Methods, architectures, apparatus, and systems for sidelink resource allocation

Abstract

Procedures, methods, architectures, apparatus, systems, devices, and computer program products are described that may be implemented in a wireless transmit / receive unit (WTRU) for sidelink (SL) communications. In one exemplary method, a WTRU estimates a primary direction of SL transmission. A first WTRU derives a paired direction associated with the primary direction. A WTRU may perform SL control information (SCI) detection in the primary and paired directions to detect SL transmissions and / or reservations from other WTRUs. The WTRU may select SL resources using any detected SCI in the primary and paired directions. The WTRU may proceed to transmit SL control and data on the selected SL resources, such as within an SL slot. For example, the transmission of SL control information may include SCI transmissions in the primary and paired directions in the same symbol of the slot.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 239,493, filed Sep. 1, 2021, which is hereby incorporated by reference in its entirety.

[0002] (Field of the Invention) This disclosure generally relates to the fields of communications, software, and coding, including, for example, methods, architectures, devices, and systems for sidelink communications.

Brief Description of the Drawings

[0003] A more detailed understanding may be provided from the following detailed description in conjunction with the accompanying drawings as examples. The figures of such drawings are, like the detailed description, examples. Accordingly, the figures and the detailed description should not be considered limiting, and other equally effective examples are possible and likely. Further, similar reference numerals ( “references”) in the figures indicate similar elements. [Figure 1A] A system diagram illustrating an exemplary communication system. [Figure 1B] A system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A. [Figure 1C] A system diagram illustrating an exemplary radio access network (RAN) and an exemplary core network (CN) that may be used within the communication system illustrated in FIG. 1A. [Figure 1D] A system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A. [Figure 2] A system diagram showing a representative vehicle - to - vehicle (V2V) scenario in which collinear SL communication may occur. [Figure 3] A diagram illustrating an exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a square grid scenario. [Figure 4] This diagram illustrates the exemplary relationship between PRR and periodic traffic intensity in a highway scenario. [Figure 5] This diagram illustrates two typical examples of paired transmitter and receiver configurations. [Figure 6] This diagram illustrates another typical example of a paired transmitter and receiver configuration. [Figure 7] This diagram illustrates two other typical examples of paired transmitter and receiver configurations. [Figure 8] This diagram illustrates another typical example of a paired transmitter and receiver configuration. [Figure 9] This diagram illustrates the structure of an SL slot, such as in the Third Generation Partnership Project (3GPP) Rel-16. [Figure 10] This diagram illustrates a typical structure of a sidelink (SL) slot for a paired SCI. [Figure 11] This diagram illustrates another typical structure of an SL slot for a paired SCI. [Figure 12] This diagram illustrates yet another typical structure of an SL slot for a paired SCI. [Figure 13] This diagram illustrates a typical example of a paired transmitter and receiver configuration for primary SL control information (SCI) received in the primary direction. [Figure 14] This diagram illustrates a typical example of a paired transmitter and receiver configuration for a primary SCI received in the paired direction. [Figure 15] This diagram illustrates a typical example of a paired transmitter and receiver configuration for a paired SCI received in the primary direction. [Figure 16] This diagram illustrates a typical example of a paired transmitter and receiver configuration for a paired SCI received in the paired direction. [Figure 17] This diagram illustrates another exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a square grid scenario. [Figure 18] This diagram illustrates another exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a highway scenario. [Figure 19] This diagram illustrates another exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a square grid scenario. [Figure 20] This diagram illustrates another exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a highway scenario. [Figure 21] This diagram illustrates another typical structure of an SL slot for a paired SCI. [Figure 22] This diagram illustrates typical examples of communication procedures using Type 1 and Type 2 SCIs. [Figure 23] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Figure 24] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Figure 25] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Figure 26] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Figure 27] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Figure 28] This diagram illustrates another typical example of a communication procedure using Type 1 and Type 2 SCI. [Modes for carrying out the invention]

[0004] The following detailed description includes numerous specific details to provide a complete understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details described herein. In other examples, well-known methods, procedures, components and circuits are not described in detail so as not to obscure the following description. Furthermore, embodiments and examples not specifically described herein may be practiced in place of, or in combination with, the embodiments and other examples described, disclosed, or otherwise provided herein, explicitly, implicitly, and / or essentially (collectively, "provided"). While various embodiments are described and / or claimed herein, where apparatus, systems, devices, etc. and / or any elements thereof perform operations, processes, algorithms, functions, etc. and / or any parts thereof, it should be understood that any embodiment described and / or claimed herein assumes that any apparatus, systems, devices, etc. and / or any elements thereof are configured to perform any operation, process, algorithm, function, etc. and / or any part thereof.

[0005] Exemplary communication system The methods, apparatus, and systems provided herein are well suited to communications, including both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with reference to Figures 1A to 1D. In Figures 1A to 1D, various elements of a network may utilize, operate, be arranged according to, and / or be adapted for and / or configured for, the methods, apparatus, and systems provided herein.

[0006] Figure 1A is a system diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, message transmission, and broadcast to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique-word OFDM (UW-OFDM), resource block filter OFDM, and filter bank multicarrier (FBMC).

[0007] As shown in Figure 1A, the communication system 100 may include radio transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, radio access networks (RANs) 104 / 113, core networks (CNs) 106 / 115, public switched telephone networks (PSTNs) 108, the Internet 110, and other networks 112, but it will be understood that the disclosed embodiments intend any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a radio environment. For example, WTRU102a, 102b, 102c, and 102d, all of which may be referred to as “station” and / or “STA”, may be configured to transmit and / or receive radio signals and may include (or be) user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, radio sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other radio devices operating in industrial and / or automated processing chain situations), consumer electronic devices, and devices operating on commercial and / or industrial radio networks. Any of WTRU102a, 102b, 102c, and 102d may interchangeably be referred to as UE.

[0008] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or network 112. As an example, base stations 114a and 114b may be any of the following: base transceiver station (BTS), Node-B (NB), eNode-B (eNB), Home Node-B (HNB), Home eNode-B (HeNB), gNode-B (gNB), NR Node-B (NR NB), site controller, access point (AP), wireless router, etc. Although base stations 114a and 114b are illustrated as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0009] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), and relay nodes. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. Cells may provide coverage of radio services to a particular geographic area that may be relatively fixed or change over time. Cells may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0010] Base stations 114a and 114b may communicate with one or more WTRUs 102a, 102b, 102c, and 102d via a radio interface 116, which may be any suitable radio communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The radio interface 116 may be established using any suitable radio access technology (RAT).

[0011] More specifically, as described above, the communication system 100 may be a multiple access system, but may use one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, base stations 114a of RAN 104 / 113 and WTRU 102a, 102b, and 102c may implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish a radio interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Advanced HSPA (HSPA+). HSPA may include High-Speed ​​Downlink Packet Access (HSDPA) and / or High-Speed ​​Uplink Packet Access (HSUPA).

[0012] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish a radio interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0013] In one embodiment, the base station 114a and WTRUs 102a, 102b, and 102c may implement radio technologies such as NR radio access, which may establish a radio interface 116 using New Radio (NR).

[0014] In one embodiment, base station 114a and WTRU 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRU 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Thus, the radio interface utilized by WTRU 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to and from multiple types of base stations (e.g., eNB and gNB).

[0015] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement wireless technologies such as IEEE 802.11 (i.e., Wireless Fidelity, Wi-Fi), IEEE 802.16 (i.e., WiMAX (Worldwide Interoperability for Microwave Access, WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communication (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0016] The base station 114b in Figure 1A is, for example, a wireless router, home node B, home e-node B, or access point, and can utilize any suitable RAT to facilitate wireless connectivity in local areas such as businesses, homes, vehicles, campuses, industrial facilities, aerial walkways (e.g., for use by drones), roads, etc. In one embodiment, the base station 114b and WTRU 102c, 102d may implement wireless technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and WTRU 102c, 102d may implement wireless technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In one embodiment, the base station 114b and WTRU 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a small cell, picocell, or femtocell. As shown in Figure 1A, base station 114b may have a direct connection to the internet 110. Therefore, base station 114b may not need to access the internet 110 via CN106 / 115.

[0017] RAN104 / 113 can communicate with CN106 / 115, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more WTRU102a, 102b, 102c, and 102d. The data may have various Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements. CN106 / 115 may provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in Figure 1A, it will be understood that RAN104 / 113 and / or CN106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as RAN104 / 113 or different RATs. For example, CN106 / 115 can connect to RAN104 / 113, which may utilize NR radio technology, and may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0018] CN106 / 115 may also function as a gateway for WTRU102a, 102b, 102c, and 102d to access PSTN108, the Internet 110, and / or other networks 112. PSTN108 may include a circuit-switched telephone network providing Plain Old Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices, where these networks and devices use common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) of the TCP / IP Internet Protocol Suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may employ the same RAT as RAN104 / 114, or a different RAT.

[0019] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multimode functionality (for example, WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different radio networks via different radio links). For example, WTRU 102c shown in Figure 1A may be configured to communicate with base station 114a, which may employ cellular-based radio technology, and base station 114b, which may employ IEEE 802 radio technology.

[0020] Figure 1B is a system diagram illustrating an example WTRU102. As shown in Figure 1B, the WTRU102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other elements / peripherals 138. It will be understood that the WTRU102 may include any partial combination of the aforementioned elements while maintaining consistency with one embodiment.

[0021] The processor 118 may be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to a transceiver 120 which may be coupled to a transmit / receive element 122. Although Figure 1B depicts the processor 118 and transceiver 120 as separate components, it will be understood that the processor 118 and transceiver 120 may be integrated, for example, into an electronic package or chip.

[0022] The transmit / receive element 122 may be configured to transmit or receive signals to and from a base station (e.g., base station 114a) via the radio interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR signals, UV signals, or visible light signals. In one embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of radio signals.

[0023] Although the transmit / receive element 122 is illustrated as a single element in Figure 1B, the WTRU 102 may include any number of transmit / receive elements 122. For example, 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 radio signals via the radio interface 116.

[0024] The transceiver 120 may be configured to modulate the signal transmitted by the transmit / receive element 122 and demodulate the signal received by the transmit / receive element 122. As described above, the WTRU 102 may have multimode capabilities. Therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0025] The processor 118 of the WTRU102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) and may receive user input from these. The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from any suitable type of memory, such as non-removable memory 130 and / or removable memory 132, and store data in such memory. 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. Removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from memory not physically located on the WTRU 102, such as on a server or home computer (not shown), and store data in that memory.

[0026] The processor 118 may be configured to receive power from the power supply 134 and distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for supplying power to the WTRU 102. For example, the power supply 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0027] The processor 118 may also be coupled to a 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 instead of, the WTRU 102 may determine its location by receiving location information from base stations (e.g., base stations 114a, 114b) via the radio interface 116 and / or based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information by any preferred location determination method while maintaining consistency with one embodiment.

[0028] The processor 118 may be further coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functions, and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (e.g., for photography and / or video), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. Element / peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, compass sensor, proximity sensor, temperature sensor, time sensor, geolocation sensor, altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor, and / or humidity sensor.

[0029] WTRU102 may include a full-duplex radio in which the transmission and reception of some or all of a signal (e.g., associated with specific subframes for both uplink (e.g., transmission) and downlink (e.g., reception) may be in parallel and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference through signal processing either through hardware (e.g., chokes) or through a processor (e.g., via a separate processor (not shown) or processor 118). In one embodiment, WTRU102 may include a half-duplex radio for the transmission and reception of some or all of a signal (e.g., associated with specific subframes for either uplink (e.g., transmission) or downlink (e.g., reception)).

[0030] Figure 1C is a system diagram illustrating RAN104 and CN106 according to one embodiment. As described above, RAN104 can communicate with WTRU102a, 102b, and 102c via the wireless interface 116 by employing E-UTRA wireless technology. RAN104 can also communicate with CN106.

[0031] RAN104 may include e-nodes-B160a, 160b, and 160c, but it will be understood that RAN104 may include any number of e-nodes-B while maintaining consistency with one embodiment. Each of e-nodes-B160a, 160b, and 160c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the wireless interface 116. In one embodiment, e-nodes-B160a, 160b, and 160c may implement MIMO technology. Thus, e-node-B160a may, for example, use multiple antennas to transmit wireless signals to and receive wireless signals from WTRU102a.

[0032] Each of the e-nodes B160a, 160b, and 160c may be associated with a specific cell (not shown) and configured to handle wireless resource management decisions, handover decisions, user scheduling on uplink (UL) and / or downlink (DL), etc. As shown in Figure 1C, the e-nodes B160a, 160b, and 160c may communicate with each other via the X2 interface.

[0033] The CN106 shown in Figure 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) and a packet data gateway (PGW) 166. Although each of the aforementioned elements is depicted as part of CN106, it will be understood that any one of these elements may be owned and / or operated by an entity other than the CN operator.

[0034] The MME162 can be connected via the S1 interface to each of the e-nodes B160a, 160b, and 160c within RAN104 and can function as a control node. For example, the MME162 may perform roles such as authenticating users of WTRU102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial attachment of WTRU102a, 102b, and 102c. The MME162 may provide control plane functionality for switching between RAN104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0035] The SGW164 can be connected to each of the e-nodes B160a, 160b, and 160c in RAN104 via the S1 interface. The SGW164 can generally route and forward user data packets to and from WTRU102a, 102b, and 102c. The SGW164 can perform other functions such as fixing the user plane during e-node B handover, triggering paging when DL data is available to WTRU102a, 102b, and 102c, and managing and storing the context of WTRU102a, 102b, and 102c.

[0036] SGW164 may be connected to PGW166, which may provide WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and IP-enabled devices.

[0037] CN106 can facilitate communication with other networks. For example, CN106 can provide WTRU102a, 102b, and 102c with access to a circuit-switched network such as PSTN108 to facilitate communication between WTRU102a, 102b, and 102c and conventional terrestrial line communication devices. For example, CN106 may include, or communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that functions as an interface between CN106 and PSTN108. In addition, CN106 may provide WTRU102a, 102b, and 102c with access to another network 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0038] Although the WTRU is described as a wireless terminal in Figures 1A to 1D, in certain representative embodiments, such a terminal is intended to be able to use a wired communication interface (e.g., temporary or permanent) with a communication network.

[0039] In a typical embodiment, the other network 112 may be a WLAN.

[0040] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interfaces with a distribution system (DS) or another type of wired / wireless network that carries traffic within and / or outside the BSS. Traffic originating outside the BSS to an STA may reach and be delivered to the STA via the AP. Traffic originating from an STA to a destination outside the BSS may be sent to the AP and then delivered to its respective destination. Traffic between STAs within the BSS may be sent, for example, via the AP, with the source STA sending traffic to the AP, and the AP delivering the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between a source STA and a destination STA (for example, directly between them) using a Direct Link Setup (DLS). In certain representative embodiments, the DLS may be an 802.11e DLS or an 802.11z Tunneled DLS (TDLS). A WLAN using Independent BSS (IBSS) mode may not have access points (APs), and STAs within or using IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to as the “ad hoc” communication mode in this specification.

[0041] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as the primary channel. The primary channel may be of a fixed width (e.g., a 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by an STA to establish a connection with the AP. In a particular representative embodiment, Carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. In the case of CSMA / CA, an STA, including the AP (e.g., all STAs), may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that STA may be backed off. A single STA (e.g., only one station) may transmit at any given time in a given BSS.

[0042] A high-throughput (HT) STA may use a 40MHz wide channel for communication, for example, by combining a primary 20MHz channel with adjacent or non-adjacent 20MHz channels to form a 40MHz wide channel.

[0043] Very high throughput (VHT) STAs can support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels can be formed by combining multiple consecutive 20 MHz channels. 160 MHz channels can be formed by combining eight consecutive 20 MHz channels, or by combining two non-consecutive 80 MHz channels, which may be referred to as an 80+80 configuration. In the 80+80 configuration, after channel coding, the data can pass through a segment parser that can split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately for each stream. The streams may be mapped to two 80 MHz channels, and the data can be transmitted by a transmitting STA. At the receiver of a receiving STA, the operation described above for the 80+80 configuration is reversed, and the combined data can be transmitted to a media access control (MAC) layer, entities, etc.

