WO2019160973A1

WO2019160973A1 - Methods for v2x autonomous directional resource selection

Info

Publication number: WO2019160973A1
Application number: PCT/US2019/017874
Authority: WO
Inventors: Benoit Pelletier; Tuong Duc HOANG; Tao Deng
Original assignee: Idac Holdings, Inc.
Priority date: 2018-02-13
Filing date: 2019-02-13
Publication date: 2019-08-22

Abstract

Systems, methods, and devices for vehicle to everything (V2X) directional resource selection may be described herein. A wireless transmit receive unit (WTRU) may receive a configuration message including a set of common sidelink reference signals and a list of available resources (i.e,. a pool) for a particular direction or beam type. The WTRU may monitor for the common sidelink reference signals in a plurality of beams (e.g., receive beams) and measure the energy for each of the common sidelink reference signals against a threshold. The WTRU may determine a set of active beams from the plurality of beams based on the measurements previously taken. The WTRU may further narrow down the set of active beams based on contextual information, such as the WTRU heading and/or location. The WTRU may select one or more beams from the set of active beams based on the available resources to transmit in.

Description

METHODS FOR V2X AUTONOMOUS DIRECTIONAL RESOURCE SELECTION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/629,952, filed February 13, 2018, and U.S. Provisional Application No. 62/630,106, filed February 13, 2018, the contents of which are incorporated herein by reference.

BACKGROUND

[0002] Wireless communication has always had to contend with the limited resources available. As technologies advance, more efficient use is required for these resources. In some circumstances, more resources also become available. For example, some authorities are now allowing for the use of higher spectrum frequencies. As the parameters change, there is a need for methods, systems, and devices that take advantage and use more efficiently the resources that are available.

SUMMARY

[0003] Systems, methods, and devices for vehicle to everything (V2X) directional resource selection may be described herein. A wireless transmit receive unit (WTRU) may receive a configuration message including a set of common sidelink reference signals and a list of available resources (i.e,. a pool) for a particular direction or beam type. The WTRU may monitor for the common sidelink reference signals in a plurality of beams (e.g., receive beams) and measure the energy for each of the common sidelink reference signals against a threshold. The WTRU may determine a set of active beams from the plurality of beams based on the measurements previously taken. The WTRU may further narrow down the set of active beams based on contextual information, such as the WTRU heading and/or location. The WTRU may select one or more beams from the set of active beams based on the available resources to transmit in.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, wherein like reference numerals in the figures indicate like elements, and wherein:

[0005] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented; [0006] 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;

[0007] 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. 1A according to an embodiment;

[0008] 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. 1A according to an embodiment;

[0001] FIG. 2 is a diagram illustrating an example V2X communication scenario;

[0002] FIG. 3 is a diagram illustrating an example antenna configuration in a vehicle;

[0003] FIG. 4 is a diagram illustrating an example resource allocation for a WTRU;

[0004] FIG. 5 is a diagram illustrating an example WTRU that performs beam selection in the resource sets assigned to the WTRU;

[0005] FIG. 6A is a diagram illustrating an example WTRU that selects beams in the resources corresponding to each group of beams;

[0006] FIG. 6B is a diagram illustrating an example WTRU that selects beams in the resources corresponding to each group of beams;

[0007] FIG. 7 is a diagram illustrating example sidelink beams for the exclusion of a wide beam;

[0008] FIG. 8 is a diagram illustrating example sidelink beams for the exclusion of narrow beams;

[0009] FIG. 9 is a diagram illustrating an example WTRU that updates the set of active beams to balance between delay and coverage;

[0010] FIG. 10A illustrates an example process of selecting beams for transmission;

[001 1] FIG. 10B illustrates an example scenario of the process of FIG. 10A;

[0012] FIG. 1 1 is an example of a resource pool in R14 V2x;

[0013] FIG. 12 is an diagram of a transmit pool configuration in each symbol time;

[0014] FIG. 13 is a table showing a slot structure configuration for V2X transmission;

[0015] FIG. 14 is an example of a pool configuration;

[0016] FIG.15 is an example Zone ID configuration;

[0017] FIG. 16 is an example pool configuration for the case M is equal to N which is equal to 2;

[0018] FIG. 17 is an example pool configuration for the case M is equal to N which is equal to 3;

[0019] FIG. 18 is an example of a WTRU’s transmit pool selection; [0020] FIG. 19 is a diagram showing use of the sensing result of wide beam to perform resource selection for the narrow beams; and

[0021] FIG. 20 is a diagram showing use of the sensing result of one beam to perform resource selection of the adjacent beams.

DETAILED DESCRIPTION

[0009] 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 discrete Fourier transform Spread OFDM (ZT-UW- DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0010] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (ON) 106, a public switched telephone network (PSTN) 108, the Internet 1 10, and other networks 1 12, 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 (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. In some embodiments a WTRU may also be associated with a vehicle, such as automobiles, trucks, trains, airplanes, helicopters, drones, or any other devices. Any of the WTRUs referenced herein, such as 102a, 102b, 102c and 102d, may be interchangeably referred to as a UE or a Vehicle.

[001 1] 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, 1 14b 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, the Internet 1 10, and/or the other networks 1 12. By way of example, the base stations 114a, 1 14b may be a base transceiver station (BTS), a NodeB, an eNode B (eNB), a Home Node B, a Home eNode B, a next generation NodeB, such as a gNode B (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 1 14a, 1 14b are each depicted as a single element, it will be appreciated that the base stations 1 14a, 1 14b may include any number of interconnected base stations and/or network elements.

[0012] The base station 1 14a may be part of the RAN 104, 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, and the like. 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 1 14a 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 1 14a 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.

[0013] The base stations 1 14a, 1 14b 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).

[0014] 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 1 14a in the RAN 104 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 1 16 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 Uplink (UL) Packet Access (HSUPA).

[0015] In an embodiment, the base station 1 14a 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 1 16 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

[0016] In an embodiment, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 1 16 using NR.

[0017] In an embodiment, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., an eNB and a gNB).

[0018] In other embodiments, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.1 1 (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.

[0019] The base station 1 14b in FIG. 1A 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 1 14b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.1 1 to establish a wireless local area network (WLAN). In an embodiment, the base station 1 14b 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 1 14b 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 1 14b may have a direct connection to the Internet 110. Thus, the base station 1 14b may not be required to access the Internet 110 via the CN 106. [0020] The RAN 104 may be in communication with the CN 106, 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 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 and/or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be utilizing a NR radio technology, the CN 106 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E- UTRA, or WiFi radio technology.

[0021] The CN 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 1 10, and/or the other networks 1 12. 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 1 12 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 or a different RAT.

[0022] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular- based radio technology, and with the base station 1 14b, which may employ an IEEE 802 radio technology.

[0023] 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 1 18, 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. [0024] The processor 1 18 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), any other type of integrated circuit (IC), a state machine, and the like. The processor 1 18 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 1 18 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 1 18 and the transceiver 120 may be integrated together in an electronic package or chip.

[0025] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 1 14a) over the air interface 1 16. 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.

[0026] 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.

[0027] 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 802.1 1 , for example.

[0028] The processor 1 18 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 1 18 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 1 18 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 1 18 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).

[0029] The processor 1 18 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.

[0030] The processor 1 18 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, 1 14b) 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.

[0031] The processor 1 18 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, a humidity sensor and the like.

[0032] 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 DL (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 1 18). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the DL (e.g., for reception)).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 (PGW) 166. While 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 1 12, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.

[0041] Although the WTRU is described in FIGS. 1A-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.

[0042] In representative embodiments, the other network 1 12 may be a WLAN.

[0043] 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 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 802.1 1 e DLS or an 802.1 1 z 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. [0044] When using the 802.1 1 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. 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 802.1 1 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.

[0045] 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.

[0046] Very High Throughput (V HT) 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 noncontiguous 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).

[0047] Sub 1 GHz modes of operation are supported by 802.1 1 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 1 af and 802.1 1 ah relative to those used in 802.1 1 h, and 802.11 ac. 802.1 1 af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.1 1 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.1 1 ah may support Meter Type Control/Machine- Type Communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life). [0048] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.1 1 h, 802.11 ac, 802.1 1 at, and 802.1 1 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 802.1 1 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, all available frequency bands may be considered busy even though a majority of the available frequency bands remains idle.

[0049] In the United States, the available frequency bands, which may be used by 802.1 1 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.

[0050] FIG. 1 D 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 NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0051] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 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 1 16. 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). [0052] 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 a varying number of OFDM symbols and/or lasting varying lengths of absolute time).

[0053] 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.

