in a group manner. For a given group, certain UE capability in support of connection-oriented communication for a given group can be required from the group member UEs. Such capability can be preconfigured into the UE (e.g., SIM or ME), configured into the UE, for example, through broadcast signaling by a scheduling entity, for example, a UE or group lead acting as a scheduling entity or assisting the scheduling entity for resource configuration, or provisioned into the UE by the V2X control function. Assistance information including, e.g., scheduling formation for group member to request connection configuration or to discover connection configuration information can be configured into the UE. Such information can be provided in dedicated signaling to group member UE, or can be provided in a groupcast manner using, for example, the SL-MCCH (SL Multicast Control Channel), or can be provided in a broadcast manner using SCCH (Sidelink Control Channel) over SL-SCH (SL Shared Channel) or using STCH (Sidelink traffic channel) over SL-SCH (SL Shared Channel, or using SBCCH (Sidelink Broadcast Control Channel). Groupcast connection configuration information can be signaled on SL-MCCH or can be provided in a broadcast manner using SCCH (Sidelink Control Channel) over SL-SCH (SL Shared Channel) or using STCH (Sidelink traffic channel) over SL-SCH (SL Shared Channel) or using SBCCH (Sidelink Broadcast Control Channel). The configuration information can be periodically signaled.

In the configuration parameter described in the section entitled “Configuration Parameters of T-UE or the I-UE,” the destination ID in the bearer configuration will be the groupcast group Identifier.

When the group management function is performed by the V2X upper layer or the application layer, the group as provided by the V2X upper layer to the AS might be too large, for groupcast connection management that is effective and efficient from a radio resource management perspective. The AS can subdivide an upper layer V2X group in subgroups which is communicated to the PHY layer in support of groupcast communication. The AS can assign a layer-2 destination ID to each subgroup with a mapping between AS subgroup IDs and the corresponding larger group layer-2 destination ID. The AS maintains a table of mappings between a subgroup layer-2 destination ID and the corresponding larger group ID. A groupcast connection configuration configured into a UE can include a table of mappings between a subgroup layer-2 destination ID and a corresponding larger group layer-2 destination ID. In one embodiment, in addition to the table of association between subgroup destination ID and group destination IDs, the groupcast connection configuration into UE can include an indication for whether V2X data for a subgroup destination ID should be relayed, and an indication indicating if the UE is requested to relay received data. For a given groupcast, the AS can configure the PHY with one or more of the following information:The group layer-2 destination ID;List of V2X UE ID (e.g., ProSe UE ID, UE ID or any other identifier that can be used by the UE as a source ID for the member UE) of the group members;The subgroup layer-2 destination ID;List of V2X UE ID (e.g., ProSe UE ID, U ID or any other identifier that can be used by the UE as a source ID for the member UE) of the subgroup members;For each subgroup, an indication requesting that data received for the subgroup is relayed or not relayed.
Configuration for V2X Broadcast Communication

A high-level Illustration of AS configuration for broadcast V2X communication is provided inFIG.24for the transmitter side andFIG.25for the receiver side. In the AS broadcast V2X communication scenario, the T-UE, i.e., the UE that is the receiving UE of the configuration request, is not provided with a dedicated configuration based on, e.g., the UE capability. Instead, the AS protocol stack is configured based on a configuration specified to default parameters, e.g., in the specification or based on configuration preconfigured into the UE (SIM or ME) or provisioned into the UE, e.g., by the V2X control function. It should be noted that although AS is configured with broadcast resources with each MAC PDU carrying a layer-2 source ID and a layer-2 destination ID, making therefore the transmission connectionless from AS protocol stack configuration point of view, the upper layer can still maintain a unicast connection or group cast connection in the V2X upper layer where a layer-2 context is configured, and association between peer V2X upper layer contexts maintained at the V2X upper layer. In step S2400ofFIG.24, V2X SL TX AS configuration—use of preconfiguration or common signaling or dedicated signaling based configuration of SL TX AS configuration for broadcast based transmission is performed. The signaling for the configuration of upper layer V2X connection and context configuration including association between Peer V2X UEs, e.g., in support of a secure data link can use one or more of the following:PC5-S signaling over a user plane in a connectionless manner where each MAC PDU carries a source ID and a destination ID.PC5-S signaling over a user plane in an AS connection-oriented manner. This might be the case if there is an AS connection (e.g., unicast) already between the two V2X UEs involved in this sidelink communicationPC5-S message embedded in an RRC signaling message.

