WO2020069175A1

WO2020069175A1 - Power control for vehicle-to-everything (v2x) communication

Info

Publication number: WO2020069175A1
Application number: PCT/US2019/053223
Authority: WO
Inventors: Fengjun Xi; Wei Chen; Chunxuan Ye; Kyle Jung-Lin Pan
Original assignee: Idac Holdings, Inc.
Priority date: 2018-09-26
Filing date: 2019-09-26
Publication date: 2020-04-02

Abstract

A first wireless transmit/receive unit (WTRU) may receive (SL)-sidelink reference signal received power (RSRP) (SL-RSRP) reports from a group of second WTRUs. The first WTRU may determine a first SL pathloss (PL) (SL-PL) for each of the second WTRUs based on the received SL-RSRP reports, and select one of the second WTRUs as a reference destination (RD)-WTRU (RD-WTRU) based on the first SL-PL for each of the second WTRUs. Further, the first WTRU may transmit an indication of the RD-WTRU to the group. Also, the first WTRU may receive an SL-RSRP report from the RD-WTRU. Moreover, the first WTRU may determine a second SL-PL for the RD-WTRU based on the received SL-RSRP report from the RD-WTRU and a first groupcast transmit power based on the second SL-PL for the RD-WTRU. The first WTRU may transmit one or more groupcast transmissions to the group using the first groupcast transmit power.

Description

POWER CONTROL FOR VEHICLE-TO-EVERYTHING (V2X) COMMUNICATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/736,776, filed September 26, 2018 and U.S. Provisional Application No. 62/753,525, filed October 31 , 2018, the contents of which are incorporated herein by reference.

BACKGROUND

[0002] In recent 3^rd Generation Partnership Project (3GPP) standards discussions, several deployment scenarios are defined, such as, for example, indoor hotspot, dense urban, rural, urban macro, high speed and the like. On top of these deployment scenarios, three use cases are defined: enhanced mobile broadband (eMBB), massive machine type communications (mMTC) and ultrareliable and low latency communications (URLLC). Different use cases may focus on different requirements such as higher data rate, higher spectrum efficiency, low power and higher energy efficiency, lower latency and higher reliability.

[0003] Vehicle-to-everything (V2X) communication architecture has been developed for wireless communication systems, including Long Term Evolution (LTE) systems and fifth generation (5G) systems. V2X communications may include one or more of vehicle-to-vehicle (V2V) communications, vehicle-to-pedestrian (V2P) communications, vehicle-to-infrastructure (V2I) communications and vehicle-to-network (V2N) communications.

SUMMARY

[0004] A method and apparatus are disclosed herein, in a wireless transmit/receive unit

(WTRU), for determining power control in vehicle-to-everything (V2X) communication, groupcast communication or both. In an example, a first WTRU may receive one or more sidelink (SL)-sidelink reference signal received power (RSRP) (SL-RSRP) reports from one or more second WTRUs of a group of second WTRUs. The first WTRU may determine a first SL pathloss (PL) (SL-PL) for each of the second WTRUs based on the received one or more SL-RSRP reports from the one or more second WTRUs. Then, the first WTRU may select one of the second WTRUs of the group as a reference destination (RD)-WTRU (RD-WTRU) based on the first SL-PL for each of the second WTRUs. Further, the first WTRU may transmit an indication of the RD-WTRU to the group. Also, the first WTRU may receive an SL-RSRP report from the RD-WTRU. Moreover, the first WTRU may determine a second SL-PL for the RD-WTRU based on the received SL-RSRP report from the RD- WTRU, and may determine a first groupcast transmit power based on the second SL-PL for the RD- WTRU. The first WTRU may transmit one or more groupcast transmissions to the group using the first groupcast transmit power.

[0005] In an example, the first WTRU may be a new radio (NR) WTRU. In another example, the second WTRU may be an NR WTRU. In a further example, the first WTRU may be a transmitting WTRU. Also, at least one second WTRU may be a receiving WTRU. Further, at least one of the groupcast transmissions may be a data transmission. Additionally, at least one of the groupcast transmissions may be a control transmission.

[0006] In examples, the RD-WTRU may be selected based on at least one of a highest SL-

PL, a lowest SL-PL, a median SL-PL or an average SL-PL. Moreover, the indication of the RD- WTRU may be transmitted via an L1 signaling sidelink control information (SCI).

[0007] In an additional example, the first WTRU may determine whether to switch to all second WTRU feedback based on a radio resource control (RRC) configuration. In another example, the first WTRU may determine whether to switch to all second WTRU feedback based on an RD-WTRU SL-PL measurement threshold. In a further example, the first WTRU may transmit one or more groupcast transmissions to the group using a second groupcast transmit power determined based on a Uu PL and a data minimum communication range.

[0008] In an example, the first groupcast transmit power determination may be further based on a data minimum communication range. In addition, the first WTRU, the second WTRU or both WTRUs may be members of a vehicle platoon. Further, one or more groupcast transmissions may be transmitted using a sidelink channel. Moreover, the sidelink channel may be a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH).

[0009] Further, a WTRU may perform reception evaluation based on a metric, wherein the metric is at least one of a signal-to-interference-plus-noise ratio (SINR), a block error rate (BLER), a reference signal received quality (RSRQ), a received signal strength indicator (RSSI), an RSRP or an energy per resource element (EPRE). The WTRU may then perform transmit power control (TPC) feedback based on the reception evaluation. In addition, a WTRU may perform power collision handling and determine transmit power based on the power collision handling. In an example, the power collision handling may include at least one of inter-WTRU power collision handling and intra-WTRU power collision handling. Moreover, transmission power may be shared between Long Term Evolution (LTE) sidelink transmissions and NR sidelink transmissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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:

[001 1] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented;

[0012] 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. 1A according to an embodiment;

[0013] 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;

[0014] 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;

[0015] FIG. 2 is a resource diagram illustrating examples options of Physical Sidelink

Control Channel (PSCCFI) and Physical Sidelink Shared Channel (PSSCH) multiplexing;

[0016] FIG. 3 is a resource diagram illustrating an example of sidelink power control for hybrid TDMed and FDMed PSSCH and PSCCH;

[0017] FIG. 4 is a flow chart diagram illustrating an example of power control for groupcast using a reference destination (RD)-WTRU (RD-WTRU);

[0018] FIG. 5 is a signaling diagram illustrating an example of transmit power control

(TPC) commands for efficient power control in vehicle platooning; and

[0019] FIG. 6 is a flow chart diagram illustrating an example of closed loop power control for vehicle platooning.

DETAILED DESCRIPTION

[0020] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0021] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104/1 13, a ON 106/1 15, a public switched telephone network (PSTN) 108, the Internet 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” and/or a“STA”, may be configured to transmit and/or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0022] The communications systems 100 may also include a base station 1 14a and/or a base station 114b. 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 106/115, the Internet 1 10, and/or the other networks 112. By way of example, the base stations 1 14a, 1 14b may be a base transceiver station (BTS), a Node-B, an eNode B, a Flome Node B, a Flome eNode B, a gNB, a 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.

[0023] The base station 114a may be part of the RAN 104/1 13, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 1 14a and/or the base station 1 14b 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 1 14a 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.

[0024] The base stations 114a, 114b may communicate with one or more of the WTRUs

102a, 102b, 102c, 102d over an air interface 1 16, 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 1 16 may be established using any suitable radio access technology (RAT).

[0025] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 1 14a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 1 15/116/1 17 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (FISPA+). HSPA may include High-Speed Downlink (DL) Packet Access (FISDPA) and/or High- Speed uplink (UL) Packet Access (FISUPA).

[0026] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 1 16 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 1 16 using New Radio (NR).

[0028] 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., a eNB and a gNB).

[0029] 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.

[0030] The base station 1 14b in FIG. 1A may be a wireless router, Flome Node B, Flome eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.1 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 1 10. Thus, the base station 1 14b may not be required to access the Internet 1 10 via the CN 106/115.

[0031] The RAN 104/1 13 may be in communication with the CN 106/1 15, 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 106/1 15 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or the CN 106/1 15 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/1 13 or a different RAT. For example, in addition to being connected to the RAN 104/1 13, which may be utilizing a NR radio technology, the CN 106/1 15 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology. [0032] The CN 106/1 15 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 1 10 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 1 12 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/113 or a different RAT.

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system

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

[0034] 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 subcombination of the foregoing elements while remaining consistent with an embodiment.

[0035] 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) circuits, 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 1 18 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.

[0036] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 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.

[0037] 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 1 16.

[0038] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.1 1 , for example.

[0039] 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).

[0040] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like. [0041] The processor 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 1 16 from a base station (e.g., base stations 1 14a, 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.

[0042] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and/or Augmented Reality (VR/AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor.

[0043] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit 139 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 downlink (e.g., for reception)).

[0044] 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 116. The RAN 104 may also be in communication with the CN 106. [0045] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 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.

[0046] 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.

[0047] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME)

162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0048] 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.

[0049] 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.

[0050] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs

102a, 102b, 102c with access to packet-switched networks, such as the Internet 1 10, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0051] The CN 106 may facilitate communications with other networks. For example, the

CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 1 12, which may include other wired and/or wireless networks that are owned and/or operated by other service providers.

[0052] Although the WTRU is described in FIGS. 1A-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.

[0053] In representative embodiments, the other network 1 12 may be a WLAN.

[0054] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point

(AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired/wireless network that carries traffic 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 1e 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.

[0055] 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 via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) may be implemented, for example in in 802.1 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. [0056] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0057] Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and/or

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

[0058] Sub 1 GHz modes of operation are supported by 802.1 1 af and 802.1 1 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 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control/Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0059] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 h, 802.1 1 ac, 802.11 af, 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, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0060] In the United States, the available frequency bands, which may be used by

802.1 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 802.1 1 ah is 6 MHz to 26 MHz depending on the country code.

[0061] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 1 15 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 1 13 may also be in communication with the CN 115.

[0062] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 1 13 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 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).

[0063] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and/or lasting varying lengths of absolute time).

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs

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

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0066] The CN 1 15 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator.

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b,

180c in the RAN 1 13 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 1 13 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as WiFi.

[0068] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 1 15 via an N1 1 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b,

180c in the RAN 1 13 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0070] The CN 115 may facilitate communications with other networks. For example, the

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

[0071] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 1 14a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, 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.

[0072] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications.

[0073] The one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data.

[0074] Vehicle-to-everything (V2X) communication architecture has been developed for wireless communication systems, including LTE systems and fifth generation (5G) systems. V2X communications may include one or more of vehicle-to-vehicle V2V communications, vehicle-to- pedestrian (V2P) communications, vehicle-to-infrastructure (V2I) communications and vehicle-to- network (V2N) communications.

