WO2019160863A1

WO2019160863A1 - Data transmission associated with nr v2x

Info

Publication number: WO2019160863A1
Application number: PCT/US2019/017659
Authority: WO
Inventors: Chunxuan Ye; Fengjun Xi; Kyle Jung-Lin Pan
Original assignee: Idac Holdings, Inc.
Priority date: 2018-02-14
Filing date: 2019-02-12
Publication date: 2019-08-22
Also published as: TW201941555A

Abstract

Systems, methods, and instrumentalities are disclosed for data transmission schemes for vehicle/platooning scenarios, e.g., in NR vehicle-to-everything (V2X). V2X communications may support network coding based data transmissions. Channel encoding, channel decoding, and/or signaling are provided, e.g., to support network coding. Sidelink (SL) code block group (CBG) based data transmissions may be supported (e.g. by signaling). Resources may be allocated for V2X transmission modes (e.g. mode 3, mode 4). A resource selection window may be determined (e.g. for mode 4). A redundancy version (RV) may be selected, for example, based on a selected resource. A group-based handover may be supported for vehicle platooning.

Description

DATA TRANSMISSION ASSOCIATED WITH NR V2X

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of United States Provisional Application Serial No. 62/630,474, filed February 14, 2018, which is hereby incorporated by reference herein.

BACKGROUND

[0002] Mobile communications continue to evolve. A fifth generation may be referred to as 5G. A previous (legacy) generation of mobile communication may be, for example, fourth generation (4G) long term evolution (LTE). Mobile wireless communications implement a variety of radio access technologies (RATs), such as New Radio (NR). Use cases for NR may include, for example, enhanced Mobile

Broadband (eMBB), Ultra High Reliability and Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC).

SUMMARY

[0003] Systems, methods, and instrumentalities are disclosed for wireless data transmission, e.g., associated with NR vehicle-to-everything (V2X). A wireless transmit/receive unit (WTRU), such as a vehicle, a WTRU associated with the vehicle, a WTRU associated with a user of the vehicle, etc., may transmit information intended for other WTRU(s), for example other vehicle(s), e.g., in a platoon scenario. The WTRU may include, among other things, a receiver, a transmitter, and a processor, e.g., to implement features described herein. In examples, the WTRU may have a transport block (TB) to send. The WTRU may append CRC bits to the TB. The WTRU may perform segmentation of the TB with appended CRC bits. The segmentation may create a plurality of code blocks (CBs). The WTRU may perform encoding associated with the plurality of CBs, e.g., using network coding as described herein, which may produce a plurality of network encoded CBs (NC-CBs).

[0004] Network coding may comprise one or more of the following. The WTRU that is performing the network coding may choose a random number of CBs from the plurality of CBs. The WTRU may perform an XOR operation on the random number of CBs. The WTRU may append CRC bits to a result of the XOR operation. The choosing of the random number of CBs, performing of the XOR operation, and appending of the CRC bits to the result of the XOR operation may be performed multiple times. In examples, the multiple number of times, e.g., degree distribution, may be determined.

[0005] The WTRU may, e.g., after the network coding, apply LDPC encoding to the plurality of NC-CBs. An LDPC code used for the LDPC encoding may be based on a submatrix of a parity check matrix. The WTRU may apply a channel interleaver and/or perform modulation. The WTRU may transmit the information (e.g., multicast, groupcast, etc.).

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented;

[0007] FIG. 1 B is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;

[0008] FIG. 1 C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;

[0009] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;

[0010] FIG. 2 shows an example of a data channel encoding (e.g. a low-density parity-check (LDPC) encoding system), e.g., in NR.

[0011] FIG. 3 shows an example of an LDPC encoding that may support network coding.

[0012] FIG. 4 shows an example of a network encoding processor.

[0013] FIG. 5 shows an example of data operations at a network encoding processor

[0014] FIG. 6 shows an example of an LDPC decoding system that may support network coding.

[0015] FIG. 7 shows an example of an LDPC decoding/encoding system that may support network coding, e.g., at a relay.

[0016] FIG. 8 shows an example of data operation at a relay's network encoding processor.

[0017] FIG. 9 shows an example of resource selection windows for different frequency bands.

[0018] FIG. 10 shows an example of resource selection windows for different sub-carrier spacing numerologies.

[0019] FIG. 11 shows an example of a vehicle density state graph.

[0020] FIG. 12 shows an example of a handover procedure.

[0021] FIG. 13 shows an example of a handover procedure in vehicle platooning. DETAILED DESCRIPTION

[0022] A detailed description of illustrative examples will now be described with reference to the various figures. Although this description provides detailed examples, it should be noted that the details are intended to be exemplary and in no way limit the scope of the application.

[0023] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0024] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104/1 13, a ON 106/1 15, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station” and/or a "STA”, may be configured to transmit and/or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g. a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0025] The communications systems 100 may also include a base station 1 14a and/or a base station 1 14b. Each of the base stations 1 14a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106/115, the Internet 110, and/or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.

[0026] The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions.

[0027] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0028] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115/116/117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access (HSUPA).

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

[0030] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., a eNB and a gNB).

[0032] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0033] The base station 114b in FIG. 1 A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106/115.

[0034] The RAN 104/113 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or the CN 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113, which may be utilizing a NR radio technology, the CN 106/115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0035] The CN 106/115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common

communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and/or the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 112 may include wired and/or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/113 or a different RAT.

[0036] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1 A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0037] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0038] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0039] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In an embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.