In step S2500ofFIG.25, V2X SL RX AS configuration—use of preconfiguration or common signaling or no signaling based configuration of SL RX AS configuration for broadcast based reception is performed.

In the following sections, methods for UE handling of multiple simultaneous sidelink RRC connections are described.

PC5 RRC Connection States

Based on the description in the previous sections, the two peer UEs may need to start a PC5 RRC connection prior to communicating over the V2X communication link. The steps to establish this PC5 RRC connection are as described below and shown inFIG.26:

Step S2600: PC5-S signaling for determining if peers are willing to communicate over the PC5 interface (DIRECT_COMMUNICATION_REQUEST)

Step S2602: UE capability exchange between the 2 peer UEs

Step S2604: Access Stratum (AS) configuration of the peer UEs to allow V2X communication

Step S2606: UE to UE communication over PC5

During step S2600to step S1604, the UE can be in a PC5_RRC_IDLE state. In this state, the UE is monitoring the (pre)configured communication receive pools to determine any possible PC5-S signaling messages from peer UEs. In this state, all communication to and from the UE can be considered to go over a sidelink common control channel (SL_CCCH). Upon reception of a valid DIRECT_COMMUNICATION_REQUEST, the PC5 Signaling layer in the UE will determine if the direct link is allowed, and respond to the peer UE. If allowed, the UE will send a DIRECT_COMMUNICATON_ACCEPT. Subsequently, the RRC layer will initiate a UE capability exchange and Access Stratum configuration exchange with the peer UE. These exchanges can also be over the SL_CCCH. After successful completion of these exchanges, the UEs can be considered to have established a PC5 RRC Connection, and the can transition to PC5_RRC_CONNECTED state. In this state, the UEs:can transmit control information over sidelink dedicated control channels (S_DCCH) and user data over sidelink dedicated traffic channels (SL_DTCH);can have sidelink radio bearers setup for communication to and from the peer UEs;can be required to send reference signals to assist the peer UE for channel quality measurements;can be required to act as a synchronization reference source and send system information signals; andcan monitor the status of the sidelink to evaluate link quality, declare link failure, and take actions in response to the link failure.

In the above, it is assumed that the PC5 RRC Connection is immediately established after the AS configuration exchange. Alternatively, the PC5 RRC connection can be established after a subsequent signaling exchange between UE1 and UE2, using a form of PC5RRCConnectionSetup message.

A PC5 RRC Connection between two peer UEs can have one UE behave as the master of the connection and one UE behave as the slave of the connection. Only the master of the connection can modify or delete the PC5 RRC connection. For example, if UE1 starts a PC5 RRC connection with UE2, UE can be the master of the PC5 RRC connection and UE2 can be the slave. Alternatively, after the capability exchange shown in step S2602, UE1 can determine that UE2 should be the master of the PC5 RRC Connection, and it can request that UE2 behave as the master (for example in the AS configuration step or optionally in the dedicated PC5RRCConnecctionSetup step). UE1 can base its decision on a number of factors, including one or more of the following:current load: for example, if it has to many active RRC connections it can ask UE2 to act as the master;connectivity to cellular network/quality of Uu link: If UE1 is out of coverage, it can ask UE2 to act as the master;power status: If UE2 has more available power or is powered by mains (e.g. plugged into an outlet), UE1 can ask UE2 to act as the master;capability: UE1 can not possess the capability to act as master and can ask UE2 to act as the master.
Multiple PC5 RRC Connections for a UE

A typical UE will have one or more RRC connections (SeeFIG.27). One of these connections can be to a gNB and one or more of these connections can be to peer UEs. These latter connections are PC5 RRC Connections. For each of the PC5 RRC connections, the UE can be the master of the connection or the slave. For example,FIG.27shows 4 PC5 RRC connections:

When a UE has multiple simultaneous RRC connections (as shown inFIG.27for UE1), the UE can need to have a process which manages the links/relations between these connections.