[0075] LTE V2X communication may include a variety of control information contents. In

LTE, downlink control information (DCI) format 5A is used for the scheduling of a Physical Sidelink Control Channel (PSCCH), as well as several sidelink control information (SCI) format 1 fields, which are used for the scheduling of a Physical Sidelink Shared Channel (PSSCH). The payload of DCI format 5A may include one or more of the following: a carrier indicator, which may be 3 bits; a lowest index of the subchannel allocation to the initial transmission, which may be one or more bits, such as ϊ^1o¾ (^subc^haⁿⁿe^l )1 bits; SCI format 1 fields, which may include a frequency resource location of initial transmission and retransmission field and a time gap between initial transmission and retransmission field; and a sidelink (SL) index, which may be two bits and present only for cases with time division duplex (TDD) operation with uplink-downlink configurations 0-6.

[0076] As used in the examples and embodiments provided herein, frequency resources and time resources may include one or more of resource elements (REs), resource blocks (RBs), resource grid and the like. In further examples, time resources may include one or more of slots, mini-slots, TTIs, frames, subframes, symbols and the like. In an example, a mini-slot may be several orthogonal frequency division multiplexed (OFDM) symbols. In additional examples, frequency resources may include one or more of channels, subchannels, carriers, subcarriers, RBs and the like.

[0077] When a format 5A cyclic redundancy check (CRC) is scrambled with an SL-semi- persistent scheduling (SPS)-V2X-radio network temporary identifier (RNTI) (SL-SPS-V-RNTI), the following fields may be present: an SL SPS configuration index field, which may be three bits; and an activation/release indication, which may be one bit. If the number of information bits in format 5A mapped onto a given search space is less than the payload size of format 0 mapped onto the same search space, zeros shall be appended to format 5A until the payload size equals that of format 0 including any padding bits appended to format 0. If the format 5A CRC is scrambled by an SL-V- RNTI and if the number of information bits in format 5A mapped onto a given search space is less than the payload size of format 5A with CRC scrambled by SL-SPS-V-RNTI mapped onto the same search space and format 0 is not defined on the same search space, zeros shall be appended to format 5A until the payload size equals that of format 5A with CRC scrambled by SL-SPS-V-RNTI.

[0078] In LTE, SCI format 1 is used for the scheduling of a PSSCH. The information payload of SCI format 1 may include one or more of the following: a priority, which may be three bits; a resource reservation, which may be four bits; a frequency resource location of initial transmission and retransmission, which may be one or more bits, such as fⁱ°^g ₂ ( ^subchannel ( ^subchannel ^{+ 1)/2)} l ; _a time gap between initial transmission and retransmission, which may be four bits; a modulation and coding scheme (MCS), which may be five bits; a retransmission index, which may be one bit; and reserved information bits, which may be added until the size of SCI format 1 is equal to thirty-two bits. The reserved bits may be set to zero.

[0079] In LTE, power control may be applied. Specifically, in LTE, the may determine the required transmission power for a type of transmission as a function of the desired receive power Po (typically signaled within system information for a given cell), the power necessary to compensate for propagation loss PLDL (typically based on an estimated pathloss estimation) possibly including a further unit or fractional compensation coefficient in case of a physical uplink shared channel (PUSCH), an offset amount of power to meet a certain error rate and/or signal-to-interference-plus- noise ratio (SINR), for example, Aformat for a physical uplink control channel (PUCCH) or AMCS for a PUSCH, a component as a function of the number“M” of RBs used for the transmission for a PUSCH, and a correction based on reception of a transmit power control (TPC) command from the network. Typically, the WTRU may include a sum of the previous quantities in the determination of the required power. [0080] For example, in an LTE framework, the expected PUSCH power intended for cell c on the i_th subframe can be described as the following,

^ PUSCH.c (0 ^{~ m}’ⁿ

Equation (1) where,

P_{CMAX c} ( ^: WTRU’s maximum transmit power in decibel-milliwatts (dBm)

M_PUSCH_{, C} (^z) ^: # ^{of RBs} allocated on the PUSCH

P_{0 p}usc_{H, c} ) ^' target received power (from SIB2)

a_c(J) : fractional power compensation factor [0: 1] (from SIB2)

PL_C : path loss (estimated from measurement on a cell-specific reference signal (CRS) and fixed transmission power information from SIB2)

: MCS specific offset; and

f_c{T) : TPC command - short term adjustments from the closed loop power control which is sent on DCI format 3/3a.

[0081] In 3GPP 5G and/or NR, the UL power control is further developed to account for certain new features. The new features may include one or more of multiple numerologies, bandwidth parts (BWPs), beam-based transmission(s) and the like.

[0082] In LTE V2X, the sidelink may be broadcast and only open loop power control may be supported. Since the PSSCH and PSCCH are frequency division multiplexing (FDM) multiplexed, the transmit power may be shared between PSSCH and PSCCH. The transmit power for PSSCH may be given by:

Equation (2) where MPSSCH and MPSCCH are the bandwidth of PSSCH and PSCCH.

[0083] For a mode 3 WTRU or a mode 4 WTRU without a configured higher layer parameter max

A = mi

Equation (3) where P_0psscH and a_PSSCH are higher layer parameters related to transmission mode, P_CMAX ^is the allowed maximum transmit power and PL is the pathloss.

[0084] For a mode 4 WTRU with a configured higher layer parameter maxTxpower,

Equation (4) where P_MaXcBR is set to maxTxpower value, based on priority level of the PSSCH and the channel busy ratio (CBR) range.

[0085] In examples, several option of multiplexing a PSCCH and a PSSCH are provided herein. The PSCCH and an associated PSSCH may be multiplexed under different arrangements of time resources and frequency resources. In examples, a PSSCH may be associated with a PSCCH if the PSCCH carries at least enough information necessary to decode the PSSCH.

[0086] FIG. 2 is a resource diagram illustrating examples options of PSCCH and PSSCH multiplexing. In a first example option shown in resource diagram 200, the PSCCH and the associated PSSCH may be transmitted using non-overlapping time resources. In examples shown in resource diagram 200, a resource grid may be used. The first example option may be referred to as option 1. Example sub-options may be used when using the first example option. In a first example sub-option under the first example option shown in FIG. 2 as multiplexed channels 210, the frequency resources used by the PSCCH and the associated PSSCH may be the same. For example, the PSCCH may use all of the available frequency resources and some of the available time resources in its transmission 214. The PSSCH may also use all of the available frequency resources and the remaining available time resources in its transmission 218. The first example suboption may be referred to as option 1A and/or TDMed PSSCH and PSCCH. Further, in a second example sub-option under the first example option shown in FIG. 2 as multiplexed channels 220, the frequency resources used by the PSCCH and the associated PSSCH may be different. For example, the PSCCH may use some of the available frequency resources and some of the available time resources in its transmission 224. In addition, the PSSCH may use all of the available frequency resources and the remaining available time resources in its transmission 228. The second example sub-option may be referred to as option 1 B and/or a special TDMed PSSCH and PSCCH.

[0087] Further, in a second example option, the PSCCH and the associated PSSCH may be transmitted using non-overlapping frequency resources in all of the available time resources used for transmission. Accordingly, the time resources used by the two channels may be the same while the frequency resources may be different. The second example option is shown in FIG. 2 as multiplexed channels 230. In an example, the PSCCH may use some of the available frequency resources and all of the available time resources in its transmission 234. In addition, the PSSCH may use the remaining available frequency resources and all of the available time resources in its transmission 238. The second example option may be referred to as option 2 and/or FDMed PSSCH and PSCCH.

[0088] Moreover, in a third example option, a part of the PSCCH and the associated

PSSCH may be transmitted using overlapping time resources in non-overlapping frequency resources for transmission, but another part of the associated PSSCH and/or another part of the PSCCH may be transmitted using non-overlapping time resources. The third example option is shown in FIG. 2 as multiplexed channels 240. In an example, the PSCCH may use some of the available frequency resources and some of the available time resources in its transmission 244. In addition, in PSSCH transmission 248, a part of the PSSCH may use the remaining available frequency resources in the overlapping time resources used by both transmissions 244, 248. Further, in transmission 248, another part of the PSSCH may use the remaining available time resources in the overlapping frequency resources used by transmissions 244, 248. Other parts of the PSCCH transmission 248 do not overlap in time or frequency with PSCCH transmission 244. The third example option may be referred to as option 3 and/or hybrid TDMed and FDMed PSSCH and PSCCH.

[0089] More stringent service requirements may be used for NR V2X than LTE V2X. In order to meet the requirements, QoS management is beneficial to help to meet the service requirement. In LTE V2X, QoS management is mainly via CBR based congestion control. In NR V2X, advanced use cases may have more and different QoS related requirements. For broadcast, the QoS related parameters may be provided with each packet to be transmitted. An enhanced power control scheme may be desired to determine a proper transmission power for the data to be transmitted which have different QoS characteristics. Accordingly, an enhanced power control for broadcast communication may be desired. Enhanced power control is therefore described herein.

[0090] Broadcast transmission is assumed in LTE V2X sidelink. Since the number of links between a source WTRU and destination WTRUs is large, it is problematic to support closed loop power control. In NR V2X, unicast transmission and groupcast transmission may be supported in addition to broadcast transmission. Accordingly, it is desired to design an accurate and efficient power control mechanism to support more reliable unicast and groupcast transmission in NR V2X.

[0091] The terms source WTRU, transmitting WTRU and transmitter WTRU may be used interchangeably and still be consistent with the examples and embodiments provided herein. The terms destination WTRU, receiving WTRU and receiver WTRU may be used interchangeably and still be consistent with the examples and embodiments provided herein.

[0092] Furthermore, as service and system aspects (SA1 ) may provide, the transmitting

WTRU may be able to control the communication range of the V2X message sent in sidelink, based on the characteristic of the messages. An accurate and efficient power control scheme is desired to control the transmitting power of the message, which may differ from one sidelink destination to another. Such control may be beneficial from a privacy and security perspective, and also favorable to reduce the interference and improve the energy efficiency in NR V2X. [0093] Examples of enhanced power control for broadcast are provided herein. In LTE

V2X, the sidelink is broadcast and no feedback is supported. Hence, only open loop power control is possible. Since the PSSCH and PSCCH are multiplexed in an FDM manner, the transmit power is shared between PSSCH and PSCCH. The transmit power for PSSCH may be given by:

Equation (5) where M_PSSCH and M_PSCCH may represent the bandwidth of PSSCH and PSCCH, respectively.

