Efficient contention window for new radio sidelink on unlicensed bands

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) can select, for a sidelink transmission on an unlicensed band and associated with a medium access control (MAC) protocol data unit (PDU), one or more candidate resources of a set of candidate resources within an adaptive contention window (ECW). The UE can adjust at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine an adjusted at least one parameter. The UE can transmit the MAC PDU using the one or more candidate resources or additional one or more candidate resources, where the additional one or more candidate resources are selected based at least in part on the adjusted at least one parameter. Numerous other aspects are provided.

Description

[0001] Cross-reference to related applications

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 62 / 706,628, filed August 28, 2020, entitled “EFFECTIVE CONTENTION WINDOWSFOR NEW RADIO SIDELINK OVER UNLICENSED BANDS,” and U.S. Non-Provisional Patent Application No. 17 / 443,241, filed July 22, 2021, entitled “EFFECTIVE CONTENTION WINDOWS FOR NEW RADIO SIDELINK OVER UNLICENSED BANDS,” which are hereby expressly incorporated by reference.

[0003] open field

[0004] Various aspects of this disclosure generally relate to wireless communications, and techniques and apparatus for an effective contention window for new radio sidelinks on unlicensed frequency bands. Background Technology

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is an enhancement set of the Universal Mobile Telecommunications System (UMTS) mobile standard issued by the 3rd Generation Partnership Project (3GPP).

[0006] A wireless network may include several base stations (BSs) capable of supporting communication for several user equipments (UEs). UEs may communicate with the BS via downlinks and uplinks. A "downlink" (or "forward link") refers to the communication link from the BS to the UE, while an "uplink" (or "backlink") refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a B-node, gNB, access point (AP), radio headend, transmit / receive point (TRP), new radio (NR) BS, 5G B-node, etc.

[0007] The multiple access technologies mentioned above have been adopted in various telecommunications standards to provide a common protocol enabling different user equipment to communicate at the city, country, region, and even global levels. NR (which can also be referred to as 5G) is an enhancement set of the LTE mobile standard issued by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and better integrating with other open standards that support beamforming, multiple-input multiple-output (MIMO) antenna technologies and carrier aggregation, using Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) on the downlink (DL) (CP-OFDM), and CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Extended OFDM (DFT-s-OFDM)) on the uplink (UL). Further improvements to LTE, NR, and other radio access technologies remain useful as the demand for mobile broadband access continues to grow.

[0008] Overview

[0009] In some aspects, a wireless communication method performed by a user equipment (UE) includes: selecting one or more candidate resources from a candidate resource set within an adaptive effective contention window (ECW) for a sidelink transmission on an unlicensed frequency band and associated with a Media Access Control (MAC) Protocol Data Unit (PDU); adjusting at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine at least one adjusted parameter; and transmitting the MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected based at least in part on the adjusted at least one parameter.

[0010] In some aspects, a UE for wireless communication includes a memory; and one or more processors coupled to the memory, the memory and the one or more processors being configured to: select one or more candidate resources from a candidate resource set within an adaptive ECW for sidelink transmissions on unlicensed frequency bands and associated with MAC Protocol Data Units (PDUs); adjust at least one parameter of the adaptive ECW based at least in part on channel access outputs associated with the one or more candidate resources to determine at least one adjusted parameter; and transmit a MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected based at least in part on the adjusted at least one parameter.

[0011] In some aspects, a non-transient computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a user-equipped UE, cause the UE to: select one or more candidate resources from a candidate resource set within an adaptive ECW for sidelink transmission on an unlicensed frequency band and associated with a MAC PDU; adjust at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine at least one adjusted parameter; and transmit a MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

[0012] In some aspects, an apparatus for wireless communication includes: means for selecting one or more candidate resources from a candidate resource set within an adaptive ECW for sidelink transmission over an unlicensed frequency band and associated with a MAC PDU; means for adjusting at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine the adjusted at least one parameter; and means for transmitting a MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected based at least in part on the adjusted at least one parameter.

[0013] The aspects generally include, as substantially described herein with reference to the accompanying drawings and description, methods, apparatus, systems, computer program products, non-transient computer-readable media, user equipment, base stations, wireless communication equipment, and / or processing systems.

[0014] The foregoing has broadly outlined the features and technical advantages of the examples according to this disclosure in an effort to facilitate a better understanding of the following detailed description. Additional features and advantages will be described thereafter. The disclosed concepts and specific examples can be readily used as the basis for modifying or designing other structures for implementing the same purposes as this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, in both their organization and manner of operation, and their associated advantages, will be better understood by considering the following description in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and not for defining limitations on the claims.

[0015] While aspects are described herein by way of example, those skilled in the art will understand that such aspects can be implemented in many different arrangements and scenarios. The techniques described herein can be implemented using different platform types, devices, systems, shapes, sizes, and / or package arrangements. For example, some aspects may be implemented via integrated chip embodiments or other devices based on non-modular components (e.g., end-user equipment, vehicles, communication equipment, computing devices, industrial equipment, retail / shopping devices, medical devices, or AI-enabled devices). Aspects can be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, or system-level components. Devices incorporating the described aspects and features may include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals may include several components (e.g., hardware components, including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders, or summers) for analog and digital purposes. The aspects described herein are intended to be practiced in a wide variety of devices, components, systems, distributed arrangements, or end-user equipment of various sizes, shapes, and configurations. Brief description of the attached diagram

[0017] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to various aspects of the above brief overview, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain typical aspects of this disclosure and should not be considered as limiting its scope, as other equivalent aspects are permissible in this description. Identical reference numerals in different drawings may identify the same or similar elements.

[0018] Figure 1 This is a diagram illustrating an example of a wireless network according to this disclosure.

[0019] Figure 2 This is a diagram illustrating an example of communication between a base station and a user equipment (UE) in a wireless network according to this disclosure.

[0020] Figure 3 This is a diagram illustrating an example of sidelink communication according to this disclosure.

[0021] Figure 4 This is a diagram illustrating examples of sidelink communication and access link communication according to this disclosure.

[0022] Figure 5 This is a diagram illustrating an example of resource selection for a side link according to this disclosure.

[0023] Figures 6-8This is a diagram illustrating an example of an effective contention window (ECW) associated with a new radio (NR) sidelink on an unlicensed frequency band, according to this disclosure.