[0054] 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, DC, 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. 1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0055] The CN 106 shown in FIG. 1D 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 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.

[0056] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of non-access stratum (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 MTC access, and the like. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 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.

[0057] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 106 via an N1 1 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 106 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 DL data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0058] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 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 DL packets, providing mobility anchoring, and the like.

[0059] The CN 106 may facilitate communications with other networks. 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 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 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.

[0060] In view of FIGs. 1 A-1 D, and the corresponding description of FIGs. 1 A-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.

[0061] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or performing testing using over-the-air wireless communications.

[0062] 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.

[0063] FIG. 2 illustrates an example of a Vehicle to Anything (V2X) communication scenario. In V2X systems, general communication protocols may apply based on the type of device, but there may also be specific communication protocols used to address vehicle communication needs. For example, a road 201 may has traffic including several cars 203 and 202, a truck 204, and adjacent to the road may be a road side unit (RSU) 205 with a pedestrian user and their hand held device WTRU 206, and all of these things may need or benefit from communicating with each other. Vehicle to vehicle (V2V) communications has the potential to improve road safety by allowing vehicles to be aware of their environment, such as the location and direction of other vehicles in their vicinity. In intelligent transportation systems (ITS), vehicles may communicate with each other (e.g., V2V) but also with infrastructure nodes, RSUs, and pedestrian devices (e.g., hand held WTRUs). V2X may generally be used to refer to communication between vehicles (e.g., WTRUs associated with or a part of a vehicle 202, 203, 204) and other devices (e.g., non-vehicle WTRUs 205, 206). For V2X, each WTRU (e.g., vehicle) may exchange status information such as speed, position, heading, or the like, with other WTRUs by broadcasting messages through a sidelink. The sidelink may generally refer to a radio link between two devices (e.g., as opposed to a downlink and an uplink which refer to communication links between a base station and a device).

[0064] For enhanced V2X (eV2X), there may be additional features to V2X that support additional use cases, such as: vehicles platooning; extended sensors; advanced driving; and, remote driving. In general, these use cases may have more stringent requirements in terms of latency, throughput and reliability, when comparing V2X to eV2X when compared to R14 V2X. As part of the eV2X feature in R15, more advanced features may be introduced such as carrier aggregation, higher order modulation, transmission diversity, pool sharing, and the like. The eV2X features may be capable of operating in the ITS spectrum in the low frequency band (i.e., 5.9GHz ITS spectrum) whose available bandwidth may not be sufficient to fulfil all possible use case requirements, such as higher data rate, very short latency, and/or ultra-high reliability. Accordingly, to obtain large bandwidth for these advanced use cases and additional features, the high frequency band may be used, such as Intelligent Transport Systems (ITS) spectrum in the higher frequencies around the 60GHz millimeter Wave (mmWave). This may relate to 3GPP support of V2X communications in the higher spectrum in conjunction with New Radio (NR) radio access technology development. For example, NR may enable exploitation of the large bandwidth resource at higher frequencies with built-in support for beam forming. V2X in NR may be utilized in order to support the new advanced use cases.

[0065] Propagation in the mmWave frequencies may be challenging due in part to the higher propagation loss compared to lower frequencies. Generally, this challenge may be addressed by beamforming with antenna arrays or multiple antennas to focus the radiation pattern energy directionally. In a high frequency system, beam-based communication may be needed to compensate for the higher propagation loss incurred due to the high frequency transmission. To support the beam-based communication, vehicle WTRUs may have different antenna configurations, such as having one antenna (e.g., panel) on each side of the vehicle or/and one (e.g., omni/circular array) on the top of the vehicle.

[0066] FIG. 3 illustrates an example of an antenna configuration for a WTRU on a conventional vehicle. As discussed herein, a vehicle may be referred to as a WTRU and/or may be associated with a WTRU that is otherwise a part of the vehicle. For example, a WTRU 102 may have its components deconstructed and integrated into the vehicle 303, such as a transmit/receive (Tx/Rx) unit 301 which is attached to one or more antennas 302. The location of these deconstructed components, such as the Tx/Rx 301 and antennas 302, and other components not shown (e.g., processor, memory, power, etc.), may be located anywhere on/in the car such that they are can accomplish their intended purpose. Further, in another example not shown, a WTRU may be a self-contained unit removeably attached to the vehicle. Any WTRU associated with a vehicle as discussed herein will be capable of carrying out the communication functions as described herein.

[0067] As noted above, transmissions in higher frequencies (e.g., in the 60GHz range) may incur a larger propagation loss than in lower bands (e.g., less than 6GHz). This large propagation loss may be mitigated or compensated by using a larger antenna aperture and/or using beamforming, however, for these techniques the energy is typically concentrated in a narrow beam, which reduces the area covered by the radio signal. Fortunately, these beams can be electronically steered in different directions. To transmit a signal in multiple directions with narrow beamforming, a single transmitter chain may be used to transmit multiple times varying the direction of the main lobe of the beam for each time. In some instances, a wider beam may be electronically created, but this wider beam may naturally have lower gain and result in reduced coverage.

[0068] In some V2X applications, data may be shared with multiple vehicle WTRUs in a given area as a result of, for example, sensor sharing, platooning, or the like. Due to the nature of the V2X application, the data may be relevant to all of the WTRUs (e.g., vehicles) within the given area. In another case, the data to be shared may be relevant only to a subset of WTRUs (e.g., vehicles) in the given area, such as for a platooning scenario where WTRUs (e.g., vehicles) in the platoon may need to share some data. In one instance, one or more WTRUs (e.g., vehicles) may not be capable of processing the data that is being transmitted. For example, in the sensor sharing scenario, some WTRUs (e.g., vehicles) may not have the capability of making use of some sensor data from other WTRUs (e.g., other vehicles), such as where one car maker uses a proprietary algorithm to take advantage of a unique type of sensor data only generated by other cars of the same manufacturer. Thus in some applications, it may not be desirable to broadcast information to all WTRUs (e.g., vehicles) in a given area (e.g., the vicinity of the WTRU that is sharing/transmitting data), and furthermore in some cases there may not be WTRUs (e.g., vehicles) in all directions covered by the granularity offered by the antenna hardware configuration of the WTRU (e.g., transmitting in all directions may be unnecessary if there are only vehicles in a particular location). It may be desirable to transmit data in a subset of the directions or beams available by the hardware, which may address some of the scenarios discussed herein.

[0069] Generally, to transmit data to multiple devices using narrow beamforming there maybe more than one technique, such as multiple unicasts or broadcasting in all directions. Multiple unicasts may involve creating a connection to all target devices (e.g., vehicles) to which the data is relevant. Each unicast connection may require close-loop beam tracking and potentially Radio Link Failure (RLF) monitoring, or the like. Flowever, this connection-oriented approach may not be ideal for the requirements of some V2X applications. In another approach, broadcasting in all directions may involve transmission of data in all directions, for example, one beam at a time (i.e., assuming a single TX chain architecture). This approach is simple as it avoids determining the target devices and complex tracking that may be associated to the multiple unicast approach. Unfortunately, this approach may also be inefficient as there may not be target devices for many of the transmit beams meaning the transmit beams are wasted energy, which may be inefficient power transmission and lead to undesired interference.

[0070] Both of these approaches may have drawbacks and may lead to undesired complexity or interference that may not be ideal for the requirements of some V2X applications. For example, there may be requirements for V2X applications such as a packet reception ratio (PRR), which is denoted as the fraction between the number of successfully decoded messages and the number of transmitted messages within a transmission range. Further, a receiver may also determine the set of beams to receive on, which may be motivated in turn by the hardware limitations for receiving simultaneously on multiple beams or directions. For example, hardware limitations such as processing capabilities and the use of analog beamforming. Thus, in order to address the drawbacks discussed herein, it may be desirable to have a system, method, and/or apparatus (e.g., WTRU, base station, etc.) that effectively transmits and/or receives on a subset of the beams in order to meet more demanding service requirements.

[0071] As discussed herein, the term beam(s) may be referred to as radio waves propagating within a lobe or a combination of lobes. For example, a beam or beams may be main lobes, side lobes or grating lobes of a radio frequency transmit radiation pattern (i.e., transmit beam), or receive gain pattern (i.e., receive beam) generated by an antenna. The term antenna may be interchangeable with an antenna array comprising one or multiple antenna elements which are placed and connected according to a geometric pattern.

[0072] A beam may be electronically steered toward different directions and altered into different beam shape and/or beamwidth by applying a set of weights to each antenna element. A beam may be used to denote a direction-of-departure (AoD) of a radio frequency transmission or direction-of-arrival (AoA) of a radio frequency reception, or generally a“direction”.