[0040] Although the transmit/receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 may include any number of transmit/receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0041] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0042] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0043] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0044] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102.

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

[0045] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and/or Augmented Reality (VR/AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0046] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)). [0047] FIG. 1 C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 1 16. The RAN 104 may also be in communication with the CN 106.

[0048] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 1 16. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a.

[0049] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0050] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0051] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA.

[0052] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0053] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 1 10, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. [0054] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.

[0055] Although the WTRU is described in FIGS. 1 A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0056] In representative embodiments, the other network 112 may be a WLAN.

[0057] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic in to and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad- hoc” mode of communication.

[0058] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0059] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0060] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0061] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 h, and 802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type

Control/Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0062] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11h, 802.11 ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode.

In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes. Carrier sensing and/or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0063] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0064] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 1 15 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0065] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 1 13 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and/or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c).

[0066] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and/or lasting varying lengths of absolute time).

[0067] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and/or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and/or throughput for servicing WTRUs 102a, 102b, 102c.

[0068] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E- UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0069] The CN 115 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0070] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 1 13 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 1 13 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as WiFi. [0071] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N1 1 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet- based, and the like.

[0072] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 1 10, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0073] The CN 115 may facilitate communications with other networks. For example, the CN 1 15 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 1 15 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 1 12, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0074] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 1 14a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b,

DN 185a-b, and/or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions.

[0075] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications.

[0076] The one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data.

[0077] Deployment scenarios (e.g. in LTE and 5G) may include, for example, indoor hotspot, dense urban, rural, urban macro, high speed, etc. Use cases (e.g. in LTE and 5G) may include, for example, Enhanced Mobile Broadband (eMBB), Massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). Use cases may focus on different requirements, such as, for example, higher data rate, higher spectrum efficiency, low power and higher energy efficiency, lower latency and higher reliability, etc.

[0078] Use cases in vehicle scenarios, such as 5G Vehicle-to-Everything (V2X), may include vehicle platooning, sensor and state map sharing, remote driving, and/or automated cooperative driving. Vehicle platooning may refer, for example, to operation of a group of vehicles in a closely linked manner, e.g., the vehicles may move like a train with virtual strings attached between vehicles. Vehicle distance may be maintained, for example, by sharing status information among vehicles. Platooning may reduce distances between vehicles and/or the number of drivers needed may be reduced. Platooning may reduce overall fuel consumption.

[0079] Vehicle blockage may result in a reduction (e.g. dramatic reduction) of signal strength, e.g., for high carrier frequencies, say above 6 GFIz. In examples, vehicle blockage may be treated as a separate state, e.g., beyond line-of-sight state and non-line-of-sight state.

[0080] In examples, transmission mode(s) may be used. A vehicle may be in (e.g. V2X) transmission mode 3 (e.g. mode 3 user). A vehicle may be in (e.g. V2X) transmission mode 4 (e.g. mode 4 user). A mode 3 user may, for example, use (e.g. directly use) resources, such as resources that are allocated by a network entity (e.g., a base station), e.g., for sidelink (SL) communication among vehicles or between a vehicle and a pedestrian. A mode 4 user may, for example, obtain a list of candidate resources, such as resources that are allocated by a network entity (e.g., a base station), and may select a resource among the list of candidate resources, e.g., for an SL communication. [0081] User or WTRU may refer to a vehicle (user). These terminologies may be interchangeable herein, e.g., in a vehicle scenario.

[0082] Code block group (CBG)-based HARQ may be used. There may be a CBG level CRC. A CBG- based transmission with single/multi-bit HARQ-ACK feedback may be supported (e.g. in eMBB use cases). CBG-based transmission may be used for downlink transmissions and/or uplink transmission.

[0083] Latency may be reduced for group communications in a vehicle platoon, e.g., using one or more features described herein. Group communications may occur within a vehicle platoon. Vehicles may join or leave a vehicle platoon. An announcement or warning may be spread (e.g., transmitted, relayed, and/or received) over vehicles in a platoon.

[0084] Vehicle blockage may degrade signal strength, e.g., in a high frequency band. A vehicle in a platoon may (e.g. due to vehicle blockage) not have a good communication link with another vehicle in the platoon. Signal strength degradation (e.g. due to vehicle blockage) may be significant, for example, when blocking vehicles are large (e.g. school buses or trucks). One or more vehicles in (e.g. in the middle of) a platoon may serve as a relay vehicle, e.g., to maintain group communications in a platoon. A relay vehicle may, for example, pass messages (e.g. received from a first vehicle) to a second vehicle (e.g., a vehicle behind it), or vice versa.

[0085] Relay operations may lead to additional delay in a data transmissions process. A delay may increase (e.g., linearly) with the number of relaying vehicles. Delay resulting from relay operations may be large, for example, for a platoon with a large number of vehicles. Delays caused by relaying operations in a vehicle platoon may be reduced, e.g., via one or features herein.

[0086] Resources may be selected for a V2X user (e.g. a mode 4 user). A key performance interface (KPI) may be related to user plane latency. End-to-end latency (e.g. in NR V2X communication) may be, for example, 3-10 ms. Resource selection for NR V2X communication may be disclosed herein, e.g., to support low latency.

[0087] Signal overhead may be reduced in vehicle platooning scenarios. Vehicles in vehicle platooning may move (e.g. almost move) in a same direction, at a same speed (e.g. almost the same speed), and/or along a same route (e.g. almost the same route). Vehicles may share common communication environments.