[0024] Figure 9 This is a diagram illustrating an example process associated with ECW for an NR side link in an unlicensed frequency band, according to this disclosure.

[0025] Figure 10 This is a block diagram of an example apparatus for wireless communication according to the present disclosure.

[0026] Detailed description

[0027] The various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be implemented in many different forms and should not be construed as being limited to any specific structure or function given throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art will appreciate that the scope of this disclosure is intended to cover any aspect of this disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of this disclosure. For example, any number of aspects set forth herein may be used to implement an apparatus or method of practice. Furthermore, the scope of this disclosure is intended to cover such apparatus or methods practiced using additional structures, functionalities, or structures and functionalities that complement or supplement the various aspects of this disclosure set forth herein. It should be understood that any aspect of this disclosure disclosed herein may be implemented by one or more elements of the claims.

[0028] Several aspects of a telecommunications system will now be described with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and explained in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively, "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0029] It should be noted that although the aspects herein may be described using terms commonly associated with 5G or NR radio access technology (RAT), the aspects of this disclosure may be applied to other RATs, such as 3G RAT, 4G RAT, and / or RATs after 5G (e.g., 6G).

[0030] Figure 1This is a diagram illustrating an example of a wireless network 100 according to this disclosure. The wireless network 100 may be a 5G (NR) network and / or an LTE network, etc., or may include its elements. The wireless network 100 may include several base stations 110 (shown as BS110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station (BS) is an entity that communicates with a user equipment (UE) and may also be referred to as an NR BS, B-node, gNB, 5G B-node (NB), access point, transmit / receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0031] A BS can provide communication coverage for macrocells, picocells, femtocells, and / or another type of cell. Macrocells can cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access by UEs with a service subscription. Picocells can cover a relatively small geographic area and allow unrestricted access by UEs with a service subscription. Femtocells can cover a relatively small geographic area (e.g., a residential area) and allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS used for macrocells may be referred to as a macro BS. A BS used for picocells may be referred to as a pico BS. A BS used for femtocells may be referred to as a femto BS or a home BS. Figure 1 In the example shown, BS 110a can be a macro BS for macro cell 102a, BS 110b can be a pico BS for pico cell 102b, and BS 110c can be a femto BS for femto cell 102c. A BS can support one or more (e.g., three) cells. The terms “eNB,” “base station,” “NR BS,” “gNB,” “TRP,” “AP,” “B node,” “5G NB,” and “cell” are used interchangeably herein.

[0032] In some respects, the cell may not be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile BS. In some respects, BSs may interconnect with each other and / or interconnect to one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces (such as direct physical connections or virtual networks, using any suitable transport network).

[0033] The wireless network 100 may also include a relay station. A relay station is an entity capable of receiving data transmissions from an upstream station (e.g., a BS or a UE) and transmitting those data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE capable of relaying transmissions for other UEs. Figure 1 In the example shown, relay BS 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay BS can also be referred to as a relay station, relay base station, relay, etc.

[0034] Wireless network 100 can be a heterogeneous network comprising different types of Base Stations (BSs) such as macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in wireless network 100. For example, macro BSs may have high transmit power levels (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

[0035] Network controller 130 can be coupled to a set of Base Stations (BSs) and can provide coordination and control over these BSs. Network controller 130 can communicate with each BS via backhaul. These BSs can also communicate with each other directly or indirectly via wireless or wired backhaul.

[0036] UE 120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE may be a cellular phone (e.g., a smartphone), personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet, camera, gaming device, netbook, smartbook, ultrabook, medical device or equipment, biometric sensor / device, wearable device (smartwatch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), entertainment device (e.g., music or video device, or satellite radio), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, GPS device, or any other suitable device configured to communicate via wireless or wired media.

[0037] Some UEs may be considered machine-type communication (MTC) devices, or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, instruments, monitors, and / or location tags that can communicate with a base station, another device (e.g., a remote device), or some other entity. Wireless nodes may provide connectivity to or to a network (e.g., a wide area network, such as the Internet or a cellular network) via wired or wireless communication links, for example. Some UEs may be considered Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs may be considered customer premises equipment (CPE). UE 120 may be included within a housing that houses components of UE 120, such as processor components and / or memory components. In some aspects, the processor components and memory components may be coupled together. For example, the processor components (e.g., one or more processors) and memory components (e.g., memory) may be operatively coupled, communicatively coupled, electronically coupled, and / or electrically coupled.

[0038] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific RAT and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks using different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0039] In some respects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary). For example, UEs 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols or vehicle-to-infrastructure (V2I) protocols), and / or mesh networks. In this scenario, UEs 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as performed by base station 110.

[0040] Devices in the wireless network 100 can communicate using the electromagnetic spectrum, which can be subdivided into various categories, bands, channels, etc., based on frequency or wavelength. For example, devices in the wireless network 100 can communicate using an operating band with a first frequency range (FR1) and / or an operating band with a second frequency range (FR2), where the first frequency range (FR1) spans from 410 MHz to 7.125 GHz and the second frequency range (FR2) spans from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as intermediate frequency bands. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as the "sub-6 GHz band." Similarly, although different from the extremely high frequency (EHF) band (30 GHz–300 GHz) designated as the "millimeter wave" band by the International Telecommunication Union (ITU), FR2 is often referred to as the "millimeter wave" band. Therefore, unless otherwise stated, it should be understood that, if used herein, the term "sub-6GHz," etc., can broadly refer to frequencies less than 6GHz, frequencies within FR1, and / or intermediate frequency band frequencies (e.g., greater than 7.125GHz). Similarly, unless otherwise stated, it should be understood that, if used herein, the term "millimeter wave," etc., can broadly refer to frequencies within the EHF band, frequencies within FR2, and / or intermediate frequency band frequencies (e.g., less than 24.25GHz). It is conceivable that the frequencies included in FR1 and FR2 can be modified, and the techniques described herein are applicable to those modified frequency ranges.

[0041] As indicated above, Figure 1 This is provided as an example. Other examples may differ from the one provided. Figure 1 The example described.

[0042] Figure 2 This is a diagram illustrating an example 200 of communication between a base station 110 and a UE 120 in a wireless network 100 according to this disclosure. The base station 110 may be equipped with T antennas 234a to 234t, while the UE 120 may be equipped with R antennas 252a to 252r, wherein generally T≥1 and R≥1.