[0044] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports bandwidths of 5 MHz, 10 MHz, and 20 MHz in the TV white space (TVWS) spectrum, while 802.11ah supports bandwidths of 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using the non-TVWS spectrum. According to a typical embodiment, 802.11ah may support machine-type communication (MTC), such as MTC devices in a macro-coverage area. MTC devices may have limited capabilities, including support for specific bandwidths and / or limited bandwidths (e.g., support for these only). MTC devices may include batteries with a battery life exceeding a threshold (for example, to maintain a very long battery life).

[0045] A WLAN system capable of supporting multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah includes a channel that can be designated as the primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by an STA from among all STAs operating in a BSS that support the minimum bandwidth operating mode. In the 802.11ah example, the primary channel may be 1 MHz wide for an STA (e.g., an MTC type device) that supports (e.g., only) the 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 detection and / or network assignment vector (NAV) settings may depend on the state of the primary channel. For example, if the primary channel is busy due to an STA (which only supports 1MHz operating mode) transmitting to the AP, a large portion of the frequency band may remain idle and could be considered busy, even if it were available.

[0046] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0047] Figure 1D is a system diagram illustrating RAN113 and CN115 according to one embodiment. As described above, RAN113 employs NR radio technology and can communicate with WTRU102a, 102b, and 102c via the radio interface 116. RAN113 can also communicate with CN115.

[0048] RAN113 may include gNB180a, 180b, and 180c, but it will be understood that RAN113 may include any number of gNBs while maintaining consistency with one embodiment. Each of gNB180a, 180b, and 180c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the radio interface 116. In one embodiment, gNB180a, 180b, and 180c may implement MIMO technology. For example, gNB180a and 180b may use beamforming to transmit and / or receive signals from WTRU102a, 102b, and 102c. Thus, gNB180a may, for example, use multiple antennas to transmit and / or receive radio signals to and from WTRU102a. In one embodiment, gNB180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB180a may transmit multiple elemental carriers to WTRU102a (not shown). A subset of these elemental carriers may lie on the unlicensed spectrum, while the remaining elemental carriers may lie on the licensed spectrum. In one embodiment, gNB180a, 180b, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU102a may receive coordinated transmissions from gNB180a and gNB180b (and / or gNB180c).

[0049] WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using transmissions associated with scalable neurology. For example, OFDM symbol intervals and / or OFDM subcarrier intervals may differ for different transmissions, different cells, and / or different parts of the radio transmission spectrum. WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using subframes or transmission time intervals (TTI) of varying or expandable lengths (e.g., including varying numbers of OFDM symbols and / or varying durations of absolute time).

[0050] gNB180a, 180b, and 180c can be configured to communicate with WTRU102a, 102b, and 102c in standalone and / or non-standalone configurations. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c without accessing other RANs (e.g., e-node-B160a, 160b, and 160c). In a standalone configuration, WTRU102a, 102b, and 102c can utilize one or more of gNB180a, 180b, and 180c as mobility anchor points. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c using signals in unauthorized bands. In a non-standalone configuration, WTRU102a, 102b, and 102c can communicate with and connect to gNB180a, 180b, and 180c, while also communicating with and connecting to other RANs such as e-nodes-B160a, 160b, and 160c. For example, WTRU102a, 102b, and 102c can implement DC principles for substantially simultaneous communication with one or more gNB180a, 180b, and 180c and one or more e-nodes-B160a, 160b, and 160c. In a non-standalone configuration, e-nodes B160a, 160b, and 160c can function as mobility anchors for WTRU102a, 102b, and 102c, and gNB180a, 180b, and 180c can provide additional coverage and / or throughput to service WTRU102a, 102b, and 102c.

[0051] Each of the gNB180a, 180b, and 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data toward User Plane Functions (UPF) 184a and 184b, routing of control plane information toward Access and Mobility Management Functions (AMF) 182a and 182b, and the like. As shown in Figure 1D, the gNB180a, 180b, and 180c may communicate with each other via the Xn interface.

[0052] The CN115 shown in Figure 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. Although each of the aforementioned elements is illustrated as part of the CN115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0053] AMF182a and 182b can be connected to one or more gNB180a, 180b, and 180c in RAN113 via the N2 interface and can function as control nodes. For example, AMF182a and 182b may perform roles such as authenticating users of WTRU102a, 102b, and 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting specific SMF183a and 183b, managing registration areas, terminating NAS signaling, and mobility management. Network slicing may be used by AMF182 and 182b to customize CN support for WTRU102a, 102b, and 102c based on the types of services utilized by WTRU102a, 102b, and 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, and services for MTC access. The AMF162 may provide control plane functionality for exchange between RAN113 and other RANs (not shown) using other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies like Wi-Fi.

[0054] SMF183a and 183b may be connected to AMF182a and 182b in CN115 via the N11 interface. SMF183a and 183b may also be connected to UPF184a and 184b in CN115 via the N4 interface. SMF183a and 183b may select and control UPF184a and 184b and configure the routing of traffic through UPF184a and 184b. SMF183a and 183b may perform other functions such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types may be IP-based, non-IP-based, Ethernet-based, etc.

[0055] UPF184a, 184b may be connected to one or more gNB180a, 180b, 180c in RAN113 via the N3 interface, which may provide WTRU102a, 102b, 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, 102c and IP-enabled devices, for example. UPF184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0056] CN115 can facilitate communication with other networks. For example, CN115 may include, or communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that functions as an interface between CN115 and PSTN108. In addition, CN115 may provide WTRU102a, 102b, 102c with access to another network 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU102a, 102b, 102c may be connected to the local data network (DN) 185a, 185b via UPF184a, 184b through an N3 interface with UPF184a, 184b, and an N6 interface between UPF184a, 184b and DN185a, 185b.

[0057] In view of Figures 1A to 1D and their corresponding descriptions, one or more of the functions described herein may be performed by one or more emulation elements / devices (not shown) with respect to any of the WTRU 102a to d, base stations 114a to b, e-nodes B160a to c, MME 162, SGW 164, PGW 166, gNB 180a to c, AMF 182a to b, UPF 184a to b, SMF 183a to b, DN 185a to b, and / or any other elements / devices described herein. An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0058] Emulation devices may be designed to perform one or more tests on other devices in a laboratory and / or carrier network environment. For example, one or more emulation devices may perform one or more or all of the functions while fully or partially implemented and / or deployed as part of a wired and / or wireless network to test other devices in a communications network. One or more emulation devices may perform one or more or all of the functions while temporarily implemented / deployed as part of a wired and / or wireless network. Emulation devices may be directly coupled to another device for testing purposes and / or may perform tests using terrestrial wireless communication.

[0059] One or more emulation devices may perform one or more functions, including all of the above, while not implemented / deployed as part of a wired and / or wireless communication network. For example, an emulation device may be used in a test laboratory test scenario, and / or in a wired and / or wireless communication network that is not deployed (e.g., for testing purposes), to perform testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation device to transmit and / or receive data.

[0060] The following abbreviations may be used in this specification. CG: Setting Grant CP: Cyclic prefix D2D: Device-to-device Dir: Directionality DL: Downlink DM-RS: Demodulation reference signal HARQ: Hybrid Automated Resend Request LTE: Long-Term Evolution MCS: Modulation coding scheme NR: New Radio OFDM: Orthogonal Frequency Division Multiplexing PSCCH: Physical Sidelink Control Channel PSSCH: Physical Sidelink Data Channel RB: Resource Block RRC: Wireless Resource Control RSRP: Received signal, received power RSSI: Received Signal Strength Indicator Rx: Receiver SCI: Side Link Control Information SL: Sidelink SPS: Semi-Persistent Scheduling SR: Scheduling Request SS / PBCH: Synchronization signal and physical broadcast control channel block S-TMSI: System Architecture Evolution (SAE)-TMSI TB: Send Block TDMA: Time Division Multiple Access TF: Time-Frequency Tx: Transmitter UL: Uplink V2X: Vehicle-to-vehicle to road-to-vehicle

[0061] Introduction D2D communication In Release-12, 3GPP standardized the first version of D2D communication for proximity services. Subsequently, in Release-14, 3GPP standardized LTE V2X based on the 4G LTE cellular standard. Further enhancements were made within 3GPP towards Release-15.

[0062] In parallel, 3GPP standardized the criteria for the 5G NR cellular standard. 5G NR is standardized with a highly flexible and future-oriented design. This involves many advanced features such as flexible neurology, advanced design for transmission control, bandwidth components, transmit configurability, and HARQ-related parameters. Standardization of SL communication by 3GPP was carried out in Release-16, also known as NR SL, which was designed on the NR foundation. As used herein, SL may refer to (e.g., direct) data communication between devices where the data does not pass through the network. However, resource allocation for SL involves various techniques that enable efficient sidelink operation of devices within and / or outside of cell coverage.

[0063] NR SL in Release 16 3GPP Technical Report (TR) 22.886 and Technical Standard (TS) 22.186 each present a description of the use cases and requirements of NR V2X, which form the basis of NR SL research in Rel-16. The use cases can be divided into the following four groups:

[0064] 1) Vehicle-following swarm driving: This group includes use cases for the dynamic formation and management of vehicle groups in a follow-up swarm. Vehicles in the follow-up swarm can periodically exchange data to ensure the swarm functions correctly. The distance between vehicles in the follow-up swarm may depend on the available QoS.

[0065] 2) Advanced Driving: This group includes use cases that enable semi-automated or fully automated driving. In this group, vehicles can share data acquired from local sensors near the vehicle with nearby vehicles. In addition, vehicles can share their driving intentions to adjust their trajectory or steering, which can lead to improved safety and / or improved traffic efficiency.

[0066] 3) Extended Sensors: This group enables the exchange of raw or processed sensor data that can be collected through nearby sensors between the vehicle, RSU, pedestrian devices, and V2X application servers. Its purpose is to improve the perception of the environment beyond the perceptual capabilities of the vehicle's own sensors.

[0067] 4) Remote Driving: This group enables a driver or V2X application located remotely (e.g., remotely controlling) to operate a vehicle. Primary use cases include occupants who are unable to drive themselves, vehicles located in hazardous environments (e.g., construction areas or locations with adverse weather conditions), and complex situations where autonomous vehicles may not be able to operate safely.

[0068] The physical layer structure of NR V2X SL is based on the Rel.-15 NR Uu design. In addition, the physical layer procedures of NR V2X SL reuse some of the concepts of Rel.-14 LTE V2X, and new procedures have been introduced to provide physical layer support for unicast and groupcast transmissions. Both frequency ranges are supported in NR V2X sidelinks, but the design of NR V2X sidelinks is primarily based on FR1. For NR V2X sidelinks, no particular optimization has been performed on FR2, other than addressing phase noise that can become noticeable at high frequencies.

[0069] NR V2X SL transmission uses orthogonal frequency division multiplexing (OFDM) waveforms, including cyclic prefixes (CPs). The sidelink frame structure is organized into radio frames (also referred to as frames), each with a duration of 10 ms. Each radio frame is divided into 10 subframes, each with a length of 1 ms. This physical structure is essentially identical to the 5G NR Uu structure standardized in Rel.-15.

[0070] SL resource allocation 3GPP Rel.-16 provides two designs for SL resource allocation. For devices within cell coverage, SL resource allocation is performed by the gNB 180, which is called Mode 1 resource allocation. SL devices can perform autonomous resource allocation based on detecting the resources themselves that have become available for sidelink communication. This autonomous sidelink resource allocation mode is called Mode 2 resource allocation. In this specification, autonomous resource allocation and Mode 2 resource allocation may be used interchangeably. A device (e.g., an SL device) can perform operations, provided it is operating according to Mode 1 (e.g., after receiving an SL resource allocation from the network) or Mode 2 (e.g., after detecting an SL resource of an available resource).

[0071] Resource allocation - Mode 1 The gNB 180 performs SL resource allocation in Mode 1. Therefore, devices operating under Mode 1 resource allocation must be within network coverage. SL radio resources can be allocated from authorized carriers dedicated to SL communications, or from authorized carriers that share resources between SL and UL communications. SL radio resources can be configured so that Mode 1 and Mode 2 use separate resource pools. One alternative is for Mode 1 and Mode 2 to share a resource pool. Sharing a pool allows for more efficient use of resources, but may lead to conflicts between Mode 1 and Mode 2 transmissions. A Mode 1 UE can inform a Mode 2 UE of resources to be allocated for future transmissions.

[0072] Mode 1 uses dynamic grant (DG) scheduling, similar to LTE V2X Mode 3, but replaces the semi-persistent scheduling of LTE V2X Mode 3 with config-grant scheduling. In DG, a Mode 1 UE must request resources from the base station each time it transmits a TB (and potentially a blind or HARQ retransmission). For this purpose, the UE must send a scheduling request (SR) to the gNB180.

[0073] Requesting resources for each TB increases latency. Mode 1 includes a configured grant scheduling option to reduce latency by pre-allocating SL radio resources. In this scheme, the gNB180 can allocate a set of SL resources to the UE for transmitting multiple TBs. This set of SL resources is called a configured grant (CG). Mode 1 defines two types of SL CG schemes: CG type 1 and CG type 2. Both are configured using radio resource control (RRC) signaling. CG type 1 can be immediately available to the UE until released by the base station (for example, also using RRC signaling). SL CG type 2 can only be used after it has been activated by the gNB180 and until it is deactivated.

[0074] Resource allocation - Mode 2 In SL resource allocation mode 2, the SL device can autonomously select SL resources from the resource pool. In some cases, the SL device may operate without network coverage. The resource pool may be (pre)configured by the base station (e.g., gNB180 or eNB) when the UE is within network coverage. Mode 2 allocation can be performed using dynamic or semi-persistent scheduling methods. The SL device can also reserve future resources indicated through sidelink control information (SCI). Reserved resources may refer to designated resources that the UE reserves for future transmissions by notifying the neighboring WTRU102 using SCI (e.g., first-stage SCI). As is well understood in the art, in the two-stage SCI procedure in 5G NR V2X, the first-stage SCI is carried by a PSCCH transmission, while the subsequent second-stage SCI is carried on the corresponding PSSCH transmission. When using a semi-persistent method, the UE can select and reserve resources for several TB (and their retransmissions) transmissions. The semi-persistent method can be enabled or disabled in the resource pool through (pre-)configuration. To briefly explain resource allocation in Mode 2, one example procedure can be defined as a two-step process consisting of resource identification and resource selection.

[0075] Resource Identification Step: The SL device can determine a suitable time period for transmitting packets (e.g., depending on its delay budget). This time period may be referred to as the resource selection window. The SL device then performs detection in the previous time slot, which may collectively be referred to as the detection window. If the detected Reference Symbol Received Power (RSRP) of the SCI is greater than a configured threshold, all slots containing future reservations or instructions for periodic transmissions are removed. This threshold may depend on the priority of detected transmissions and the priority of intended transmissions. For example, if the remaining resources in the resource selection window fall below 20%, the RSRP threshold can be increased by 3 dB and the process repeated.

[0076] Resource Selection Step: From the candidate resources identified in the Resource Identification Step, the SL device can randomly select a candidate SL Tx resource. Random selection can lead to interference randomization and / or avoid scenarios where neighboring devices have selected the same resource for transmission.

[0077] Detailed instructions for Mode 2 resource allocation are provided in [4], which are reproduced in the following subsections.

[0078] Procedure for determining the subset of resources that should be reported in PSSCH resource selection in SL resource allocation mode 2. In Rel.-16, TS38.214 describes a resource allocation procedure conforming to Mode 2. In Mode 2, the upper layer can request the UE to determine a subset of resources from which to select resources for PSSCH / PSCCH transmission. To trigger this procedure, in slot n, the upper layer provides the following parameters for this PSSCH / PSCCH transmission: - Resource pools where resources are reported - L1 priority, prio TX - Remaining allowable delay time - Number of subchannels to be used for PSSCH / PSCCH transmission within the slot, L subCH - Resource reservation interval P in milliseconds, as needed rsvp_TX . - If, as part of a re-evaluation or preemption procedure, the upper layer requests the UE to determine a subset of resources from which the upper layer will select resources for PSSCH / PSCCH transmission, the upper layer will determine the set of resources (r0, r1, r2, ...) that may be subject to re-evaluation and the set of resources that may be subject to preemption.