[0073] A beam may be denoted/identified with an index and/or identity of a reference signal transmitted using the beam (e.g., Sounding Reference Signal (SRS), Channel State Information-Reference Signal (CSI- RS), or the like). For example, the index and/or identity may be based on the reference sequence index and/or the index of the scrambling sequence applied to the reference signal.

[0074] A beam may also be denoted/identified with an antenna port associated with such a reference signal. Radio frequency signals may be transmitted and/or received within a beam at a specific time and frequency. [0075] Additionally the term beam may be associated with one or more of the following: a set of pre-coding weights applied to antenna elements in a WTRU or in a network equipment (e.g., Total Radiated Power (TRP)) for reception or transmission; an antenna or radiation pattern resulting from the application of such pre-coding weights; a set of properties associated to the antenna pattern, such as a gain, directivity, beamwidth, beam direction, with respect to a plane of reference, in terms of azimuth and elevation and peak-to-side lobe ratio; one antenna port associated to this beam; one reference signal transmitted while applying the set of pre-coding weights to the antenna elements; an associated number and/or configuration of antenna elements (e.g., uniform linear array, uniform rectangular array, etc.); and/or, direction.

[0076] In determining a subset of beams to transmit on, a WTRU may perform measurements and/or calculations. The subset of beams to transmit on may be referred to as the set of active beams. The set of active beams may be determined from one or more of a set of occupied beams, a set of unoccupied beams, or the set of all beams. The set of occupied beams may be determined based on some metric or measurement, and the set of unoccupied beams may be determined based on some other metric or measurements. In some cases, the set of occupied and unoccupied beams may be determined using the same metric or measurement. In some cases, the determination of the occupied beams may determine the unoccupied beams, and vice versa. As discussed herein, there are several approaches concerning WTRU measurements that can be used to assist in determining a subset of beams to transmit/receive on, and each approach may be used in isolation, or in combination with one another. Further, once the set(s) of beams is determined, they may then be allocated or categorized into an occupied or unoccupied beam.

[0077] In one approach of transmitting on a subset of beams the level of radio activity per beam may be measured by a WTRU to determine the presence of other WTRUs in that direction. For example, the WTRU may be configured to measure the level of radio activity on a per-beam basis to determine the presence of other WTRUs in the direction of the beam and thereby determining the subset of beams appropriate for the transmission. This approach may be useful in determining the presence of vehicles in a specific direction (e.g., is there a vehicle immediately behind, to the side, in front of, etc.). The WTRU may determine that there are no WTRUs (i.e., no presence of vehicles within a certain range) for a given direction if the level of radio activity is smaller than a threshold. The radio activity level of the WTRU may be determined when the WTRU performs sensing. This may be relevant in some application of V2X where WTRUs (e.g., vehicles) transmit signals or data traffic at regular or semi-regular intervals. For one or more approaches and techniques discussed herein, the transmission/reception of beacon signals (e.g., discovery signals, synchronization, safety messages or the like) and energy measurements may be used to make measurements and other determinations. [0078] A WTRU may use measurements and a threshold to determine beam“occupancy”. As it relates to performing measurements, a WTRU may be configured to determine a set of active beams. This can be achieved, for example, using obtained measurements and comparing them to a pre-configured threshold. The threshold may be configured by the network, specified in a technical specifications, or based on WTRU implementations such that some specified requirement is met.

[0079] WTRUs may be configured to periodically transmit presence indicators (e.g., beacons) over one or multiple beams. For example, the presence indicators may comprise a sequence of bits or signature that may be based on an identity. This identity may be associated with one or more of a WTRU, network, vehicle, synchronization source, or the like. The presence indicator may also comprise a data transmission such as a message carrying a small amount of information including an identity. In some cases, a WTRU may utilize a beacon so that other WTRUs can determines its presence, where a beacon may be any broadcasted signal.

[0080] A WTRU may use a group-based per-beam sidelink measurement, where the WTRU may be configured with one or multiple sets of common sidelink reference signals. In one example, the common sidelink reference signals may be common to all WTRUs of one NR cell. In another example, the common sidelink reference signals may be common to a configured group of devices. Each common sidelink reference signal may be denoted by an index within the set.

[0081] The common sidelink reference signal configuration may include one or multiple sets of common sidelink reference signal resources (e.g., in time and frequency). Each of the common sidelink reference signal resources may include at least a time domain resource (e.g., transmission slot/symbol, transmission duration per WTRU and per beam), frequency resource (e.g., Bandwidth Part (BWP)/occupied Physical Resource Block (PRB)/hopping pattern), and sequence configuration (e.g., cyclic shift/sequence ID). Each common sidelink reference signal resource set may be denoted with an index in the measurement configuration signaled to the WTRUs via higher layer signaling.

[0082] A WTRU may transmit the common sidelink reference signal according to a network configuration, which may be referred to as the measurement configuration. The transmission of the common sidelink reference signal may be periodical, semi-persistent, and/or aperiodic upon request. The measurement configuration may include parameters based on reported WTRU capability, such as the number of beams to use, beam coverage in azimuth, elevation plane for transmission, or the like. The measurement configuration may be used for the WTRU transmitting the sidelink reference signal and potentially also by the WTRU measuring the reference signal. The content of the measurement configuration may be different depending on the role of the WTRU (i.e., transmitting or receiving). The name of the configuration message may be changed and may be different for the receiving WTRU than for the transmitting WTRU.

[0083] A WTRU may select a set of sidelink transmit beams based on the measurement configuration and transmit one common sidelink reference signal chosen in a pre-defined order from the configuration set in each selected sidelink transmit beam. The WTRU may maintain an association and/or a mapping between a common sidelink reference signal index and the sidelink transmit beam carrying the reference signal.

[0084] In one case, a WTRU may transmit an identical sidelink common reference signal in all selected transmit beams. In this case, the common sidelink reference signal set may be configured with one sequence. The WTRU may transmit the same common sidelink reference signal in a time domain resource (e.g., a symbol or slot) in a pre-defined order from the configured measurement time domain resource. For example, the configured transmission start may be symbol 0. The duration per WTRU may be one slot and the duration per beam may be two symbols. A WTRU may select seven (7) different transmit beams and transmit the same reference signal in each beam consecutively over one slot.

[0085] A WTRU may report to the network the WTRU sidelink beamforming capability including at least: the number of antenna arrays; the number of antenna elements per antenna array; and/or, the size of precoding weight set for each antenna array (i.e., number of beams).

[0086] A WTRU may measure and obtain per-beam measurements. For example, a WTRU may sweep its receive beam, and in each receive beam the WTRU may detect and measure the common sidelink reference signal at the resources specified in the measurement configuration. In one instance, the WTRU may identify the sidelink transmit beam and calculate/obtain the per-beam measurement result based on the sequence and cyclic shift of the reference signal transmitted in each transmit beam. In another instance, the WTRU may identify the sidelink transmit beam and obtain the per-beam measurement result based on the time domain resource (e.g., symbol number) of the sidelink transmit beam.

[0087] Where the WTRU measures the amount of radio level activity for transmitting on a subset of beams, the WTRU may be configured to measure the energy received on a per-beam basis. For example, the WTRU may be configured to measure the Received Signal Strength Indicator (RSSI) on a per-beam basis over the entire configured bandwidth. The WTRU may further be configured with a threshold and estimate for each beam whether there is significant activity by comparing the measured RSSI with the configured threshold. For example, beams where the measured RSSI is above the configured threshold may be categorized as “occupied”. This may be motivated by the hypothesis that radio activity in one beam is indicative of the presence of devices. [0088] Alternatively or additionally the WTRU may be configured to measure the channel busy ratio (CBR) on a per-beam basis instead of, or in addition to, measuring the RSSI. In some At a high level, the CBR may be interpreted as the ratio of radio resources within the configured bandwidth that are being used (e.g., by another device). The CBR may be measured by comparing the RSSI on a per-PRB or per-sub-channel basis to a first threshold. The sub-channel may be defined, for example, in the 3GPP specifications as a set of PRBs, possibly spanning the entire bandwidth. The PRB or sub-channels for which the RSSI measurement is above the threshold may be considered as“busy”. The CBR is then obtained by taking the ratio of“busy” PRBs or sub-channels to the total number of PRBs or sub-channels, respectively. The WTRU may further determine whether the beam should be considered as“occupied” by comparing the CBR to a second pre-configured threshold.