[0088] A common environment may be related to handover. In an example, vehicles in a platoon may perform handover at approximately the same time, for example, with the same source and destination network entity, e.g., gNB. There may be significant signal overhead, for example, when each vehicle performs handover separately. A group-based handover may be performed for two or more (e.g. all) vehicles in a platoon. Group based handover may be configured, for example, during a platoon formation period. A platoon formation process may support group-based handover.

[0089] Vehicles may move at a high speed (e.g. up to 250 km/h or 155 mph) in a platoon. High speed of a vehicle platoon may pose a requirement on handover duration. Handover preparations may be made ahead of time. In an example, a first vehicle in a platoon may handover earlier than other vehicles in the platoon, for example, when a vehicle platoon may be leaving cell coverage. Other vehicles may be prepared to handover in advance even though one or more may not have to handover at the same time as the first vehicle.

[0090] Network coding associated with data transmissions may be provided. One or more of the following may apply: channel encoding features associated with supporting network coding (e.g., at a transmitting entity); channel decoding features associated with supporting network coding (e.g., at a receiving entity); channel decoding/encoding features associated with supporting network coding (e.g., at a relay entity); or signaling associated with supporting network coding.

[0091] FIG. 2 shows an example of a data channel encoding (e.g. a low-density parity-check (LDPC) encoding for NR). In LDPC encoding one or more of the following may apply. A transport block (TB) may be received from an upper layer. A TB level CRC may be generated and appended to the TB. A TB may be segmented (e.g. segment the TB that includes the appended CRC bits) into several (e.g. equal size) code blocks (CBs). A CB level CRC may be attached to one or more (e.g. each) CB. A lifting size may be determined for a given LDPC base graph, for example, based on CB size (e.g. including CB CRC). Filler bits may be inserted (e.g. if needed) to a (e.g. each) CB, for example, e.g., to match a selected lifting size.

A CB (e.g. with or without filler bits) may be encoded, for example, by a given low code rate LDPC parity check matrix. LDPC encoded bits may be saved to a circular buffer. One or more bits may be selected from a circular buffer for transmissions, e.g., based on Redundancy Version (RV) and code rate. Selected bits may be interleaved, for example, by a row-column interleaver, e.g., to compensate for the impact of a fading channel. Interleaved bits may be modulated, for example, after they are concatenated (e.g. from multiple CBs).

[0092] Channel encoding features associated with supporting network coding (e.g., at a transmitting entity) are disclosed. A V2X communication may, for example, be considered a mesh network. A vehicle or road side unit (RSU) may multicast a message (e.g. the same message) to multiple vehicles in a vicinity.

[0093] A group of vehicles may compose a vehicle platoon. A vehicle in a group or platoon may transmit a common message to multiple (e.g. all) vehicles in a platoon. A vehicle at the front of a platoon may not have a direct link with a vehicle at the end of the platoon (e.g. due to vehicle blockage). A vehicle in the middle of the platoon may serve as a relay. In examples, an extended sensor, such as an RSU, may be used. One or more vehicles may send raw or processed sensor data to an RSU, which may (e.g. in turn) multicast the data to one or more nearby vehicles in the vicinity. Examples may be presented based on a vehicle platooning use case, e.g., where a vehicle in a platoon may serve as a relay node. Examples may be extended or applied to other V2X use cases, such as, for example, where a vehicle and/or an RSU may serve as relay node.

[0094] In examples, a decode and forward relaying scheme may be used, for example, since a relay vehicle may receive the same message as another vehicle. A common message may need to reach an end vehicle within a time threshold, e.g., to meet latency requirements. In examples, a network coding based partial decode and forward relaying scheme may be used. Information (e.g. partial or full information) may be forwarded (e.g. to one or more other vehicles), for example, even when a relay vehicle has not finished decoding a TB. This may reduce message transmission latency, for example as compared to decode and forward, to permit a vehicle at the end of a platoon to promptly receive a message.

[0095] A partial decode and forward relaying scheme may be implemented, for example, with an LDPC encoding system that supports network coding, e.g., as described herein. In examples, techniques utilizing LDPC encoding may be implemented using other channel codes, such as, for example, a polar code or a Turbo code.

[0096] FIG. 3 shows an example of an LDPC encoding that may include network coding. One or more of the following may be performed.

[0097] A TB may be received, e.g., from an upper layer, for example as shown in FIG. 3. A TB level CRC may be calculated (e.g., determined) and/or appended to the TB. CB segmentation may be applied to a TB (e.g. the TB with the appended CRC bits). A number C of CB segments may be calculated (e.g., determined). The TB may be segmented (e.g. equally segmented) into C CB segments. A CB level CRC may or may not be appended to a (e.g. each) CB segment.

[0098] A calculation of CB segments may vary between LDPC encoding system examples. In examples (e.g. given the same TB size), a number of CB segments in an LDPC encoding that supports network coding may be larger than a number of CB segments in an LDPC encoding that does not support network coding.

[0099] K_cb may be a maximum code block size of a LDPC code and B may be a TB size (e.g. including TB CRC). An LDPC encoding system (e.g. one that does not support network coding), may calculate a

B

number of CB segments, for example, according to C = , where L may be a CB CRC length. An

Kcb-L

LDPC encoding system (e.g. that supports network coding) may calculate a number of CB segments, for example, according to: 1 ) A_t C; or 2) A₂ + C; or 3) A₃ + A₄ C, or 4) max(C, Tl₅), or any combination of these, e.g., for integer values A_lt A₂, A₃, A₄, A₅.