[0043] At base station 110, transmit processor 220 can receive data destined for one or more UEs from data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQI) received from each UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Transmit processor 220 can also process system information (e.g., semi-static resource allocation information (SRPI)) and control information (e.g., CQI requests, grants, and / or upper-layer signaling), and provide overhead symbols and control symbols. Transmit processor 220 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS) or demodulation reference signals (DMRS)) and synchronization signals (e.g., primary synchronization signal (PSS) or secondary synchronization signal (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, where applicable, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can process its respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t, respectively.

[0044] At UE 120, antennas 252a to 252r can receive downlink signals from base station 110 and / or other base stations and can provide the received signals to demodulators (DEMODs) 254a to 254r respectively. Each demodulator 254 can condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM) to obtain received symbols. MIMO detector 256 can obtain the received symbols from all R demodulators 254a to 254r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 258 can process (e.g., demodulate and decode) these detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information and system information to controller / processor 280. The term "controller / processor" can refer to one or more controllers, one or more processors, or a combination thereof. The channel processor can determine parameters such as Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), Reference Signal Received Quality (RSRQ), and / or Channel Quality Indicator (CQI). In some respects, one or more components of the UE 120 may be included in the housing 284.

[0045] Network controller 130 may include communication unit 294, controller / processor 290, and memory 292. Network controller 130 may include one or more devices, such as those in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

[0046] Antennas (e.g., antennas 234a to 234t and / or antennas 252a to 252r) may include, or be included therein, one or more antenna panels, antenna groups, antenna element sets, and / or antenna arrays. Antenna panels, antenna groups, antenna element sets, and / or antenna arrays may include one or more antenna elements. Antenna panels, antenna groups, antenna element sets, and / or antenna arrays may include coplanar antenna element sets and / or non-coplanar antenna element sets. Antenna panels, antenna groups, antenna element sets, and / or antenna arrays may include antenna elements within a single housing and / or multiple antenna elements within housings. Antenna panels, antenna groups, antenna element sets, and / or antenna arrays may include elements coupled to one or more transmission and / or reception components (such as...). Figure 2 One or more antenna elements (one or more components).

[0047] On the uplink, at UE 120, transmit processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., reports including RSRP, RSSI, RSRQ, and / or CQI). Transmit processor 264 can also generate reference symbols for one or more reference signals. Symbols from transmit processor 264 may be pre-encoded by TX MIMO processor 266 where applicable, further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In some aspects, modulators and demodulators (e.g., MOD / DEMOD 254) of UE 120 may be included in the modem of UE 120. In some aspects, UE 120 includes a transceiver. The transceiver may include any combination of antennas 252, modulators and / or demodulators 254, MIMO detectors 256, receiver processors 258, transmitter processors 264, and / or TX MIMO processors 266. The transceiver may be used by a processor (e.g., controller / processor 280) and memory 282 to perform aspects of any of the methods described herein (e.g., as referenced). Figures 6-10 (As described).

[0048] At base station 110, uplink signals from UE 120 and other UEs can be received by antenna 234, processed by demodulator 232, detected by MIMO detector 236 where applicable, and further processed by receiver processor 238 to obtain decoded data and control information transmitted by UE 120. Receiver processor 238 can provide the decoded data to data sink 239 and the decoded control information to controller / processor 240. Base station 110 may include communication unit 244 and communicate with network controller 130 via communication unit 244. Base station 110 may include scheduler 246 to schedule UE 120 for downlink and / or uplink communications. In some aspects, the modulator and demodulator (e.g., MOD / DEMOD 232) of base station 110 may be included in the modem of base station 110. In some aspects, base station 110 includes a transceiver. The transceiver may include (such as) antenna 234, modulator and / or demodulator 232, MIMO detector 236, receiver processor 238, transmitter processor 220, and / or any combination of TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller / processor 240) and memory 242 to perform aspects of any of the methods described herein (e.g., as referenced). Figures 6-10 (As described).

[0049] The controller / processor 240 of base station 110, the controller / processor 280 of UE 120, and / or Figure 2 Any other component may perform one or more techniques associated with an effective contention window (ECW) for a new radio (NR) sidelink on an unlicensed frequency band, as described in more detail elsewhere herein. For example, the controller / processor 240 of base station 110, the controller / processor 280 of UE 120, and / or Figure 2 Any other component that can execute or direct, for example Figure 9 The operation of process 900 and / or other processes as described herein. Memory 242 and 282 may store data and program code for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include: a non-transitory computer-readable medium storing one or more instructions (e.g., code and / or program code) for wireless communication. For example, when executed by one or more processors of base station 110 and / or UE 120 (e.g., direct execution, or execution after compilation, transformation, and / or interpretation), the one or more processors, UE 120, and / or base station 110 may cause the one or more processors, UE 120, and / or base station 110 to perform or direct, for example... Figure 9 The process 900 and / or other processes as described herein. In some respects, the execution instructions may include run instructions, translate instructions, compile instructions, and / or interpret instructions, etc.

[0050] In some aspects, UE 120 may include: means for selecting one or more candidate resources from a candidate resource set within an adaptive effective contention window (ECW) for sidelink transmission on an unlicensed frequency band and associated with a Media Access Control (MAC) Protocol Data Unit (PDU); means for adjusting at least one parameter of the adaptive ECW at least in part based on channel access output associated with the one or more candidate resources to determine at least one adjusted parameter; and means for transmitting the MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter, etc. In some aspects, such means may include a combination of Figure 2 One or more components of the described UE120, such as controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, etc.

[0051] although Figure 2The boxes in the diagram are interpreted as different components, but the functions described above with respect to these boxes can be implemented by a single hardware component, software component, or combination of components. For example, the functions described with respect to transmit processor 264, receive processor 258, and / or TX MIMO processor 266 can be performed by controller / processor 280 or under the control of controller / processor 280.

[0052] As indicated above, Figure 2 This is provided as an example. Other examples may differ from the one provided. Figure 2 The example described.

[0053] Figure 3 This is a diagram illustrating example 300 of sidelink communication according to this disclosure.