[0089] Alternatively or additionally, the WTRU may be configured to estimate the presence of at least one other device on a per-beam basis. This may be achieved, for example, by measuring the RSSI for a set of preconfigured number of PRBs or sub-channels and then comparing to a pre-configured threshold. The WTRU may be configured to carry out this operation for multiple sets of PRBs or sub-channels, possibly covering the entire bandwidth. The presence of at least one other device on a per-beam basis may also be determined by decoding the SCI (sidelink control information). The WTRU may determine that at least one other device is present on a beam if it successfully detects an SCI from another device. The WTRU may further determine whether the beam may be considered as“occupied,” for example, if at least one of such RSSI measurement is above the threshold or if at least one SCI has been successfully decoded.

[0090] A WTRU may measure Angle of Arrival (AoA) where the WTRU may determine beam direction of other WTRUs (e.g., vehicles) by AoA measurement/estimation. The estimated directions may be obtained using known technique typically based on measuring either time of arrival or phase difference between elements in the antenna array. The WTRU may perform the AoA measurement whenever it is possible. In one example, the WTRU may be configured to measure the AoA during the ranging procedure, which is a procedure designed for the WTRUs to determine its position and may involve transmission/reception of signature sequences. Hence, by performing the AoA measurement from the ranging procedure, the WTRU may determine the presence of other WTRU from different directions. The time and indication of the ranging procedure may be periodic or aperiodic depending on network configuration. In another example, the WTRU may measure the AoA during other WTRU(s) transmissions (e.g. for synchronization, sounding, or data transmissions). [0091] A WTRU may perform uplink (UL) measurement opportunistically in some cases. Specifically, a WTRU may perform a measurement over a set of measurement resources based on UL frequency resources. A WTRU may perform these measurements within one or multiple slots in which the WTRU is not scheduled for data transmission/reception, beam management/CSI measurement, and/or other regular activities. In these slot(s), a WTRU may opportunistically measure UL transmissions of other WTRUs, such as the Sounding Reference Signal (SRS) (i.e., for NR), Physical Uplink Control Channel (PUCCH) and/or Physical Uplink Shared Channel (PUSCH) transmissions. The WTRU may be configured by the network with these measurement occasions, for example, via dedicated RRC signaling, dynamic DCI allocation, or via the system information broadcast.

[0092] A WTRU may determine measurement resources, such as a center frequency, a bandwidth based on PUCCH/PUSCH frequency resource configuration including active UL BWP, a frequency resource block group (RBG), a PRB, sub-carrier spacing, or the like. The measurement resource may be configured by the network, or determined by the application that the WTRU is using, for example, via pre-configuration.

[0093] In one example, the WTRU may determine the measurement resource based on the SRS frequency resource configuration including SRS frequency domain position and SRS bandwidth. The SRS resource of one WTRU may be configured from the network via RRC message. The SRS occasion of a WTRU may be periodic or aperiodic depending on the network configuration. The gNB may indicate the presence of the SRS occasions from one WTRU to the other WTRUs in a group, for example, by a group ID or a common Radio Network Temporary Identifier (RNTI) in a Downlink Control Information (DCI).

[0094] In one example, the WTRU may determine the measurement resource based on Random Access Channel (RACH) frequency resource configuration. This configuration may be obtained from System Information Block (SIB) message from the gNB.

[0095] A WTRU may sweep receive beams and obtain a wide-band energy measurement result based on automatic gain control (AGC) output without baseband processing. Additionally/alternatively, the WTRU may perform Fast Fourier Transform (FFT) and sub-carrier de-mapping to obtain an energy measurement result at a more refined granularity, for example per RBG, PRB, or sub-carrier.

[0096] In an example, a WTRU may report a measurement result of an RF energy metric in terms of dBm per measurement resource. In another example, the WTRU may report an indication per measurement resource based on a pre-configured threshold, such as a bit value of one (1 ) may indicate the measured energy of the measurement resource being above threshold, and a bit of value zero (0) may indicate otherwise. [0097] A WTRU may associate the measurement result with a spatial element or beam/direction index, such as an index to a receive beam used for the measurement and/or a direction, or an index to a tabulated set of directions, denoted by one or multiple receive beams. In addition to this spatial element or beam/direction index, a WTRU may also include the measurement occasion such as a slot index, a symbol index, a sub-frame index, or the like in the measurement report.

[0098] A gNB may determine what UL transmission and which WTRU the measurement result may be applicable to, based on the reported measurement resource and occasion. For example, based on the reported slot index and associated measurement resources, the gNB may identify one or several WTRUs that have transmitted a SRS in these time and frequency resources by cross-referencing the WTRU SRS configuration.

[0099] The gNB may further process and adjust the measurement result based on, for example, one or more of: carrier frequency between NR UL and NR sidelink; WTRU-specific power headroom report (PHR); and/or, WTRU measurement supplementary information. The gNB may, based on the adjusted measurement result, determine which frequency resource is available for the sidelink transmission of a WTRU.

[0100] A WTRU may provide the network with measurement supplementary information, for example, in WTRU capability reporting, including one or more of: WTRU UL beamforming capability (e.g., number of beams, beamforming gain, beamwidth, WTRU UL beam side lobe ratio which is the difference between the main lobe and side lobe, etc.); WTRU SL beamforming capability (e.g., number of beam, beamforming gain, beamwidth, etc.); spatial relation between WTRU UL antenna solution and SL antenna solution; and/or, WTRU UL beam and SL beam main lobe elevation offset.

[0101] A WTRU may determine a set of active beams (i.e., subset of beams for transmission) based on the scenario of the vehicle associated with the WTRU. For example, in a platooning scenario, WTRUs in one platooning group may communicate to each other and may perform multicasting. Moreover, in a platooning scenario the vehicles may be in one line, therefore the WTRU may need to transmit in its backward and/or forward directions. Hence, each WTRU may consider the directions corresponding to its backward and/or forwards direction as the active beam directions.

[0102] A WTRU may determine a subset of beams based on contextual and/or cross-layer information. Specifically, a WTRU may determine that there are no vehicles in a subset of directions based on context, and use this information to update or determine the set of active beams. The WTRU may be configured to exclude a set of beams corresponding to the directions where there are no vehicles present from the set of active beams. For example, the WTRU may determine the context based on the road configuration. For example, the WTRU may determine that there is no vehicle in the directions corresponding to its right if it already is in the right-most lane. In another example, the WTRU may determine that there is no vehicle corresponding to the left and right directions if the vehicle is driving in a one lane tunnel. In another example, the vehicle may determine that there is no vehicle in the directions corresponding to its right if there are buildings in the right hand side. In another example, the vehicle may determine that there is no vehicle in the directions corresponding to its left side if it is already in the left most lane on a one-way road. The point of these examples are to demonstrate that the WTRU may determine subsets of appropriate beams based on the contextual information of the car and the facts that can be derived from this contextual information.

[0103] A WTRU, or an application(s) on the WTRU, or a sensor(s) in combination with the WTRU and/or the application(s), may determine the contextual information. This context may then be indicated to the Access Stratum (AS) via an interface. For example, the context may include a set of relevant directions, potentially associated with a WTRU position or heading. For example, the WTRU may determine its context by using one or multiple applications/sensors of the following technologies: GPS, radar, LIDAR, camera, or the like, which may be a part of or connected to the WTRU (e.g., as part of the vehicle). The context of the WTRU may be semi-statically configured. The context may be changed as the WTRU changes its lane, road, or the like. As the context changes, the Access Stratum (AS) may be notified via an interface. Then, it may trigger some measurement procedures and alter the active beam update procedure.

[0104] A WTRU may determine its context based on the messages from at least one of the WTRU, gNB, or Road Side Unit (RSU). For example, the WTRU may determine its context based on AoA from other WTRUs, gNB(s), or RSU(s).

[0105] A WTRU may be configured with a set of contextual rules associated to a geographical position. The WTRU may determine its geographical position, then based on this position determine the context and the set of active beams.

[0106] A WTRU may determine the position of other WTRUs (e.g., other vehicles) based on message(s) from the other WTRUs (e.g., other vehicles).

[0107] A WTRU may determine the position of other vehicles based on application-layer GPS information and/or vehicle heading (i.e., orientation) information. The WTRU may determine the relative position between itself and other WTRUs based on the position of other WTRUs and its position. The WTRU may be configured to update the set of active beams based on the relative position/heading of the WTRU and the positions of the other vehicles. The position of other vehicles may be obtained, for example, from decoding the safety messages, possibly transmitted on a different band (e.g., the 5.9GHz ITS band or other bands). [0108] A WTRU may determine the position of other WTRUs by decoding control messages. The control messages may be transmitted in the control channels, for example, in the physical sidelink control channels (PSCCH). In one example, the position is indicated explicitly in the control message. The position may be in the form of geographical coordinates, possibly relative to a reference point close by (e.g., to reduce the message size). The WTRU may then be configured to decode the position of the other WTRU in the control message. In another example, the WTRU may be configured to decode the geographical ID or zone ID, which indicates the location area of the transmit vehicle. Based on the information about the position or geographical ID of the other vehicle, the WTRU may determine its relative position between itself and the other WTRU. The WTRU may update the set of active beams based on the obtained relative position.