[0100] Network coding may be included in an LDPC encoding chain (e.g., as shown in FIG. 3 as network encoding processor), for example, after CB segmentation. FIG. 4 shows an example of a network encoding processor (e.g., network encoding processor may refer to network coding, for example network coding performed by a device, e.g., a processor or other mechanism associated with the device). For example, one or more of the features illustrated in FIG. 4 may be performed via the network encoding processor function (e.g., as described herein).

[0101] A network encoding processor may treat one or more CBs (e.g. all CBs) from the segmented TB as the source for network encoding processing. Input CBs may be stored in a buffer. A degree distribution A may be determined for the network encoding processing. A degree distribution may, for example, depend on a data QoS (e.g. a latency requirement of a message, a reliability level of the data), a channel condition, a number of CBs after a CB segmentation, and/or a maximum number of network coded CBs (NC-CBs) to be generated. A degree distribution A may be dynamically determined. A degree distribution A may be configured, for example, using high layer signaling. A degree distribution A may be pre-defined.

[0102] Degree distribution may be a distribution of random variable (e.g., uniform distribution, Gaussian distribution, etc.). A list of degree values may be generated, e.g., based on degree distribution. Each generated degree value may indicate how many CBs may be used to generate a NC-CB. An example may be a total of 10 CBs. Consider a single example of degree distribution A may be a uniform distribution, where degree random variable A may follow: Pr(A=1 ) = 1/10, Pr(A=2) = 1/10,... , Pr(A=10)=1/10. Another exemplary degree distribution A (e.g., non-uniform) may be Pr(A=1) = 1/2, Pr(A=3)=1/4, Pr(A=5) = 1/8, Pr(A=7) = 1/8.

[0103] An instance of degree generation may be generated or obtained (e.g., on a condition that degree distribution A has been determined). In an example, a number A may be generated, e.g., based on the degree distribution A. A CBs may be selected (e.g. randomly selected) from K source CBs, e.g., the stored CBs. The selected CBs may be XORed, for example, to generate an NC-CB. CRC bits may be attached to an (e.g. each) NC-CB. Additional NC CB(s) may be generated (e.g. when more NC CBs may be transmitted), for example, following the same technique. Otherwise, the process may stop.

[0104] The determination of stopping the process may depend on one or more of the following: a channel condition, data QoS, a number of CBs after a CB segmentation, the degree distribution, the possible feedback from a receiver, etc. Consider an example of a total of 10 CBs and the degree distribution A may be uniform distribution (e.g., as show herein). For a distribution A, we may generate a list of values, such as 4, 7, 2, 9, 1 , 8, 2, 5, 7, 10, 8, 9, 2, 3, 4, 5, 7,9, 8, 2, 4, 6, 7, .... Each value may be less than or equal to 10 (e.g., 10 CBs); each value may be equally likely between 1 and 10. The number of this list of values may be a number larger than or equal to 10. In examples (e.g., Fig. 5), the number of CBs may be K, and the number of NC-CBs may be N. In examples, N>=K. Each value may correspond to a NC- CB (e.g., it may indicate how many CBs are used to generate this NC-CB).

[0105] FIG. 5 shows an example of data operations at a network encoding processor, such as a transmitter's network encoding processor. N NC-CBs may be generated by a list of K CBs (e.g. from K CBs segmented from a TB). As shown in the example of FIG. 5, for each NC CB to be created, a random number of the K CBs is chosen and an XOR operation is performed on the chosen random number of the K CBs. A result of the XOR operation (e.g., with or without CRC bits appended) may produce an NC CB. Ai may be randomly chosen, and as shown in the example of FIG. 5, the randomly chosen value of Ai is 2 (e.g., two of the K CBs are chosen to perform the XOR operation on). A2 may be randomly chosen, and as shown in the example of FIG. 5, the randomly chosen value of A2 is 1 (e.g., one of the K CBs are chosen). A3 may be randomly chosen, and as shown in the example of FIG. 5, the randomly chosen value of A3 is 2 (e.g., two of the K CBs are chosen to perform the XOR operation on).

[0106] CRC bits may be appended at one or more times. In examples, CRC bits may be appended: at a CB level CRC; at an NC CB level; or at the CB level CRC and the NC CB level.

[0107] Filler bit insertion, e.g., as shown for example in FIG. 3, may be applied before or after a network coding. Filler bit insertion may perform a function similar to or the same operation as in FIG. 2, for example, padding zeros to a CB or to an NC-CB, e.g., to match a supported information block length of an LDPC parity check matrix.

[0108] LDPC encoding may be provided. LDPC encoding may be provided with a sub-parity check matrix, e.g., as shown for example in FIG. 3. A circular buffer may not be used, for example, when a single transmission on an (e.g. each) LDPC codeword of an NC CB is expected. A submatrix of an LDPC parity check matrix may be selected from a mother LDPC parity check matrix, e.g., to match a desired encoding rate in the current transmission. Part or all of an LDPC codeword may be transmitted in a current transmission. One or more encoded systematic bits may not be transmitted, for example, to achieve better BLER (block error rate) performance.

[0109] Channel interleaving operations may be applied, e.g., to an (e.g. each) LDPC codeword.

Modulation may be applied, e.g., to a concatenated channel that may, for example, interleave bits from multiple NC CBs.