[0094] For a mode 3 WTRU or a mode 4 WTRU without a configured higher layer parameter maxTxpower,

A = mi n{P_CMAX, 10 logio (M_PSSCH + 10 °^'3M_PSCCH) + Po PSSCH + ^a PSSCH ' PL}’

Equation (6) where P₀_P_SSCH and UP_SSCH may be higher layer parameters related to transmission mode, PCMAX is the allowed maximum transmit power and PL is the pathloss.

[0095] For a mode 4 WTRU with a configured higher layer parameter maxTxpower,

Equation (7) where P_Max_CBR ^m ^ be set to maxTxpower value, based on priority level of the PSSCH and the CBR range.

[0096] In NR V2X, the QoS parameters used for the physical layer may include priority, latency, reliability, communication range for sidelink communication and the like. QoS enhanced power control may be proposed for broadcast to meet QoS management below.

[0097] If the PSSCH and PSCCH are multiplexed in an FDM fashion, also considering different numerologies or sub-carrier spacings (for example, a 15 2^m kHz spacing) may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU without a configured higher layer parameter maxTxpower, may determine the transmit power for PSSCH transmission based on the equation below:

Equation (8)

[0098] For a mode 2 WTRU with a configured higher layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

PL),

Equation (9)

[0099]

^may ^{be 13386(1 on one or more of} P^riority level, reliability or latency of the

PSSCH and the CBR range. For example, for higher priority data and/or the data with higher reliability and/or lower latency requirements, the value of P_Max_CBR may be set larger. For lower priority data and/or the data with lower reliability and/or higher latency requirements, the value of

[0100] If the minimum communication range of the data transmissions is also known to the physical layer, then the following could be used:

Equation (10) where P_COmrange may be ^a higher layer parameter, which is based on the minimum communication range of the data. The terms minimum communication range of the data, minimum communication range and data minimum communication range may be used interchangeably and still be consistent with the examples and embodiments provided herein.

[0101] In examples, a data minimum communication range may be a QoS parameter. In further examples, the data minimum communication range may relate to one or more QoS requirements, characteristics, levels or parameters. In an example, the data minimum communication range may be pre-defined and/or pre-configured at the WTRU. In a further example, the data minimum communication range may be received by the WTRU. For example, the data minimum communication range may be received by the WTRU from a base station. In a further example, the data minimum communication range may be received by the WTRU from another WTRU. Also, the data minimum communication range may be received by the WTRU from another WTRU, which may have received the data minimum communication range from a base station. Further, the data minimum communication range may be received or determined by the WTRU using one or more of an indication, a pointer, an index value or the like. For example, a pointer may be received by the WTRU and the WTRU may use the received pointer to look up values in a lookup table to determine the data minimum communication range. The look-up table may be predefined and/or pre-configured at the WTRU. Further, the table may be an index pre-defined and/or pre-configured at the WTRU. In an example, the WTRU may receive or determine a QoS requirement and may determine the data minimum communication range based on the QoS requirement. For example, the WTRU may use the QoS requirement with a look-up table to determine the data minimum communication range. Further, the WTRU may determine the data minimum communication range based on the QoS requirement and a received pointer. For example, the WTRU may use the QoS requirement and the received pointer with a look-up table to determine the data minimum communication range.

[0102] The mapping between P_COmrange and the minimum communication range may be pre-defined or may be configured, for example, via radio resource control (RRC) messages. In general, the larger the minimum communication range may be, the larger the value of P_COmrange · When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the minimum communication range.

[0103] In the assumption of P_COmrange £ P CM AX _> one could have the following alternative scheme to ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

Equation (1 1 )

[0104] The pathloss value used in the above formulas for NR V2X may be per the measurement of a reference signal index (or beam) or may be per carrier. The details are provided in other example, embodiments and sections herein.

[0105] The above examples include power control for data channels. A similar scheme could be used for control channels. For example,

10⁰³MpscCH

PPSCCH — 10 l°§io (^' + A,

mPSSCH+¹⁰°^3MPSCCH '

Equation (12) where the value of A follows the provided methods above.

[0106] If the PSSCH and PSCCH are multiplexed in time division multiplexing (TDM) fashion, also considering different numerologies or sub-carrier spacings (for example, a 15 2^m kHz spacing) may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU without a configured high layer parameter maxTxpower, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

Equation (13)

[0107] For a mode 2 WTRU with a configured high layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

Equation (14)

[0108]

^may be based on one or more of priority level, reliability or latency of the

PSSCH and the CBR range. For example, for higher priority data and/or the data with higher reliability and/or lower latency requirements, the value of P_Max_CBR ^may b^e set larger. For lower priority data and/or the data with lower reliability and/or higher latency requirements, the value of

PMUXCBR ^may ^{be set} smaller.

[0109] If the minimum communication range of the data transmissions is also known to the physical layer, then the following could be used:

Equation (15) where P_COmrange may be a higher layer parameter, which is based on the minimum communication range of the data.

[01 10] The mapping between P_COmrange and the minimum communication range may be pre-defined or may be configured, for example, via one or more RRC messages. In a general example, the larger the minimum communication range may be, the larger the value of P_COmrange - When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the minimum communication range.

[01 1 1] In the assumption of P_COmrange £ ^Pc MAX’ the following alternative scheme may be used. The scheme may ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

Equation (16)

The terms above may be defined as follows: m may be a higher layer parameter to indicate p

numerology or subcarrier spacings; ^CMAX may be the configured maximum WTRU output power, and may be configured per carrier or serving cell; ^^PSSCH _may be the bandwidth of the PSSCH resource assignment expressed in number of resource blocks; PL may be the pathloss estimation calculated by one or any combination of the methods proposed in herein, whose value may be measured for NR V2X in a beam-specific manner (for example, on a per-beam basis), by using a reference signal (RS) index and/or per BWP and/or per carrier and/or per cell; P₀_PSSCH and ^aPsscH may be higher layer parameters related to a transmission mode and may be associated with the corresponding PSSCH resource configuration.

[01 12] In examples, the transmission mode may be NR V2X transmission mode 1 or NR

V2X transmission mode 2. The terms NR transmission mode, V2X transmission mode and NR V2X transmission mode may be used interchangeably and still be consistent with the examples and embodiments provided herein. Further, the higher layer parameters may be configured with the same or different values for NR V2X transmission mode 1 and NR V2X transmission mode 2. As another example, transmission mode may be related to a pathloss (PL) calculation, and so alpha and Po may be configured to be the same value or different values for SL-PL and DL PL. In an example, alpha and Po may be pre-configured to be the same value or different values for SL-PL and DL PL.

[01 13] Examples of power control for unicast are provided herein. In specific examples, sidelink PL for unicast transmission is discussed herein. For broadcast, a maximum transmission power may be used to make sure the message can be transmitted as far as possible so that more vehicles can receive the message. However, for unicast, only one receiver may need to be considered. The PL between the transmitter WTRU and the receiver WTRU may be estimated and fed back to the transmitter WTRU to assist power control or provide closed-loop power control. Alternatively, sidelink PL between the receiver and transmitter WTRU for unicast may be calculated by one or any combination of the following methods.

[01 14] In a first example method, a PL between a gNB and a transmitter (Tx) WTRU may be calculated. The first example method may be used when no TPC feedback or no sidelink reference signal is received by the transmitter WTRU from a receiver (Rx) WTRU. Such an approach may keep backward compatible to LTE V2X. The first example method may be referred to as method 1 , unicast method 1 or a first example method for unicast and still be consistent with examples and embodiments provided herein.

[01 15] In a second example method, PL between an Rx WTRU and a Tx WTRU may be calculated based on sidelink reference signal power and filtered reference signal received power (RSRP). PL may be the sidelink path loss calculated by the Tx WTRU as a combination of RSRP measurements and knowledge of the sidelink reference signal transmit power from the Rx WTRU. For example, PL = Sidelink Reference Signal Transmit Power - sidelink_RSRP measurements. The sidelink reference signal transmit power from the Rx WTRU may be signaled with an RRC message and/or indicated with L1 signaling via DCI format 5A and/or SCI format 1 or the like. The second example method may be referred to as method 2, unicast method 2 or a second example method for unicast and still be consistent with examples and embodiments provided herein. tOH 6] In a third example method, PL may be calculated by combining the first example method and the second example method above to adapt to dynamic transmission between unicast and groupcast or broadcast. For example, the third method may be suited for the fall back to groupcast or broadcast from unicast. When a WTRU is engaged in unicast communications according to the second method, the WTRU may suddenly want to broadcast some time-sensitive information to all WTRUs. In an example, the time-sensitive information may include an earthquake warning message. Then, the WTRU may use maximum power as outlined in the first method to guarantee all WTRU can receive the time-sensitive information. The third example method may be referred to as method 3, unicast method 3 or a third example method for unicast and still be consistent with examples and embodiments provided herein.

[01 17] For NR V2X sidelink unicast, closed-loop power control may be proposed to determine the transmit power at the transmit WTRU by feeding a back power adjustment such as a TPC command from the receiver WTRU and/or gNB to the transmitter WTRU. A new field may be introduced in DCI format 5A and/or SCI format 1 or the like for the scheduling of the PSSCH to indicate the TPC command for the PSCCH and/or PSSCH. The TPC command for the PSCCH and/or PSSCH field may be M bits. In examples, M may be pre-specified as an integer number, such as one or two bits. Alternatively, a new DCI format and/or SCI format or the like may include the new field to carry the TPC command for the PSCCH and/or PSSCH.

[01 18] Examples of closed-loop power control for the PSSCH are provided herein. In an example, if the PSSCH and PSCCH are multiplexed in FDM fashion, also considering different numerologies or sub-carrier spacings (for example, a 15 2^m kHz spacing) which may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU without a configured high layer parameter maxTxpower, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

Equation (17) where

TF + /}

Equation (18)

[01 19] For a mode 2 WTRU with a configured high layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

+ /}

Equation (19)

[0120]

^may be based on one or more of priority level, reliability or latency of the

[0121] If the minimum communication range of the data transmissions is also known to the physical layer, then the following may be used:

Equation (20) where P_COmrange may be a high layer parameter, which is based on the minimum communication range of the data.

[0122] The mapping between P_COmrange and the minimum communication range may be pre-defined or may be configured, for example, via one or more RRC messages. In general, the larger the minimum communication range may be, the larger the value of P_COmrange· When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the minimum communication range.