[0079]

number

[0080]

Number

[0081]

Number

[0082]

Number

[0083]

Number

[0084]

Number

[0085]

number

[0086]

number

[0087]

number

[0088]

number

[0089]

number

[0090]

number

[0091]

number

[0092]

number

[0093]

number

[0094]

number

[0095]

number

[0096]

number

[0097]

number

[0098]

number

[0099]

number

[0100]

number

[0101]

number

[0102]

number

[0103]

number

[0104]

number

[0105] UE is set S A This information will be reported to the higher layer.

[0106] Resources r from set (r0, r1, r2, ...) i S A If not a member, UE is resource r i The re-evaluation will be reported to the higher layer.

[0107] set

[0108]

number

[0109]

number

[0110]

number

[0111]

number

[0112]

number

[0113] [Table 1]

[0114] [Table 2]

[0115] For very high-frequency carriers, omnidirectional transmission and reception may be impractical due to significant propagation loss, and can also result in significant coverage loss. Larger antenna arrays can be used to increase antenna gain and configure high-gain directional transmission and reception. When legacy-designed autonomous resource allocation procedures are applied to extremely high-frequency carriers, the strong directivity associated with the Tx and Rx beams can significantly degrade performance, and most procedures may not perform adequately. In certain use cases, autonomous resource allocation can be performed in highly directional sidelink systems. If a potential transmitter performs sensing for resource allocation only in its intended transmission direction, it may fail to detect ongoing transmissions between adjacent devices that do not align with the intended transmission direction. This can result in conflicts, potentially exposing one or both transmissions to the risk of false reception. On the other hand, if a potential transmitter can perform sensing for resource allocation omnidirectionally, it will detect surrounding transmissions from all directions, even those that may not be subject to directional degradation. In certain scenarios, performance degradation can occur due to the exposed terminal problem (for example, when a node detects that a resource is busy due to transmissions from other nodes, and transmissions from other nodes are blocked even though they do not cause contention). For example, the exposed terminal problem may result from detection in a broader direction than the target transmission that should be used, and from considering transmissions detected from these broader directions during the resource allocation procedure.

[0116] To take into account the directivity of the transmit and receive beams, an efficient detection-based resource allocation strategy can be implemented for high-frequency systems.

[0117] In highly directional systems operating over very high carrier frequencies (e.g., mm waves and above), problems can arise if the communication pairs of devices are (e.g., nearly) collinear. For example, such directional problems can occur at carrier frequencies of around 6 GHz, and this tendency can become stronger as the frequency increases. A typical collinear scenario occurs in vehicles traveling on roads and highways. Figure 2 is a system diagram showing a typical V2V scenario in which collinear SL communication can occur. For ease of explanation, in Figure 2, we can assume that vehicle 202 is traveling in two directions on a two-lane highway. As those skilled in the art will understand, collinear transmission and / or reception 204 between devices can occur more frequently between vehicles communicating over a sidelink compared to a cellular Uu interface where all mobile devices communicate with a central base station (e.g., gNB180). In certain typical embodiments, efficient autonomous sidelink resource allocation procedures can mitigate contention in such scenarios.

[0118] Simulation of a square grid scenario Figure 3 illustrates the relationship between the packet reception rate (PRR) and periodic traffic intensity (also known as traffic arrival rate) in a square grid system. Figure 3 shows the performance of omnidirectional and directional SCI transmission and detection as traffic intensity increases. Details of the system and parameter settings for the simulation will be described later.

[0119] As seen in Figure 3, when SCI detection and SCI (e.g., first-stage SCI) transmission are performed omnidirectionally (e.g., an omnidirectional-omnidirectional system labeled "omni-omni" in Figure 3), interference reception from all directions can cause many packet failures as the periodic traffic intensity increases up to 1 ms. When the first-stage SCI transmission and detection are performed directionally (e.g., a directional-directional system labeled "dir-dir" in Figure 3), performance is significantly improved compared to the omnidirectional system. In this scheme, the transmitter performs detection only in its target transmission direction, and the receiver receives data only from its intended transmitter direction. Nevertheless, this performance may still not meet QoS requirements. For example, in a square grid scenario with a periodic traffic intensity of 1 ms, the average PRR of the "omni-omni" system decreased to 2.1%, while the average PRR of the "dir-dir" system at the same traffic intensity was 87.8%.

[0120] Highway scenario simulation Figure 4 illustrates the relationship between packet reception rate (PRR) and periodic traffic intensity in a highway scenario (e.g., a collinear scenario). Figure 4 shows the performance of omnidirectional and directional SCI detection and transmission as traffic intensity increases. For vehicle communications, the highway scenario may be more plausible and / or more common than the square grid scenario. As seen in Figure 4, the omnidirectional system (labeled "omni-omni" in Figure 4) shows a significant performance degradation as traffic intensity increases, with an average PRR of 58% at a traffic intensity of 1 ms compared to an average PRR of 85.3% for the "dir-dir" system.

[0121] Figures 3 and 4 illustrate that autonomous sidelink operation may not provide sufficient performance to meet the demands of future applications. For example, with a packet reception rate requirement of 90%, both omnidirectional and directional schemes may fail to guarantee the required QoS at high traffic intensity in highway scenarios. Generally, applications and systems tend to evolve towards higher traffic. This is even more true for future applications envisioned for sidelink-based systems. To provide an acceptable level of QoS metrics, an enhanced solution for SL resource allocation (e.g., in autonomous mode) will be required.

[0122] Overview - SCI transmission and related detection technologies In highly directional systems, collinear transmission can be detrimental due to competition, and this must be considered when performing detection for autonomous resource allocation in SLs. To address this issue in directional SL systems, this specification describes SCI transmission for SL resources suitable for highly directional systems operating at very high carrier frequencies, and extensions for autonomous resource allocation of SLs based on the procedure for resource allocation (e.g., autonomous).

[0123] SCI transmission with a primary direction (0°) and a paired direction (180°) in the opposite direction. In a particular representative embodiment, an SL transmission is transmitted via an SL, where the SL transmission (e.g., SCI) is transmitted in the intended transmission direction (e.g., 0° transmission) and (e.g., subsequently) in the opposite direction to the intended transmission direction (e.g., 180° transmission). For example, the intended transmission direction may be referred to herein as a first direction, a first beam direction, and / or a primary direction. For example, the first beam direction may refer to and / or associated with a first antenna panel, and / or transmission and / or reception through the first antenna panel (with or without the application of specific weighting and / or phase to the antenna elements forming the antenna panel). For example, the antenna panel may refer to an antenna panel radiation pattern or antenna panel directional radiation pattern that appropriately applies weighting and / or phase to direct transmission and / or reception to and from the intended transmission direction. In this specification, “paired direction” may refer to a direction opposite to the intended transmission direction. For example, a paired transmission direction may be referred to herein as a second direction, a second beam direction, and / or a secondary direction. For example, a second beam direction may refer to and / or transmission to and / or reception through a second antenna panel (with or without the application of specific weightings and / or phases to the antenna elements forming the antenna panel). For example, a second antenna panel may refer to an antenna panel radiation pattern or antenna panel directional radiation pattern that appropriately applies weightings and / or phases to direct transmission and / or reception to and from the paired direction. The two transmissions may be performed sequentially, for example, when the SL device uses an antenna panel or set of antennas in different directions for the two transmissions. For autonomous resource allocation, SCI transmission in a paired direction, in addition to the intended transmission direction, achieves technical advantages, which will be apparent to those skilled in the art. As used herein, the terms direction, beam direction, antenna panel, antenna, and / or radiation pattern may be used interchangeably.

[0124] SCI detection with a primary direction (0°) and a paired direction (180°) in the opposite direction. In certain representative embodiments, SCI detection (e.g., for resource allocation) may not be omnidirectional (e.g., as in legacy SL designs) nor limited to the intended transmission direction. For example, a potential transmitter may perform SCI detection (e.g., for autonomous resource allocation) in (i) the intended transmission direction and (ii) a direction paired with the intended transmission direction. An SL device performing the detection may know (e.g., be configured to determine) the sequence of primary and paired SCI transmissions and adapt its received beam accordingly. It is assumed that the SL device can perform detection in the primary and paired directions simultaneously.

[0125] When an SL device is performing detection for its next SL transmission (for example, for autonomous resource allocation) in its intended and paired transmission direction, the SL device detects the majority of transmissions that could potentially put its own transmission at risk of conflict.

[0126] SCI detection in paired direction Figure 5 illustrates two examples of paired transmitter and receiver configurations. In Figure 5 and the following figures, "Tx" refers to a target transmitter SL device 502 (e.g., WTRU102), and "Rx" refers to a target receiver SL device 504 (e.g., second WTRU102). Tx502 can perform SL detection in the intended direction (e.g., for SL autonomous resource allocation) and the paired direction. "TxA" designates another transmitter SL device 506 (e.g., third WTRU102), and "RxA" designates another receiver SL device (e.g., fourth WTRU102). TxA506 and RxA508 form a communicating SL pair, in which TxA506 transmits data to RxA508. In both embodiments of Figure 5, TxA506 is located to the left of Tx502, but the relative positions of Rx504 and RxA508 vary in the embodiments.

[0127] For example, if Tx502 performs sensing only in its intended transmission direction (e.g., toward its intended receiver Rx504), Tx502 will not be able to detect reservations and / or transmissions from TxA506. The intended receiver Rx504 will receive transmissions from TxA506 because it matches the transmission direction of TxA506. By sensing only in the intended transmission direction, Tx502 does not detect reservations and / or transmissions from TxA506. This could lead to Tx502 selecting the same time and frequency resources, potentially causing conflict and interference in both receivers Rx504 and RxA508. This scenario can be avoided if Rx504 transmits some form of feedback and / or participates in a sensing process that provides some information to Tx502.

[0128] For example, Tx502 performs detection in the paired direction and also in the primary (e.g., intended) direction. In doing so, Tx502 can detect reservations and / or transmissions from TxA506. Subsequently, Tx502 may remove the SL resource(s) used and / or reserved by TxA506 from Tx502's list of candidate SL resources. Removal by Tx502 may depend on the estimated SNR of the TxA506 transmission and / or the resource allocation threshold. Based on the decoded SCI from TxA506 in the paired direction, Tx502 may proceed without transmitting. Tx502 may proceed with transmission using SL resources other than those detected by TxA506.

[0129] Figure 6 illustrates another example of a paired transmitter and receiver configuration. In Figure 6, if paired sensing is not properly applied, it can lead to an exposed terminal problem. For example, Tx502 is performing sensing (e.g., for autonomous resource allocation) for a transmission to the intended receiver Rx504. Assume another pair of TxA506 and RxA508 are already communicating with each other, and TxA506 may indicate a reservation for a given time-frequency resource (e.g., by transmitting an SCI). In Figure 6, Tx502 can perform sensing in the paired direction to decode the reservation from TxA506. This can result in a terminal being exposed, in which case transmissions from TxA506 (e.g., SL reservations and / or transmissions) reach the intended Rx508 with minimal power consumption. A terminal exposure is an example of a device being exposed to an interfering signal, and while this resource may be avoided considering the risk of conflict, in practice, this exposure is not detrimental to transmission. Tx502 may be able to estimate the impact of TxA's transmission on the intended receiver Rx504 based on some knowledge of the direction and / or location of Rx. Tx502 can determine that a detected reservation from TxA506 is not detrimental to its transmission (e.g., transmission from Tx502) targeting Rx504, and / or that its transmission (e.g., transmission from Tx502) does not adversely affect reception at RxA508, and Tx502 does not have to remove the detected resource from its candidate list of SL resources. In certain representative embodiments, one or more thresholds may be used in conjunction with the estimated power of TxA (e.g., with respect to the location of Rx) to avoid a terminal exposure. For example, if Tx502 determines that the estimated power of TxA is below a first threshold, and the position of Rx is above a second threshold, then Tx502 can use the SL resources associated with the reservation and / or transmission of TxA.As another example, if Tx502 determines that the estimated power of TxA at the Rx location is below a certain threshold, Tx502 can use the SL resource associated with the reservation and / or transmission of TxA. Otherwise, for example, Tx502 may remove an SL resource from the list of candidate SL resources.

[0130] The effect of SCI transmission in the paired direction In certain representative embodiments, SCI transmission in a paired direction (e.g., paired SCI) can improve detection for directional systems. In some embodiments, this may lead to the terminal being exposed.

[0131] Figure 7 shows two other examples of paired transmitter and receiver configurations, with two collinear arrangements for two pairs of SL devices. In Figure 7, TxA506 transmits to RxA508 indicating a reservation for a future time-frequency resource (e.g., an SL resource). Tx502 performs sensing (e.g., for autonomous resource allocation) to transmit to its intended receiver Rx504. In legacy systems, TxA506 transmits SCI in the intended transmission direction for RxA508 (e.g., transmit only), and Tx502 does not receive or decode its reservation. If the resource selection procedure used by Tx502 selects the same time-frequency resource indicated by TxA506, the two transmissions will compete with the two receivers, potentially leading to detection errors. While it may be possible to avoid this situation by implementing receiver-transmitter coordination, this comes at the cost of delay and additional signaling.

[0132] In a particular representative embodiment, an SL transmitter can transmit SCI in the primary direction and in the paired direction. For example, TxA506 can transmit SCI in the primary direction (e.g., towards the intended receiver RxA) and in the paired direction (e.g., 180° opposite to the intended direction). Tx502 may not receive energy transmitted in the primary direction by TxA506, but Tx502 may receive SCI from TxA506 transmitted in the paired direction. Decoding the paired SCI (e.g., SCI transmitted in the paired direction) transmitted by TxA506 in Tx502 can indicate to Tx502 that a time-frequency resource (e.g., an SL resource) is reserved by TxA506. Tx502 can associate the reserved resource in use by TxA506 with the RSRP estimated while decoding the paired SCI. For example, paired SCI transmissions by TxA506 can allow Tx502 to avoid scenarios where TxA506 could otherwise cause a hidden terminal condition and / or require receiver feedback. It will be understood that in this case, the hidden terminal condition may not be resolvable by obtaining some kind of directional or omnidirectional detection in the target transmitter Tx502. Paired directional SCI transmissions from TxA506 allow Tx502 to receive, decode, and process the reservations transmitted by TxA506.

[0133] Figure 8 illustrates another example of a paired transmitter and receiver configuration that can lead to a terminal exposure condition due to a paired SCI. In Figure 8, TxA506 is transmitting to its intended receiver RxA508. In a particular representative embodiment, in addition to transmitting an SCI in the intended transmission direction toward RxA508, TxA506 also transmits an SCI in the paired direction (e.g., carrying a reservation for future time-frequency resources). The paired SCI targets another transmitter Tx that may be performing detection (e.g., for resource allocation) to transmit to its intended receiver Rx504. Due to relative position and channel realization, the paired SCI from TxA506 can be successfully decoded by Tx502. In this situation, what Tx502 detects is the exposed terminal problem. For example, Tx502 may apply (e.g., determine) information about the position of its intended receiver Rx504 and / or the position of TxA506 to estimate whether TxA506 is located before (e.g., closer to) or after (e.g., further away from) its intended receiver Rx504. If TxA506 is located between Tx502 and Rx504, Rx504 may be affected by interference from TxA506. If TxA506 is located after Rx504 and transmitting in the opposite direction, Rx504 may not be receiving interference from TxA506, or may be receiving only minimal interference. For example, Tx502 may determine and / or receive information associated with the position of Rx, such as information used as part of open-loop power control and / or through processing of signals received from Rx504. For example, Tx502 may determine and / or receive information that estimates the location of TxA506, such as through measurements taken on paired SCIs indicating future reservations. Tx502 may use such information to determine the location of TxA506. For example, if Tx506 is estimated to be located further away from Rx, Tx502 may ignore resource reservation instructions (e.g., SCIs) from TxA506 and / or use the resources associated with resource reservation instructions (e.g., SCIs) from TxA.