[0110] V2X communications may be grant-free, e.g., a transmitter may keep sending data without a grant and without waiting for ACK/NACK feedback from a receiver. A transmitter vehicle may keep sending NC CBs to a receiver vehicle (e.g. a vehicle behind the transmitter vehicle), for example, unless it receives an ACK from the receiver vehicle.

[0111] Channel decoding may be provided, e.g., to support network coding. FIG. 6 shows an example of an LDPC decoding that may support network encoding operations, e.g., as described herein. One or more of the functions illustrated in FIG. 6 may be performed. For example, one or more of the following may apply.

[0112] A receiver may receive data. A receiver may demodulate symbols and apply a channel de interleaver. A channel de-interleaved LDPC encoded NC CB may be decoded, for example, using LDPC decoding (e.g. using a sub-matrix of a LDPC parity check matrix).

[0113] Successfully decoded NC CBs may be saved to a buffer. An NC CB level CRC may be used, for example, to decide whether a decoding of an NC CB is successful. An inherent parity check of an LDPC code may be used to decide whether an NC CB is successfully decoded, for example, when an NC CB CRC is not attached. An NC CB level CRC may be removed, for example, before a decoded NC CB is saved to a buffer.

[0114] A network decoding process may try to decode CBs (e.g., all CBs), for example, when a number of successfully decoded NC CBs in the buffer is larger than a total number of CBs (e.g. K CBs). CBs may be decoded. A CB level CRC check may be performed, for example, if K CBs are decoded and/or when a CB level CRC is used. If a CB level CRC is not used, a TB level CRC check may be performed.

[0115] Feedback may be provided. In an example, an ACK bit at a TB level may be fed back to a transmitter, for example, when a TB level CRC check passes. A receiver may not (e.g. intermediately) send a NACK bit to a transmitter, for example, when a TB level CRC check fails. A receiver may wait to receive more NC CBs for the next network decoding attempts. A receiver may send a NACK bit to a transmitter, for example, when a timer expires for receiving the data.

[0116] Channel decoding/encoding is provided that may support network coding (e.g. at a relay vehicle). A vehicle in the middle of a platoon (e.g. unlike a vehicle at the end of a platoon), may serve as a relay node and/or may decode data by itself. FIG. 7 shows an example of an LDPC decoding/encoding that may support network coding at a relay. One or more of the functions illustrated in FIG. 7 may be performed.

For example, one or more of the following may apply.

[0117] Decoding at a relay vehicle may be similar to decoding by the last vehicle in a platoon (e.g., see FIG. 6). A relay vehicle may schedule a data transmission, which may involve a network encoding processor. [0118] A source for network encoding operations may be decoded NC CBs stored in a buffer. A source for network encoding operations at a relay vehicle may be decoded NC CBs. This may be different from a transmitter, whose source for network encoding operations may be CBs.

[0119] Network encoding operations may start, for example, when the number of decoded NC CBs in a buffer may be larger than a threshold. A threshold may be smaller than a total number of CBs (e.g. K CBs). This may speed up relay data transmission, for example, because network encoding operations may start to work before a relay decodes CBs (e.g., all CBs).

[0120] FIG. 8 shows an example of data operation at a relay's network encoding processor. Operation may be based on decoded NC CBs, for example rather than source CBs (e.g. as shown in FIG. 5).

[0121] NC CBs may be zero-padded, for example, to match supported information block length of an LDPC parity check matrix. An LDPC parity check matrix may be a sub-matrix of a mother LDPC parity check matrix. A circular buffer may not be used to store LDPC encoded bits, for example, when a single transmission of each NC CB may be applied. Channel interleaving may be applied, e.g., to LDPC encoded bits. Modulation may be performed, e.g., concatenated channel interleaved bits may be modulated for transmission.

[0122] Network coding may be supported by signaling. Signaling may be related to network coding operations in V2X SL.

[0123] A network coding feature may be, for example, a mandatory feature or an add-on or optional feature for V2X SL, e.g., based on a configuration and/or activation. In examples, a network coding feature may be applied, for example, when it is configured and/or activated. A network coding feature may be configured, for example, via high layer signaling, e.g., RRCConnectionReconfiguration,

RRCConnectionEstablishment, etc. An encoding feature may be activated, for example, by a MAC CE.

[0124] A network coding feature may be associated with a WTRU capability or a WTRU category. A WTRU category may include a network coding capability, while another WTRU category may not include a network coding capability.

[0125] Degree distribution A may be configured, for example, by high layer signaling, e.g.,

RRCConnectionReconfiguration, RRCConnectionEstablishment, etc. Degree distribution A may be activated, for example, by a MAC CE and/or physical layer signaling, e.g., SCI, DCI, UCI.

[0126] A network coding configuration may be provided. An NC CB (e.g. each NC CB) may be an XOR of several CBs. Component CB information may be included in control information, for example, to permit a network decoding processor to make use of this information to decode CBs from NC CBs. A network coding configuration may, for example, be included in L1 control signaling, e.g., SCI, DCI, UCI. A configuration for an NC CB may be a list or a bitmap of component CBs. A configuration for multiple NC CBs may be multiplexed, for example, when more than one NC CB may be transmitted.

[0127] A relay may have its own network coding configuration, which may be signaled in SCI that may be associated with relaying data.

[0128] Signaling may be provided for SL CBG based data transmissions. One or more of the following may apply.