Keeping UE1 in Connected Mode

This process can monitor the number of simultaneous PC5 RRC connections, If this number is greater than a configurable threshold (K), UE1 should keep the RRC Connection to the gNB in RRC_CONNECTED mode. This will allow UE1 to send buffer status request (BSR) reports to the gNB without needing to first send a Scheduling Request. This can expeditate the resource allocation for the sidelink transmissions on the PC5. If UE1 is in RRC_IDLE mode (with respect to the gNB), and the number of PC5 RRC connections exceeds this threshold, the UE can initiate an RRC Connection with the gNB with an establishment cause set to indicate to the gNB that UE1 is requesting the connection to be able to send BSR for sidelink transmissions. For example, the establishment cause can be “sidelinkResourceAllocation”.

Release all RRC Connections

This process can receive a request from the gNB to stop all sidelink communications. A UE in RRC_IDLE mode (with respect to the gNB) can still transmit on the sidelink using autonomous resource selection. In some cases, the gNB can need to stop all sidelink transmissions to limit interference to neighbour cells and/or reduce the load on the cell. In such cases, it can be useful to provide the gNB with a mechanism to tell the UEs to go to RRC_IDLE and stop all sidelink transmissions. For example, the gNB can move UE1 to RRC_IDLE by releasing the RRC Connection. This message can also include an indication to release one or more or all of the PC5 RRC connections. Upon reception of the message from the gNB, UE1 will release all PC5 RRC connections for which it is a master. Based onFIG.27, this would be for PC5 RRC Connection 2 and PC5 RRC Connection 3. At the same time, UE1 can send a PC5RRCConnectionReleaseIndication message to UE2 and UEk, to have these UEs release their PC5 RRC connections to UE1. The PC5RRCConnectionReleaseIndication can contain a reason for the release (e.g ‘gNBRelease’).

Manage Priority of PC5 RRC Connections

Each PC5 RRC connection can be assigned a priority upon being setup. The process in UE1 can monitor the priority of all PC5 RRC connections and can decide to pause or release one or more of these PC5 RRC connections based on a number of factors, such as available power, load, proximity to a peer UE, etc. UsingFIG.27as an example, PC5 RRC Connection 3 can be of the highest priority. If necessary, UE can pause or release PC5 RRC connections 1, 2, and 4. UE1 will release all PC5 RRC connections for which it is a master. Based onFIG.27, this would be for PC5 RRC Connection 2. At the same time, UE1 can send a PC5RRCConnectionReleaseIndication message to UE2 and UEk, to have these UEs release their PC5 RRC connections to UE1. The PC5RRCConnectionReleaseIndication can contain a reason for the release (e.g ‘priority Release’).

Granularity of PC5 Unicast Link, Unicast Link Update and Unicast Link Addition Procedures

In LTE D2D, the direct link setup procedure is used to establish a secure direct link between two ProSe-enabled UEs. No AS configuration is exchanged between the initiating UE and the target UE. As discussed in this document, in NR V2X, unicast link establishment require AS (Access Stratum) configuration exchanges between the initiating UE and the target UE. One example of such configuration is bearers related configuration. Such bearer configuration in the AS level requires configuration in the V2X layer of the corresponding QoS Flows associated with the V2X services to be supported over the unicast link. QoS Flows (identified by QoS Flow Identifiers—QFI) i.e. the finest granularity QoS level available include QoS characteristics identified by PQI and QoS rules with packet filter sets, that maps to the AS bearers configuration, associated with V2X services to be supported over the PC5 unicast link. A V2X application running on the UE can support one or more services where data traffic associated with each service can be mapped to one or more QoS Flows. Several V2X applications can run concurrently on the UE, which in each application can generate data in support of different services, wherein data from each service can mapped to one or more QoS flows.

Based on the above, it is proposed that for NR V2X, the direct PC5-S link setup procedure, in addition to configuring QoS flows in V2X layer in support of the services data to be carried over the PC5 link, also configure a secure link between the two V2X peer UEs. It is therefore proposed that the PC5 direct unicast link setup procedure be used for both the establishment of a secure link security context between the peer V2X UEs as well as the configuration of QoS Flows in support of the service(s) data transported over the unicast links.