[0134] SL control and data multiplexing for SCI TDM transmission in the primary and paired directions. Figure 9 illustrates the structure of an SL slot 902 (e.g., a legacy slot), as in 3GPP Rel-16. As seen in Figure 9, an SL slot 902 may contain 14 symbols (e.g., S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, and S13). The first symbol of an SL slot 901 may be reserved for automatic gain control (AGC). The next two or three (e.g., second, third, and / or fourth) symbols can be used for PSCCH transmission of the SCI, according to the SL configuration. In Figure 9, two symbols are associated with PSCCH transmission. For an SL slot 902 that does not carry HARQ feedback (e.g., by PSFCH transmission), except for the final guard symbol (e.g., S13), the remaining symbols may carry SL data via PSSCH transmission.

[0135] In a particular representative embodiment, primary transmission and paired transmission can be performed sequentially. For example, SL control transmission and SL data transmission may be multiplexed, and SL control transmission may include SCI transmission in the primary direction and paired direction.

[0136] Primary SCI-paired SCI-data Figure 10 illustrates a typical structure of SL slot 1002 for paired SCIs. As seen in Figure 10, SL slot 1002 may contain multiple symbols, such as 14 symbols. Following a first symbol which may be reserved for AGC, one or more symbols (e.g., second and third symbols) may be used for PSSCH transmissions of the primary SCI (e.g., in the intended direction). Following the primary SCI, one or more symbols (e.g., fourth and fifth symbols) may be used for PSSCH transmissions of the paired SCI (e.g., in the paired direction). For example, the same number of symbols as the primary SCI transmission can be used for the paired SCI transmission. In other embodiments, fewer symbols may be allocated to paired SCI transmissions to reduce overhead. The guard period may be included in SL slot 1002 (e.g., within the last symbol of the SL slot).

[0137] One advantage of the SL slot structure in Figure 10 is backward compatibility from a detection perspective. A legacy WTRU102 that performs detection based on (e.g., simply using) the primary SCI transmitted at the beginning of slot 1002 can continue processing the primary SCI. What should be understood from Figure 10 is that two beam switching events occur within slot 1002: first from the primary SCI to the paired SCI, and then from the paired SCI to the primary data. This switching, and the gap resulting from the paired SCI transmission, can affect channel estimation quality. Furthermore, if the SCI is not configured to use all resource blocks (e.g., to insert a new SCI to transmit in an additional direction), some limitations may be imposed on the multiplexing of data within the primary SCI symbol.

[0138] Paired SCI-Primary SCI-Data Figure 11 illustrates another typical structure of the SL slot 1102 for paired SCIs. As seen in Figure 11, the SL slot 1102 may contain multiple symbols, such as 14 symbols. Following a first symbol which may be reserved for AGC, one or more symbols (e.g., second and third symbols) may be used for PSSCH transmissions of paired SCIs (e.g., in the paired direction). Following the paired SCIs, one or more symbols (e.g., fourth and fifth symbols) may be used for PSSCH transmissions of primary SCIs (e.g., in the primary direction). For example, the same number of symbols as primary SCI transmissions may be used for paired SCI transmissions. In other embodiments, fewer symbols may be allocated to paired SCI transmissions to reduce overhead. Guard periods may be included in the SL slot 1102 (e.g., within the last symbol of the SL slot).

[0139] One advantage of the SL slot structure in Figure 11 is that primary control and primary data can be transmitted without gaps, resulting in a single beam switching event from paired SCIs to primary SCIs (assuming, for example, that the AGC symbol is transmitted in the paired direction). It should be understood from Figure 11 that, in the case of a single beam switching event, the AGC symbol may not be available in the primary direction. If the AGC symbol is transmitted in the primary direction, two beam switching events occur within the slot. Furthermore, as seen in Figure 11, primary SCIs and data can be transmitted within a continuous symbol (e.g., without gaps).

[0140] The legacy WTRU102 can only decode paired SCIs, which may seem to present a backward compatibility issue. Primary SCIs received through the primary direction may be ignored (e.g., by the legacy WTRU102) for detection purposes. The legacy WTRU102 can receive paired SCIs in their primary directions and can be used to avoid interference scenarios.

[0141] Primary SCI-Data-Paired SCI Figure 12 illustrates yet another typical structure of the SL slot 1202 for paired SCIs. As seen in Figure 12, the SL slot 1202 may contain multiple symbols, such as 14 symbols. Following a first symbol which may be reserved for AGC, one or more symbols (e.g., second and third symbols) may be used for PSSCH transmission of the primary SCI (e.g., in the primary direction). Following the primary SCI, one or more symbols may be used for PSSCH transmission of data (e.g., in the primary direction). Following the data, before a guard period (e.g., guard symbols), one or more symbols (e.g., 12th and 13th symbols) may be used for PSSCH transmission of the paired SCI (e.g., in the paired direction). For example, the same number of symbols as the primary SCI transmission can be used for the paired SCI transmission. In other embodiments, fewer symbols may be allocated to the paired SCI transmission to reduce overhead. The guard period may be included in SL slot 1202 (for example, within the last symbol of the SL slot).

[0142] The slot structure in Figure 12 may be similar to the legacy SL slot in Figure 9 in terms of the arrangement of the AGC symbol, PSCCH symbol, and PSSCH symbol. One advantage of the SL slot structure in Figure 12 is that the legacy WTRU 102 may be able to decode the second-stage SCI carried by the PSSCH transmission within the PSCCH symbol. In Figures 10 and 11, the legacy WTRU 102 may not be able to decode the second-stage SCI compared to the legacy SL slot 902 in Figure 9 due to the differences in the slot structures shown in Figures 10 and 11. In Figure 12, if the DM-RS for PSSCH is understandable to the legacy WTRU 102, the legacy WTRU 102 may be able to estimate the channel using the DM-RS and decode the second-stage SCI carried by the PSSCH transmission. Furthermore, the AGC, primary SCI, and data may not have gaps in Figure 12 (similar to Figure 10, for example), which can result in better detection quality compared to Figures 10 and 11, etc.

[0143] Although not shown in Figures 10-12, the SL slot may be modified to include a PSFCH symbol. The symbol associated with the paired SCI may follow the data symbol transmitted in the primary direction and may precede the PSFCH symbol. By incorporating the PSFCH symbol, the legacy WTRU102 may be able to receive HARQ feedback.

[0144] For example, the same number of symbols as the primary SCI transmission can be used for the paired SCI transmission. In other embodiments, fewer symbols may be assigned to the paired SCI transmission to reduce overhead.

[0145] Enhanced detection in additional paired directions based on scenarios, terrain, geographical information, lanes, traffic patterns, and / or camera images. In a particular representative embodiment, the WTRU102 is capable of (i) transmitting an SCI in the primary direction of interest toward the intended Rx, and (ii) transmitting an SCI in a paired direction which may be a direction other than the primary direction (e.g., the direction opposite to the primary direction). Paired SCI transmissions can be useful in solving hidden terminal problems and exposed terminal problems, such as in combination with paired sensing for resource allocation which may be performed by the WTRU102 in the primary and paired directions.

[0146] For example, the paired direction may be different from the (e.g., substantially) opposite direction, which is 180° opposite to the intended direction from which the primary SCI is transmitted. In many real-world scenarios arising from road curvature, road bends, and / or properties commonly found in the surrounding terrain, transmitting a paired SCI in a 180° direction may not make sense and / or be the most desirable beam direction for performing paired transmission and / or paired detection. If a vehicle is traveling on a road and on a curve in the road, and the vehicle may attempt and / or perform SL communication with another vehicle, the primary direction may be forward of the vehicle, but the 180° direction may not be the desired paired direction. For example, according to the angled curve of the vehicle path, the paired direction may be selected with respect to a paired detection moving from behind the vehicle. SL devices may have such information from various sources, such as GPS, camera output, and maps in various formats. Unlike a 180° orientation, the SL Tx can select a paired orientation that adapts to the environment based on information available from different sensors.

[0147] In certain embodiments, WTRU102 may be capable of SL transmission with a variable beamwidth, and further, WTRU102 may need to perform sensing with a beam slightly wider in the paired direction compared to the intended direction of the primary SCI transmission, or transmit an SCI (e.g., a paired one). WTRU102 may be configured to transmit with two or more beams to achieve effective wide-angle coverage in a given direction. For example, WTRU102 may transmit two additional beams (e.g., paired SCIs) on each side of its intended direction.

[0148] In certain embodiments, if a vehicle is traveling in the far right (or far left) lane, it may determine that there are no lanes further to the right (or left) (e.g., no vehicles), and therefore may not perform paired SCI transmissions using an additional beam or beamwidth in that direction.

[0149] In a particular embodiment, when the vehicle is turning, the vehicle's WTRU102 may decide to align the primary beam and / or paired beams for SL detection and / or SL transmission along this turning.

[0150] In certain embodiments, if several vehicles are stuck or in a collision area (e.g., by camera imaging), the detection direction and / or transmission direction may be aligned to that direction for the purpose of information gathering and / or avoidance.

[0151] In certain embodiments, there may be one or more paired directions. Additional paired directions may be derived based on information collected through different sensors. In certain embodiments, additional paired directions may be added after receiving feedback from the intended receiver. For example, if Rx is experiencing strong interference from a given angle, Rx may indicate an angle relative to Tx. Tx can then add this position and / or angle to determine an additional paired direction and perform paired SL transmission and / or SL transmission in this direction.

[0152] For example, if there is only one paired direction that may differ from the 180° direction, the control and data multiplexing in the SL slot structure described herein can be used to simultaneously transmit the paired SCI using two antennas or antenna panels. If there are multiple paired directions, the SL slot structure described herein may allow the SL device to transmit and / or receive from multiple directions simultaneously.

[0153] Detection guidelines and thresholds In certain representative embodiments, primary transmission and paired SCI transmission may be performed in a TDMA manner. Multiplexing may be directed according to the selected design. Many SL devices may have multiple antennas or antenna panels, but not all devices may have the hardware (digital / analog / RF functions, etc.), software, and / or power supply components necessary for simultaneous transmission. For example, multiple SL devices may be capable of receiving and processing signals in two directions. Thus, a receiving SL device may perform sensing in the primary and paired directions. Due to the TDMA transmission design, the SL device will know that the received SCI was transmitted by the transmitting device in the primary or paired direction. Below, we will provide some guidelines on how an SL UE performing sensing for resource allocation can handle and process SCI detected in the primary direction (intended transmission direction) and paired directions (additional directions (multiple) in which sensing is performed according to the proposed embodiments).

[0154] The SL WTRU102 can perform detection (e.g., for resource allocation) and process SCIs detected in its primary direction (e.g., intended transmission direction) and paired directions (e.g., additional directions(s) in which detection may be performed). For example, if an SL device detects SCIs in its primary direction (e.g., primary SCI) and paired direction (e.g., paired SCI) transmitted by another device in the primary direction of the transmitting device, the estimated RSRP for these SCIs in the receiving device may be expressed as follows: RSRP prTx=>prRx : RSRP of the primary SCI received in the primary direction, RSRP prTx=>paRx : RSRP of the primary SCI received in the paired direction, RSRP paTx=>prRx : RSRP of paired SCIs received in the primary direction, and RSRP paTx=>paRx: RSRP of the paired SCI received in the paired direction.

[0155] Primary SCI received in the primary direction Figure 13 illustrates a typical example of a paired transmitter and receiver configuration. In Figure 13, two pairs of devices are shown in each embodiment where TxA506 is transmitting and sending a reservation to the intended receiver RxA508. The reservation may be for a given future resource within a selection window for another SL device Tx502 performing a detection for resource allocation to transmit to the intended receiver Rx504. The potential transmitter Tx502 (e.g., SCI detection WTRU102) can receive a reservation instruction for a future resource from TxA506 in the primary direction and can determine that the detected SCI is related to TxA506 in the primary direction.

[0156] For example, when a potential transmitter Tx502 detects an SCI transmitted in the primary direction from TxA, which has reserved the resource, the two directional transmissions may not cause any interference at each of their receivers. This happens because both receivers attempt to receive aligned in their respective primary directions and receive no energy from the other transmission (or only minimal energy).

[0157] In a particular representative embodiment, when the first transmit WTRU 102 performs detection (e.g., for resource allocation) and detects an SCI indicating a future resource reservation in the intended primary direction, and the SCI is transmitted from the second transmit WTRU 102 in the primary direction of the second transmit device, the first transmit WTRU 102 may ignore the indicated resource reservation. For example, the first transmit WTRU 102 can proceed to perform SL communication (e.g., in the intended direction) using the same SL resource.

[0158] Primary SCI received in the paired direction Figure 14 illustrates a typical paired transmitter and receiver configuration with respect to a primary SCI received in the paired direction. Figure 14 shows two pairs of devices, with TxA506 transmitting and sending a reservation to the intended receiver RxA508. The reservation may be for a given future resource within a selection window for another SL device Tx502 performing a detection for resource allocation to transmit to the intended receiver Rx504. The potential transmitter Tx502 (e.g., SCI detection WTRU102) can receive the reservation instruction for the future resource from TxA506 in the paired direction and can determine that the detected SCI is related to TxA506's primary direction. In legacy directional schemes, the potential transmitter Tx502 would not receive a reservation that could lead to a hidden terminal failure.

[0159] In a particular representative embodiment, the potential transmitter Tx502 has an estimated RSRP, and the RSRP prTx=>paRx >RSRP pr=>pa_TH For example, it may determine that the value is higher than a configured threshold. A potential transmitter Tx502 may remove the indicated resource from its resource selection window (for example, due to the detection of a reservation). For example, a threshold (e.g., RSRP) pr=>pa_TH The threshold can be pre-configured. The threshold can be communicated to the SL device by the base station (e.g., gNB180) via system information, Layer 1 control signaling (e.g., part of downlink control information), or higher layer signaling (e.g., RRC). To ensure compatibility between hidden and exposed terminal conditions, a potential transmitter performing detection may adapt (e.g., modify) the threshold based on the location of the intended receiver and / or the distance to the intended receiver. The values ​​of the offset or weighting coefficients that may be used to adapt the threshold can be communicated to the SL device by the base station (e.g., gNB180) via system information, Layer 1 control signaling (e.g., part of downlink control information), or higher layer signaling (e.g., RRC).

[0160] Paired SCI received in the primary direction Figure 15 illustrates a typical paired transmitter and receiver configuration for a paired SCI received in the primary direction. Figure 15 shows two pairs of devices, with TxA506 transmitting and sending a reservation to the intended receiver RxA508. The reservation may be for a given future resource within a selection window for another SL device Tx502 performing a detection for resource allocation to transmit to the intended receiver Rx. The potential transmitter Tx502 (e.g., SCI detection WTRU102) can receive the reservation instruction for the future resource from TxA506 in the primary direction and can determine that the detected SCI is related to the paired direction of TxA506. In legacy directional schemes, the potential transmitter Tx502 would not receive a reservation that could lead to a hidden terminal failure.

[0161] In a particular representative embodiment, the potential transmitter Tx is estimated to have an RSRP of RSRP paTx=>prRx >RSRP pa=>pr_TH For example, it may determine that the value is higher than a configured threshold. A potential transmitter Tx502 may remove the indicated resource from its resource selection window (for example, due to the detection of a reservation). For example, a threshold (e.g., RSRP) pr=>pa_THThe threshold can be pre-configured. The threshold can be communicated to the SL device by the base station (e.g., gNB180) via system information, Layer 1 control signaling (e.g., part of downlink control information), or higher layer signaling (e.g., RRC). To ensure compatibility between hidden and exposed terminal conditions, a potential transmitter performing detection may adapt (e.g., modify) the threshold based on the location of the intended receiver and / or the distance to the intended receiver. The values ​​of the offset or weighting coefficients that may be used to adapt the threshold can be communicated to the SL device by the base station (e.g., gNB180) via system information, Layer 1 control signaling (e.g., part of downlink control information), or higher layer signaling (e.g., RRC).