[0054] like Figure 3 As shown, the first UE 305-1 can communicate with the second UE 305-2 (and one or more other UEs 305) via one or more sidelink channels 310. UEs 305-1 and 305-2 can use the one or more sidelink channels 310 to communicate for P2P communication, D2D communication, V2X communication (e.g., which may include V2V communication, V2I communication, and / or V2P communication) and / or mesh networking. In some aspects, UEs 305 (e.g., UEs 305-1 and / or UEs 305-2) may correspond to one or more other UEs described elsewhere herein, such as UE 120. In some aspects, the one or more sidelink channels 310 may use a PC5 interface and / or may operate in a high-frequency band (e.g., the 5.9 GHz band). Additionally or alternatively, UEs 305 may use Global Navigation Satellite System (GNSS) timing to synchronize the timing of transmission time intervals (TTIs) (e.g., frames, subframes, time slots, or symbols).

[0055] As in Figure 3As further illustrated, the one or more sidelink channels 310 may include a Physical Sidelink Control Channel (PSCCH) 315, a Physical Sidelink Shared Channel (PSSCH) 320, and / or a Physical Sidelink Feedback Channel (PSFCH) 325. PSCCH 315 may be used to convey control information, similar to a Physical Downlink Control Channel (PDCCH) and / or a Physical Uplink Control Channel (PUCCH) for cellular communication with base station 110 via an access link or access channel. PSSCH 320 may be used to convey data, similar to a Physical Downlink Shared Channel (PDSCH) and / or a Physical Uplink Shared Channel (PUSCH) for cellular communication with base station 110 via an access link or access channel. For example, PSCCH 315 may carry Sidelink Control Information (SCI) 330, which may indicate various control information for sidelink communication, such as one or more resources (e.g., time resources, frequency resources, and / or spatial resources, etc.), wherein a Transport Block (TB) 335 may be carried on PSSCH 320. TB 335 may include data. PSFCH 325 may be used to communicate sidelink feedback 340, such as Hybrid Automatic Repeat Request (HARQ) feedback (e.g., ACK / NACK information), Transmit Power Control (TPC), and / or Schedule Request (SR).

[0056] Although shown on PSCCH 315, SCI 330 may, in some respects, include multiple communications in different phases, such as a first-phase SCI (SCI-1) and a second-phase SCI (SCI-2). SCI-1 may be transmitted on PSCCH 315. SCI-2 may be transmitted on PSSCH 320. SCI-1 may include, for example, indications of one or more resources on PSSCH 320 (e.g., time resources, frequency resources, and / or spatial resources), information for decoding sidelink communications on PSSCH, Quality of Service (QoS) priority values, resource reservation periods, PSSCH Demodulation Reference Signal (DMRS) mode, SCI format of SCI-2, β offset of SCI-2, number of PSSCH DMRS ports, and / or modulation and coding scheme (MCS). SCI-2 may include information associated with data transmission on PSSCH 320, such as Hybrid Automatic Repeat Request (HARQ) procedure ID, New Data Indicator (NDI), source identifier, destination identifier, and / or Channel State Information (CSI) report triggering.

[0057] In some aspects, one or more sidelink channels 310 may use resource pools. For example, specific resource blocks (RBs) may be used across time to transmit scheduling assignments in subchannels (e.g., included in SCI 330). In some aspects, data transmissions associated with scheduling assignments (e.g., on PSSCH 320) may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, scheduling assignments and associated data transmissions are not transmitted on adjacent RBs.

[0058] In some aspects, UE 305 may operate using a transmission mode in which resource selection and / or scheduling is performed by UE 305 (e.g., instead of base station 110). In some aspects, UE 305 may perform resource selection and / or scheduling by sensing channel availability for transmission. For example, UE 305 may measure Received Signal Strength Indicator (RSSI) parameters (e.g., sidelink-RSSI (S-RSSI) parameters) associated with various sidelink channels; may measure Reference Signal Received Power (RSRP) parameters (e.g., PSSCH-RSRP parameters) associated with various sidelink channels; and / or may measure Reference Signal Received Quality (RSRQ) parameters (e.g., PSSCH-RSRQ parameters) associated with various sidelink channels; and may select the channel for transmission of sidelink communication based at least in part on (these) measurements.

[0059] Alternatively or concurrently, UE 305 may use SCI 330 received in PSCCH 315 (which may indicate the occupied resources and / or channel parameters) to perform resource selection and / or scheduling. Alternatively or concurrently, UE 305 may perform resource selection and / or scheduling by determining the Channel Busy Rate (CBR) associated with various sidelink channels, which may be used for rate control (e.g., by indicating the maximum number of resource blocks available to UE 305 for a particular subframe set).

[0060] In a transport mode where resource selection and / or scheduling is performed by UE 305, UE 305 may generate sidelink grants, and these grants may be transmitted in SCI 330. Sidelink grants may indicate one or more parameters (e.g., transport parameters) to be used for an upcoming sidelink transport, such as one or more resource blocks (e.g., for TB335) to be used for an upcoming sidelink transport on PSSCH 320, one or more subframes to be used for an upcoming sidelink transport, and / or the MCS to be used for an upcoming sidelink transport. In some aspects, UE 305 may generate sidelink grants indicating one or more parameters for semi-persistent scheduling (SPS), such as the periodicity of the sidelink transport. Additionally or alternatively, UE 305 may generate sidelink grants for event-driven scheduling (such as for on-demand sidelink messages).

[0061] As indicated above, Figure 3 This is provided as an example. Other examples may differ from the one provided. Figure 3 The example described.

[0062] Figure 4 This is a diagram illustrating example 400 of sidelink communication and access link communication according to this disclosure.

[0063] like Figure 4 As shown, the transmitting (Tx) / receiving (Rx) UE 405 and the Rx / Tx UE 410 can communicate with each other via a side link, as described above. Figure 3 As further illustrated, in some sidelink modes, base station 110 may communicate with Tx / Rx UE 405 via a first access link. Additionally or alternatively, in some sidelink modes, base station 110 may communicate with Rx / Tx UE 410 via a second access link. Tx / Rx UE 405 and / or Rx / Tx UE 410 may correspond to one or more UEs described elsewhere herein, such as... Figure 1 UE 120. Therefore, the direct link between UEs 120 (e.g., via the PC5 interface) can be referred to as a side link, and the direct link between base station 110 and UE 120 (e.g., via the Uu interface) can be referred to as an access link. Side link communication can be transmitted via the side link, and access link communication can be transmitted via the access link. Access link communication can be downlink communication (from base station 110 to UE 120) or uplink communication (from UE 120 to base station 110).