Unicast Link Modelling

There is only one unicast link between two peer V2X UEs as shown inFIG.28. The PC5 unicast link establishment procedure creates a secure link between the two peer V2X UEs and also configures the QoS Flows for one or more services, wherein the services mapped to one or more applications. Establishment of security context during the unicast link establishment procedure is mandatory. In this model, it is proposed that subsequent QoS Flow addition be realized by PC5 unicast link update procedure. This procedure essentially configures additional QoS Flows, after the establishment of the unicast link, and that mapped to data of one or more services to be transported over the PC5 unicast link. Security contexts may not be updated as part of the unicast link update procedure, and therefore security parameters might not be exchanged between the V2X peer UEs during the unicast link update procedure.

In this model, there can be more than one PC5 unicast link between two peer UEs, wherein there is one unicast cast link between two peer applications for each pair of two peer UEs as shown inFIG.29.

In this embodiment, the PC5 unicast link establishment procedures creates a secure link between the two peer V2X UEs and also configures the QoS Flows for one or more services, wherein the services are mapped to one application. In alternative embodiment, more than one uncast link can be concurrently created during the same unicast link establishment procedure, wherein the PC5 unicast link establishment procedures creates a secure link between the two peer V2X UEs and also configures the QoS Flows for one or more services, wherein the services are mapped to more than one application. In this model, it is proposed that subsequent QoS Flow addition be realized by PC5 unicast link update procedure. This procedure essentially configures additional QoS Flows, after the establishment of the unicast link, which map to data of one or more services to be transported over the PC5 unicast link. The one or more services added over the PC5 unicast link can belong to existing applications which have unicast link(s) established during unicast link establishment procedure. In this model, it is also proposed to introduce a new unicast link management procedure, that is PC5 unicast link addition procedure. This procedure adds additional link between two peer V2X applications and configures one or more QoS flows in support of one or more services of the V2X application for which a new unicast link is being added. More than one unicast link can concurrently be added with this procedure. Security contexts may not be updated as part of the unicast link update procedure, and therefore security parameters might not be exchanged between the V2X peer UEs during the unicast link update procedure.

In this model, there can be more than one PC5 unicast link between two peer UEs, wherein there is one unicast cast link per service for each two peer UEs as shown inFIG.30.

In this embodiment, the PC5 unicast link establishment procedures creates a secure link between the two peer V2X UEs and also configures the QoS Flows for one service. In alternative embodiment, more than one unicast link can be concurrently created during the same unicast link establishment procedure, wherein the PC5 unicast link establishment procedures creates a secure link between the two peer V2X UEs and also configures the QoS Flows for one or more V2X services, wherein the services mapped to one or more application. In this model, it is proposed that subsequent QoS Flow addition be realized by PC5 unicast link update procedure. This procedure essentially configures additional QoS Flows, after the establishment of the unicast link, which map to data of one or more of the existing services to being transported over the PC5 unicast link. The one or more services added over the PC5 unicast link can belong to existing applications which have unicast link(s) established during unicast link establishment procedure. In this model, it is also proposed to introduce a new unicast link management procedure, that is a PC5 unicast link addition procedure. This procedure adds additional link between two peer UEs for a new service, and configures one or more QoS flows in support of the V2X service for which a new unicast link is being added. More than one unicast link can concurrently be added with this procedure. Security contexts may not be updated as part of the unicast link update procedure, and therefore security parameters might not be exchanged between the V2X peer UEs during the unicast link update procedure.

An exemplary embodiment of the present disclosure provides a first apparatus (a UE, e.g., a mobile device102a, a computer, a vehicle (e.g., a car102b, motorcycle, boat, etc.), etc.) including: a processor (e.g., processor118); a memory (e.g., non-removeable memory130, removeable memory132, etc.); and communication circuitry (which includes, e.g., transceiver120). The first apparatus is connected to a communications network (e.g., RAN103/104/105/103b/104b/105b) via the communication circuitry. The first apparatus further includes computer-executable instructions stored in the memory which, when executed by the processor, causes the first apparatus to: discover a second apparatus (a second UE, e.g., a mobile device102a, a computer, a vehicle (e.g., a car102b, motorcycle, boat, etc.), etc.) that the first apparatus can communicate with; obtain device information related to the second apparatus; and configure a radio protocol (e.g., a PC5 signaling protocol) of the first apparatus for direct sidelink communication with the second apparatus.