[0109] A WTRU may report or may be triggered to report to the network. Specifically, to support the gNB in resource scheduling to a WTRU autonomous control scenario, the WTRU may use any report schemes in order to help the network control the resources. The motivation for doing this may be to inform the network with the spatial information so that it can perform proper resource scheduling.

[01 10] The WTRU may be configured to send a report via one or more of the following mechanisms: via RRC signaling; via new or special MAC message; and/or, via L1 indications (e.g., using a PUCCH-like structure). The exact mechanism used may depend on the message size, delay and reliability requirements.

[01 1 1] A WTRU may receive an explicit measurement request from a network. The WTRU may receive a measurement request to measure the common sidelink reference signal transmission of another WTRU. The measurement request may be carried in DCI format including a bit field to indicate the common sidelink resource used for the transmission to be measured. The bit field may carry a resource index or a bit map with each bit corresponding to a resource index.

[01 12] In one example, WTRUs camping on the same cell may receive the measurement request. In another example, a specific group of WTRUs may be configured to measure the common sidelink reference signal transmission of one WTRU. One benefit of this latter example may be reduced measurement-related signaling overhead and WTRU measurement processing, since many WTRUs in the same cell may not be close enough for a measurement. By selecting a specific group of WTRUs, as opposed to all WTRUs in the cell, to perform the measurement, the signaling overhead may be reduced.

[01 13] In some situations, certain WTRUs may not be applicable for V2X communication with a WTRU scheduled for the common sidelink reference signal transmission. For example, different WTRUs may subscribe to different applications and/or services and no direct communication may be enabled. In these situations, a measurement may not be necessary. [01 14] The network may determine the set of WTRUs that will be making measurements (i.e., the measuring WTRUs) based on location information of each WTRU. For example, WTRUs within a pre-defined proximity to a WTRU transmitting a common sidelink reference signal may be configured for a measurement. The proximity may be estimated/evaluated in terms of WTRUs in an area within the cell of a pre-defined geographic zone, or based on network measurements of the WTRU signal strength, sector, network beam direction, or the like. Thus, a WTRU may be configured with an identity, which may be a group-specific identity, for example, that is received in the measurement request. The group-specific identity may be a WTRU measurement RNTI. A WTRU may determine whether a measurement request DCI is received based on the RNTI. Alternatively, the group-specific identity may be embedded in the control signaling to enable multi-cast transmission.

[01 15] A WTRU may update the proximity-based group-specific identity based on the geographic location, such as a geographical zone identity that the WTRU may receive during its movement. Additionally/alternatively, a WTRU may receive group-specific identity update information from the network due to the WTRU mobility. The network may update the group-specific identity based on the WTRU location information. In some cases, the network may not be aware of the WTRU-to-WTRU link condition for the WTRUs in an area (e.g., whether two WTRUs are blocked by a wall or other obstacle).

[01 16] Further, a WTRU may be configured with an association between the group identity and transmission/reception resource configuration. For example, a certain geographic zone may have specific transmission/reception allocated resources.

[01 17] WTRUs may be assigned with a group based on their subscription to certain service(s) and/or application usage. For example, WTRUs subscribing to the same information sharing service may be configured with the same group-specific identity.

[01 18] A WTRU may detect change in its context/radio environment and send a report to the network. The WTRU may be configured to monitor for changes in its environment and send measurement information and/or a report to indicate the change to the network. For example, a WTRU may be configured to trigger a measurement report when the WTRU detects a change of active beams based on its own measurements. In another example, the WTRU may be configured to trigger a measurement report when one or more new beams are added/removed from the set of active beams, based on energy thresholds, as discussed herein.

[01 19] Additionally/alternatively, the WTRU may be configured to monitor for the presence of other WTRUs (e.g., vehicles) in its surrounding. For example, the WTRU may be configured to trigger a measurement report when it detects a new WTRU in the vicinity, and/or a WTRU is no longer in the vicinity. The WTRU presence may be detected by using a discovery procedure or via detection of the broadcasted basic safety messages, potentially on a different frequency (e.g., on the 5.9GHz spectrum reserved for ITS safety applications).

[0120] A WTRU may report quality metric(s) to a network per reference signal. A WTRU may report a measured quality metric of a common sidelink reference signal transmission of another WTRU with reference to both the reference signal index (i.e., for the beam) and associated resource set index, as seen in Table 1. Table 1 shows an example of a common sidelink reference signal measurement report where values xj are the reported values for beam index i and resource set j. The measurement quality metric may be for example one or more of Reference Signal Received Power (RSRP), RSSI, Signal to Interference Ration (SIR) and/or Signal to Interference plus Noise Ratio (SINR).

Table 1 Common sidelink reference signal measurement report

[0121] A WTRU may report measurement statistics to a network in order to reduce the reporting overhead, where the WTRU may be configured to report statistics (e.g., average, min, max, median, or the like) obtained from the measurements. In an example, the WTRU may be configured to calculate the average metric on a per-beam basis and report it to the network. In another example, the WTRU may be configured to calculate the average metric on a per-resource index basis and report it to the network.

[0122] A WTRU may report beam occupancy indications to the network. For example, the WTRU may be configured to make the determination of beam occupancy and report it to the network. In another example, the WTRU may be configured to transmit the beam index associated to the occupied beams, or alternatively to the unoccupied beams. In another example, a WTRU may indicate to the network via a bitmap which beam are occupied (e.g., with value 1 ) and which beams are not occupied (e.g., with value 0).

[0123] A WTRU may report contextual information to a network. For example, the WTRU may be configured to report the contextual information to the network. While the contextual information may be available at the application layer in general, the Access Stratum (AS) may be indicated (e.g., via an index of pre-defined contexts) with the actual context as determined by the application layer. The WTRU may then report this context to the network.

[0124] A WTRU may be configured to report the resource utilization status to the network (e.g., a gNB). The resource utilization status may be defined as the ratio between the number of beam which have been used for transmission and the number of active beams (e.g., over a predefined time window). This information may be reported to the network by indicating one or more of: the ratio between the number of beam which have been used for transmission and the number of active beams (i.e., the resource utilization ratio); and/or, the number of active beams and the number beam having resource to transmit (i.e., separately). This kind of report may be useful to support the gNB with radio resource management.

[0125] A WTRU may receive an indication of subsets from the network. Generally, unicast communication with the network may be different in V2X communication since the WTRU may have to transmit (e.g., the same message) in multiple directions with beamforming. Further, control channels and protocols (i.e., resource information) for WTRU-gNB operations with beamforming may provide the WTRU with transmission parameters towards the gNB, but resource information towards other WTRUs may also be needed. As discussed herein, there may be mechanisms and techniques that provide means for the WTRU to receive indications from the network to enable transmission over multiple beams.

[0126] FIG. 4 illustrates an example resource allocation for a WTRU. A WTRU may receive an indication of sidelink transmission resource sets and associated transmit (TX) beam(s). As shown, there is a first resource set 401 , a second resource set 402, and so on until a resource set J 403. Underneath each set of resources are individual resources of that set and are indicated by numbers 1 , 2, ... , where G is the number of resources for that given set. Not shown, there may be a bit map to indicate which transmit beam out of the i measured beams to use for each of the J resource sets used for the common sidelink reference signal transmission. The size of the bit field may be J times i and the bit corresponding to the transmit beam to use in each resource set may, in one example, be set to one. The indication may also comprise pairs of a transmit beam index and an associated transmit resource set index. When a fix-sized bit field is used for this information, padding bits may be used. [0127] The WTRU may receive the indication of resource information included in a DCI format. For example, the WTRU may receive the indication in Medium Access Control Control Element (MAC CE) or via Radio Resource Control (RRC) signaling.

[0128] One resource set may comprise i resources and each resource may comprise one or multiple PRBs. The number of PRB per resource and the values for i and j may be configured by the network, for example, via RRC signaling. The value of i may further depend on WTRU capabilities, and j may depend on the resource allocated by the network to the sidelink (i.e., for V2X).