[0129] LTE SL control information (SCI) may include formats, for example, SCI format 0 and SCI format 1 . SCI format 0 may be used (e.g. primarily) for transmission mode 1 and 2; SCI format 1 may be used (e.g. primarily) for transmission mode 3 and 4. SCI format 1 may include, for example: 1) priority; 2) resource reservation; 3) frequency resource location; 4) time gap; 5) modulation and coding scheme; 6) retransmission index; and/or 7) reserved bits.

[0130] There may be one bit on a retransmission index. More retransmissions may be implemented, for example, to support reliable data transmission for V2X. A field of a retransmission index may be increased, for example, from 1 bit to 2 or more bits. A maximum number of redundancy version (RV) may be, for example, 4. A retransmission index (e.g. each retransmission index) may be associated with an RV ID.

CC and IR type of HARQ may be supported. An RV ID may be used, for example, to indicate a CC or IR type of HARQ.

[0131] A CBG based transmission may be supported in an NR eMBB use case. A CBG based transmission may be used for V2X, for example, to reduce a number of data retransmissions. An SCI may include CBG information, for example, to support CBG based transmissions. An SCI may, for example, include a bitmap showing which CBGs are included in a current (re)transmission. A bitmap length may be a configured maximum number of supported CBGs (e.g. C). Feedback may include C bits, each may indicate whether a CBG is decoded successfully.

[0132] CBG signaling may be optimized. In examples, bitmap length may be a minimum of a configured maximum number of supported CBGs and a number of CBs. Feedback may include bits for (e.g., only for) transmitted CBGs. A TB level ACK/NACK bit may be included, e.g., added on top of a CBG level ACK/NACK.

[0133] Resources may be allocated for a user, e.g., a mode 4 user. Resource allocation may include one or more determining a resource selection window or RV selection based on a selected resource. Resources may refer to time domain sub-frames (or slots) and/or frequency domain sub-carriers (or resource blocks, or sub-channels).

[0134] A resource selection window may be determined. One or more of the following may apply. [0135] Packets may arrive for a user (e.g. for a mode 4 user, such as a mode 4 user in V2X) at a MAC Tx buffer for transmission at subframe n. A candidate resource set may be selected, for example, within a time interval, e.g., [n + T₁, n + T₂ ] . A minimum value of T₂ may be, for example, 20 ms (e.g. in LTE). This may guarantee that, at most, 20 ms latency may be supported. End-to-end latency (e.g. in LTE) may be 100 ms, which may permit a maximum of 20 ms for T₂ to be used.

[0136] A latency requirement for NR V2X may be 3-10 ms. The value of T₂ (or minimum value of T₂) may be reduced, for example, to support more challenging use cases. This may guarantee that a duration between a packet arrival MAC Tx buffer and transmission of the packet may be reduced. Reduction on the value of T₂ (or minimum value of T₂) may increase the possibility of resource collision, for example, when the same number of WTRUs may be selecting a candidate resource set within a smaller set of candidate resource pool.

[0137] In examples, different T₂ values (or minimum values of T₂) may be applied on different frequency bands. An operational band (e.g. in NR V2X) may be categorized, for example, as below 6 GHz and above 6 GHz. A frequency band below 6 GHz may be shared with LTE V2X while a frequency band above 6 GHz may be used (e.g. only) for NR. NR V2X use cases may include more latency sensitive use cases, which may be assigned to an above 6 GHz band. Latency requirements of use cases may be achieved, for example, by restricting a time window to select a candidate resource set to a smaller value. In an example, user plane latency may be, for example, 3-10 ms for direct communication via SL and 2 ms for a packet that may be relayed, e.g., via a BS.

[0138] Resource selection may be performed on multiple bands, for example, when a WTRU may operate on an above 6 GHz band and a below 6 GHz band. A resource selection time window upper bound T₂ (or minimum value of T₂) may be smaller in a frequency band above 6 GHz, and may be larger in a frequency band below 6 GHz. A selected resource in a frequency band below 6 GHz may be used, for example, when it satisfies a latency requirement. A selected resource in a frequency band below 6 GHz may otherwise be ignored.

[0139] FIG. 9 shows an example of resource selection windows for different frequency bands.

[0140] In an example, different T₂ values (or minimum values of T₂) may be applied on different numerologies. There may be different numerology options (e.g. in NR), for example, in terms of sub-carrier spacing. In an example, there may be 15 KHz, 30 KHz, 60 KHz, 120 KHz, and 240 KHz, sub-carrier spacing options.

[0141] Symbol duration may be larger for smaller sub-carrier spacing. There may be fewer OFDM symbols within a given time slot. This may imply that there may be fewer time-domain resources for selection. A value of T₂{ or minimum value of T₂) may be larger, for example, to enable a larger number of possible resources in time and/or to achieve low resource collision.

[0142] Symbol duration may be smaller for larger sub-carrier spacing. There may be more OFDM symbols within a given time slot. This may imply that there may be more time-domain resources for selection. The value of T₂ (or minimum value of T₂) may be smaller, for example, to maintain the same number of candidate resources.

[0143] FIG. 10 shows an example of resource selection windows for different sub-carrier spacing numerologies.

[0144] Different T₂ values (or minimum values of T₂) may be applied, for example, depending on vehicle density in an area. Vehicle density may be estimated, for example, depending on vehicle speed, and/or vehicle environment (e.g. highway or local street). A high vehicle density environment may have more potential contenders for resources. A value of T₂ (or minimum value of T₂) may be larger, for example, to avoid resource collision. A low vehicle density environment may have fewer potential contenders for resources. A value of T₂ (or minimum value of T₂) may be smaller, for example, to ensure low latency requirements.