[0064] As indicated above, Figure 4 This is provided as an example. Other examples may differ from the one provided. Figure 4 The example described.

[0065] Figure 5 This is a diagram illustrating Example 500 for resource selection for a sidelink according to this disclosure. Example 500 illustrates a scheme for sensing a sidelink channel based on a resource selection window to select resources for sidelink communication.

[0066] like Figure 5 As shown, the UE can execute sensing procedures within the sensing window. In some cases, the sensing window can be 100 milliseconds (ms) (e.g., for aperiodic resource reservations, such as aperiodic reservations in one or more time slots up to 32 logical time slots in the future) or 1100 ms (e.g., for periodic resource reservations). In some cases, a UE configured for communication in an NR network can use sensing procedures for either aperiodic or periodic resource reservations.

[0067] According to the sensing procedure, the UE can decode control messages related to resource reservations with other UEs, and perform measurements associated with one or more sidelink channels (e.g., RSRP measurements). For example, the UE can transmit reservation information (e.g., in the SCI) indicating resource reservations for the current time slot (e.g., the time slot for which reservation information is transmitted) and for one or more (e.g., up to two) future time slots. The resource allocation associated with the resource reservation can be one or more sub-channels in the frequency domain and a time slot in the time domain. In some cases, resource reservations can be aperiodic or periodic. In periodic resource reservations, the UE can signal (e.g., in the reservation information in the SCI) the time period for which the resource reservation is used (e.g., a value between 0 ms and 1000 ms). In some cases, the sensing procedure can be executed by the UE's physical layer based on a request from the UE's Media Access Control (MAC) layer.

[0068] like Figure 5 As shown, the UE can determine the resources to select for sidelink communication based at least in part on resource selection triggers. For example, resource selection can be triggered when the UE has packets to transmit. Based at least in part on resource selection triggers, the UE can determine one or more resources available for selection in the Resource Selection Window (RSW). That is, the UE can determine the one or more available resources based at least in part on sensing procedures performed by the UE. For example, sensing procedures can provide indications of occupied candidate resources in the RSW and / or resources in the RSW associated with high interference.

[0069] The UE's physical layer can report the candidate resource set to the UE's MAC layer. The MAC layer randomly selects one or more resources from the reported candidate resource set for transmission. In some cases, the UE may be reserving resources for Hybrid Automatic Request Response (HARQ) transmissions and / or retransmissions, and resources for multiple Physical Side Link Shared Channels (PSSCH) for the same transport block may be randomly selected by the MAC layer.

[0070] Figure 5 The RSW shown can be defined by a first time period T1 and a second time period T2. In some cases, if resource selection triggering occurs in subframe n, the resource selection window is from n+T1 to n+T2. In this case, T1 can be less than the processing time (T... proc,1 Furthermore, T2 can be greater than or equal to T. 2,min It can be a value configured for the UE based at least in part on the UE's priority, and is less than or equal to 100 or the UE's remaining packet delay budget (PDB) (e.g., T2 can be less than or equal to the remaining PDB).

[0071] PDB is a constraint that specifies the maximum delay between packet arrival time and the last transmission time of a packet. For example, each packet arriving at the UE's transmitter for transmission is associated with a PDB and a transmission count (the number of times the packet is to be transmitted). The PDB and transmission count may vary between packets, depending on, for example, the application or service associated with the packet (e.g., to achieve desired coverage, range, reliability, etc.).

[0072] Some aspects described herein relate to unlicensed radio spectrum bands that can be used for communications in a wireless network (such as wireless network 100). In some aspects, unlicensed radio spectrum bands can be used by base stations 110 and UEs 120 of a cellular network for cellular communications (e.g., NR communications), and by Wi-Fi access points and Wi-Fi stations of a Wi-Fi network for Wi-Fi communications. Unlicensed radio spectrum bands can be used in combination with licensed radio spectrum bands within the cellular network or independently of them. In some examples, an unlicensed radio spectrum band can be a radio spectrum band that a device might need to contend for access to, because the radio spectrum band is at least partially available for unlicensed use, such as Wi-Fi use.

[0073] Before gaining access to and communicating on an unlicensed radio spectrum band, the UE can perform a Listen-Before-Speak (LBT) procedure to contend for access to that band. The LBT procedure may include determining the Channel Busy Ratio (CBR) to ascertain the availability of channels on the unlicensed spectrum band. The UE can use a pre-configured mapping from CBR to Channel Utilization Ratio (CR) to self-regulate channel access attempts to avoid severe congestion and contention in the system. When the estimated CBR value is high, the UE can perform fewer channel access attempts.

[0074] In some situations, the presence of interference associated with that NR RAT from one or more other RATs can lead to erroneous CBR estimates. For example, when a subchannel is actually occupied by one or more other RATs, it may be detected as "busy" in the CBR estimate. Therefore, typical cases of CBR-based congestion control can fail. If the UE reacts to an erroneous CBR, it may be cut off from access by one or more other RATs. Furthermore, particularly for low-complexity receiver implementations, the robustness of CBR-based congestion control can often be challenged due to potentially strong inter-subchannel leakage. In some environments, a UE may be cut off from access to channels in unlicensed RF bands due to the activity of another RAT (such as Wi-Fi).

[0075] In some scenarios, for certain RATs, the UE employs Load-Based Equipment (LBE) channel access, where its primary channel access engine has a contention management scheme designed to manage channel access. In the LBE, upon observing one or more lost packets as a possible congestion symptom, the LBE code can double its contention window (CW) to cool down channel access contention. However, as a node in a synchronous system, the UE cannot operate entirely like an LBE node, and the UE cannot solely rely on LBE control for contention / congestion management.

[0076] In some scenarios, the RSW can be understood as the initial contention window (CW) of the NR sidelink autonomous sensing procedure. In other scenarios, the physical layer can filter these candidate resources to report only available resources to the MAC layer. The slot index randomly selected by the MAC layer from the filtered RSW can be understood as a random number of the Listen-Before-Speak (LBT) counter. Generally, the closer the slot indices selected by the UE are to each other, the shorter the channel access latency. However, smaller slot indices may increase the risk of collisions and / or congestion. Because the CBR mechanism described above is used to manage collisions and / or congestion, there is currently no adaptive management for collisions and / or congestion associated with the initial CW in the NR sidelink. However, as mentioned above, the CBR mechanism may not work well in unlicensed frequency bands.