[0162] Paired SCI received in the paired direction Figure 16 illustrates a typical paired transmitter and receiver configuration for a paired SCI received in the paired direction. Figure 16 shows two pairs of devices, with TxA506 transmitting and sending a reservation to the intended receiver RxA508. The reservation may be for a given future resource within a selection window for another SL device Tx502 performing a detection for resource allocation to transmit to the intended receiver Rx504. The potential transmitter Tx502 (e.g., SCI detection WTRU102) can receive the reservation instruction for the future resource from TxA506 in the paired direction and can determine that the detected SCI is related to the paired direction of TxA506.

[0163] Due to SCI transmission in the paired direction and detection in the paired direction, a sensing device may detect extremely strong SCI indicating a future reservation. However, those skilled in the art should understand that if the two pairs in this situation use the same time-frequency resources simultaneously, the resulting directional reception may be interference-free (e.g., completely) in each receiving device.

[0164] In a particular representative embodiment, when a first transmit WTRU 102 performing a detection for resource allocation detects an SCI indicating a future resource reservation in the paired direction, and the SCI is transmitted from the second transmit WTRU 102 in the paired direction of the second transmit WTRU 102, the first transmit WTRU 102 may ignore the indicated resource reservation. For example, the first transmit WTRU 102 can proceed to perform SL communication (e.g., in the intended direction) using the same SL resource.

[0165] Primary and paired SCI thresholds As described herein, an SL device performing SL detection (e.g., autonomous resource allocation) may ignore future resource reception reservations when interference transmission is not expected at each receiver, such as when a primary SCI is received in the primary direction and / or a paired SCI is received in the paired direction. When a primary SCI is received in the paired direction and / or a paired SCI is received in the primary direction, the SL device may compare the RSRP of the detected SCI against a threshold. The use of a threshold can be compatible in that it suppresses hidden terminal scenarios and / or exposed terminal conditions.

[0166] In certain embodiments, resource allocation thresholds (e.g., legacy thresholds) configured as part of the configuration of the resource allocation procedure may be applied without modification. In legacy systems, resource allocation thresholds may be configured for pairs of priorities, where one priority is for detected transmissions and the other is for the transmission in which resource selection is performed. Such thresholds can then be iteratively increased if sufficient resources are not available in the resource selection window.

[0167] In certain other representative embodiments, the resource allocation threshold configured for the resource selection procedure may be modified using the available distance and / or location information (e.g., with respect to reserved Tx and / or intended Rx) at the SL device performing SL detection. For example, the offset applied to the configured pair may be part of the configuration. The network may set different offsets, such as setting one offset for primary SCIs received in the paired direction and a different offset for paired SCIs received in the primary direction.

[0168] performance results Figure 17 illustrates another exemplary relationship between packet reception rate (PRR) and periodic traffic intensity in a square grid scenario. Figure 17 shows the performance of paired detection and paired SCI (e.g., first-stage SCI) transmission (indicated as pair-pair in Figure 17) compared to detection and SCI transmission in omnidirectional and directional (e.g., directional-directional systems) as traffic intensity increases. In the square grid scenario, the performance of paired detection and paired SCI transmission outperforms that of omnidirectional and directional systems.

[0169] Figure 18 illustrates another example of the relationship between packet reception rate (PRR) and periodic traffic intensity in a highway scenario (e.g., a collinear scenario). Figure 18 shows the performance of paired detection and paired SCI (e.g., first-stage SCI) transmission (indicated as pair-pair in Figure 18) compared with detection and SCI transmission in omnidirectional and directional systems (e.g., directional-directional systems) as traffic intensity increases. In the highway scenario, the performance of paired detection and paired SCI transmission outperforms that of omnidirectional and directional systems.

[0170] The antenna gain and beamwidth of the paired beam are 5 dB and 30°, respectively, for each transmission and reception. As can be seen in FIGS. 17 and 18, as described herein, by using paired detection and paired SCI transmission, an improvement in PRR is achieved across both omnidirectional and directional systems. In the square grid scenario, with a traffic intensity of 1 millisecond, in the directional system, the PRR was 87.8%, but it was improved to 92% in the paired system. In the collinear highway scenario, the average PRR improved from 85.3% in the directional system to 94.5% in the paired system.

[0171] FIG. 19 is a diagram illustrating another exemplary relationship between the packet reception rate (PRR) and the periodic traffic intensity in a square grid scenario. In FIG. 19, the slot duration is increased to 0.25 ms compared to 0.125 ms in FIG. 17.

[0172] FIG. 20 is a diagram illustrating another exemplary relationship between the packet reception rate (PRR) and the periodic traffic intensity in a highway scenario. In FIG. 20, the slot duration is increased to 0.25 ms compared to 0.125 ms in FIG. 18.

[0173] As can be seen in FIGS. 19 and 20, as the slot duration extends, the available transmission opportunities decrease, and it can be easily confirmed that the performance gap between the paired system and the directional system further widens. In the highway scenario with a traffic intensity of 1 ms, the paired system achieved a PRR of 85.6% compared to the directional system with a PRR of 72.3%, and as a result, the paired system was 13.3% more advantageous in terms of performance.

[0174] As can be seen from FIGS. 17 to 20, the possible performance improvement realized by the paired detection and paired SCI transmission procedures described herein can be significant compared to the prior art.

[0175] Exemplary method For example, to allocate resources for SL transmission from a first WTRU 102 (e.g., a WTRU 102 configured for SL transmission) to a second WTRU 102 (e.g., a WTRU 102 configured for SL reception), a representative method that can be performed by this first WTRU 102 may include the first WTRU 102 determining an estimate of the primary transmission direction. The first WTRU 102 can derive at least one paired direction associated with the primary transmission direction. Thereafter, the first WTRU 102 can perform SCI detection in the primary direction and the paired directions to detect ongoing SL transmissions and / or reservations (e.g., current or future TTIs such as slots). Next, the first WTRU 102 can use any detected SCI in the primary direction and the paired directions to select SL resources for transmission to the second WTRU 102. Thereafter, the first WTRU can proceed to SL control and data transmission on the selected SL resources. For example, the transmission of SL control information may include SCI transmission in the primary direction and the paired directions (e.g., using TDMA).

[0176] In certain representative embodiments, the multiplexing pattern of SL transmissions for an SL slot may be a primary SCI, a paired SCI, and SL data. In certain representative embodiments, the multiplexing pattern of SL transmissions for an SL slot may be a paired SCI, a primary SCI, and SL data. In certain representative embodiments, the multiplexing pattern of SL transmissions for an SL slot may be a primary SCI, SL data, and a paired SCI.

[0177] In certain representative embodiments, the first symbol in an SL slot may be an AGC symbol that includes signals present in subsequent symbols. The transmission of the AGC symbol may be aligned with the same transmission direction as subsequent symbols (e.g., the primary direction or a paired direction).

[0178] In a particular representative embodiment, the paired direction may be 180° opposite to the primary direction.

[0179] In a particular representative embodiment, the paired directions may include one or more paired directions. For example, the paired directions may be determined by the first WTRU 102 based on feedback information received from the second WTRU 102.

[0180] In a particular representative embodiment, the first WTRU 102 can select a paired direction using geographical information, terrain information, road information, and / or camera information.

[0181] In a particular representative embodiment, the first WTRU 102 may completely ignore the presence of primary SCI received in the primary transmission direction of the first WTRU 102 when selecting an SL resource.

[0182] In a particular representative embodiment, the first WTRU 102 may completely ignore the presence of a paired SCI received in the paired transmission direction of the first WTRU 102 when selecting an SL resource.

[0183] In a particular representative embodiment, the first WTRU 102 can apply a first threshold to determine whether to ignore primary SCIs received in the paired direction. In a particular representative embodiment, the first WTRU 102 can apply a second threshold to determine whether to ignore paired SCIs received in the primary direction. In a particular representative embodiment, the first WTRU 102 can apply the same threshold to determine whether to ignore primary SCIs received in the paired direction and paired SCIs received in the primary direction.

[0184] In a particular representative embodiment, the first WTRU 102 may receive information indicating one of the thresholds as part of a resource allocation configuration. For example, the resource allocation configuration may include information indicating threshold information for each priority pair between the first WTRU's own transmission priority and the detected transmission priority.

[0185] In a particular representative embodiment, the first WTRU 102 may modify either threshold based on the location of the third WTRU 102 associated with the detected SCI, and / or the location of the second WTRU 102.

[0186] SCI transmission in the primary and paired directions with parallel transmission For highly directional systems operating at very high carrier frequencies (e.g., above 6 GHz), collinear transmission can be detrimental from a competition standpoint, and this must be considered when performing SL detection (e.g., for autonomous resource allocation of SLs).

[0187] In certain representative embodiments, the SL Tx is capable of SL transmission, and can transmit SCI in the primary direction and the paired direction. In such cases where such transmission capability exists, the SCI can be transmitted at the same time (e.g., simultaneously) in the primary direction and the paired direction. For example, if the SL device has two or more antenna panels, simultaneous transmission may be possible.

[0188] SCI detection for autonomous resource allocation In a particular representative embodiment, a potential SL transmitter (e.g., WTRU102) may perform an autonomous resource allocation procedure that may include SCI detection in (i) the intended transmission direction and (ii) at least one direction paired with the intended transmission direction. For example, an SL transmitter may be capable of transmitting in multiple directions simultaneously, such as when it is equipped with multiple antenna panels. In the case of a vehicle, the vehicle (e.g., a WTRU102 provided on the vehicle) may be equipped with multiple antenna panels that may enable it to operate as an SL device capable of transmitting and / or receiving signals simultaneously in multiple directions.

[0189] For example, if an SL device performs paired sensing for autonomous resource allocation regarding future SL transmissions in the intended transmission direction and paired direction (e.g., simultaneously), it may be advantageous for the SL device itself to receive the majority of transmissions that may pose a conflict risk.

[0190] As described above, Figure 9 illustrates the structure of an SL slot (e.g., a legacy slot) as in 3GPP Rel-16. In Figure 9, an SL slot may contain, for example, 14 symbols. The first symbol may be used for automatic gain control (AGC), and the next two or three symbols can be used to send SCI via PSCCH transmission according to the SL configuration. In Figure 9, two symbols are assigned to PSCCH. In the case of an SL slot that does not include HARQ feedback sent via PSFCH transmission, the remaining symbols, except for the final guard symbol, can carry the SL data carried by PSSCH transmission.

[0191] In a particular representative embodiment, the SCI may be transmitted simultaneously in the primary direction and in the paired direction (e.g., via the same symbol in the SL slot). Figure 21 illustrates another representative structure of the SL slot 2102 for paired SCIs, where the SCI is transmitted simultaneously in the primary direction and in the paired direction. For example, the SL device may use separate antenna panels and power amplifiers to transmit parallel transmissions simultaneously. In some cases, the SCI transmissions in the primary and paired directions may undergo different signal processing, but this would be minimal. In Figure 21, the primary SCI may be transmitted in the primary direction with two or three symbols following the AGC symbol. The paired SCI may be transmitted in at least one paired direction with two or three symbols following the AGC symbol. The primary SCI and paired SCI may be transmitted via PSCCH transmission. The data may be multiplexed as PSCCH symbols in the SL slot 2102. Paired transmits for SL control (e.g., primary SCI and paired SCI) are transmitted via the same set of symbols, for example, by using multiple antennas and / or antenna panels. The AGC symbol in SL slot 2102 may be a copy of the second symbol. For example, the AGC symbols for the primary SCI and paired SCI may be transmitted in their respective directions. As another example, the AGC symbol transmission in the paired direction may be ignored (e.g., omitted). This may reduce the power consumption of the transmitter WTRU102, but may degrade the detection quality of the paired SCI.

[0192] Enhanced detection in additional paired directions based on scenarios, terrain, geographical information, lanes, traffic patterns, and / or camera images. In certain representative embodiments, SCI can be transmitted (i) in the primary direction of interest toward the intended Rx504, and (ii) in the opposite direction to the primary direction (e.g., the paired direction). This paired SCI transmission, combined with paired detection for resource allocation, which is also performed in the primary and paired directions, can be extremely useful in solving the hidden terminal problem and the exposed terminal problem.

[0193] In a particular representative embodiment, the paired directions are 180 degrees relative to the primary direction. ° The opposite direction may be a different direction. In many real-world scenarios arising from road curvature, road bends, and / or common characteristics of the surrounding terrain, transmitting a paired SCI in the 180° direction may not make sense and / or be the most desirable beam direction for performing paired transmission and / or paired detection. When a vehicle is traveling on a road and on a curved section of the road, if the vehicle can attempt and / or perform SL communication with other vehicles, the primary direction may be forward of the vehicle, but the 180° direction may not be the desired paired direction. For example, according to the angled curve of the vehicle path, the paired direction may be selected with respect to a paired detection moving from behind the vehicle. SL devices may have such information from various sources, such as GPS, camera output, and maps in various formats. The SL Tx502 can select a paired direction that is different from the 180° direction and is appropriate for the environment based on the information available from different sensors.

[0194] In certain embodiments, the WTRU 102 may be capable of SL transmissions with a varying beamwidth. Further, the WTRU 102 may perform detection with a slightly wider beam in the paired direction as compared to the intended direction of the primary SCI transmission, or may need to transmit a (paired, for example) SCI. The WTRU 102 may be configured to transmit with two or more beams in order to achieve effective wide-angle coverage in a given direction. For example, the WTRU 102 may be able to transmit two additional beams (e.g., of a paired SCI) on each side of its intended direction.

[0195] In certain embodiments, when a vehicle is moving in the rightmost (or leftmost) lane, this vehicle may determine that there are no further lanes to the right (or left) (e.g., no vehicles), and may not perform paired SCI transmissions using additional beams or beamwidths in such a direction.

[0196] In certain embodiments, when a vehicle is changing direction, the vehicle's WTRU 102 may determine to align the primary beam and / or paired beams for SL detection and / or SL transmission along this direction change.

[0197] In certain embodiments, when several vehicles are jammed or in a collision area (e.g., by camera imaging), the detection direction and / or transmission direction may be aligned accordingly for information collection and / or avoidance purposes.

[0198] In certain embodiments, there may be one or more paired directions. Additional paired directions may be derived based on information collected through different sensors. In certain embodiments, additional paired directions may be added after receiving feedback from the intended receiver. For example, if Rx is experiencing strong interference from a given angle, Rx may indicate an angle relative to Tx. Tx can then add this position and / or angle to determine an additional paired direction and perform paired SL transmission and / or SL transmission in this direction.

[0199] For example, if there is only one paired direction that may differ from the 180° direction, the control and data multiplexing in the SL slot structure described herein can be used to simultaneously transmit the paired SCI using two antennas or antenna panels. If there are multiple paired directions, the SL slot structure described herein may allow the SL device to transmit and / or receive from multiple directions simultaneously.

[0200] Primary SCI transmission and paired SCI transmission In certain representative embodiments, an SCI may be transmitted (i) in the primary direction of interest toward the intended Rx, and (ii) in the opposite direction to the primary direction (e.g., paired direction) (e.g., simultaneously) in the same symbol of the same SL slot. For example, when WTRU102 decodes an SCI, WTRU102 may not know, for the detection purposes described herein, whether the decoded SCI is from the primary transmission direction (where subsequent PSSCH transmissions may occur) or from the paired direction (where PSSCH transmissions may not occur). Generally, this allows additional WTRU102s to decode SCIs transmitted in the primary and paired directions, but in practice, this may increase the exposed terminal problem as they may not be subject to interference or competition on the same time-frequency resources. If an adjacent WTRU102 decoding a given SCI can determine whether the decoded SCI is from the primary or paired direction, it may have better information for resource allocation.

[0201] In certain representative embodiments, information (e.g., instructions) can be provided that a decoding SL device can use to determine whether a given SCI is associated with an intended transmission direction or a paired transmission direction. For example, this information can distinguish between a paired SCI transmission and a primary SCI transmission, or vice versa.