[0145] Multiple (e.g. two or more) states may be defined, e.g., in terms of vehicle density. A value of T₂ may be smaller, for example, when a probability of collision is lower (e.g. in a low vehicle density state). A value of T₂ (or minimum value of T₂) may be larger, for example, in a low vehicle density state, e.g., to avoid collision of selected resources with other vehicles.

[0146] FIG. 11 shows an example of a vehicle density state graph. A state switch may depend, for example, on vehicle speed and/or a road condition. In examples, as shown in FIG. 11 , a decrease in vehicle speed and/or a condition of a reduced speed limit from a present state may trigger use of a higher density state (e.g., higher than a present state). In examples, as shown in FIG. 11 , an increase in vehicle speed and/or a condition of an increased speed limit from a present state may trigger use of a lower density state (e.g., lower than a present state).

[0147] Different T₂ values (or minimum values of T ) may be applied, for example, depending on the data traffic types. In examples, a value of T₂ may be large when a type of data (e.g., it is expected that a type of data) does not have strict low latency requirements (e.g. a periodic data type). In examples, a value of T₂ (or minimum value of T₂) may be small when a type of data (e.g., it is expected that a type of data) may need urgent delivery (e.g. an aperiodic data type or event-triggered data type). A QoS requirement of data may be associated with a selection of T2 (or minimum value of T₂) (e.g., alone or in combination with other factors described herein). [0148] RV may be selected based on a selected resource or resources. One or more of the following may apply.

[0149] Data transmission and retransmission may occur in a selected resource. A different selection window T₂ (or minimum value of T₂) may be used, for example, in a resource selection. Data transmission may be associated with a selection window T₂ (or minimum value of T ).

[0150] A chance of resource collision may be high for small T₂ (or small minimum value of T₂) (e.g., 2 ms). A transmission may (e.g. in such a case) not be combined with other transmissions for better decoding performance. A selected RV for this (re)transmission may be an RV with self-decodable capability (e.g. RVO or RV3).

[0151] A chance of resource collision may be low for large T₂ (or large minimum value of T₂) (e.g., 20 ms). A transmission may (e.g. in such a case) be combined with other transmissions for better decoding performance. A selected RV for this (re)transmission may not need a self-decodable capability (e.g. all RVs may be applied). In examples, RV selection may be between RVO and RV3 only, for example, when T₂ < Thre (e.g., T₂ is less than a threshold) or minimum value of T₂ < Thre (e.g., minimum value of T₂ is less than a threshold). RV selection may be between RVO, RV1 , RV2, and RV3, for example, when T₂ > Thre (e.g., T₂ is greater than a threshold) or minimum value of T₂ > Thre (e.g., minimum value of T₂ is greater than a threshold).

[0152] A group based handover may be provided in vehicle platooning, e.g., a V2X use case where a group of vehicles may be operated in a closely linked manner, for example like a train with virtual strings between vehicles. Distance between vehicles may be maintained (e.g. and/or minimized), for example, by sharing status information.

[0153] A handover among a group of vehicles may be simplified, for example, when the group of vehicles is traveling in the same direction with small inter-vehicle distance. A Uu interface may be simplified. A vehicle in a platoon may perform handover between two cells, which may mean other vehicles in the platoon may perform a similar handover between the two cells.

[0154] FIG. 12 shows an example of a handover, where one or more of the illustrated features may be performed. A WTRU may send a measurement report to a serving (or source) eNB, which may decide to handover the WTRU to a neighbor (or target) eNB. Handover preparation between the source eNB and a target eNB may be performed, for example, via an S1 interface or an X2 interface. The target eNB may set up resources for the WTRU, for example, at the end of handover preparation. The source eNB may send a handover command, for example, via an RRCConnectionReconfiguration message to the WTRU. The source eNB may send a status tranfer message to the target eNB. The WTRU may use a received RACH configuration to imitate (e.g., perform) a random access procedure to the target eNB. The WTRU may (e.g. upon successful completion of a random access procedure) send an

RRCConnectionReconfigurationComplete message to the target eNB.

[0155] A handover may be simplified, for example, when multiple WTRUs are in a same group of platooning vehicles.

[0156] FIG. 13 shows an example of a handover procedure, e.g., in a platoon scenario, where one or more of the illustrated features may be performed. WTRU2 may join a platoon. WTRU2 may register for handover coordination, for example, with a leader vehicle of a platoon. Information may be exchanged within a platoon, for example, via a PC5 link or through RSU. Contents of the message (e.g. in a PC5 link) may include, for example, one or more of the following: (i) WTRU ID; (ii) WTRU vehicle information; (iii) WTRU network information; (iv) WTRU handover coordination; or (v) WTRU capability/willingness to become a lead vehicle in a platoon.

[0157] A platoon leader vehicle may pass handover coordination information to a gNB, for example, via a Uu interface. A member (e.g., member vehicle) of a platoon may not need to report its measurement to a gNB for a handover, for example, when the member selects the handover coordination. This may reduce measurement reporting. A platoon leader vehicle may send its own measurement report to a gNB, which may represent one or more (e.g. all) measurement conditions of the platoon.

[0158] A member vehicle may send its measurement report to a platoon leader vehicle, for example, on fewer occasions. A vehicle platoon leader may send measurement reports from one or more (e.g. all) members of a platoon to a gNB, for example, when a platoon leader vehicle receives a measurement report from another member vehicle in the platoon. A vehicle platoon leader may (e.g. alternatively) process measurement reports from multiple (e.g. all) members of the platoon (e.g. take an average of measurement reports) before sending to a gNB. The group-based measurement report may be sent to a gNB for handover.