In an exemplary embodiment, the first apparatus can initiate the obtainment of the device information related to the second apparatus by sending, to the second apparatus, a request for the device information related to the second apparatus (see, e.g.,FIG.16A, SL RRC signaling-target device info request).

In an exemplary embodiment, the first apparatus can receive a response to the request for the device information related to the second apparatus. The response (see, e.g.,FIG.16A, SL RRC signaling-target device info response) includes the device information related to the second apparatus.

In an exemplary embodiment, the device information related to the second apparatus includes one or more of: device capability, QoS configuration parameters of V2X communication, and sidelink measurements. The device capability can be, for example, related to one or more of the following: V2X Upper layer capability (e.g., security capability), SDAP capability, PDCP capability, RLC capability, MAC capability, baseband capability, RF including RF band and subband capability, etc. The sidelink measurements can be, for example, RSRP, RSRQ, RSSI, CBR, CR, etc.

In an exemplary embodiment, the first apparatus can determine radio protocol configuration parameters of the first apparatus, and determine radio protocol configuration parameters of the second apparatus. Alternatively, the first apparatus can request from a third apparatus (e.g., a scheduling entity), the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus, and receive the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus.

In an exemplary embodiment, the determination of the radio protocol configuration parameters of the second apparatus takes into account the device information related to the second apparatus. In an exemplary embodiment, the determination of the radio protocol configuration parameters of the second apparatus takes into account the device information related to the second apparatus and device information related to the first apparatus.

In an exemplary embodiment, the first apparatus can send radio protocol configuration parameters of the second apparatus to the second apparatus or the second apparatus receives the radio protocol configuration parameters of the second apparatus from the third apparatus. In an exemplary embodiment, the radio configuration parameters of the second apparatus that are sent to the second apparatus are used by the second apparatus to configure its radio protocol.

In an exemplary embodiment, the first apparatus can send, to the second apparatus, device information related to the first apparatus. In an exemplary embodiment, the device information related to the first apparatus includes one or more of: device capability, QoS configuration parameters of V2X communication, and sidelink measurements.

In an exemplary embodiment, a PC5 interface (see, e.g.,FIG.10) allows communication between the first apparatus and the second apparatus, and PC5 RRC signaling or PC5-S signaling is used over the PC5 interface. In an exemplary embodiment, a PC5 interface allows communication between the first apparatus and the third apparatus or a PC5 interface allows communication between the second apparatus and the third apparatus. In an exemplary embodiment, PC5 RRC signaling or PC5-S signaling can be used over the PC5 interface.

In an exemplary embodiment, the radio protocol includes, for example, an SDAP layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. See, e.g.,FIGS.2and6.

In an exemplary embodiment, the first apparatus or the second apparatus is a vehicle. The first apparatus and the second apparatus can both be vehicles. One of the first apparatus and the second apparatus can be a mobile device, and the other can be a vehicle.

In an exemplary embodiment, the first apparatus can transmit, by a transceiver (e.g., transceiver120), data from the first apparatus to a second apparatus.

In an exemplary embodiment, the third apparatus is a road side unit (e.g., RSU120b), a base station (e.g., base station114a,114b), a relay node, a vehicle (e.g., vehicle102b), or an integrated access and backhaul unit.