[0077] According to some aspects of the techniques and apparatus described herein, a UE can be configured with an effective contention window (ECW) for NR sidelinks in unlicensed frequency bands. These ECWs can be used as an effective CW-based congestion / contention control mechanism for sensing procedures used for resource selection. In some aspects, the techniques and apparatus described herein can include selecting one or more candidate resources from a candidate resource set within an adaptive ECW. A channel access attempt can be performed, and the UE can adjust at least one parameter of the adaptive ECW to determine at least one parameter of the adjusted adaptive ECW. The UE can adjust the at least one parameter at least in part based on a channel access output associated with the one or more candidate resources. The UE can use the one or more candidate resources or additional one or more candidate resources to transmit a MAC PDU. The additional one or more candidate resources can be selected at least in part based on the adjusted at least one parameter.

[0078] In some aspects, adaptive ECW can be configured to facilitate resource selection in the autonomous sensing procedure of NR sidelink mode 2 when operating in unlicensed bands. The aspects can implement adaptive ECW management based on the channel access output at the selected sidelink resource. For example, the UE can increase adaptive ECW in response to channel access failure and decrease adaptive ECW when channel access is successful. In this way, the aspects can provide an adaptive resource selection scheme that can adjust ECW in response to channel access output. As a result, the aspects of the techniques and apparatus described herein can increase channel access reliability in unlicensed band uplinks, increase the efficiency of unlicensed band uplink communication, and reduce conflicts in unlicensed band uplink communication.

[0079] As indicated above, Figure 5 This is provided as an example. Other examples may differ from the one provided. Figure 5 The example described.

[0080] Figure 6 This is a diagram illustrating an example 600 associated with an ECW for an NR sidelink in an unlicensed frequency band according to this disclosure. (See diagram for example.) Figure 6 As shown, UE 605 and UE 610 can communicate with each other via a side link. UE 605 and / or UE 610 can be, similar to, include, or be included in. Figure 1 In UE 120 shown.

[0081] As shown by reference numeral 615 in the attached figure, UE 605 can select one or more candidate resources from the candidate resource set within the adaptive ECW. UE 605 can select these one or more candidate resources for sidelink transmission on unlicensed frequency bands. Sidelink transmission can be associated with MAC Protocol Data Units (PDUs). UE 605 can randomly select one or more candidate resources from the candidate resource set within the adaptive ECW.

[0082] UE 605 can use the physical layer to determine the candidate resource set and use the MAC layer to select one or more candidate resources from that set. The physical layer of UE 605 can determine the candidate resource set at least in part based on sensing operations performed by the physical layer. Figure 7 As shown below and in conjunction with Figure 7 The candidate resource set described herein may include a set of valid available resources. The set of valid available resources may include a subset containing multiple identified resources available within the resource selection window.

[0083] As shown by reference numeral 620 in the accompanying figure, UE 605 may adjust at least one parameter of the adaptive ECW to determine the adjusted parameter. UE 605 may adjust the at least one parameter based at least in part on a channel access output associated with the one or more candidate resources. The channel access output may include an indication of channel access failure. For example, UE 605 may attempt to access the corresponding channel using one or more selected candidate resources. If UE 605 fails to access the channel, UE 605 may adjust the adaptive ECW and select an additional set of candidate resources within the adjusted adaptive ECW. The indication of channel access failure may include failure to receive an acknowledgment (ACK) feedback message associated with an ACK-based PSSCH transmission, failure of an LBT procedure associated with a slot boundary, failure to achieve a specified channel occupancy time at a specified sidelink slot, etc.

[0084] The at least one parameter of the adjusted adaptive ECW may include anchor time, adaptive ECW offset associated with anchor time, adaptive ECW width, etc. Adaptive ECW offset may include the number of symbols between anchor time and the initial symbol corresponding to the adaptive ECW. Adaptive ECW width may include the number of symbols.

[0085] As indicated by reference numeral 625 in the accompanying figure and as stated above, UE 605 may adjust the adaptive ECW offsets associated with the anchor time. UE 605 may adjust the adaptive ECW offsets linearly (e.g., by adding an adjustment factor to the adaptive ECW offset, by adjusting the adaptive ECW offset using a linear equation, etc.), multiplicatively (e.g., by multiplying the adaptive ECW offset by an adjustment factor, by adjusting the adaptive ECW offset using a nonlinear equation, etc.). UE 605 may establish a fixed adaptive ECW width w and adjust the dynamic adaptive ECW offsets. The channel access output may include an indication of channel access failure, and UE 605 may increase the adaptive ECW offsets at least in part based on the indication of channel access failure. The channel access output may include an indication of successful channel access, and UE 605 may decrease the adaptive ECW offset at least in part based on the indication of successful channel access.

[0086] UE 605 can introduce randomness beyond that introduced by random selection from a set of candidate resources. For example, UE 605 can set a distribution upper limit based at least in part on the channel access output. The distribution upper limit can be determined based on the initial adaptive ECW offset value of the adaptive ECW offsets s. UE 605 can set the distribution upper limit equal to the initial adaptive ECW offset value of the adaptive ECW offsets s. UE 605 can select a random number S from a uniform distribution between zero and the distribution upper limit, and adjust the adaptive ECW offset at least in part based on this random number to determine the adjusted adaptive ECW offset value. For example, UE 605 can shift the start of the ECW, the middle of the ECW, the end of the ECW, etc., to align with the selected random number S.

[0087] As indicated by reference numeral 630 in the attached figure and as indicated above, UE 605 may adjust the adaptive ECW width w. UE 605 may adjust the offset s linearly, multiplicatively, etc. UE 605 may establish a fixed adaptive ECW offset s and adjust the adaptive ECW width w. The channel access output may include an indication of channel access failure, and UE 605 may increase the adaptive ECW width w at least in part based on the indication of channel access failure. The channel access output may include an indication of successful channel access, and UE 605 may decrease the adaptive ECW width w at least in part based on the indication of successful channel access.