[0202] Reserved bits within SCI In certain representative embodiments, an SCI (e.g., a primary SCI and / or a paired SCI) may have reserved bits to distinguish it from a paired SCI. For example, the reserved bits may be used to indicate (e.g., identify) a paired SCI. A paired SCI may have one or more reserved bits set to predetermined values ​​(e.g., to indicate that the SCI was transmitted in the pairing direction). When a legacy WTRU102 decodes an SCI having such reserved bits, it may discard the SCI if a different value is expected for these reserved bits. If the legacy WTRU102 treats an SCI having such reserved bits as a normal SCI, it may not discard the SCI. A WTRU102 configured to operate according to a pairing scheme can predict the signaling of the reserved bits and process the SCI as a paired SCI.

[0203] Reformation of SCI bitfield In a particular representative embodiment, an SCI transmitted in a paired direction may not have associated data (e.g., one or more PSSCH transmissions) within the symbol of the same SL slot from which the SCI is transmitted. For example, one or more bit fields used to indicate a second-stage SCI and / or several aspects of a PSSCH (e.g., PSSCH DM-RS, second-stage SCI identifier, PSSCH MCS, etc.) may be reshaped (e.g., reused) to indicate that the SCI is transmitted as a paired SCI. For example, a fixed value may be assigned (e.g., used) to one or a combination of bit fields associated with a second-stage SCI and / or PSSCH to identify that the SCI in an SL slot is a paired SCI. When the WTRU102 detects such a fixed value, it can determine that the decoded SCI was transmitted in a paired direction (e.g., is a paired DCI). A legacy WTRU102 may discard such SCI if the fixed value of such bit fields is not expected.

[0204] SCI Scrambling In a particular representative embodiment, the SCI may be scrambled (e.g., by XOR operation) in an order (e.g., predetermined or set). For example, this sequence may be known to all WTRU102s (e.g., those performing SL communication). Scrambling of the sequence may be performed in the SL Tx502 before the channel coding step when calculating the cyclic redundancy check (CRC). The SL Rx504 decodes the SCI and performs the CRC check. For example, the CRC check may be performed once without scrambling and once with the sequence scrambled to indicate a paired SCI. If the CRC check passes without scrambling, the receiving WTRU102 can determine that the SCI is from the primary transmission direction. If the CRC check passes with the sequence scrambled, the receiving WTRU102 can determine that the SCI is from a paired transmission direction. For example, a simple scrambled sequence may be a sequence of all ones. This is all 1 bit inverted to all bits, and vice versa. A legacy WTRU102 may not be able to decode paired SCIs transmitted in this manner, as it may not have a scrambling array or perform decoding that uses a scrambling array.

[0205] SCI reference signal In certain representative embodiments, an SCI can be distinguished as either a primary SCI or a paired SCI, using a reference signal (e.g., SCI DM-RS) as an indicator. For example, different DM-RS sequences may be used between primary SCI transmissions and paired SCI transmissions. Scrambling may be performed on the DM-RS sequence using a predetermined sequence known to all WTRU102s (e.g., those performing SL communication). A receiving WTRU102 can perform correlation using two different DM-RS sequences, one scrambled and one unscrambled. From this correlation result, the WTRU102 can determine whether the received SCI is a primary SCI or a paired SCI, and accordingly prepare channel estimation and perform SCI decoding. A legacy WTRU102 may not apply appropriate DM-RS processing and thus may be unable to decode such a paired SCI.

[0206] performance instructions In certain representative embodiments, the paired SCI may be transmitted in TDMA manner together with the primary SCI. In certain representative embodiments, the assumed SL device is capable of transmitting the primary SCI and the paired SCI simultaneously (e.g., on the same symbol in the SL slot). Such performance may depend on additional antennas, RF, HW, and processing requirements for simultaneous transmission in two or more directions. Apart from performance, simultaneous transmission also presents HW and computing power issues. Simultaneous transmission of the primary SCI and the paired SCI may increase the interference level during control symbols.

[0207] As a performance issue, TDMA transmission of an SCI paired with a primary SCI may lead to a reduction in data resources within the slot (e.g., a reduction in the resource elements available to carry actual data). For example, smaller data packets can be transmitted using the TDMA method. Another example is that since the data packet size may not decrease, puncturing and rate matching operations may be used to fit the same data packets into the reduced time-frequency resources. Regarding the performance of such examples, assuming a traffic arrival rate of 1 ms and all packets transmitted on a single subchannel, the TDMA method throughput can reach approximately 1.92 Mbps, while the parallel transmission method throughput can reach approximately 2.4 Mbps. In other words, throughput can be improved (e.g., by an additional 20%) by using parallel transmission of SCIs (e.g., within the same symbol in the slot). As mentioned above, throughput may depend on all HW / SW requirements of the SL device implementing each method. Both the TDMA method and the parallel transmission method have achieved performance improvements over legacy systems, and depending on the device performance and / or application requirements, either of these methods described herein can be adopted.

[0208] Example method For example, a typical method that a first WTRU102 (e.g., a WTRU102 configured for SL transmission) can perform to allocate resources to a second WTRU102 (e.g., a WTRU102 configured for SL reception) for use in SL transmissions may include the first WTRU102 determining the estimation of the primary transmission direction. The first WTRU102 can derive at least one paired direction associated with the primary transmission direction. The first WTRU102 can then perform SCI detection in the primary direction and the paired direction to detect ongoing SL transmissions and / or reservations (e.g., current or upcoming TTI such as slots). The first WTRU102 can then use any detected SCI in the primary direction and the paired direction to select an SL resource for transmission to the second WTRU102. The first WTRU102 can then proceed with SL control and simultaneous transmission of data on the selected SL resource. For example, the transmission of SL control information may include SCI transmissions in the primary direction and paired directions for the same symbol in the slot.

[0209] In a particular representative embodiment, the first symbol in the SL slot may be an AGC symbol containing signals present in the subsequent symbols. The transmission of the AGC symbol may be aligned with the same transmission direction as the subsequent symbols (e.g., the primary direction or the paired direction). The transmission of the AGC symbol may be aligned with the same transmission direction as the primary SCI and the paired SCI.

[0210] In a particular representative embodiment, the paired direction may be 180° opposite to the primary direction.

[0211] In a particular representative embodiment, the paired directions may include one or more paired directions. For example, the paired directions may be determined by the first WTRU 102 based on feedback information received from the second WTRU 102.

[0212] In a particular representative embodiment, the first WTRU 102 can select a paired direction using geographical information, terrain information, road information, and / or camera information.

[0213] In a particular representative embodiment, the first WTRU 102 may completely ignore the presence of primary SCI received in the primary transmission direction of the first WTRU 102 when selecting an SL resource.

[0214] In a particular representative embodiment, the first WTRU 102 may completely ignore the presence of a paired SCI received in the paired transmission direction of the first WTRU 102 when selecting an SL resource.

[0215] In a particular representative embodiment, the first WTRU 102 can apply a first threshold to determine whether to ignore primary SCIs received in the paired direction. In a particular representative embodiment, the first WTRU 102 can apply a second threshold to determine whether to ignore paired SCIs received in the primary direction. In a particular representative embodiment, the first WTRU 102 can apply the same threshold to determine whether to ignore primary SCIs received in the paired direction and paired SCIs received in the primary direction.

[0216] In a particular representative embodiment, the first WTRU 102 may receive information indicating one of the thresholds as part of a resource allocation configuration. For example, the resource allocation configuration may include information indicating threshold information for each priority pair between the first WTRU's own transmission priority and the detected transmission priority.

[0217] In a particular representative embodiment, the first WTRU 102 may modify either threshold based on the location of the third WTRU 102 associated with the detected SCI, and / or the location of the second WTRU 102.

[0218] In a particular representative embodiment, the first WTRU 102 may include an instruction in the transmitted SCI to distinguish the primary SCI and the paired SCI from each other and / or from their transmission direction. For example, this instruction may be included in the paired SCI to identify that the SCI was transmitted in the paired direction.

[0219] In a particular representative embodiment, the first WTRU 102 may have one or more reserved bits set within the paired SCI to indicate transmission in the paired direction.

[0220] In a particular representative embodiment, the first WTRU 102 may have one or more bit fields (for example, in combination) set within the paired SCI to indicate transmission in the paired direction.

[0221] In a particular representative embodiment, the first WTRU 102 can scramble the SCI with an array indicating the transmission direction. For example, the first WTRU 102 can scramble paired SCIs using an array configured to indicate that the transmission was performed in the paired direction.

[0222] In a particular representative embodiment, in the first WTRU 102, indication of the transmission direction of the primary SCI and / or paired SCI may be provided by the DM-RS. For example, the DM-RS associated with the paired SCI may be configured to indicate the paired SCI.

[0223] Simulation parameters Figures 3-4 and 17-20 use a square grid and a highway scenario. In the square grid scenario, a 100m x 100m grid was simulated with 100 randomly deployed pairs of unicast SL communications, each consisting of one SL WTRU102 acting as a transmitter and another SL WTRU102 acting as a receiver (e.g., a total of 200 SL devices deployed in a square grid). The Tx-Rx distance between pairs was uniformly distributed between 10 and 40m. In the highway scenario, 100 vehicle-mounted WTRUs were deployed on a 4km road section according to the guidelines specified in 3GPP TR 37.885. In the highway scenario, there were 50 Tx-Rx pairs. For each Tx WTRU102, the corresponding Rx WTRU102 was randomly selected from vehicles within a 150m distance.

[0224] The simulation used a periodic traffic model in which a new packet arrives at each WTRU every Xms. Our simulation shows results for X={5,4,3,2,1}ms. The resource reservation interval (RRI) of the Mode 2 resource allocation procedure was kept the same as the traffic intensity. There were 10 subchannels available for SL transmission, with each subchannel sized at 10PRB. The packet size of the traffic for each Tx WTRU was evenly distributed among the 1 to 10 subchannels. In a single run of the simulation, the packet size of the traffic for each Tx WTRU remained the same.

[0225] For directional transmission and reception of data (such as PSSCH transmission), a directional antenna beamwidth of 30° is assumed for both Tx WTRU and Rx WTRU. For directional detection and transmission of SCI (such as PSCCH transmission), the directional antenna beamwidth is also assumed to be 30°. The gain of the directional antenna is assumed to be equal to 5dB for both Tx WTRU and Rx WTRU. When using omnidirectional detection or omnidirectional SCI transmission ("omni-omni" system), no additional antenna gain is assumed, and transmission / reception is performed in all directions (e.g., 360°). Furthermore, unless otherwise noted, a slot time of 0.125ms (e.g., SCS=120kHz) was used for both the square grid and single-lane highway scenarios.

[0226] Retransmissions based on HARQ ACK / NACK feedback were not considered in the simulation. For each packet, three possible outcomes were considered. If the packet was sent and received successfully, it was counted as a "success". If the packet was sent after resource selection using the Mode 2 procedure but received with an error (e.g., a low signal-to-interference noise ratio (SINR)), it was counted as a conflict. If the Mode 2 resource selection procedure could not find enough available resources for the packet (e.g., more than 20% of candidate resources in the selection window), it was discarded and counted as a "failure".

[0227] Packet detection and decoding are based on the received SINR. For the data channel, the SINR threshold for successful data reception was 10 dB. For the control channel, a 5 dB SINR threshold was considered for decoding the received SCI. In the Mode 2 resource allocation procedure, the same 5 dB threshold was applied, taking into account the set of received and decoded SCIs. The system carrier frequency was 28 GHz. 3GPP line-of-sight (LoS) path loss models for highway V2X and indoor office scenarios were used, for single-lane highway and square grid deployments, respectively.

[0228] Figure 22 illustrates a typical example of a communication procedure using first and second type SCIs. The procedure in Figure 22 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2202 of Figure 22, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2204, the WTRU 102 can determine a first beam direction (e.g., antenna panel, first beam, and / or first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. In 2206, following 2204, WTRU102 can monitor a second SL transmission that uses a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2208, WTRU102 may transmit the first SL transmission using the second SL resource, as described herein, provided that any of the second SL transmissions includes information indicating that (1) it is received using a second beam direction (e.g., from the paired direction), (2) it is associated with a first SL resource, and (3) the second SL transmission includes information indicating that it contains a first type of SCI (e.g., a primary SCI from another WTRU102), and / or (4) the received power of the second SL transmission is greater than a (e.g., first) threshold. For example, sending a first SL transmission sent via 2208 may include (A) sending a first type of SCI and data of the first SL transmission using the second SL resource with the first beam direction, and (B) sending a second type of SCI of the first SL transmission using the second SL resource with the second beam direction.

[0229] Figure 23 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 23 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2302 of Figure 23, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2304, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. In 2306, following 2304, WTRU102 can monitor a second SL transmission that uses a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2208, WTRU102 may transmit a first SL transmission using the second SL resource, as described herein, provided that any of the second SL transmissions includes information indicating that (1) it is received using a first beam direction (e.g., from the primary direction), (2) it is associated with a first SL resource, and (3) the second SL transmission includes a second type of SCI (e.g., a primary SCI from another WTRU102), and / or (4) the received power of the second SL transmission is greater than a (e.g., second) threshold. For example, sending a first SL transmission sent at 2308 may include (A) sending a first type of SCI and data of the first SL transmission using the second SL resource with the first beam direction, and (B) sending a second type of SCI of the first SL transmission using the second SL resource with the second beam direction.

[0230] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, the first beam direction may be associated with the first antenna panel and / or the first beam, and / or the second beam direction may be associated with the second antenna panel, the second direction (e.g., the opposite side of the first direction), and / or the second beam (e.g., the opposite side of the first beam). For example, the first antenna panel may be located on the first side of the WTRU 102, and the second antenna panel may be located on the second side of the WTRU 102.

[0231] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, monitoring of a second SL transmission using a first beam direction and a second beam direction may include receiving the second SL transmission (e.g., from another WTRU102) using the first SL resource (e.g., via a first antenna panel or a second antenna panel).

[0232] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, the SCI (e.g., first type and / or second type) of the second SL transmission may include information indicating a resource reservation (e.g., of a first SL resource or a second SL resource).

[0233] For example, in certain representative embodiments such as those shown in Figures 22 and / or 23, sending a first type of SCI of a first SL transmission using a second SL resource with a first beam direction may occur within one or more first symbols of a transmission time interval (TTI), such as a subframe (for example, it may occur therein). For example, in certain representative embodiments such as those shown in Figures 22 and / or 23, sending a second type of SCI of a first SL transmission using a second SL resource with a second beam direction may occur within one or more second symbols, distinct from one or more first symbols of the same TTI, such as the same subframe.

[0234] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, the first type of SCI of the first SL transmission may include one or more bits (e.g., reserved bits and / or a combination of bits) that distinguish the first type of SCI of the first SL transmission from the second type of SCI of the first SL transmission.

[0235] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, the second type of SCI of the first SL transmission may include one or more bits (e.g., reserved bits and / or a combination of bits) that distinguish the second type of SCI of the first SL transmission from the first type of SCI of the first SL transmission.

[0236] For example, in certain representative embodiments such as those shown in Figures 22 and / or 23, using a first beam direction may include transmitting a first type of SCI for a first SL transmission using a second SL resource, and transmitting data using a first beam direction may include transmitting a first demodulated reference signal (DM-RS) array associated with (e.g., identifying) the first type of SCI.

[0237] For example, in certain representative embodiments such as those shown in Figures 22 and / or 23, using a second beam direction to send a second type of SCI of a first SL transmission using a second SL resource may include using a second beam direction to send a second demodulated reference signal (DM-RS) array associated with (e.g., identifying) the second type of SCI.

[0238] For example, in certain representative embodiments such as Figure 22 and / or Figure 23, a first type of SCI of a first SL transmission may be scrambled (e.g., before transmission) using a first scrambling sequence associated with the first type of SCI, and / or a second type of SCI of a first SL transmission may be scrambled (e.g., before transmission) using a second scrambling sequence associated with the second type of SCI.