In an exemplary embodiment, the second apparatus includes a processor (e.g., processor118), a memory (e.g., non-removeable memory130, removable memory132) and communication circuitry (including, for example, transceiver120). The second apparatus is connected to the communications network via the communication circuitry. The second apparatus includes computer-executable instructions stored in the memory which, when executed by the processor, causes the second apparatus to: 1) determine radio protocol configuration parameters of the first apparatus, and determine radio protocol configuration parameters of the second apparatus; or 2) request from a third apparatus, the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus, and receive the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus. In an exemplary embodiment, the determination of the radio protocol configuration parameters of the first apparatus takes into account the device information related to the first apparatus or the determination of the radio protocol configuration parameters of the first apparatus takes into account the device information related to the second apparatus and device information related to the first apparatus. In an exemplary embodiment, the second apparatus can send radio protocol configuration parameters of the first apparatus to the first apparatus or the first apparatus receives the radio protocol configuration parameters of the first apparatus from the third apparatus. In an exemplary embodiment, the radio configuration parameters of the first apparatus that are sent to the first apparatus are used by the first apparatus to configure its radio protocol.

In an exemplary embodiment, the first apparatus can send, to the second apparatus, device information related to the first apparatus. The device information related to the first apparatus includes one or more of: device capability, QoS configuration parameters of V2X communication, and sidelink measurements. The second apparatus includes a processor, a memory, and communication circuitry. The second apparatus is connected to the communications network via the communication circuitry. The second apparatus includes computer-executable instructions stored in the memory which, when executed by the processor, causes the second apparatus to: determine radio protocol configuration parameters of the first apparatus, and determine radio protocol configuration parameters of the second apparatus. Alternatively, the second apparatus can request from a third apparatus, the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus, and receive the radio protocol configuration parameters of the first apparatus and the radio protocol configuration parameters of the second apparatus.

An exemplary embodiment of the present disclosure provides a method for direct sidelink communication using a first apparatus that includes a processor, a memory, communication circuitry, and the first apparatus is connected to a communications network via the communication circuitry. The method includes: discovering a second apparatus that the first apparatus can communicate with; obtaining device information related to the second apparatus; and configuring a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

An exemplary embodiment of the present disclosure provides a non-transitory computer readable storage medium having computer-readable instructions tangibly recorded thereon which, when executed by processing circuitry, cause the processing circuitry to perform a method for direct sideling communication using a first apparatus. The method including: discovering a second apparatus that the first apparatus can communicate with; obtaining device information related to the second apparatus; and configuring a radio protocol of the first apparatus for direct sidelink communication with the second apparatus.

In an exemplary embodiment, the PC5 interface is a unicast link between the first apparatus and the second apparatus which allows communication between one or more pairs of peer services in the first apparatus and the second apparatus.

In an exemplary embodiment, all services using the same PC5 unicast link use the same application.

In an exemplary embodiment, one PC5 unicast link supports one or more service types if the one or more service types are at least associated with a pair of peer applications for this one PC5 unicast link.

It will be understood that any of the methods and processes described herein can be embodied in the form of computer executable instructions (i.e., program code) stored on a computer-readable storage medium, and when the instructions are executed by a machine, such as a computer, server, M2M terminal device, M2M gateway device, or the like, perform and/or implement the systems, methods and processes described herein. Specifically, any of the steps, operations or functions described above can be implemented in the form of such computer executable instructions. Computer readable storage media include both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, but such computer readable storage media do not include signals. Computer readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other physical medium which can be used to store the desired information, and which can be accessed by a computer.

In describing preferred embodiments of the subject matter of the present disclosure, as illustrated in the Figures, specific terminology is employed for the sake of clarity. The claimed subject matter, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

Thus, it will be appreciated by those skilled in the art that the disclosed systems and methods can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. It is not exhaustive and does not limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or can be acquired from practicing of the disclosure, without departing from the breadth or scope. Thus, although particular configurations have been discussed herein, other configurations can also be employed. Numerous modifications and other embodiments (e.g., combinations, rearrangements, etc.) are enabled by the present disclosure and are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the disclosed subject matter and any equivalents thereto. Features of the disclosed embodiments can be combined, rearranged, omitted, etc., within the scope of the invention to produce additional embodiments. Furthermore, certain features can sometimes be used to advantage without a corresponding use of other features. Accordingly, Applicant(s) intend(s) to embrace all such alternatives, modifications, equivalents, and variations that are within the spirit and scope of the disclosed subject matter.

Reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone can be present in an embodiment, B alone can be present in an embodiment, C alone can be present in an embodiment, or that any combination of the elements A, B and C can be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.

No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.