[0088] In some respects, UE 605 may adjust the adaptive ECW offset s and the adaptive ECW width w. The channel access output may include an indication of channel access failure, and UE 605 may increase the adaptive ECW offset s and the adaptive ECW width w based at least in part on the indication of channel access failure. The channel access output may include an indication of successful channel access, and UE 605 may decrease the adaptive ECW offset s and the adaptive ECW width w based at least in part on the indication of successful channel access.

[0089] As indicated above, at least one parameter of the adaptive ECW may include the anchor time. The anchor time may be defined by the UE's MAC layer as including a first slot index of the resource selection window associated with the candidate resource set, a slot index corresponding to the first available resource within the RSW, a slot index corresponding to the expected LBT completion time associated with the MAC PDU, a maximum slot index of any combination thereof, etc.

[0090] UE 605 can determine the estimated LBT completion time based at least in part on the Channel Access Priority Class (CAPC) of the MAC PDU. UE 605 can use the MAC layer and request the contention window size corresponding to the CAPC of the MAC PDU from the physical layer. UE 605 can use the MAC layer and determine the estimated LBT completion time based at least in part on the contention window size. UE 605 can use the MAC layer and request the LBT counter value corresponding to the CAPC of the MAC PDU from the physical layer. UE 605 can use the MAC layer and determine the estimated LBT completion time based at least in part on the LBT counter value.

[0091] UE 605 may use the Binary Exponential Backoff (BEB) algorithm to adjust the at least one parameter to determine the adjusted value of the at least one parameter. UE 605 may use the BEB algorithm by determining the minimum parameter value and the maximum parameter value of the at least one parameter. UE 605 may set the at least one parameter to the minimum parameter value. For a single iteration, UE 605 may set the at least one parameter to the minimum of the maximum parameter value and twice the value of the at least one parameter corresponding to a previous iteration, based at least in part on the channel access output including an indication of channel access failure. Otherwise, UE 605 may set the at least one parameter to the minimum parameter value, based at least in part on the channel access output including an indication of channel access success.

[0092] UE 605 can adjust at least one parameter by setting it to its maximum value over several iterations. UE 605 can determine that the number of iterations meets an iteration threshold, and set at least one parameter to its minimum value based at least in part on the determination that the number of iterations meets the iteration threshold.

[0093] UE 605 can adjust the at least one parameter by determining a minimum parameter value and a maximum parameter value, as well as determining an increment step size and a decrement step size. For a single iteration, UE 605 can set the at least one parameter to the minimum of the sum of the maximum parameter value and the value of the at least one parameter corresponding to a previous iteration plus the increment step size, based at least in part on the channel access output including an indication of channel access failure. UE 605 can also set the at least one parameter to the maximum of the difference between the minimum parameter value and the value of the at least one parameter corresponding to a previous iteration plus the decrement step size, based at least in part on the channel access output including an indication of channel access success. The increment step size and / or decrement step size can correspond to a collision rate based at least in part on the block error rate determined in the outer loop rate control procedure of the channel quality information.

[0094] UE 605 may adjust at least one parameter based at least partially on determining that the LBT CW parameter includes a maximum LBT CW value. UE 605 may adjust the at least one parameter by increasing the value of the at least one parameter and setting the LBT contention window (CW) value to a minimum LBT CW value based at least partially on increasing the value of the at least one parameter. UE 605 may determine that the channel access output includes an indication of channel access failure and that the time slot includes one or more side link control information (SCI) transmissions with signal strength meeting a signal strength threshold. UE 605 may increase the value of at least one parameter corresponding to the time slot based at least partially on determining that the time slot includes one or more SCI transmissions with signal strength meeting a signal strength threshold. UE 605 may determine that the size of the LBT CW is greater than the size of the time slot and increase the value of at least one parameter corresponding to the time slot based at least partially on determining that the size of the LBT CW is greater than the size of the time slot.

[0095] In some respects, UE 605 can transmit and retransmit HARQ transmissions and can adjust adaptive ECW parameters at least in part based on the channel access output associated with the resource requested for transmitting the HARQ transmission. UE 605 can select one or more resources for one or more HARQ transmissions at least in part based on the adaptive ECW. UE 605 can select one or more resources for the one or more HARQ transmissions by: selecting a first resource for the initial HARQ transmission from a candidate resource set within the adaptive ECW, and determining the anchor time associated with the HARQ retransmission of the initial HARQ transmission based at least in part on the slot index corresponding to the initial resource and the expected LBT completion interval. UE 605 can determine an adaptive ECW for repositioning the anchor time associated with the initial HARQ transmission. UE 605 can select a second resource for HARQ retransmission from an additional candidate resource set within the repositioned adaptive ECW.

[0096] UE 605 may determine the adaptive ECW for relocation based at least in part on at least one PDB. The at least one PDB may include a first PDB associated with the initial HARQ transmission (wherein the first PDB has a first PDB value) and a second PDB associated with the HARQ retransmission (wherein the second PDB has a second PDB value lower than the first PDB value).

[0097] UE 605 may adjust at least one parameter of adaptive ECW based at least in part on CBR. UE 605 may receive a configuration indicating a mapping associated with the CBR. UE 605 may adjust at least one parameter of adaptive ECW based at least in part on this mapping. This configuration may be carried in a System Information Block (SIB) or Radio Resource Control (RRC) message. The mapping may include a mapping from CBR to activation or deactivation of adaptive ECW, a mapping from CBR to at least one parameter of adaptive ECW, a mapping from CBR to the minimum parameter value of at least one parameter of adaptive ECW, a mapping from CBR to the maximum parameter value of at least one parameter of adaptive ECW, binary exponential backoff associated with at least one parameter of adaptive ECW, or a collision rate associated with at least one parameter of adaptive ECW.

[0098] UE 605 can determine that a first traffic priority among a plurality of traffic priorities corresponds to a MAC PDU. UE 605 can select one or more candidate resources from a candidate resource set within the adaptive ECW, at least in part, based on determining that the first traffic priority corresponds to a MAC PDU among the plurality of traffic priorities. The adaptive ECW can be associated with the first traffic priority, and an additional adaptive ECW can be associated with a second traffic priority among the plurality of traffic priorities. The adaptive ECW can be associated with a first bandwidth among a plurality of bandwidths corresponding to the candidate resource set. An additional adaptive ECW can be associated with a second bandwidth among the plurality of bandwidths.