[0129] A WTRU may have autonomous control over determining the subset of beams that it operates on. The network (e.g., gNB) may initially select and schedule a resource for a WTRU and using the scheduled resource the WTRU may select the beam to transmit based on received or measured information (e.g., measurements, context, etc.). In some instances the WTRU may be assigned a set of resource sets for transmission and the WTRU may further be configured to select the transmit beam on its own. The WTRU may be assigned a set of j resource sets, where each resource set may comprise i resources. Further, each resource may be used for transmission of one PDU. The resources may have the same size or may have different sizes.

[0130] FIG. 5 illustrates an example resource allocation for a WTRU. Similar to FIG. 4, 530 shows the resources assigned to a WTRU, where there may be J resource sets (501 , 502, 503) each with G resources. The WTRU may determine to transmit on K beams which may belong to the set of active beams. The value of J and G may be configured by the network, and the value of K may be obtained from the list of active beams.

[0131] In example 510, the WTRU may sequentially determine a beam for transmission for each resource. The sequence may be repeated as the WTRU has already determined the resources for all K beams. Further in example 510, the WTRU may quickly transmit one message in K directions (i.e., beams, since each beam has a specific direction), however, the WTRU may have to sweep the transmission beams frequently. For example, resource 1 from the first Resource Set 501 may correspond with the beam 1. Note that K may be less than G.

[0132] In example 520, the WTRU may determine to divide the assigned resources into K parts, and each part may be used to transmit one beam. The resource assigned for each beam may be different depending on the availability of the vehicles or the radio activity in each direction (i.e., beam direction). In example 520, the WTRU may require more time to cover the necessary directions as compared to the example 510, however, the beam sweeping frequency may be minimized. [0133] A base station, such as a gNB, may determine a set of beams and the WTRU may determine a specific beam for a particular resource. The WTRU may be assigned one or multiple resource sets, and each set of resources may be intended for one group of beams. Then, for each resource set intended for a particular group of beams, the WTRU may determine one beam in the intended group of beams for transmission of each resource.

[0134] A group of beams/directions may be defined based on one or more of the following criteria: the antenna panel/physical antenna to which the beam is associated to; the beamwidth; and/or whether the beam is active or not for a direction (e.g., range of directions).

[0135] FIG. 6A and 6B are diagrams illustrating an example where a WTRU selects beams from a group of resources corresponding to a common categorization. In the example of FIG. 6A, at 610 one or more resources may be assigned to a WTRU. There may be a group of resources associated with a direction, such as a group of resources for a 1 ^st direction 61 1 , a group of resources for a 2^nd direction 612, all the way to a group of resources for a D^,h direction 613. There may be G resources for each group of resources. For example, the group of resources for the 1 ^st direction may have Gi blocks. Each block in a group of resources may be a single resource of time and/or frequency. Further, each block of resources may have the same or different number of PRBs. At 620, the WTRU may select one or more beams from a group of beams for a given direction. There may be a group of beams for a 1^st direction 621 , a group of the beams for a 2^nd direction 622, all the way to a group of beams for a D^,h direction 623.

[0136] In the example of FIG. 6B, at 630, or more resources may be assigned to a WTRU. There may be a group of resources associated with a beamwidth, such as a group of resources for a 1 ^st beamwidth 631 , a group of resources for a 2^nd beamwidth 632, all the way to a group of resources for a W^,h beamwidth 633. There may be G resources for each group of resources. For example, the group of resources for the 1 ^st beamwidth may have Gi blocks. Each block in a group of resources may be a single resource of time and/or frequency. Further, each block of resources may have the same or different number of PRBs. At 640, the WTRU may select one or more beams from a group of beams for a given beamwidth. There may be a group of beams for a 1 ^st beamwidth 641 , a group of the beams for a 2^nd beamwidth 642, all the way to a group of beams for a W^th beamwidth 643.

[0137] A WTRU may determine beamwidth based on context. The WTRU may need to further determine the set of active beams before a transmission. For example, the WTRU may further exclude some beams from the set of the active beams based on the relationship between the assigned resource and the number of active beams. The beam exclusion procedure may depend on beamwidth, direction, and/or radio activity of each beam. For example, if the number of time resources available for transmission is insufficient to allow for all beams to be transmitted, then the WTRU may adjust the beamwidth to cover a wider area with less transmission occasions.

[0138] FIG. 7 illustrates an example of a WTRU determining a subset of beams, where there are sidelink beams and the wide beam is excluded. Specifically, the WTRU 700 may be assigned a resource set 710 of three resources in time, however, it has four active beams, therefore, the WTRU 700 in this example may determine to keep beams 701 , 702, 703 and exclude the widest beam, beam 704.

[0139] FIG. 8 illustrates an example of a WTRU determining a subset of beams, where there are sidelink beams and the narrow beams are excluded. The WTRU 800 may be assigned a resource set 810 with only one time/frequency resource, however, it may have four active beams, therefore, the WTRU 800 in this example may determine to use the wider beam 804 and exclude the narrow beams 801 , 802, 803, from the set of the active beams since there is only one resource available. The WTRU decision may impact whether service requirements may be met.

[0140] FIG. 9 illustrates an example WTRU that updates the set of active beams to balance between delay and coverage. Here, the WTRU 900 may further exclude a beam from the set of active beams to balance some aspects of service requirements (e.g., to balance between transmission delay and coverage). The WTRU 900 may decide not to transmit all narrow beams since it may result in a long delay. Instead, it may transmit the narrow beams in some directions (91 1 , 912, 913, 933, 932, 931 ) and a wide beam in some other directions (920). By excluding these beams the WTRU may reduce the delay, and the coverage requirement may be still satisfied.

[0141] FIG. 10A illustrates a process of an example procedure for determining a set of beams to transmit on. Initially, a WTRU may receive a measurement configuration message that contains a set of common sidelink reference signal parameters. At step 1002 the WTRU may determine a set of directions where target WTRUs may be present by monitoring these common sidelink reference signals for each receive beam. At 1004 the WTRU may measure the energy for each of the common sidelink reference signals. At 1006, the WTRU may determine a set of beams to use of transmission based on the set of active beams and the time resources available. The set of active beams and their directions of where target WTRUs are expected to be present may be based on the measurements (e.g., measured energy, successful detection of signals from other WTRUs, etc.), a predetermined threshold, and/or contextual information (e.g., the location of the measuring WTRU on the road). The WTRU may select the set of beams for transmission from the set of active beams based on the available resources for the set of active beams. At 1008 the WTRU may broadcast/transmit on the determined set of beams. Note that the WTRU 1056 does not broadcast in all beams 1067 since they were not selected.

[0142] FIG. 10B illustrates a diagram of an example scenario related to the process of FIG. 10A. At 1020, the WTRU 1056 is monitoring for the target WTRUs 1052 and 1054. The WTRU 1056 may receive reference signals in receive beams 1062 (i.e., sidelink) from the target WTRUs 1052 and 1054 and their respective transmit beams 1064. Next at 1030, the WTRU 1056 selects the transmit beams 1066 based on the previous steps described herein, in order to transmit/broadcast to target WTRUs 1054 and 1052

[0143] FIG. 1 1 are diagrams diagram illustrating an example of a transmit resource pool (i.e., available physical resources of time and frequency patterns that may repeat over time) of a WTRU. In this example, a frame diagram 1 1 10 is shown where each subframe 1 108 has a corresponding bitmap 1 107 and may be 1 ms. The frame diagram 1010 may have a horizontal axis of time 1 101. The shaded subframes represent the subframes that are in a subframe pool 1 109 (i.e., a resource pool). A frequency diagram 1 120 may represent each subframe, where frequency is shown on a vertical axis 1 102. In the frequency diagram 1 120 there may be a plurality of subchannels 1121 (e.g., Nsu_bcn subchannels 1 125), where the first subchannel (i.e., the subchannel at the bottom) may be startRBSubchannel 1 124. Each subchannel 1 121 may have a plurality of RBs 1034 (e.g., n_SUbCHsize RB 1032). Generally, any time there is an ellipses in any of the figures (e.g., 1 103, 1 123, 1 133) this indicates that there may be more of the same of whatever is preceding or following the ellipses but is not shown in order to simplify the example illustrated.

[0144] In V2X communication, there may be two modes associated with scheduling. These modes may be designated as mode 3 and mode 4. Mode 3 may corresponds to network-control scheduling and mode 4 may correspond to WTRU autonomous scheduling. Physical resources may be defined via a“resource pool” which is a set of time-frequency patterns that repeat over time. In mode 3 V2X communication, the network may be responsible to assign the time and frequency resource for the WTRU transmission. Generally, for resource allocation for mode 3 WTRU, the eNB may assign the resource to attempt to avoid interference.