[0123] In the assumption of P_COmrange £ PCMAX> the following example scheme may be used in addition or as an alternative to other schemes provided herein. This example scheme may ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

+ Po_PSSCH + ^aPSSCH- PL + D_tr + /}}

Equation (21 ) where the terms may be defined as follows. The term k may be pre-specified to a fixed value between 0 and 1 or may be configured by RRC signaling depending on the resources or number of RBs used for PSSCH and PSCCFI within a scheduling unit, for example, a subframe, slot or mini- slot. In an example, the fixed value may be 0.3. m may be a higher layer parameter to indicate p

numerology or subcarrier spacings. ^CMAX may be the configured maximum WTRU output power. It may be configured per carrier or serving cell

_may b_e the bandwidth of the PSSCH resource assignment expressed in number of resource blocks. PL may be the pathloss estimation calculated by one or any combination of the methods proposed elsewhere herein. The pathloss value may be measured for NR V2X in a beam-specific manner, by using an RS index, per BWP, per carrier and/or per cell. In an example, the pathloss value may be measured on a per-beam basis. P_{0 p}ssc_H and UP_SSCH may be higher layer parameters related to a transmission mode and may be associated with the corresponding PSSCH resource configuration. In examples, the transmission mode may be NR transmission mode 1 or NR transmission mode 2. The parameters could be configured the same or different values for NR transmission mode 1 and mode 2. _TF may be a higher layer configured PSSCH transmission power adjustment component for different MCS used for PSSCH transmission. / may be the close-loop component for PSSCH power control adjustment based on TPC command feedback from the receiver WTRU.

[0124] If the PSSCH and PSCCH are multiplexed in TDM fashion, also considering different numerologies or sub-carrier spacings (for example, a 15 2^m kHz spacing) may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU, without a configured high layer parameter maxTxpower, may determine the transmit power for PSSCH transmission based on the equation below:

Equation (22)

[0125] For a mode 2 WTRU with a configured high layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

+ /}

Equation (23)

[0126] PM_UXCBR ^may ^be based on one or more of priority level, reliability or latency of the

PSSCH and the CBR range. For example, for higher priority data and/or the data with higher reliability and/or lower latency requirements, the value of P_Max_CBR ^may ^{be set lar}9^er- For ^lower priority data and/or the data with lower reliability and/or higher latency requirements, the value of

[0127] If the minimum communication range of the data transmissions is also known to the physical layer, then the following may be used:

Equation (24) where P_COmrange may be a higher layer parameter, which is based on the minimum communication range of the data.

[0128] The mapping between P_COmrange and the minimum communication range may be pre-defined or may be configured, for example, via one or more RRC messages.

[0129] In general, the larger the minimum communication range may be, the larger the value of P_COmrange· When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the minimum communication range.

[0130] In the assumption of P_COmrange £ Pc MAX’ the following alternative scheme may ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

Equation (25) where the terms may be defined as follows m may be a higher layer parameter to indicate

P

_may b_e the bandwidth of the PSSCH resource assignment expressed in number of resource blocks. PL may be the path loss estimation calculated by one or any combination of the methods proposed elsewhere herein. The path loss value may be measured for NR V2X in a beam-specific manner (for example, a per-beam basis), by using a reference signal (RS) index and/or per BWP and/or per carrier and/or per cell. P₀_PSSCH and ccpsscH may be high layer parameters related to a transmission mode and may be associated with the corresponding PSSCH resource configuration. In examples, the transmission mode may be NR transmission mode 1 or NR transmission mode 2. The parameters could be configured the same or different values for NR transmission mode 1 and NR transmission mode 2. D_tr may be the higher layer configured PSSCH transmission power adjustment component for different MCS used for PSSCH transmission. / may be the close-loop component for PSSCH power control adjustment based on TPC command feedback from the receiver WTRU. [0131] Examples for closed-loop power control for the PSCCH are provided herein. If the

PSSCH and PSCCH are multiplexed in an FDM fashion, also considering different numerologies or sub-carrier spacings (for example, a 15 2^m kHz spacing) may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU without a configured high layer parameter maxTxpower, may determine the transmit power for PSCCH transmission based on the equation below:

Equation (26) where

Equation (27)

[0132] For a mode 2 WTRU with a configured high layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below:

Equation (28)

[0133] PMax_CBR ^may be based on one or more of priority level, reliability or latency of the

PSSCH and the CBR range. For example, for higher priority data and/or the data with higher reliability and/or lower latency requirements, the value of P_Max_CBR ^may be set larger. For lower priority data and/or the data with lower reliability and/or higher latency requirements, the value of

Smaller.

[0134] If the minimum communication range of the data transmissions is also known to the physical layer, then the following may be used:

Equation (29) where P_COmrange may be a higher layer parameter, which is based on the minimum communication range of the data.

[0135] The mapping between P_COmrange and the data minimum communication range may be pre-defined or may be configured, for example, via one or more RRC messages. In general, the larger the data minimum communication range may be, the larger the value of P_COmrange · When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the data minimum communication range.

[0136] In the assumption of P_COmrange £ Pc MAX, we could have the following alternative scheme to ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

Equation (30) where the terms may be defined as fallows. The term k may be pre-specified to a fixed value between 0 and 1 , such as, for example, 0.3. Further, the term k may be configured by RRC messaging depending on the resources or number of RBs used for PSSCH and/or PSCCH within a p scheduling unit, such as, for example, a subframe, a slot, a mini-slot or the like. The term ^CMAX may be the configured maximum WTRU output power. The term may be configured per carrier or serving cell. M_PSSCH may be the bandwidth of the PSSCH resource assignment expressed in number of resource blocks. M_PSCCH may be the bandwidth of the PSCCH resource assignment expressed in number of resource blocks. PL may be the pathloss estimation calculated by one or any combination of the methods proposed elsewhere herein. The pathloss value may be measured for NR V2X in a beam-specific manner, for example, on a per-beam basis, by using an RS index, per BWP, per carrier, per cell or the like. The terms P₀_PSSCH and UPSSCH may be higher layer parameters related to a transmission mode and may be associated with the corresponding PSSCH resource configuration. In examples, the transmission mode may be NR transmission mode 1 or NR transmission mode 2. The terms could be configured with the same or different values for NR transmission mode 1 and NR transmission mode 2. D_{TR F} may be a higher layer configured PSCCH transmission power adjustment component for different PSCCH formats for PSCCH transmission g may be the close-loop component for PSCCH power control adjustment state based on TPC command feedback from the receiver WTRU after previous PSCCH transmission.

[0137] If the PSSCH and PSCCH are multiplexed in TDM fashion, also considering that different numerologies or sub-carrier spacing (for example, 15 2^m kHz) may be supported in NR V2X, for sidelink transmission, a mode 1 WTRU or a mode 2 WTRU without a configured high layer parameter maxTxpower may determine the transmit power for PSSCH transmission based on the equation below.

Equation (31)

[0138] For a mode 2 WTRU with a configured high layer parameter P_{Ma cBR}, the WTRU may determine the transmit power for PSSCH transmission based on the equation below.

Equation (32)

[0139] PM_UXCBR ^may be based on one or more of priority level, reliability or latency of the

^PMax_CBR ^may ^{be Set smalle}r.

[0140] If the minimum communication range of the data transmissions is also known to the physical layer, then the following may be used.

Equation (33) where P_COmrange may be a higher layer parameter, which is based on the minimum communication range of the data.

[0141] The mapping between P_COmrange and the data minimum communication range may be pre-defined or may be configured, for example, via one or more RRC messages. In general, the larger the minimum communication range may be, the larger the value of P_COmrange · When a transmitting WTRU receives the data, it could check the minimum required transmit power corresponding to the data minimum communication range.

[0142] In the assumption of P_COmrange £ PCMAX> the following alternative scheme may ensure the data minimum communication range requirement is prioritized over the data priority level, reliability or latency requirements.

Equation (34)

The terms of Equation (34) may be defined as follows. The term m may be a higher layer parameter p

to indicate numerology or subcarrier spacings. The term ^CMAX may be the configured maximum WTRU output power. The term may be configured per carrier of serving cell. M_PSCCH may be the bandwidth of the PSCCH resource assignment expressed in number of resource blocks. PL may be the path loss estimation calculated by one or any combination of the methods proposed elsewhere herein. The path loss value may be measured for NR V2X in a beam-specific manner, for example, on a per-beam basis, by using an RS index, per BWP, per carrier, per cell or the like. A_TF-F may be a higher layer configured PSCCH transmission power adjustment component for different control channel transmission formats for PSCCH transmission g may be the close-loop component for PSCCH power control adjustment state based on TPC command feedback from the receiver WTRU after a previous PSCCH transmission.

[0143] FIG. 3 is a resource diagram illustrating an example of sidelink power control for hybrid TDMed and FDMed PSSCH and PSCCH. As shown in examples resource diagram 300, the sidelink power control may be open loop power control. FIG. 3 shows the resources used for the transmission of a PSCCH 340 and the resources used for the transmission of an associated PSSCH, shown in parts 320, 330, 350. The transmission of the PSCCH 340 may use some frequency resources and some time resources. The remaining frequency resources in the time resources used by the transmission of the PSCCH 340 may be used by parts 320, 330. Part 350 may use the remaining time resources.

[0144] As used in the examples herein, P may represent a power, M may represent a bandwidth in the frequency domain, and K may represent power-spectral density (PSD) boosting for a PSCCH with respect to an associated PSSCH. Resource diagram 300 may show a modification of the third example option of PSSCH and PSCCH multiplexing provided elsewhere herein. Sidelink transmit power control for hybrid TDMed and FDMed PSSCH and PSCCH may be determined by using the following proposed example two-step method to make the total sidelink transmit power the same in the symbols used for PSCCH/PSSCH transmissions in a slot.

[0145] In one example, the WTRU may select a K such that

PPSSCH=P’PSSCH⁺P’PSCCH. Equation (35).

[0146] PPSSCH may represent the transmission power for the PSSCH, P’ PSSCH may represent the transmission power for parts 320, 330 and P’ PSCCH may represent the transmission power for the transmission of the PSCCH 340.

[0147] Additionally or alternatively, K may be selected based on M’PSSCH and M’PSCCH.

M’PSSCH may represent the bandwidth of parts 320, 330. M’PSCCH may represent the bandwidth of the transmission of the PSCCH 340. In an example:

MPSSCH=M’PSSCH+M’PSCCH. Equation (36)

[0148] In a first step of an example two-step method, the WTRU may calculate the PSSCH transmit power using a TDM equation. In a second step, the WTRU may calculate the PSCCH and PSSCH power using an FDM equation. For example, the WTRU may calculate P’PSSCH and P’PSCCH using an FDM equation.