[0239] Figure 24 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 24 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2402 of Figure 24, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2404, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. In 2406, following 2404, WTRU102 can monitor a second SL transmission using a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2408, WTRU102 may send a first SL transmission using the first SL resource, as described herein, provided that any of the second SL transmissions includes information indicating that (1) it is received using the first beam direction, (2) it is associated with the first SL resource, and / or (3) the second SL transmission includes a first type of SCI (e.g., a primary SCI from another WTRU102). For example, sending a first SL transmission sent in 2308 may include (A) sending a first type of SCI and data of the first SL transmission using the first SL resource with the first beam direction, and (B) sending a second type of SCI of the first SL transmission using the first SL resource with the second beam direction.

[0240] Figure 25 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 25 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2502 of Figure 25, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2504, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. In 2506, following 2504, WTRU102 can monitor a second SL transmission using a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2408, WTRU102 can send a first SL transmission using the first SL resource, as described herein, provided that any of the second SL transmissions includes information indicating that (1) it is received using the second beam direction, (2) it is associated with the first SL resource, and / or (3) the second SL transmission includes a second type of SCI (e.g., a paired SCI from another WTRU102). For example, sending a first SL transmission sent in 2308 may include (A) sending a first type of SCI and data of the first SL transmission using the first SL resource with the first beam direction, and (B) sending a second type of SCI of the first SL transmission using the first SL resource with the second beam direction.

[0241] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, the first beam direction may be associated with the first direction and / or the first beam, and / or the second beam direction may be associated with the second direction (e.g., the opposite side of the first direction) and / or the second beam (e.g., the opposite side of the first beam). For example, the first antenna panel may be located on the first side of the WTRU 102, and the second antenna panel may be located on the second side of the WTRU 102.

[0242] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, monitoring of a second SL transmission using a first beam direction and a second beam direction may include receiving the second SL transmission (e.g., from another WTRU102) using the first SL resource (e.g., from the first or second panel).

[0243] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, the SCI (e.g., first type and / or second type) of the second SL transmission may include information indicating a resource reservation (e.g., of a first SL resource or a second SL resource).

[0244] For example, in certain representative embodiments such as those shown in Figures 24 and / or 25, sending a first type of SCI of a first SL transmission using a first SL resource with a first beam direction may occur within one or more first symbols (e.g., of a transmission time interval (TTI)). Sending a second type of SCI of a first SL transmission using a first SL resource with a second beam direction may occur within one or more second symbols (e.g., further) that may differ from one or more first symbols of the same TTI (e.g., slots).

[0245] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, the first type of SCI of the first SL transmission may include one or more bits that distinguish the first type of SCI of the first SL transmission from the second type of SCI of the first SL transmission.

[0246] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, the second type of SCI of the first SL transmission may include one or more bits that distinguish the second type of SCI of the first SL transmission from the first type of SCI of the first SL transmission.

[0247] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, using a first beam direction to transmit a first type of SCI of a first SL transmission using a first SL resource, and transmitting data may include WTRU102 transmitting (e.g., a first) DM-RS array associated with (e.g., identified) the first type of SCI using the first beam direction.

[0248] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, sending a second type of SCI of a first SL transmission using a first SL resource using a second beam direction may include WTRU102 sending (e.g., identifying) a (e.g., second) DM-RS array associated with the second type of SCI using a second beam direction.

[0249] For example, in certain representative embodiments such as Figure 24 and / or Figure 25, a first type of SCI of a first SL transmission may be scrambled (e.g., before transmission) using a first scrambling sequence associated with (e.g., identifying) the first type of SCI, and / or a second type of SCI of a first SL transmission may be scrambled using a second scrambling sequence associated with (e.g., identifying) the second type of SCI.

[0250] Figure 26 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 26 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2602 of Figure 26, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2604, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. In 2606, following 2604, WTRU102 can monitor a second SL transmission using a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2608, WTRU102 may transmit the first SL transmission using the second SL resource, as described herein, provided that the second SL transmission includes information indicating that (1) it is received using the first beam direction, (2) it is associated with the first SL resource, (3) the second SL transmission includes a second type of SCI (e.g., a paired SCI from another WTRU102), and / or (4) the received power of the second SL transmission is greater than a (e.g., first) threshold.For example, sending a first SL transmission in 2608 may include (A) sending a first type of SCI of the first SL transmission that uses a second SL resource in one or more symbols, and data, using a first beam direction; (B) sending a second type of SCI of the first SL transmission that uses a second SL resource in the same one or more symbols (e.g., the first type of SCI of the first SL transmission), using a second beam direction; and / or (C) sending information that distinguishes the first type of SCI from the second type of SCI, using the first and / or second beam directions.

[0251] Figure 27 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 27 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2702 of Figure 27, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2704, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. After 2704, in 2706, WTRU102 can monitor a second SL transmission using a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2708, the first SL transmission is sent using the second SL resource, provided that the second SL transmission includes information indicating that (1) it is received using the second beam direction, (2) it is associated with the first SL resource, (3) the second SL transmission contains a first type of SCI (e.g., a primary SCI from another WTRU102), and / or (4) the received power of the second SL transmission exceeds a certain threshold. For example, sending a first SL transmission in 2608 may include (A) sending a first type of SCI of the first SL transmission that uses a second SL resource in one or more symbols, and data, using a first beam direction; (B) sending a second type of SCI of the first SL transmission that uses a second SL resource in the same one or more symbols (e.g., the first type of SCI of the first SL transmission), using a second beam direction; and / or (C) sending information that distinguishes the first type of SCI from the second type of SCI, using the first and / or second beam directions.

[0252] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, information distinguishing a first type of SCI from a second type of SCI may be transmitted in one or more symbols using a first beam direction (e.g., only this) and a second SL resource.

[0253] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, the information that distinguishes a first type of SCI from a second type of SCI may include one or more bits that identify the first type of SCI. For example, one or more bits may be included in the first type of SCI of the first SL transmission.

[0254] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, information distinguishing a first type of SCI from a second type of SCI may be transmitted in one or more symbols using a second beam direction (e.g., only) and a second SL resource. For example, the information distinguishing a first type of SCI from a second type of SCI may include one or more bits that identify the second type of SCI. One or more bits may be included in the second type of SCI of the first SL transmission.

[0255] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, the information distinguishing a first type of SCI from a second type of SCI may include a first DM-RS sequence associated with the first type of SCI. The first DM-RS sequence may be delivered using a first beam direction (e.g., this alone).

[0256] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, the information distinguishing a first type of SCI from a second type of SCI includes a second DM-RS array associated with the second type of SCI. The second DM-RS array may be delivered using a second beam direction (e.g., this alone).

[0257] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, the information distinguishing a first type of SCI from a second type of SCI may include information indicating that the first type of SCI in a first SL transmission is scrambled (e.g., before transmission) using a first scrambling sequence associated with (e.g., identifying) the first type of SCI.

[0258] For example, in certain representative embodiments, such as Figure 26 and / or Figure 27, the information distinguishing a first type of SCI from a second type of SCI may include information indicating that the second type of SCI in the first SL transmission is scrambled using a second scrambling sequence associated with (e.g., identifying) the second type of SCI.

[0259] Figure 28 illustrates another typical example of a communication procedure using first and second type SCIs. The procedure in Figure 28 can be implemented by a WTRU 102 including a processor 118 and a transceiver 120. For example, the first type SCI may be a primary SCI, and / or the second type SCI may be a paired SCI. In 2802 of Figure 28, the WTRU 102 can receive information indicating the configuration of at least a first SL resource and a second SL resource. For example, the first SL resource may be a first set of frequency resources configured for SL communication, and the second SL resource may be a second set of frequency resources configured for SL communication. In 2804, the WTRU 102 can determine a first beam direction (e.g., a first antenna panel, a first beam, and / or a first direction) associated with the first SL transmission. For example, the first beam direction may be associated with the primary direction of the first SL transmission. Following 2804, in 2806, WTRU102 can monitor a second SL transmission (e.g., from another WTRU102) using a first beam direction and a second beam direction different from this first beam direction. For example, the second beam direction may be associated with the paired direction of the first SL transmission. In 2808, WTRU102 can receive the second SL transmission. In 2810, WTRU102 can send a first SL transmission (e.g., to another WTRU102) (e.g., using the first and second beam directions), including first and second type SCIs. For example, as described herein, the first SL transmission may be sent based on one or more conditions associated with the received second SL transmission.

[0260] For example, sending a first SL transmission in 2810 can be performed using any of the procedures shown in Figures 22 to 27, or a combination thereof, and / or modified forms. In one example, the first SCI and the second SCI may be transmitted according to a configured slot structure in which the first SCI is transmitted with a first set of symbols of a given TTI, and the second SCI is transmitted with a second set of symbols of a given TTI. In another example, the first SCI and the second SCI may be transmitted according to a configured slot structure in which the first SCI and the second SCI are transmitted with the same set of symbols (e.g., of the same slot).

[0261] In a particular representative embodiment, WTRU102 may include a processor 118 and a transceiver 120 configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the first SL resource to send the first SL transmission, provided that (1) the second SL transmission is received from the first direction, (2) it is associated with a first SL resource, and / or (3) it includes an SCI indicating that the SL control information (SCI) of the second SL transmission is a primary SCI. Sending a first SL transmission using a first SL resource may include (1) sending a primary SCI using the first SL resource and the data for the first SL transmission in a first direction, and (2) sending a paired SCI of the first SL transmission using the first SL resource in a second direction.

[0262] In a particular representative embodiment, WTRU102 may include a processor and a transceiver configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the first SL resource to send the first SL transmission, provided that (1) the second SL transmission is received from the second direction, (2) it is associated with a first SL resource, and / or (3) the SL control information (SCI) for the second SL transmission includes an SCI indicating that it is a paired SCI. Sending a first SL transmission using a first SL resource may include (1) sending a primary SCI using the first SL resource and the data for the first SL transmission in a first direction, and (2) sending a paired SCI of the first SL transmission using the first SL resource in a second direction.

[0263] In a particular representative embodiment, WTRU102 may include a processor and a transceiver configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the first SL resource to send the first SL transmission if (1) the second SL transmission is received from the second direction, (2) it is associated with a first SL resource, (3) the SL control information (SCI) of the second SL transmission includes an SCI indicating that it is a primary SCI, and / or (4) the received power of the second SL transmission is below a certain threshold. Sending a first SL transmission using a first SL resource may include (1) sending a primary SCI using the first SL resource and the data for the first SL transmission in a first direction, and (2) sending a paired SCI of the first SL transmission using the first SL resource in a second direction.

[0264] In a particular representative embodiment, WTRU102 may include a processor and a transceiver configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the second SL resource to send the first SL transmission if (1) the second SL transmission is received from the second direction, (2) it is associated with a first SL resource, (3) the SL control information (SCI) of the second SL transmission includes an SCI indicating that it is a primary SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. Sending a first SL transmission using a second SL resource may include (1) sending a primary SCI using the second SL resource and the data for the first SL transmission in the first direction, and (2) sending a paired SCI of the first SL transmission using the second SL resource in the second direction.

[0265] In a particular representative embodiment, WTRU102 may include a processor and a transceiver configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the first SL resource to send the first SL transmission if (1) the second SL transmission is received from the first direction, (2) it is associated with a first SL resource, (3) the SL control information (SCI) of the second SL transmission includes an SCI indicating that it is a paired SCI, and / or (4) the received power of the second SL transmission is below a certain threshold. Sending a first SL transmission using a first SL resource may include (1) sending a primary SCI using the first SL resource and the data for the first SL transmission in a first direction, and (2) sending a paired SCI of the first SL transmission using the first SL resource in a second direction.

[0266] In a particular representative embodiment, WTRU102 may include a processor and a transceiver configured to implement a method that includes WTRU102 receiving information indicating the configuration of at least a first SL resource. WTRU102 can determine a first direction associated with the first SL transmission (e.g., corresponding to a first beam and / or antenna panel). WTRU102 can monitor a second SL transmission in the first direction and a second direction different from the first direction (e.g., corresponding to a first beam and / or antenna panel). WTRU102 may use the second SL resource to send the first SL transmission if (1) the second SL transmission is received from the first direction, (2) it is associated with a first SL resource, (3) the SL control information (SCI) of the second SL transmission includes an SCI indicating that it is a paired SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. Sending a first SL transmission using a second SL resource may include (1) sending a primary SCI using the second SL resource and the data for the first SL transmission in the first direction, and (2) sending a paired SCI of the first SL transmission using the second SL resource in the second direction.

[0267] In a particular representative embodiment, monitoring second SL transmissions in the first and second directions may include using the first SL resource to receive second SL transmissions in the first or second direction.

[0268] In a particular representative embodiment, the SCI of the second SL transmission may include information indicating a reservation for the first SL resource. For example, the reservation for the first SL resource may be for a slot containing multiple symbols.

[0269] In a particular representative embodiment, the primary SCI of the first SL transmission may be transmitted in the slot prior to the paired SCI of the first SL transmission being transmitted in the same slot.

[0270] In a particular representative embodiment, the primary SCI of the first SL transmission may be transmitted in a later slot in which the paired SCI of the first SL transmission is transmitted in the same slot.

[0271] In a particular representative embodiment, the primary SCI of the first SL transmission and the paired SCI of the first SL transmission may be transmitted with the same one or more symbols in the same slot.

[0272] In a particular representative embodiment, the first SL transmission may be associated with the second WTRU, and the second SL transmission may be associated with the third WTRU.

[0273] In a particular representative embodiment, the second direction may be substantially opposite to the first direction.

[0274] In a particular representative embodiment, WTRU102 may include a processor and transceivers configured to implement a method in which WTRU102 receives information indicating the configuration of a set of sidelink (SL) resources. WTRU102 may decode one or more SL control information (SCIs) received via the set of SL resources in a first direction associated with a target SL device and / or a second direction associated with the first direction. Using the decoded SCIs, WTRU102 may select an SL resource from the set of SL resources. In the first direction, WTRU102 may use the selected SL resource to send the primary SCI and data of the target SL device. In the second direction, WTRU102 may use the selected SL resource to send a paired SCI.

[0275] In a particular representative embodiment, the primary SCI, paired SCI, and data from the target SL device may include SL transmission within the SL slot.

[0276] In a particular representative embodiment, the multiplexing pattern of SL transmissions in an SL slot is in the order of primary SCI, paired SCI, and data relating to the target SL device.

[0277] In a particular representative embodiment, the multiplexing pattern of SL transmissions in an SL slot is in the order of data relating to the paired SCI, primary SCI, and target SL device.

[0278] In a particular representative embodiment, the multiplexing pattern of SL transmissions in an SL slot is in the order of primary SCI, data about the target SL device, and paired SCI.

[0279] In a particular representative embodiment, the primary SCI may be transmitted in a first direction within one or more identical symbols in the SL slot, and the paired SCI may be transmitted in a second direction within one or more identical symbols in the same SL slot.

[0280] conclusion While the features and elements are provided above in specific combinations, those skilled in the art will understand that each feature or element can be used individually or in any combination with other features and elements. This disclosure is not limited in terms of the specific embodiments described in this application, which are intended to be illustrative of various aspects. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from the spirit and scope of the invention. No element, action, or instruction used in the description of this application should be construed as important or essential to the invention unless it is so expressly presented. In addition to those enumerated herein, functionally equivalent methods and apparatus within the scope of this disclosure will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to fall within the scope of the appended claims. This disclosure is limited only by the terminology of the appended claims, and together with the entirety of the equivalents to which such claims are entitled. It should be understood that this disclosure is not limited to any particular method or system.

[0281] For the sake of brevity, the embodiments described above are considered in relation to the terminology and structure of infrared-compatible devices (i.e., infrared radiators and receivers). However, the embodiments considered are not limited to these systems and may also be applicable to other systems using other forms of electromagnetic waves, or non-electromagnetic waves such as acoustic waves.