[0145] In network-controlled scheduling (i.e., mode 3) the vehicle may be assigned resources such as time and frequency for each transmission. Flowever, in the WTRU autonomous control V2X (i.e., mode 4) the vehicle may be responsible for determining its transmission resource autonomously.

[0146] Generally, in V2X a Radio Resource Control (RRC) message may configure each transmission pool with a geographical zone or area. The WTRU may select the transmission pool based on its geographical location using whatever sensors and/or information is available (e.g., GPS, etc.). For example, as shown in FIG. 1 1 each resource pool may be a set of time and frequency resources, where the set of time resource repeats every B (ms) (1105, 1106). The value of B may either be preconfigured or configured by the network via RRC signalling.

[0147] In high frequency transmission, the propagation loss may be more severe than that of the low frequency transmission. Such propagation loss may be mitigated by using a large antenna array and by applying beam forming, and when using narrow beam forming techniques, the transmission range of the vehicle may be extended (e.g., as discussed herein); however, one narrow beam transmission may only cover a very narrow set of directions around the vehicle. Additionally, the interference caused by the narrow beam transmission may be limited to small sets of directions.

[0148] To improve high frequency transmissions, specific resource selection may be performed, such as a V2X resource pool design. For example, a vehicle may select the transmission pool for itself based on its location. The WTRU may then select the resource within this resource pool for transmission with beamforming, however this approach may result in inefficient spectrum use. This may be the case since with narrow beams, the interference created becomes highly directional and resources may be re-used more effectively. Therefore, techniques disclosed herein may determine how a WTRU may autonomously select the resource for beam transmission.

[0149] FIG. 12 is a diagram illustrating an example of a transmit resource pool (i.e., available physical resources of time and frequency patterns that may repeat over time) of a WTRU configured using a hierarchical approach. The pool design may comprise two layers: the first layer 1201 and the second layer 1202. In the first layer there may be a plurality of slots/subframes 121 1 (e.g., diagram 1 110) and a bitmap for each slot 1211 , where the horizontal axis 1210 is time. There may be a second layer 1202 for each slot 121 1 , which comprises an index of a plurality of symbols 1212. The first layer 1201 may determine whether the WTRU can perform a transmission in each time slot/subframe 1211. This first layer 1201 may be implemented, for where the transmission opportunity of the WTRU in the selected subframe may be determined by the value of the corresponding bit in the resource pool bitmap. If the first layer 1201 indicates that the WTRU may transmit in a slot, the second layer 1202 may determine the transmission opportunities of the WTRU in a specific symbol in that slot.

[0150] FIG. 13 is a table illustrating an example of a configuration table where each row 1301 in the table may indicate transmission opportunities of the WTRU in each symbol to avoid excessive overhead. Each row 1301 in the table corresponds to a configuration and each entry, column 1302, in that row indicates whether the WTRU is allowed to transmit in the corresponding symbol as represented by value 1 , or not allowed to transmit as represented by value 0. The first row (e.g., index 0) may indicate that the WTRU can transmit in all symbols in the slot; however, the second row (e.g., index 1 ) may indicate that the WTRU can only transmit in the first 7 symbols in the slot. The transmission opportunities of the WTRU in the second layer may be indicated by the index in the table.

[0151] FIG. 14 is a table illustrating an example pool configuration. Each slot may have the same or different configurations for each pool, and the slot configuration of all pools may be the same or different based on the network configuration. The pool configuration of the WTRU may be preconfigured or it may be configured by the network by, for example, RRC signaling. There are four example pools shown in FIG. 14 (1401 , 1402, 1403, 1404), but there may be more configurations not shown.

[0152] The transmit resource pool may be configured based on the geographical location of the vehicle. The WTRU may be configured to select the transmission pool based on the current geographical location (i.e. Zone ID), after first determining/receiving the current location. The transmit resource pool may be further configured with a set of beam directions or other beam properties as described herein (e.g., beamwidth). The WTRU may then be configured to choose different sets of resource pools for resource selection depending on the beam direction. As discussed herein, multiple transmit pools may be configured for the same geographical zone ID, but each may have the same or different beam directions.

[0153] A WTRU may be configured to determine the set of resource pools for each transmission beam based on a property of the beam, such as beam direction, beamwidth, or the like.

[0154] A WTRU may be configured to determine the set of transmission pools for a group of beams. A group of beams/directions may be defined based on one or more of: the antenna panel or physical antenna to which the beam is associated with; the beamwidth; whether the beam is active or not; and/or, direction (e.g., a range of directions).

[0155] A WTRU may be configured with transmission resource pools, each associated with an absolute direction such as north/south/west/east and/or location identification (e.g., GPS coordinates). The WTRU may determine a beam group to use for each configured transmission resource pools based on the direction/coverage of the transmit beams of the beam group and the absolute direction and/or location information associated with the transmission resource pool. For example, a WTRU may determine, given the real-time traveling direction and antenna solution placement and orientation, which transmit beams may cover the north direction, and select the transmit beams to use with the transmission resource pool associated with the north direction.

[0156] FIG. 15 are diagrams illustrating an examples of zone identification (ID) configuration. There are three examples (1510, 1520, 1530). Note, that relative to any zone described herein, there may be a North, South, East, and West as shown 1501. For each example shown, each zone (i.e., cell) of the diagram (i.e., table) has an ID and is counted from left to right, and then starting at the next row left to right again, and so on. For example 1510, the diagram starts at 1 and goes to 4. For example 1520, the diagram starts at 1 and goes to 9. The example 1530 shows the theoretical construction of the diagram based on the variables N and M, where M is the last number counted for the first row and N is the number of rows. The geographical location of WTRUs may be divided into NM zones, or geographical IDs, as shown in FIG. 15. The values of /W and N may be preconfigured in the WTRU or the network, for example, by RRC signaling. The network may also configure the dimensions of each zone. A reason for using geographical zones for a transmit pool(s) may be to reduce the risk of transmission collision due to a hidden node problem. Accordingly, by using different resources for different zones for the transmission between WTRUs in two different zones, the interference between WTRUs may be reduced. Note, for purposes of this illustration, a zone may have a beam that is transmitted in a North, East, West, or South direction, and each zone may be North, East, West, or South relative to another zone.

[0157] The configuration of the transmit resource pool may follow one or more geographic transmit pool design principles including that the WTRUs having the same zone ID, meaning the WTRUs in the same zone, may use the same transmit resource pool, or the transmit beam of the WTRUs having different zone IDs, meaning WTRUs in different zones, may use the same transmit resource pool if beam transmission of the WTRU in one zone creates negligible interference to the beam transmission of the WTRU in the other zone.

[0158] FIG. 16 is a diagram illustrating a transmit pool configuration, where M is equal to N which is equal to 2. North, East, West, and South may be shown at 1610. A zone may be any of the boxes 1612, and the number 161 1 in the bottom left corner of the box may be the zone ID. Here, multiple pool design for beam- based transmission may be present. The beam transmission of each WTRU may be divided into four groups from a first group of beams 1601 to the fourth group of beams 1604. The WTRU may be configured to assign each transmit resource pool to one group of beams. Note, that in this configuration, a WTRU in zone 1 uses the group of beams 1602 associated with a specific transmit resource pool so that it does not interfere with a WTRU in zone 2 using a different group of beams 1603 associated with a different transmit pool as they relate to an east and west direction. Further, a WTRU in zone 1 may use the same transmit pool for the group of beams 1601 as zone 2 since this group of beams is in the north south direction and may cause negligible interference as the beams will not theoretically cross paths. The same logic is applied for the choice of the groups of beams for each of the remaining zones 3 and 4 as shown. The transmit pool design in this example may satisfy the aforementioned geographic transmit pool design principles. [0159] FIG. 17 is a diagram illustrating a transmit pool configuration, where M is equal to A/ which is equal to 3. Just as in FIG. 16 North, East, West, and South may be shown at 1710, a zone may be any of the boxes 1712, and the number 171 1 in the bottom left corner of the box may be the zone ID. The beam transmission of each WTRU may be divided into six groups from the group of beams 1 to the group of beams 6. Therefore, the WTRUs may be configured to assign 6 transmit resource pools to these 6 group of beams. This transmit resource pool configuration may result in a higher system spectrum efficiency since this configuration may result in the reduction of the number of transmit resource pools (e.g., from 9 transmit resource pools to 6 transmit resource pools). For example, for zone’s 1 , 2, and 3 the group of beams 1706, 1705, and 1704 may be used, respectively, in the East-West axis, thereby ensuring diversity for that axis and minimizing interference. Further note that for zone’s 1 , 2, and 3, the same group of beams 1701 may be used for each of these zones since they run in the North-South axis and minimal interference is already expected since they are similar to being parallel.