[0149] An exemplary application of the proposed two-step method above may be illustrated as below. The first step above, of the WTRU calculating the PSSCH transmit power using a TDM equation, may be applied by:

PpsscH=min{PcMAx, Pmax_cBR, 10logio (2^UMPSSCH) ⁺Po_psscH+apsscH^*PL}} Equation (37)

[0150] The second step above, of the WTRU calculating the PSCCFI and PSSCH power using an FDM equation, may be applied by:

P’PSSCH = 10logio (M’PSSCH/(M’PSSCH+10^KMPSCCH)) + min{PcMAx, Pmax_cBR, 10logio (2^U(MPSCCH + 1 0^KMPSSCH)) ⁺Po_psscH+apsscH*PL}} Equation (38)

P’PSCCH = 10logio (10^K MpsccH/(M’psscH⁺10^KMpsccH))+min{PcMAx, Pmax_cBR, 10logio (2^U(MPSSCH + 1 0^KMPSCCH)) ⁺Po_psscH+apsscH*PL}} Equation (39)

[0151] In the equations above, K may be selected based on M’PSSCFI and M’PSCCFI.

Further, PL may refer to the pathloss of a sidelink transmission from a transmitting WTRU to a reference receiving WTRU. Also, MPSSCH may represent the bandwidth of the transmission of the PSSCH. MPSCCH may represent the bandwidth of the transmission of the PSCCH. In addition, the term PCMAX may represent the maximum transmission power of the transmitting WTRU. Moreover, the term Pmax_CBR may represent the maximum transmission power of the transmitting WTRU based on data priority and CBR. Additionally, the term Po_PSSCH may represent a nominal power for the PSSCH. Further, aPSSCH may represent the fractional pathloss compensation factor for PSSCH. Also, u may represent a subcarrier spacing indicator.

[0152] For groupcast, multiple receiver WTRUs need to be considered. The pathloss between the transmitter WTRU and one or more of the receiver WTRUs may be estimated and fed back to the transmitter WTRU to assist power control or closed-loop power control. Alternatively, sidelink pathloss between the receiver WTRU and transmitter WTRU for groupcast may be calculated by one or any combination of the following methods.

[0153] In a first example method, a PL between a gNB and a Tx WTRU may be calculated.

The first example method may be used when no TPC feedback, more than one TPC feedback with different power increase and/or power decrease indication(s), or no sidelink reference signal is received by a transmitter WTRU from an Rx WTRU. The first example method may be referred to as method 1 , groupcast method 1 or a first example method for groupcast and still be consistent with examples and embodiments provided herein.

[0154] In a second example method, a PL between a group of Rx WTRUs and a Tx WTRU may be calculated based on sidelink reference signal power and filtered RSRP received from all Rx WTRUs within the group. Path loss may be the sidelink path loss calculated by the Tx WTRU as a combination of RSRP measurements and knowledge of the sidelink reference signal transmit power from one or more Rx WTRUs. For example, PL = Sidelink Reference Signal Transmit Power - SL_RSRP measurements. The sidelink reference signal transmit power from a group of Rx WTRUs may be signaled with an RRC message and/or indicated with L1 signaling via DCI format 5A and/or SCI format 1 or the like. If the same sidelink reference signal transmit power is used by the Tx WTRU for a PL calculation regarding multiple Rx WTRUs in a group, while SL_RSRP measurements from different Rx WTRUs within the group may be different, the Tx WTRU may take the minimum, average, median, mode or maximum of SL_RSRP measurements as the group sidelink_RSRP for the PL calculation. If different sidelink reference signal transmit powers are used, then the Tx WTRU may have to calculate the PL for each link between the Tx WTRU and each Rx WTRU. Then the WTRU may take largest, average or median PL as the group PL. Note for a specific Tx WTRU, PL between the Tx WTRU and different groups of WTRUs may use different transmitting powers for different groupcasts. The second example method may be referred to as method 2, groupcast method 2 or a second example method for groupcast and still be consistent with examples and embodiments provided herein. A sideline reference signal used for a SL-PL calculation may be a sidelink channel-state-information reference signal (SL-CSI-RS) and/or demodulation reference signal (DMRS) of the PSCCH and/or the PSSCH. Filtered RSRP may be layer-1 or layer-3 filtered RSRP.

[0155] In a third example method, a PL between a Tx WTRU and a reference destination

WTRU within a group of Rx WTRUs may be calculated as follows. A reference destination WTRU may be defined/pre-specified/configured and signaled/indicated as a WTRU within a group of destination or Rx WTRUs for groupcast based on one or any combination of rules below.

[0156] In a first example rule, a WTRU with the highest or lowest PL among all destination

WTRUs or Rx WTRUs for the groupcast may be determined as the reference destination WTRU. The first example rule may be referred to as Rule 1.

[0157] In a second example rule, a WTRU with the average or median target location area for groupcast may be determined as the reference destination WTRU. The second example rule may be referred to as Rule 2.

[0158] In a third example rule, a WTRU with pre-defined or configured rule(s) for QoS requirement(s) may be determined as the reference destination WTRU. In an example, a higher QoS requirement may require more transmit power to compensate for the PL. For example, a reference destination WTRU may be determined based on the highest priority data and/or the data with highest reliability and/or lowest latency requirements. Then the PL value between the Tx WTRU and group of Rx WTRUs may be determined by the highest PL between the Tx WTRU and a Rx WTRU within the group of Rx WTRUs. The third example rule may be referred to as Rule 3.

[0159] In a fourth example rule, a reference destination WTRU for a groupcast may be prespecified, configured and/or signaled by one or more RRC messages and/or indicated in an L1/MAC control element (CE). The reference destination WTRU may be dynamically changed. For example, different WTRUs within the group may have different velocities and moving directions, and accordingly, the PL between different WTRUs within the group and the Tx WTRU may vary. If the first example rule is used to determine the initial reference destination WTRU, the reference destination WTRU may change dynamically depending on the PL measurements among the group under the fourth example rule. The fourth example rule may be referred to as Rule 4.

[0160] FIG. 4 is a flow chart diagram illustrating an example of power control for groupcast using a reference destination (RD)-WTRU (RD-WTRU). As shown in an example in flow chart diagram 400, a transmitting WTRU may transmit a groupcast transmission to a group of receiving WTRUs 410. The groupcast transmission may use a transmit power determined based on a Uu PL, a data minimum communication range or both. In an example, the Uu PL may be the PL measured in a transmission between a base station and the transmitting WTRU. The base station may be a gNB, in an example. In a further example, the transmitting WTRU may be an NR WTRU. In an additional example, one or more of the receiving WTRUs may be an NR WTRU.

[0161] Further, the transmitting WTRU may receive one or more SL-RSRP measurements or SL-RSRP reports from receiving WTRUs in the group of receiving WTRUs 420. In an example, the transmitting WTRU may receive SL-RSRP measurements or SL-RSRP reports from all receiving WTRUs in the group. The terms SL-RSRP measurement and SL-RSRP report may be used interchangeably and still be consistent with the examples and embodiments provided herein.

[0162] Further, the transmitting WTRU may calculate or determine an SL-PL for each receiving WTRU in the group. In an example, the transmitting WTRU may make the calculation or determination based on the received SL-RSRP measurements or SL-RSRP reports from the receiving WTRUs.

[0163] Then the transmitting WTRU may select one of the receiving WTRUs of the group as a RD-WTRU based on the calculated or determined SL-PL for each receiving WTRU 430. In an example, the RD-WTRU may be selected based on using a highest SL-PL of the calculated SL-PLs. In another example, the RD-WTRU may be selected based on using a lowest SL-PL of the calculated SL-PLs. In a further example, the RD-WTRU may be selected based on using a median SL-PL of the calculated SL-PLs. In still another example, the RD-WTRU may be selected based on using an average SL-PL of the calculated SL-PLs. In yet a further example, the RD-WTRU may be selected based on using a mode SL-PL of the calculated SL-PLs.

[0164] Accordingly, the transmitting WTRU may transmit an indication of the selected RD-

WTRU to the group of receiving WTRUs 440. The indication may be transmitted via L1 signaling. For example, the indication may be transmitted using SCI. In another example, the indication may be transmitted using DCI. In a further example, indication may be transmitted using RRC signaling. In an additional example, indication may be transmitted using other, higher layer signaling. In examples, the indication may be transmitted as an index, pointer or the like.

[0165] Further, the transmitting WTRU may receive an SL-RSRP measurement or SL-

RSRP report from the selected RD-WTRU 450. In an example, the transmitting WTRU may not receive an SL-RSRP measurement or SL-RSRP report from another receiving WTRUs in the group. In another example, the transmitting WTRU may receive an SL-RSRP measurement or SL-RSRP report from another receiving WTRU in the group. Moreover, the transmitting WTRU may calculate or determine an SL-PL for the selected RD-WTRU. In an example, the SL-PL for the selected RD- WTRU may be calculated or determined based on the received SL-RSRP measurement or SL- RSRP report from the selected RD-WTRU.

[0166] Accordingly, the transmitting WTRU may calculate or determine a groupcast transmit power based on the determined SL-PL for the selected RD-WTRU 460. Additionally or alternatively, the groupcast transmit power may be calculated or determined based on a data minimum communication range. Moreover, in an example, the transmitting WTRU may calculate or determine a groupcast transmit power based on the determined SL-PL for the selected RD-WTRU and a data minimum communication range.

[0167] The transmitting WTRU may transmit one or more groupcast transmissions to the group of receiving WTRUs using the calculated or determined groupcast transmit power 470. The one or more groupcast transmissions may include one or more data transmissions, one or more control transmissions or both.

[0168] In a further example, the transmitting WTRU may determine whether to switch to using SL-PL feedback from all receiving WTRUs in the group 480. If the transmitting WTRU does not make this switch, the transmitting WTRU may then receive a further SL-RSRP measurement or SL-RSRP report from the RD-WTRU as in step 450 and continue the process from that point, as shown in FIG. 4. If the transmitting WTRU does make this switch, the transmitting WTRU may then receive one or more additional SL-RSRP measurements or SL-RSRP reports from receiving WTRUs in the group of receiving WTRUs an in step 420 and continue the process from that point, as shown in FIG. 4. Further, the transmitting WTRU may determine whether to switch to using SL- PL feedback from all receiving WTRUs in the group based on an RRC configuration. The transmitting WTRU may receive the RRC configuration during the process as shown in FIG. 4, or may have received the RRC configuration before beginning the process. Additionally or alternatively, the transmitting WTRU may determine whether to switch to using SL-PL feedback from all receiving WTRUs in the group based on an RD-WTRU SL-PL measurement threshold. In an example, the transmitting WTRU may switch based on an SL-PL that exceeds the RD-WTRU SL-PL measurement threshold. In another example, the transmitting WTRU may switch based on an SL-PL that falls below the RD-WTRU SL-PL measurement threshold. In a further example, the transmitting WTRU may switch based on not receiving an SL-PL that exceeds the RD-WTRU SL-PL measurement threshold within a certain amount of time. In an additional example, the transmitting WTRU may switch based on not receiving SL-PL within a certain amount of time.