[0159] A source gNB may decide to hand over a platoon to a target gNB. A source gNB may (e.g. after handover preparation) send a group-based handover command to a platoon leader vehicle (e.g. via an RRCConnectionReconfiguration message). A handover command may include, for example, one or more of a new C-RNTI, a target gNB security algorithm ID, a dedicated RACH preamble, target eNB SIBs, etc. A dedicated RACH preamble may be, for example, per platoon based, or may be per member vehicle based.

[0160] A platoon leader vehicle may send an RRCConnectionReconfiguration message to member vehicles in a platoon. A component vehicle (e.g. each component vehicle) of a platoon may perform an independent random access procedure. A member vehicle (e.g. each member vehicle) in a platoon may use a different preamble to access a target gNB, for example, when a random access procedure is non contention based (e.g. with dedicated RACH preamble). [0161] A platoon member vehicle may (e.g. at the end of a random access procedure), for example, send a handover complete message (e.g. via an RRCConfigurationComplete message) to a platoon leader vehicle. A platoon leader vehicle may send a group-based handover complete message to a target gNB, for example, when member vehicles (e.g., all member vehicles) in a platoon finish a handover. A platoon leader vehicle may send a group-based handover complete message, indicating which member WTRUs have finished a handover, for example, when fewer than all platoon member vehicles finish a handover. Remaining WTRUs may start with another (e.g. a legacy) handover procedure.

[0162] Features, elements, and actions (e.g. processes and instrumentalities) are described by way of non-limiting examples. Each feature, element, action or other aspect of the described subject matter, whether presented in figures or description, may be implemented alone or in any combination, including with other subject matter, whether known or unknown, in any order, regardless of examples presented herein. While examples may be directed to LTE, LTE-A, New Radio (NR) or 5G protocols, subject matter herein is applicable to other wireless communications, systems, services, and protocols.

[0163] A WTRU may refer to an identity of the physical device, or to the user's identity such as subscription related identities, e.g., MSISDN, SIP URI, etc. WTRU may refer to application-based identities, e.g., user names that may be used per application.

[0164] The processes described above may be implemented in a computer program, software, and/or firmware incorporated in a computer-readable medium for execution by a computer and/or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and/or wireless connections) and/or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and/or optical media such as CD-ROM disks, and/or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and/or any host computer.

Claims

CLAIMS What is Claimed:

1. A wireless transmit/receive unit (WTRU), comprising:

a memory; and

a processor, the processor configured to:

append CRC bits to a transport block (TB);

perform segmentation of the TB with appended CRC bits, wherein the segmentation creates a plurality of code blocks (CBs);

apply network coding on the plurality of CBs, wherein the network coding of the plurality of CBs produces a plurality of network encoded CBs (NC-CBs), and wherein the network coding comprises the processor being configured to:

choose a random number of CBs from the plurality of CBs, and

perform an XOR operation on the random number of CBs and append CRC bits to a result of the XOR operation;

apply LDPC encoding to the plurality of NC-CBs, wherein an LDPC code is based on a submatrix of a parity check matrix; and

send a transmission.

2. The WTRU of claim 1 , wherein the processor is further configured to apply a channel interleaver and a modulation to the LDPC encoded NC-CBs.

3. The WTRU of claim 1 , wherein the network coding is performed a number of times that is larger than a number of the plurality of CBs.

4. The WTRU of claim 3, wherein a number of the plurality of NC-CBs is larger than the number of the plurality of CBs.

5. The WTRU of claim 1 , wherein a number of CBs created by the segmentation is larger than a number of CBs generated in a legacy encoding system for a same transport block size.

6. The WTRU of claim 1 , wherein the processor is further configured to append respective CRC bits to respective CBs

7. The WTRU of claim 1 , wherein the submatrix is chosen to match an encoding rate associated with a current transmission.

8. The WTRU of claim 1 , wherein the following are signaled together with network coding data:

a network coding feature activation,

a degree distribution for the random number of CBs, and

a network coding configuration.

9. A method associated with wireless communications, the method comprising:

appending CRC bits to a transport block (TB);

performing segmentation of the TB with appended CRC bits, wherein the segmentation creates a plurality of code blocks (CBs);

applying network coding on the plurality of CBs, wherein the network coding of the plurality of CBs produces a plurality of network encoded CBs (NC-CBs), and wherein the network coding comprises:

choosing a random number of CBs from the plurality of CBs, and

performing an XOR operation on the random number of CBs and appending CRC bits to a result of the XOR operation;

applying LDPC encoding to the plurality of NC-CBs, wherein an LDPC code is based on a submatrix of a parity check matrix; and

sending a transmission.

10. The method of claim 9, further comprising applying a channel interleaver and a modulation to the LDPC encoded NC-CBs.

11. The method of claim 9, wherein the network coding is performed a number of times that is larger than a number of the plurality of CBs.

12. The method of claim 11 , wherein a number of the plurality of NC-CBs is larger than the number of the plurality of CBs.

13. The method of claim 9, wherein a number of CBs created by the segmentation is larger than a number of CBs generated in a legacy encoding system for a same transport block size.

14. The method of claim 9, further comprising appending respective CRC bits to respective CBs

15. The method of claim 9, wherein the submatrix is chosen to match an encoding rate associated with a current transmission.