[0160] FIG. 18 is a flow chart illustrating an example of a WTRU determining transmit pool(s) based at least in part on configuration information. Initially, a WTRU may have a certain number of transmit beams determined based on the antennae panel configuration. At 1802, for each zone ID, a WTRU may be configured by the network multiple transmission pools for a specified direction (e.g., absolute direction like north, south, etc.) or geographical area (e.g., zone). Each pool may be associated with a set of beam directions using, for example, compass/absolute directions North, East, West, South, or a coordinate system such as GPS coordinates. The WTRU may be notified about the configuration through control signaling, such as system information (SIB) or RRC signaling. At 1804, the WTRU may determine/select beams/directions/beamwidth for transmission based on monitoring/measuring/sensing/feedback as discussed further herein. At 1806, the WTRU may determine location/heading information such as the zone ID based on its geo-location and/or the known antenna panel positions. At 1808, the WTRU may select a transmit resource pool for each transmit beam or group of beams based on the network configuration. At 1810, the WTRU may transmit in the selected beams using the resources of the selected transmission resource pool.

[0161] Referring to the process of FIG. 18, an example implementation may be as follows: a WTRU may have 8 transmit beams ranging from 1 to 8. At 1802, the WTRU may receive the configuration from the network specifying that for zone 1 , beams in the North and South direction use pool 1 and beams in East and West direction may use pool 2. At 1804 the WTRU may determine to use beams 1 and 2 because they are directed at target WTRUs. At 1806, using the received network configuration, the WTRU may determine which transmission resource pool to use for each beam group. If the WTRU may determines that it belongs to zone 1 , then, the WTRU may know that beams 1 to 4 belong to the North and South directions and beams 5 to 8 belong to the East and West directions. Therefore, the WTRU may then determine the transmit pools for beams 1 to 4 to be pool 1 and for beams 5 to 8 to be pool 2 based on the determined zone information and the network configuration. Finally, the WTRU may transmit in beams 1 and 2 using the resources from pool 1.

[0162] In another example, for the case M equals N which equals 2 (M=N=2) as discussed herein, the resource for each beam transmission of the WTRU may belong to one of four transmit resource pools corresponding to four groups of beams. Therefore, the WTRU may determine the group of beams and the corresponding transmit resource pool for each transmit beam. The WTRU may perform sensing and beam transmission on the resource of the selected transmit pool for each beam.

[0163] Once a WTRU has determined a transmit resource pool, there may be one or more ways for selecting a resource within the pool. After a WTRU determines the set of resource pools for each transmission beam or for a group of transmit beam, the WTRU may need to determine a specific set of resource for the transmission of each beam. One set of resources may comprise of one or multiple PRBs depending on the network configuration or WTRU pre-configuration. The WTRU may separately determine the set resource for each transmission beam or may concurrently determine multiple sets of resources for multiple beam transmissions.

[0164] A WTRU may determine information for each beam, such as by sensing, measuring, and/or monitoring. The WTRU may be configured to decode the control message of other WTRUs to determine occupied resources. The WTRU may be configured to decode the control message of other WTRUs to determine some parameters of each WTRU that are included in the control message. These parameters may be the priority of the other WTRUs, the resources for transmission, and similar information. Additionally/alternatively, a WTRU may be configured to measure RSSI/RSRP/RSRQ of each received beam for each set of resources (i.e., pool). This measurement may be used by the WTRU to select a suitable resource for beam transmission.

[0165] For beam specific resource selection, a WTRU may select a resource for transmission for each beam separately. If a sensing result of one beam has a negligible correlation with that of the other beams, the WTRU may determine to perform resource selection solely based on the sensing result of that beam.

[0166] FIG. 19 is a diagram illustrating an example of beam selection based on the sensing of other beam(s). A WTRU may use the sensing results of one beam to perform resource selection of other beam(s). The WTRU may do this, for example, because the WTRU may not be able to perform sensing for all beams due to limitations in the time domain. Also, the WTRU may perform sensing by using one small set of beams. [0167] As shown in FIG. 19, a WTRU (e.g., vehicle) 1900 may have a wide beam 1910 and three narrow beams 1911 , 1912, and 1913. Some beams may have correlated sensing results due to their spatial correlation, where the WTRU may reuse the sensing information of one beam to perform resource selection of other beams. As shown, the WTRU 1900 may use the sensing result of the wider beam 1910 to perform resource selection for the narrow beams 191 1 , 1912, and 1913.

[0168] FIG. 20 is a diagram illustrating an example of beam selection based on the sensing of other beam(s). Here, the WTRU 2000 may use the sensing result of narrow beam 2012 to perform the resource selection for beam 201 1 and 2013. Additionally, to perform resource selection, the WTRU may adjust the threshold appropriately to determine whether one resource is occupied or not.

[0169] A WTRU may coordinate the sensing results of a group of beams to perform resource selection for each beam in the group of beams. In one example of coordination, the WTRU may exclude all resources that are detected as busy/occupied by one or multiple beams in the group of beams. In another example, the WTRU may apply some averaging techniques to determine the occupancy status of each set of resources (i.e., pool). The occupancy status of each set of resources may be determined by the average measured RSSI / RSRP/CQI of that resource set (e.g., where the WTRU performed the measuring). Subsequently, the WTRU may use this information to perform resource selection for a group of beams.

[0170] In the resource selection for a group of beams, a WTRU may use the same frequency resource for a different transmission time instance for each beam in the group of beams.

[0171] A WTRU may determine a set of receiving beams. Specifically, the WTRU may use different beamwidth levels to perform reception for different purposes. In one example, the WTRU may use a wide beam to receive the broadcast message from other vehicles in order to receive the broadcast message from all possible directions of a WTRU. In another example, the WTRU may use narrow beam and perform beam sweeping to measure the radio activity in different directions, which may support the WTRU in updating the set of the active beams for transmission.

[0172] Although presented in the context of NR, the embodiments described herein may also be applicable to other radio access technologies such as LTE or others radio access technologies such as based on 802.1 1 technologies. Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magnetooptical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, Vehicle, terminal, base station, RNC, or any host computer.

Claims

What is Claimed:

1 A method performed by a wireless transmit/receive unit (WTRU) comprising: receiving a configuration message including parameters for a set of common sidelink reference signals; monitoring a plurality of beams for the set of common sidelink reference signals; measuring the energy for each of the monitored common sidelink reference signals against a threshold; determine a set of active beams from the plurality of beams based on the monitored common sidelink reference signals measured above the threshold and contextual information; selecting one or more beams from the set of active beams based one or more available resources; transmitting in the selected one or more beams using a set of resources of the one or more available resources.

2. The method of claim 1 , wherein the WTRU is a vehicle.

3. The method of claim 1 , wherein the contextual information includes road information, map information, WTRU heading, or WTRU location information.

4. The method of claim 1 , wherein the configuration message further includes the set of resources of the one or more available resources.

5. The method of claim 4, wherein the set of resources of the one or more available resources are associated with an absolute direction.

6. The method of claim 5, further comprising selecting the set of resources for transmitting the one or more beams based on the contextual information and the absolute direction associated with the set of resources.

7. The method of claim 1 , wherein the configuration message is sent in two layers comprising a bitmap layer and an index layer.

8. A wireless transmit receive unit (WTRU) comprising: a processor operatively connected to a transceiver, the processor and transceiver configured to receive a configuration message including parameters for a set of common sidelink reference signals, monitor a plurality of beams for the common sidelink reference signals, and measure the energy for each of the monitored common sidelink reference signals against a threshold; and the processor and transceiver further configured to determine a set of active beams from the plurality of beams based on the monitored common sidelink reference signals measured above the threshold and contextual information, select one or more beams from the set of active beams based on one or more available resources, and transmit in the one or more beams using a set resources of the one or more available resources.

9. The WTRU of claim 8, wherein the WTRU is a vehicle.

10. The WTRU of claim 8, wherein the contextual information includes road information, map information, WTRU heading, or WTRU location information.

1 1. The WTRU of claim 8, wherein the configuration message further includes the set of resources of the one or more available resources.

12. The WTRU of claim 1 1 , wherein the set of resources of the one or more available resources are associated with an absolute direction.

13. The WTRU of claim 12, further comprising selecting the set of resources for transmitting the one or more beams based on the contextual information and the absolute direction associated with the set of resources.

14. The WTRU of claim 8, wherein the configuration message is sent in two layers comprising a bitmap layer and an index layer.