[0169] In an additional example, the transmitting WTRU may receive one or more SL-

RSRP measurements or SL-RSRP reports from receiving WTRUs in the group of receiving WTRUs. Further, the transmitting WTRU may calculate or determine an SL-PL for each receiving WTRU in the group. The transmitting WTRU may then select one of the receiving WTRUs of the group as a RD-WTRU based on the calculated or determined SL-PL. Further, the transmitting WTRU may then calculate or determine a groupcast transmit power based on the already calculated or determined SL-PL for the selected RD-WTRU. The transmitting WTRU may then transmit one or more groupcast transmissions to the group of receiving WTRUs using the calculated or determined groupcast transmit power. In an example, the transmitting WTRU may transmit an indication of the selected RD-WTRU to the group of receiving WTRUs.

[0170] Feedback-dependent closed-loop power control example may be provided herein for groupcast, for unicast or for both. In an example, unicast may be treated as a special case of groupcast which may only consist of one receiver identifier (ID) or one destination ID for the groupcast transmission. If the feedback, which may include TPC feedback, hybrid automatic repeat request (HARQ) feedback or both, is not supported or is disabled in at least one or any combination of a semi-static way, a dynamic way or an implicit way in groupcast and/or unicast sidelink, the close loop power control may not be used, and instead the open-loop power control which may be based on any of the PL methods proposed for groupcast elsewhere herein may be used to determine the transmit power in the WTRU. In an example, the semi-static way maybe be through an RRC configuration. In another example, the dynamic way may be through a DCI indication, an SCI indication or both. In a further example, the implicit way may be an automatous determination based on a pre-defined rule and/or configured/signaled/indicated parameters such as a group size and the associated closed-loop power control disabling/enabling threshold based on the group size. In a further example, closed-loop power control may be enabled and/or disabled based on QoS and/or load for a better tradeoff between TPC feedback signal overhead/system performance and system resource utilization. For example, in a highly loaded system, closed-loop power control may be disabled to reduce the TPC feedback overhead and thereby avoid the congestion for the data transmission. In comparison, in a low load system, closed-loop power control may be enabled to improve system performance. In a low or moderately loaded system, some WTRUs or some groups of WTRUs with higher QoS requirements may be enabled to use the closed-loop power control to meet high QoS requirement; while the other WTRUs or the other groups of WTRUs with lower QoS requirement may be disabled from using the closed-loop power control to reduce TPC feedback signal overhead and provide better system resource utilization. If the feedback, TPC feedback or HARQ feedback is supported or enabled in at least one of a semi-static way, a dynamic way or an implicit way in groupcast and/or unicast sidelink, the power control related parameters may be sent and closed-loop power control may be used based on the feedback, such as TPC feedback. The power control related parameters may be pathgain, pathloss and/or TPC command(s), which could be either accumulated value or absolute value. A two-bits TPC command could be used to indicate (-1 , 0, 1 , 3) dB of accumulated value or (-4, -1 , 1 , 4) dB of absolute value. It is possible to use a one- bit TPC command to indicate (-1 , 1 ) dB of accumulated value.

[0171] The TPC command may be a separate field in the feedback information. It may be separately or jointly encoded with other parameters in the feedback information. It can be jointly encoded with HARQ-acknowledgement (ACK) bit(s). A total of two bits may be assumed here: a first bit may indicate ACK/negative acknowledgement (NACK), and the second bit may indicate TPC accumulated value of 0 dB or 1 dB. For example, the bits“00” may imply the NACK and 1 dB of accumulated value, the bits“01” may imply the NACK and 0 dB of accumulated value, the bits“1 1” may imply the ACK and 0 dB of accumulated value, and the bits“10” may imply the ACK and 1 dB of accumulated value.

[0172] In groupcast sidelink, the TPC command feedback from different receiving WTRUs may indicate different power control directions. The transmitting WTRU may need to combine these feedbacks to make a power control decision. It may take the average of the TPC command feedback, it may take the worst-case scenario, for example, the largest TPC command feedback, or it may only consider the feedback from a smaller set of receiving WTRUs. For example, a group member in a vehicle platoon may take the feedback from the platoon lead, the front vehicle of the platoon, or the end vehicle of the platoon.

[0173] In another example, if the group size or the number of group member(s) is larger than the pre-specified, configured or signaled threshold, the transmitter WTRU may ignore all TPC commands and disable or not execute the closed-loop power control to determine the transmission power for the next transmission. Further, the WTRU may use any pathloss based the open-loop power control scheme proposed herein, keep the same transmission power as previous transmission(s), for example, the last transmission or the average of the previous N transmission(s), or simply increase or decrease the power for the next transmission based on the high or low data QoS requirement. If the group size or the number of group member(s) is smaller than the prespecified, configured or signaled threshold, the transmitter WTRU may take into account the received TPC commands and execute the proposed closed-loop power control to determine the transmission power for the next transmission.

[0174] The TPC command may also be included in the SCI of the data transmissions. It may indicate information to the receiving WTRU for its future control information transmissions.

[0175] Example mechanisms of power control for vehicle platooning are described herein.

In NR V2X, the transmitting WTRU may be required to control the communication range of the V2X message sent in sidelink, based on one or more characteristics of the messages. An accurate and efficient power control scheme is desired to control the transmitting power of the message, which may differ from one sidelink destination to another. Especially for a platooning scenario, a typical size of a platoon may be limited, so the maximum power may not be desired due to the short- distance between adjacent vehicles within a platoon. For example, larger power may only be needed for the platoon leader while smaller power may be used for platoon members. Furthermore, different platoons may have different sizes. From a privacy and security perspective, efficient power control mechanisms may be provided below to reduce the interference and improve the energy efficiency for vehicle platooning in NR V2X.

[0176] In a vehicle platooning scenario, sidelink power control may be considered in at least the following example multiple links. The example multiple links may include one or more of: a unicast link between a platoon leader (PTL) and a road side unit (RSU) or between one PTL and another PTL, a groupcast link between an RSU and multiple PTLs, a groupcast link between a PTL and multiple platoon members (PTMs) within a group, a unicast link between a PTL and PTMs, and a unicast/and or groupcast link between one PTM and other PTMs.

[0177] Side power control may be used in a unicast link between a PTL and an RSU or between one PTL and another PTL. For example, there may be multiple platooning groups near each other. To avoid interference and traffic collision between different platooning groups, crossgroup coordination may be needed. The coordination messages may be communicated by unicast or by broadcast/groupcast. In an example, the coordination messages communicated by unicast may be between two PTLs. In a further example, the coordination messages communicated by broadcast/groupcast may be between the RSU and multiple PTLs.

[0178] Side power control also may be used in a groupcast link between an RSU and multiple PTLs. In some application scenarios such as emergency cases, an RSU may need to broadcast messages to all nearby platooning groups. Emergency cases may include, for example, an earthquake, hurricane, tornado, tsunami, forest fire, road way construction, and the like. In some less emergent cases, for example, traffic congestion in an area, an RSU may need to groupcast to only large size of platooning groups for traffic avoidance while not interfering with other, small size platooning groups.

[0179] In addition, side power control may be used in a between a PTL and multiple PTMs within the group. In an example, status information such as speed, heading and intentions may be spread to PTMs within the group for platoon management and distance maintenance between adjacent vehicles. Intentions may include, for example, braking, acceleration, and the like. Further, platoon management may include, for example, lane changing, merging, passing other vehicles outside the platoon group and the like.

[0180] Further, side power control may be used in a unicast link between a PTL and

PTMs. Group join events, update events and leave events may happen as needed. Further, a PTL vehicle may request a specific PTM to be a leader. For example, if a platoon group is cut into two parts when crossing a road intersection, then such a request may be made. Also, aperiodic information may be exchanged between a PTM and the PTL. For example, a PTM may update the surrounding traffic data to the PTL.

[0181] Moreover, side power control may be used in a unicast link, a groupcast link or both between one PTM and other PTMs. In an example, one PTM may communicate with adjacent PTMs to maintain the vehicle-to-vehicle distance.

[0182] The above links may be differentiated by two categories: intra-group communication links and inter-group/external-group communication links. In power control, it may be beneficial to configure/indicate or specify two sets of parameters. The two sets may include intra-group communication links and inter-group/external-group communication links.

[0183] Intra-group communication links may involve relatively fixed directions, distances and unobstructed transmissions. Path loss and close-loop feedback may not need to be determined before each PSCCH/PSSCH transmission. Power control parameters may need to be adjusted/compensated for an individual platooning group because each platoon group has a different length and each PTM within the group may have a different distance between the PTL and PTMs. Further, the distances may be precisely estimated, for example, due to a relatively fixed vehicle-to-vehicle distance. The power control parameters may adjusted/ compensated, for example, with configurable offset value(s) or scaling factor(s). Interference to other vehicles within the group or outside the group may be minimized if the power control parameters are optimized. As a result, the spectral efficiency may be improved since low interference results in a high reuse rate of spectral resources. For example, the same resources may be allocated to two simultaneous links if the two links are not interfering each other, resulting in improved spectral efficiency.

[0184] Inter-group or external-group communication links are typically with diverse directions and distance, but with predictable path distance. Path loss and close-loop feedback may be needed before each PSCCH/PSSCH transmission. With predictable path distance, the power control parameters may be adjusted as a function of the distance as well.

[0185] FIG. 5 is a signaling diagram illustrating an example of TPC commands for efficient power control in vehicle platooning. In an example shown in signaling diagram 500, when a platoon member transmits PSSCH/PSCCH to next platoon member, the transmit power may be determined such that the PSSCH/PSCCH may be properly received by the target receiver but generate minimum interference to other vehicles. An example is shown in FIG. 5, where the platoon member i has data for the member i+1 , both member i+1 and the member i+2 may send TPC feedback to the transmitter member i. Two types of TPC feedback may be used as follows.

[0186] A first type of TPC feedback may be used. The type for TPC feedback may be from target receiver(s). It may indicate whether the transmit power used in the last transmission is large enough for proper reception at the receiver. This type of TPC feedback may be considered to be positive feedback. The content of the feedback may indicate power increase or decrease, but the feedback itself is considered as a positive feedback. The first type of TPC feedback may be referred to as TPC feedback type 1.