[0282] It should also be understood that the terms used herein are for the purpose of describing only specific embodiments and are not intended to limit them. When used herein, the terms “video” or “image” may mean any of a snapshot, a single image, and / or multiple images displayed over time. As another example, when referred to herein, the terms “user equipment” and its abbreviation “UE,” “remote,” and / or “head-mounted display” or its abbreviation “HMD” may mean or include (i) a wireless transmit and / or receive unit (WTRU), (ii) any of several embodiments of a WTRU, (iii) a wireless-enabled and / or wired (e.g., tetherable) device configured to have some or all of the structures and functions of a WTRU, (iii) a wireless-enabled and / or wired device configured to have fewer structures and functions than all of the structures and functions of a WTRU, or (iv) other. Details of exemplary WTRUs that may represent any WTRU listed herein are provided herein with respect to Figures 1A to 1D. As another example, the various embodiments described above and below disclosed herein utilize a head-mounted display. Those skilled in the art will recognize that devices other than head-mounted displays may be used, and that some or all of the disclosure and the various disclosed embodiments can be modified accordingly without excessive experimentation. Examples of such other devices may include drones or other devices configured to stream information for providing an adaptive reality experience.

[0283] In addition, the methods provided herein may be implemented in computer programs, software, or firmware embedded in a computer-readable medium to be executed by a computer or processor. Examples of computer-readable mediums include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital multipurpose disks (DVDs). A processor associated 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.

[0284] Modifications of the methods, apparatus, and systems provided above are possible without departing from the scope of the present invention. Considering the wide variety of applicable embodiments, it should be understood that the illustrated embodiments are merely examples and should not be construed as limiting the scope of the following claims. For example, embodiments provided herein include a portable device which may include, or be utilized with, any suitable voltage source, such as a battery, providing any suitable voltage.

[0285] Furthermore, note that in the embodiments described above, other devices including processing platforms, computing systems, controllers, and processors may also be included. These devices may include at least one central processing unit (CPU) and memory. According to the convention of those skilled in the art in the field of computer programming, references to actions and symbolic representations of operations or instructions may be performed by various CPUs and memories. Such actions and operations or instructions may be referred to as “executed,” “executed by the computer,” or “executed by the CPU.”

[0286] Those skilled in the art will understand that actions and symbolically represented operations or instructions involve the manipulation of electrical signals by a CPU. The electrical system represents data bits that can cause a resulting transformation or reduction of electrical signals, and maintains these data bits in memory locations of a memory system, thereby reconfiguring or altering the operation of the CPU and the processing of other signals. The memory locations where the data bits are maintained are physical locations having specific electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be understood that the embodiments are not limited to the platforms or CPUs mentioned above, and other platforms and CPUs may support the methods provided.

[0287] Data bits may also be maintained on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read-only memory (ROM)) mass storage systems readable by the CPU. The computer-readable media may include cooperative or interconnected computer-readable media distributed among multiple interconnected processing systems, which may reside only in the processing system or be local or remote to the processing system. It should be understood that embodiments are not limited to the memories mentioned above, and other platforms and memories may support the methods provided.

[0288] In illustrative embodiments, any of the operations, processes, etc., described herein may be implemented as computer-readable instructions stored on a computer-readable medium. These computer-readable instructions may be executed by processors in mobile devices, network elements, and / or any other computing devices.

[0289] There is little distinction between hardware and software implementations of a system configuration. The choice between using hardware and software is generally a design choice representing a cost-effectiveness trade-off (although in some situations the choice between hardware and software may be important). Various media (e.g., hardware, software, and / or firmware) may be effective for the processes and / or systems and / or other technologies described herein, and the preferred medium may vary depending on the context in which the processes and / or systems and / or other technologies are deployed. For example, if the implementer determines that speed and accuracy are paramount, they may primarily choose a hardware and / or firmware medium. If flexibility is paramount, the implementer may primarily choose a software implementation. Alternatively, the implementer may choose any combination of hardware, software, and / or firmware.

[0290] In the detailed description above, various embodiments of devices and / or processes have been illustrated through the use of block diagrams, flowcharts, and / or examples. To the extent that such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, it will be understood by those skilled in the art that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware, or substantially any combination thereof. In one embodiment, some parts of the subject matter described herein may be implemented via application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integrated forms. However, it will be recognized by those skilled in the art that some aspects of the embodiments disclosed herein can be equivalently implemented in an integrated circuit as one or more computer programs running on one or more computers (e.g., one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., one or more programs running on one or more microprocessors), as firmware, or substantially any combination thereof, and that designing circuits and / or writing software and / or firmware code is within the scope of the art of those skilled in the art in light of this disclosure. In addition, it will be understood by those skilled in the art that the mechanisms of the subject matter described herein can be distributed as various forms of program products, and that the illustrative embodiments of the subject matter described herein are applicable regardless of the particular type of signal-carrying medium used to actually carry out the distribution. Examples of signal-carrying media include, but are not limited to, recordable media such as floppy disks, hard disk drives, CDs, DVDs, digital tapes, and computer memory, as well as transmitting media such as digital and / or analog communication media (e.g., optical fiber cables, waveguides, wired communication links, wireless communication links, etc.).

[0291] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner described herein and then to integrate such described devices and / or processes into a data processing system using engineering techniques. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system may generally include one or more of the following: a system unit housing, a video display device, memory such as volatile and non-volatile memory, a processor such as a microprocessor and a digital signal processor, computing entities such as an operating system, a driver, a graphical user interface, and an application program, one or more interactive devices such as a touchpad or a screen, and / or a control system including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, as is typically found in data computing / communication systems and / or network computing / communication systems.

[0292] The subject matter described herein may illustrate different components that are contained within or connected to other different components. Such illustrated architectures are merely examples, and it should be understood that in practice, many other architectures can be implemented to achieve the same function. Conceptually, any arrangement of components to achieve the same function is effectively “associated” in such a way that the desired function can be achieved. Therefore, any two components in this specification combined to achieve a particular function can be considered “associated” with each other, regardless of the architecture or intervening components, in such a way that the desired function can be achieved. Similarly, any two components thus associated can be considered “operably connected” or “operably coupled” with each other to achieve the desired function, and any two components that can be associated in such a way can be considered “operably coupled” with each other to achieve the desired function. Specific examples of components that can be operably coupled include, but are not limited to, physically matable and / or physically interacting components, and / or wirelessly interactable and / or wirelessly interacting components, and / or logically interacting and / or logically interactable components.

[0293] With regard to the use of substantially any plural and / or singular terms herein, those skilled in the art can convert from plural to singular and / or singular to plural as appropriate to the context and / or use. For clarity, various singular / plural rearrangements may be explicitly described herein.

[0294] In general, it will be understood by those skilled in the art that the terms used herein, and especially in the appended claims (e.g., in the body of the appended claims), are generally intended to be “non-limiting” terms (for example, the term “including” should be interpreted as “including, but not limited to,” the term “having” should be interpreted as “having at least,” and the term “includes” should be interpreted as “including, but not limited to.”). Furthermore, it will be understood by those skilled in the art that if a particular number of claims introduced are intended to be described, such intent is explicitly stated in the claim, and if such statement is not present, such intent does not exist. For example, if only one item is intended, the term “single” or similar word may be used. To aid understanding, the following appended claims and / or descriptions herein may include the use of the introductory phrases “at least one” and “one or more” to introduce the description of the claims. However, the use of such phrases should not be interpreted as meaning that the introduction of a claim description with the indefinite article “a” or “an” limits any particular claim containing such introduced description to embodiments containing only one such description, even if the same claim contains the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (for example, “a” and / or “an” should be interpreted as meaning “at least one” or “one or more”). The same applies to the use of definite articles used to introduce a claim description. In addition, even if a particular number of descriptions in an introduced claim are explicitly stated, it will be recognized by those skilled in the art that such a statement should be interpreted as meaning at least the number stated (for example, the simple statement “two descriptions” without other modifiers means at least two descriptions or two or more descriptions).Furthermore, when similar notations to "at least one of A, B, and C, etc." are used, such structures are generally intended to mean what a person skilled in the art would understand (for example, "a system having at least one of A, B, and C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). When a notation similar to "at least one of A, B, or C, etc." is used, such a structure is generally intended to mean what a person skilled in the art would understand (for example, "a system having at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together). It will further be understood by a person skilled in the art that substantially any disjunct words and / or phrases presenting two or more alternative terms in the specification, claims, or drawings should be understood as intending to include the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B". Furthermore, as used herein, the term “any of” followed by a list of items and / or a list of categories of items is intended to include, individually or in combination with other items and / or categories of items, any of, any combination of, any multiple of, and / or any multiple combination of. Furthermore, as used herein, the term “set” is intended to include any number of items, including zero. Additionally, as used herein, the term “number” is intended to include any number, including zero.Furthermore, as used herein, the term "multiple" is intended to be synonymous with "a plurality."

[0295] In addition, if any feature or aspect of the present disclosure is described in terms of the Markush group, a person skilled in the art will recognize that the present disclosure is also described in terms of any individual element or subgroup of elements of the Markush group.

[0296] For all purposes, including providing written explanations, as will be understood by those skilled in the art, all scopes disclosed herein also encompass all possible sub-scopes and combinations of sub-scopes. Each listed scope is readily recognizable as fully explainable and enabling the decomposition of the same scope into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each scope considered herein can easily be decomposed into the lower third, middle third, upper third, etc. Furthermore, as will be understood by those skilled in the art, all terms such as “up to,” “at least,” “greater than,” and “less than” refer to scopes that include the number mentioned and can be further decomposed into sub-scopes as considered above. Finally, as will be understood by those skilled in the art, a scope includes each individual element. Therefore, for example, a group having 1 to 3 cells refers to a group having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to a group having 1, 2, 3, 4, or 5 cells, and so on.

[0297] Furthermore, unless otherwise specifically stated, the claims should not be read as being limited to the order or elements provided. In addition, in any claim, the use of the term “means for” is intended to appeal to Section 112, paragraph 6 of the U.S. Patent Act, or the means-plus-function claim format, and no claim without the term “means for” is intended to appeal in that way.

Claims

1. A method implemented in a wireless transmitter / receiver (WTRU) for communicating a first type of sidelink (SL) control information (SCI) and a second type of SCI, Receiving information indicating the configuration of at least the first SL resource and the second SL resource, To determine the first beam direction associated with the first SL transmission, Monitoring a second SL transmission that uses the first beam direction and a second beam direction different from the first beam direction, Sending the first SL transmission using the second SL resource, provided that the second SL transmission is (1) received using the second beam direction, (2) associated with the first SL resource, (3) includes information indicating that the second SL transmission includes the first type of SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. The above-mentioned method of sending the first SL transmission using the second SL resource is as follows: Using the first beam direction, the first type of SCI and data of the first SL transmission using the second SL resource, A method comprising sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction.

2. The first beam direction is associated with a first direction, and the second beam direction is associated with a second direction opposite to the first direction. The method according to claim 1, wherein monitoring the second SL transmission using the first beam direction and using the second beam direction includes receiving the second SL transmission using the first SL resource.

3. The method according to claim 1, wherein the first type of SCI for the second SL transmission includes information indicating the reservation of the first SL resource.

4. Sending the first type of SCI of the first SL transmission using the second SL resource using the first beam direction is performed during one or more first symbols of the transmission time interval (TTI), The method according to claim 1, wherein the act of sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction is performed in one or more second symbols which are different from the one or more first symbols of the TTI.

5. The method according to claim 1, wherein one or more bits, a scrambled array, and / or a demodulation reference signal (DMRS) array distinguish the first type of SCI from the second type of SCI.

6. A method implemented in a wireless transmitter / receiver (WTRU) for communicating a first type of sidelink (SL) control information (SCI) and a second type of SCI, Receiving information indicating the configuration of at least the first SL resource and the second SL resource, To determine the first beam direction associated with the first SL transmission, Monitoring a second SL transmission that uses the first beam direction and a second beam direction different from the first beam direction, Sending the first SL transmission using the second SL resource, provided that the second SL transmission is (1) received using the first beam direction, (2) associated with the first SL resource, (3) includes information indicating that the second SL transmission includes the second type of SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. The above-mentioned method of sending the first SL transmission using the second SL resource is as follows: Using the first beam direction, the first type of SCI and data of the first SL transmission using the second SL resource, A method comprising sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction.

7. The first beam direction is associated with a first direction, and the second beam direction is associated with a second direction opposite to the first direction. The method according to claim 6, wherein monitoring the second SL transmission using the first beam direction and using the second beam direction includes receiving the second SL transmission using the first SL resource.

8. The method according to claim 6, wherein the first type of SCI for the second SL transmission includes information indicating the reservation of the first SL resource.

9. Sending the first type of SCI of the first SL transmission using the second SL resource using the first beam direction is performed during one or more first symbols of the transmission time interval (TTI), The method according to claim 6, wherein sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction is performed in one or more second symbols which are different from the one or more first symbols of the TTI.

10. The method according to claim 6, wherein one or more bits, a scrambled array, and / or a demodulation reference signal (DMRS) array distinguish the first type of SCI from the second type of SCI.

11. A wireless transmitter / receiver (WTRU) for communicating a first type of sidelink (SL) control information (SCI) and a second type of SCI, A processor, memory, and transceiver are provided, and the processor, memory, and transceiver are, Receiving information indicating the configuration of at least the first SL resource and the second SL resource, To determine the first beam direction associated with the first SL transmission, Monitoring a second SL transmission that uses the first beam direction and a second beam direction different from the first beam direction, The second SL transmission is configured to send the first SL transmission using the second SL resource, provided that the second SL transmission is (1) received using the second beam direction, (2) associated with the first SL resource, (3) includes information indicating that the second SL transmission includes the first type of SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. Using the first beam direction, the first type of SCI and data of the first SL transmission using the second SL resource, A WTRU comprising sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction.

12. The first beam direction is associated with a first direction, and the second beam direction is associated with a second direction opposite to the first direction. The WTRU according to claim 11, wherein monitoring the second SL transmission using the first beam direction and using the second beam direction includes receiving the second SL transmission using the first SL resource.

13. The WTRU according to claim 11, wherein the first type of SCI for the second SL transmission includes information indicating the reservation of the first SL resource.

14. The first type of SCI of the first SL transmission is sent using the second SL resource for the duration of one or more first symbols of the transmission time interval (TTI). The WTRU according to claim 11, wherein the second type of SCI of the first SL transmission is transmitted using the second SL resource between one or more second symbols that are different from the one or more first symbols of the TTI.

15. The WTRU according to claim 11, wherein one or more bits, a scrambled array, and / or a demodulation reference signal (DMRS) array distinguish the first type of SCI from the second type of SCI.

16. A wireless transmitter / receiver (WTRU) for communicating a first type of sidelink (SL) control information (SCI) and a second type of SCI, A processor and a transceiver are provided, and the processor and the transceiver are Receiving information indicating the configuration of at least the first SL resource and the second SL resource, To determine the first beam direction associated with the first SL transmission, Monitoring a second SL transmission that uses the first beam direction and a second beam direction different from the first beam direction, The second SL transmission is configured to send the first SL transmission using the second SL resource, provided that the second SL transmission is (1) received using the first beam direction, (2) associated with the first SL resource, (3) includes information indicating that the second SL transmission includes the second type of SCI, and / or (4) the received power of the second SL transmission exceeds a certain threshold. Using the first beam direction, the first type of SCI and data of the first SL transmission using the second SL resource, A WTRU comprising sending the second type of SCI of the first SL transmission using the second SL resource using the second beam direction.

17. The first beam direction is associated with a first direction, and the second beam direction is associated with a second direction opposite to the first direction. The WTRU according to claim 16, wherein monitoring the second SL transmission using the first beam direction and using the second beam direction includes receiving the second SL transmission using the first SL resource.

18. The WTRU according to claim 16, wherein the first type of SCI for the second SL transmission includes information indicating the reservation of the first SL resource.

19. The first type of SCI of the first SL transmission is sent using the second SL resource for the duration of one or more first symbols of the transmission time interval (TTI). The WTRU according to claim 16, wherein the second type of SCI of the first SL transmission is transmitted using the second SL resource between one or more second symbols that are different from the one or more first symbols of the TTI.

20. The WTRU according to claim 16, wherein one or more bits, a scrambled array, and / or a demodulation reference signal (DMRS) array distinguish the first type of SCI from the second type of SCI.

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