[0187] In an example shown in signaling diagram 500, when a platoon member i may have data to transmit to member i+1. Platoon member i may then initially determine a transmit power 510. Accordingly, platoon member i may transmit data to target receiver member i+1 520, based on the determined transmit power. Platoon member i+1 may then send TPC feedback 1 back to member i 530. The TPC feedback 1 may be the first type of TPC feedback. Member i may then determine a new transmission power 590 and may incorporate the TPC feedback 1 in its determination.

[0188] A second type of TPC feedback may be used. The type for TPC feedback may be from non-target receiver(s). It may indicate whether the transmit power used in the last transmission is large enough for unacceptable interference at the non-target receiver(s). This type of TPC feedback may be considered to be negative feedback. The content of the feedback may indicate that transmission power may be increased since the interference level is very small or the transmission power should be decreased since the interference level is too high. The second type of TPC feedback may be referred to as TPC feedback type 2.

[0189] Further, this type of TPC feedback may be sent to nearby neighbors and then forwarded to the transmitter member, which may be called forward mode, a first mode or mode 1. Alternatively, this type of TPC feedback may directly sent to the transmitter member, which may be called direct mode, a second mode or mode 2.

[0190] As shown in signaling diagram 500, platoon member i+2 may be a non-target receiver which may encounter unacceptable interference due to the data transmission from member i to target receiver member i+1 520. Accordingly, platoon member i+2 may send TPC feedback 2 back to member i. The TPC feedback 2 may be the second type of TPC feedback. Further, the TPC feedback 2 may be sent by forward mode, by direct mode or by both modes.

[0191] For example, platoon member i+2 may send the TPC feedback 2 to member i+1 by forward mode 540. As a result, platoon member i+1 may forward the received TPC feedback 2 to member i 550. Member i may then determine a new transmission power 590 and may incorporate the TPC feedback 1 , the TPC feedback 2 or both in its determination.

[0192] Further example, platoon member i+2 may send the TPC feedback 2 to member i+1 by direct mode 560. Accordingly, member i may receive the TPC feedback 2 by forward mode, by direct mode or by both. Member i may then determine a new transmission power 590 and may incorporate the TPC feedback 1 , the TPC feedback 2 or both in its determination.

[0193] Moreover, the transmission power may be calculated to avoid interfere at members starting from the k-th platoon member after the target member(s). In this case, the platoon member that sends the type 2 TPC feedback may be the k-th platoon member behind the target platoon member. The value of k may be configurable. In an example shown in FIG. 5, the value of k may be 1

[0194] Examples of two-type TPC feedback based power control procedures are provided herein. The examples provided herein may apply to vehicle platooning or other multi-vehicle V2X situations.

[0195] FIG. 6 is a flow chart diagram illustrating an example of closed loop power control for vehicle platooning. In an example shown in flow chart diagram 600, within a platoon, each platoon member, including the special members such as the one or multiple leaders, may become a transmitter dynamically, according to the possible links defined/introduced elsewhere herein. In order to maintain efficient and effective vehicle platooning, each transmission may involve one or multiple target receivers. For example, one PTM may communicate with adjacent PTMs to maintain the vehicle-to-vehicle distance. In the meantime, the adjacent platoon members which are not target receivers but located within the interference/transmission range of the transmitter, may consider the transmission to be interference. As a result, FIG. 6 illustrates a possible flow chart of closed loop power control which may involve three entities: a platoon transmitter, platoon target receiver(s) and platoon non-target receiver(s).

[0196] At one time instance, the platoon transmitter may transmit PSSCH/PSCCH based on assumed power control parameters without close loop feedback, and this transmission may be considered as a last transmission 610. Upon receiving the last transmission, platoon target receiver(s) and non-target receiver(s) may need perform reception evaluation 620, 630 based on certain metrics as below.

[0197] The metrics may be configured or dynamically signaled or indicated to the platoon members. For target receiver(s), the metrics may be SINR, block error rate (BLER), reference signal received quality (RSRQ), received signal strength indicator (RSSI), or any combinations of these, which may be used to evaluate the quality of the received signals. Certain threshold values may be configured/signaled/indicated to be associated with a metric. For non-target receiver(s), the metrics may be RSRP, energy per resource element (EPRE), or any combinations of these, which may be used to evaluate the significance of interference.

[0198] Based on the results of metric evaluation 620, 630, platoon target receiver(s) and non-target receiver(s) may decide whether TPC feedback needs to be sent back to the platoon transmitter or not 640, 650. For example, platoon target receiver(s) may decide whether to send TPC feedback type 1 640. Further, platoon non-target receiver(s) may decide whether to send TPC feedback type 2 650.

[0199] In an example, TPC feedback may not be needed for each received transmission.

In a further example, TPC feedback may be positive or negative, which indicate suggested power increase or decrease respectively at the platoon transmitter for the next transmission. One exemplary criteria may be based on the difference between a measured/estimated metric value and a corresponding configured/specified/indicated threshold value. For example, for target receiver(s), if the configured/indicated SINR value may be X dB, while the actual measured SINR is Y dB, and the difference ratio (positive or negative) is within a certain range, such as 10%, the target receiver(s) may not send TPC feedback.

[0200] In a further example, if platoon target receiver(s), non-target receiver(s) or both decide to send TPC feedback, these receiver(s) need to decide how to send the TPC feedback 660, 670. In an example, a group of factors may be considered for sending TPC feedback. The group of factors may include one or more of TPC command content, which channels and/or resources to be used, a multiplexing method, a transmission mode, power needed or the like. [0201] In terms of the TPC command content, as shown in an example in FIG. 5, there may be two types of TPC commands (or feedback). In one example, the TPC command type may be transparent to the platoon transmitter since the feedback content is simply indicating power increase or power decrease and the platoon transmitter may not need the TPC type information for further interpretation. In another example, the TPC command type information may be useful for the platoon transmitter to make a more optimized power determination. For example, if low SI NR at the target receivers results in a power increase value in one TPC command while high interference measured at the non-target receivers results in a power decrease value in another TPC command, the platoon transmitter may need make a compromise such that signal quality is prioritized. In this case, TPC command type information may be needed. Additionally or alternatively, the platoon transmitter may perform weighted averaging of TPC command value(s) if multiple TPC commands are received. In this case, different TPC command types may be configured/indicated with different weights. An example of non-transparent TPC command content is shown in Table 1 , where the platoon transmitter receives three TPC commands from three neighboring platoon members. Table 1 includes a weighted mapping of TPC command fields for different TPC types.

TABLE 1

[0202] For target receiver(s), the TPC command may be multiplexed or piggybacked on existing channels/resources since some messages like FIARQ or/and response transmissions may be needed fairly regularly. For non-target receiver(s), the TPC feedback command may impose an extra transmission cost and a dedicated transmission may be needed. In this case, two extra steps may be needed.

[0203] For example, a determination of resources, channels or both may be made.

Sidelink sensing may be performed and the latency may depend on whether forward mode or direct mode is used for transmitting the TPC feedback type 2. The sidelink sensing may be based on decoding of sidelink control channel transmissions, sidelink measurements or/and detection of sidelink transmissions. [0204] In a further example, a determination of power may be made. If the non-target receivers have simultaneous transmission of NR and LTE V2X sidelink transmissions, mechanisms for sharing the total device power may be needed. In addition, depending on the selection of forward mode or direct mode, the power may be determined without causing significant interference to target receivers.

[0205] Once the platoon transmitter receives TPC feedback from one or multiple target or non-target receiver(s) 680, it may need to combine multiple open loop and closed loop power parameters and determine a single transmission power value to be used for the next transmission. In this case, the platoon transmitter may need to perform inter-WTRU and intra-WTRU power collision handling 685 as detailed below.

[0206] The platoon transmitter may perform inter-WTRU power collision handling 685 in example cases. In an example case, a conflict may arise between desired signal quality at target receiver(s) and minimized signal interference at non-target receiver(s). One solution may be based on the proper combinations of multiple TPC feedback commands such as the example shown in Table 1. Based on Table 1 , the final power adjustment value may be a weighted average value from the three received TPC command values, where TPC feedback type 2 is assigned with a weight value 0.25, while TPC feedback type 1 is assigned with a weight value 0.5.

[0207] In another example, the final transmission power may be decided according to the methods and formulas proposed elsewhere herein. In a further example, the final transmission power may be decided according to any combination of the weighted average closed loop power parameters and the formula proposed elsewhere herein.

[0208] The platoon transmitter may perform intra-WTRU power collision handling 685 in example cases. In an example case, a conflict may arise between simultaneous transmission, for example, FDM transmission, of sidelink transmissions for sharing total device power. Such an example case may arise due to the coexistence of NR and LTE V2X on the WTRU. In addition, a V2X WTRU may have multiple active connections over sidelink such as video sharing, platooning, and the like.

[0209] In this case, prioritized transmission may need to be considered for power sharing among multiple simultaneous transmissions. The prioritization rules may take any combination of following aspects into account. For example, control signals may have priority over data signals. Further, for the same type of transmission, the traffic with higher priority value may be assigned with enough power first. Types of transmissions may include a platoon control message, data sharing messages, and the like. [0210] Further, a scalable adjustment may be made if one or more requirements are configured, indicated or both. The one or more requirements may include one or more of priority, latency, reliability or minimum communication range. Here scalable adjustment may include that the power is assigned such that the base requirements should be satisfied. For example, traffic A requires power from X1 to X2 in order to get minimum required SINR or maximum required SINR, and traffic B requires power from Y1 to Y2 in order to get minimum required reliability or maximum required reliability. Then the power may be first assigned to traffic A and B with X1 and Y1 respectively, then the possible power value may be gradually increased within the total device maximum power.

[021 1] Further, the platoon transmitter may then decide upon a new transmission power for the next transmission 690. The platoon transmitter may incorporate feedback from platoon target receiver(s), platoon non-target receiver(s) or both in its determination regarding a new transmission power for the next transmission. Further, in examples, the platoon transmitter may incorporate the TPC feedback 1 , the TPC feedback 2 or both in its determination. The platoon transmitter may then transmit its next transmission 695. The next transmission may include a PSSCH, a PSCCH or both.

[0212] Further, one of ordinary skill in the art will understand and appreciate that a transmitter may transmit to and receive feedback from target receivers(s) and not non-target receivers(s), and would still be consistent with examples and embodiments provided herein. Similarly, one of ordinary skill in the art will understand and appreciate that a transmitter may transmit to and receive feedback from non-target receivers(s) and not target receivers(s), and would still be consistent with examples and embodiments provided herein. Further different TPC feedback types may be used and still be consistent with examples and embodiments provided herein.

[0213] Examples of power sharing between LTE sidelink transmissions and NR sidelink transmissions are provided herein. In an example, in-device coexistence between LTE sidelink and NR sidelink could occur via the power sharing of the LTE sidelink transmissions and NR sidelink transmissions. The power sharing could be performed in a semi-static way, in a dynamic way or in a combination of ways.

[0214] Examples of semi-static power sharing between LTE sidelink and NR sidelink are provided herein. If a WTRU is in dual mode, for example, operating on both LTE sidelink and NR sidelink, a new maximum transmit power

^may be defined for LTE sidelink, which may be configured by higher layers. This maximum transmit power could be used to replace the maximum transmit power P_CMAX used in the existing LTE power control formulas. In an example, PCMAX^LTE £ PCMAX For example, the transmit power for PSSCH may be given by

PL}

Equation (42)

[0215] Similar modifications may apply to LTE PSCCH power control in case the WTRU is in dual mode. Similarly, a new maximum transmit power P_EMAX^{NR m}ay be defined for NR sidelink, which may be configured by higher layers. This maximum transmit power could be used to replace the maximum transmit power P_CMAX used in the NR power control formulas without dual mode. This replacement may be applied to both FDM-based and TDM-based PSCCH/PSSCH multiplexing.

[0216] Examples of dynamic power sharing between LTE sidelink and NR sidelink are provided herein. In an example, power sharing between LTE sidelink and NR sidelink could be performed in a dynamic fashion. In semi-static power sharing, the maximum transmit power of LTE sidelink or NR sidelink may not be utilized if LTE sidelink or NR sidelink is not simultaneous even if the WTRU is in the dual mode. This may reduce the transmission reliability of LTE sidelink and NR sidelink.

[0217] With dynamic power sharing between LTE sidelink and NR sidelink, the maximum transmit power of LTE sidelink or NR sidelink could be utilized whenever LTE sidelink and NR sidelink are not transmitted at the same time. In an example, suppose LTE sidelink has the transmit power of P_LTE and NR sidelink has the transmit power of P_NR. The maximum transmit power of the device may be P_limit. If P_LTE + P_NR £ P_limit, then the transmit power of P_NR and P_LTE may not need to be adjusted. If P_LTE + P_NR > Pii_mit, then the transmit power of P_NR and P_LTE may need to be adjusted. The adjusted transmit power for LTE sidelink may be denoted as P'_LTE and the adjusted transmit power for NR sidelink may be denoted as P'_NR. Let b = P_LTE + P_NR - Pi_irnit. Note the units of the power values are in dBm. An example setting could include the following:

P'LTE — PLTE ^ai ^' b

Equation (43) P'NR ⁼ PNR— ^a2 b

Equation (44) [0218] In an example, the values of a_1 and a_2 may be configured by higher layers, which may lead to semi-static power sharing but depend on the power outage value. In a further example, values of a and a₂ may be fixed, which may lead to proportional power reduction on LTE sidelink and NR sidelink. For example, a_t = a ₂ = ^maY provide equal power reduction on LTE sidelink and NR sidelink.

[0219] In a further example, the values of a and a₂ may depend on LTE data QoS and

NR data QoS. The priority level of the data may be taken as examples in the following discussion. In LTE V2X, the priority level ( PR_LTE ) may be between 1 and 8. In examples, the lower the PR value, the higher the priority. Examples herein assume in NR V2X, the similar PR levels ( PR_nr ) may be defined.

[0220] One way of setting a₁ and a₂ is based on the comparison of LTE data priority level and NR data priority level. For example, the below may apply:

if P RLTE > P PNR’

a₁ = 1, a₂ = 0;

else if PR_LTE < PR_NR

a₁ = 0, a₂ = 1

else ai = ^a2 = \

end

Equation (45)

[0221] In NR sidelink, the priority, for example, ProSe per-packet priority (PPPP), and other parameters, for example, latency, reliability, minimum required communication range, and the like, may be known to the physical layer. The latency and reliability of NR sidelink data could be also taken into account in prioritizing the NR sidelink transmit power over the LTE sidelink transmit power. The prioritization process between NR sidelink and LTE sidelink could follow one or any combination of the schemes proposed, depending on comparing QoS parameters of NR sidelink and QoS parameters of LTE sidelink. Examples of QoS parameters of NR sidelink may include priority, latency, reliability, minimum required communication range, and the like. Examples of QoS parameters of LTE sidelink may include priority and the like. In examples, the prioritization may follow a PPPP first and latency second scheme, a latency first and PPPP second scheme, a PPPP first and reliability second scheme, or a reliability first and PPPP second scheme. Once the prioritization of NR sidelink and LTE sidelink is determined, the transmit power level could be determined using an above scheme. [0222] Another way of setting a_x and a₂ may be based on the precise value of the priority level. The transmit power level may be proportional to the data priority level. For example, the following may apply: a _ PRLTE

Equation (46)

¹ P^RLTE+P^rNR

a₂ = ^PRNR Equation (47)

P^RLTE+P^rNR

[0223] In examples provided herein, the presented solutions may be applied on the basic model for PSCCH and PSSCH power control, but may be extended or applied to other channels and physical signals where appropriate. A similar process holds for other sidelink channels without loss of generality.

[0224] Although the solutions described herein consider NR, 5G, LTE, or LTE-A specific protocols, one of ordinary skill in the art will understand that the solutions described herein are not restricted to these scenarios and are applicable to other wireless systems such as those based on IEEE 802.1 1 technologies as well.

[0225] 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, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks

(DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

CLAIMS What is claimed:

1. A method performed in a first wireless transmit/receive unit (WTRU) for groupcast power control, the method comprising:

receiving one or more sidelink (SL)-sidelink reference signal received power (RSRP) (SL- RSRP) reports from one or more second WTRUs of a group of second WTRUs;

determining a first SL pathloss (PL) (SL-PL) for each of the second WTRUs based on the received one or more SL-RSRP reports from the one or more second WTRUs;

selecting one of the second WTRUs of the group as a reference destination (RD)-WTRU (RD-WTRU) based on the first SL-PL for each of the second WTRUs;

transmitting an indication of the RD-WTRU to the group;

receiving an SL-RSRP report from the RD-WTRU;

determining a second SL-PL for the RD-WTRU based on the received SL-RSRP report from the RD-WTRU;

determining a first groupcast transmit power based on the second SL-PL for the RD-WTRU; and

transmitting one or more groupcast transmissions to the group using the first groupcast transmit power.

2. The method of claim 1 , wherein the first WTRU is a new radio (NR) WTRU and at least one second WTRUs is an NR WTRU.

3. The method of claim 1 , wherein the first WTRU is a transmitting WTRU and at least one second WTRU is a receiving WTRU.

4. The method of claim 1 , wherein at least one of the groupcast transmissions is a data transmission.

5. The method of claim 1 , wherein at least one of the groupcast transmissions is a control transmission.

6. The method of claim 1 , wherein the RD-WTRU is selected based on at least one of a highest SL-PL, a lowest SL-PL, a median SL-PL or an average SL-PL.

7. The method of claim 1 , wherein the indication of the RD-WTRU is transmitted via an L1 signaling sidelink control information (SCI).

8. The method of claim 1 , further comprising:

determining whether to switch to all second WTRU feedback based on a radio resource control (RRC) configuration.

9. The method of claim 1 , further comprising:

determining whether to switch to all second WTRU feedback based on an RD-WTRU SL-PL measurement threshold.

10. The method of claim 1 , further comprising:

transmitting one or more groupcast transmissions to the group using a second groupcast transmit power determined based on a Uu PL and a data minimum communication range.

1 1. The method of claim 1 , wherein the first groupcast transmit power determination is further based on a data minimum communication range.

12. The method of claim 1 , wherein at least one of the first WTRU or the second WTRUs is part of a vehicle platoon.

13. A first wireless transmit/receive unit (WTRU) for groupcast power control, the first WTRU comprising:

a transceiver; and

a processor operatively coupled to the transceiver;

wherein:

the transceiver is configured to receive one or more sidelink (SL)-sidelink reference signal received power (RSRP) (SL-RSRP) reports from one or more second WTRUs of a group of second WTRUs;

the processor is configured to determine a first SL pathloss (PL) (SL-PL) for each of the second WTRUs based on the received one or more SL-RSRP reports from the one or more second WTRUs;

the processor is configured to select one of the second WTRUs of the group as a reference destination (RD)-WTRU (RD-WTRU) based on the first SL-PL for each of the second WTRUs;

the transceiver and the processor are configured to transmit an indication of the RD-WTRU to the group;

the transceiver is configured to receive an SL-RSRP report from the RD-WTRU; the processor is configured to determine a second SL-PL for the RD-WTRU based on the received SL-RSRP report from the RD-WTRU;

the processor is configured to determine a first groupcast transmit power based on the second SL-PL for the RD-WTRU; and

the transceiver and the processor are configured to transmit one or more groupcast transmissions to the group using the first groupcast transmit power.

14. The first WTRU of claim 13, wherein first WTRU is a new radio (NR) WTRU and at least one second WTRUs is an NR WTRU.

15. The first WTRU of claim 13, wherein the first WTRU is a transmitting WTRU and at least one second WTRU is a receiving WTRU.

16. The first WTRU of claim 13, wherein at least one of the groupcast transmissions is a data transmission.

17. The first WTRU of claim 13, wherein at least one of the groupcast transmissions is a control transmission.

18. The first WTRU of claim 13, wherein the RD-WTRU is selected based on at least one of a highest SL-PL, a lowest SL-PL, a median SL-PL or an average SL-PL.

19. The first WTRU of claim 13, wherein the indication of the RD-WTRU is transmitted via an L1 signaling sidelink control information (SCI).

20. The first WTRU of claim 13, wherein the processor is further configured to determine whether to switch to all second WTRU feedback based on a radio resource control (RRC) configuration.

21. The first WTRU of claim 13, wherein the processor is further configured to determine whether to switch to all second WTRU feedback based on an RD-WTRU SL-PL measurement threshold.

22. The first WTRU of claim 13, wherein the transceiver and the processor are further configured to transmit one or more groupcast transmissions to the group using a second groupcast transmit power determined based on a Uu PL and a data minimum communication range.

23. The first WTRU of claim 13, wherein the first groupcast transmit power determination is further based on a data minimum communication range.

24. The first WTRU of claim 13, wherein at least one of the first WTRU or the second WTRUs is part of a vehicle platoon.