[0099] UE 605 may use its MAC layer to send a sidelink sensing request to its physical layer, wherein the sidelink sensing request indicates the RSW based at least in part on an adaptive ECW. The sidelink sensing request indicates a first time period and a second time period, wherein the first time period includes the offset between resource selection triggering and the RSW, and the second time period includes the width of the RSW. The second time period may include additional packet data budget associated with the MAC PDU. The sidelink sensing request may indicate the RSW based at least in part on an additional adaptive ECW. In some aspects, UE 605 may adjust the RSW and / or sensing window based on the adaptive ECW. For example, UE 605 may expand the sensing window at least in part based on the adaptive ECW to avoid resource conflicts (such as time-domain resource conflicts and / or frequency-domain resource conflicts).

[0100] An adaptive ECW can be associated with the initial HARQ transmission, and an additional adaptive ECW can be associated with a retransmission of the initial HARQ transmission. A sidelink sensing request indicates an additional RSW based at least in part on the additional adaptive ECW. The adaptive ECW is associated with the initial Hybrid Automatic Repeat Request (HARQ) transmission, and the additional adaptive ECW can be associated with a retransmission of the initial HARQ transmission. An adaptive ECW can be associated with the initial HARQ transmission. UE 605 can use the UE's MAC layer to send an additional sidelink sensing request to the UE's physical layer. The additional sidelink sensing request can indicate an additional RSW based at least in part on the additional adaptive ECW. The additional adaptive ECW can be associated with a retransmission of the initial HARQ transmission.

[0101] As shown by reference numeral 635 in the accompanying figure, UE 605 may use the one or more candidate resources or additional one or more candidate resources to transmit the MAC PDU. The additional one or more candidate resources may be selected at least in part based on at least one adjusted parameter.

[0102] As indicated above, Figure 6 This is provided as an example. Other examples may differ from the one provided. Figure 6 The example described.

[0103] Figure 7 This is a diagram illustrating Example 700 associated with ECW for an NR sidelink on an unlicensed frequency band according to this disclosure. Example 700 shows an ECW already implemented by a UE (e.g., Figure 6 The UE 605 shown Figure 1 The physical layer of UE 120 (as shown) identifies multiple identified resources.

[0104] As shown in the figure, the UE (e.g., the MAC layer of the UE) can apply adaptive ECW to multiple identified resources within the RSW to determine a candidate resource set within the adaptive ECW. The adaptive ECW can be defined by the adaptive ECW offset s (shown as s=1) of the Orthogonal Frequency Division Multiplexing (OFDM) symbols and the adaptive ECW width w (shown as w=2). The UE (e.g., the MAC layer of the UE) can randomly select one or more resources from the candidate resource set within the adaptive ECW. In the illustrated example, UE605 can select from the resources indexed {2,3,4}.

[0105] As shown by reference numeral 710 in the figure, the UE (e.g., using the MAC layer) can select one or more candidate resources from a valid set of available resources. The valid set of available resources may include a subset containing a plurality of identified resources within the resource selection window. As shown, the UE (e.g., using the MAC layer) can determine the valid set of available resources by excluding one or more time slots from the plurality of identified resources that do not contain one or more available resources. Therefore, in the illustrated example, the UE can exclude the fourth time slot, which does not contain available resources. As a result, the valid set of available resources includes resources associated with the first, second, third, and fifth time slots. The UE can apply adaptive ECW to this valid set of available resources. As a result, additional processing efficiency during resource selection can be achieved through various aspects of the techniques described herein.

[0106] As indicated above, Figure 7 This is provided as an example. Other examples may differ from the one provided. Figure 7 The example described.

[0107] Figure 8 This is a diagram illustrating Example 800 associated with ECW for an NR side link on an unlicensed frequency band according to this disclosure. Example 800 illustrates a procedure for resource selection for HARQ transmission and retransmission based at least in part on adaptive ECW.

[0108] As shown in the figure, UE (for example, Figure 6 The UE 605 shown Figure 1The UE 120 shown can select one or more resources for one or more HARQ transmissions, at least in part, based on the adaptive ECW. The UE can select these one or more resources by choosing a first resource from a set of candidate resources within the adaptive ECW for the initial HARQ transmission. Candidate resources may include valid available resources (as described above). Figure 7 (As shown and described). The UE can determine the anchor time associated with the HARQ retransmission of the initial HARQ transmission based at least in part on the slot index corresponding to the initial resource and the expected LBT completion interval.

[0109] The UE can also determine an adaptive ECW for relocation with respect to the anchor time associated with the initial HARQ transmission, as shown in the figure, by selecting a second resource for HARQ retransmission from an additional set of candidate resources within the adaptive ECW for relocation. The UE can determine the adaptive ECW for relocation based at least in part on at least one PDB. The at least one PDB may include a first PDB associated with the initial HARQ transmission (wherein the first PDB has a first PDB value) and a second PDB associated with the HARQ retransmission (wherein the second PDB has a second PDB value lower than the first PDB value). At least one parameter of the adaptive ECW may include at least one first parameter value, and at least one additional parameter of the adaptive ECW for relocation may include at least one second parameter value smaller than the at least one first parameter value.

[0110] The UE can adjust at least one parameter of the adaptive ECW, at least in part, based on the CBR. The UE can (e.g., from a base station, such as...) Figure 1 The base station 110 shown receives a configuration indicating the mapping associated with the CBR. This configuration may be carried in SIB, RRC messages, etc. The UE may adjust at least one parameter of the adaptive ECW based at least in part on this mapping. The mapping may include a mapping from the CBR to the activation or deactivation of the adaptive ECW, a mapping from the CBR to at least one parameter of the adaptive ECW, a mapping from the CBR to the minimum parameter value of at least one parameter of the adaptive ECW, a mapping from the CBR to the maximum parameter value of at least one parameter of the adaptive ECW, binary exponential backoff associated with at least one parameter of the adaptive ECW, a collision rate associated with at least one parameter of the adaptive ECW, etc.

[0111] As indicated above, Figure 8 This is provided as an example. Other examples may differ from the one provided. Figure 8 The example described.

[0112] Figure 9This is a diagram illustrating an example procedure 900 performed by a UE, for example, according to this disclosure. Example procedure 900 is an example in which a UE (e.g., UE 120) performs operations associated with ECW for an NR sidelink on an unlicensed frequency band.

[0113] like Figure 9 As shown, in some aspects, process 900 may include one or more candidate resources (block 910) within an adaptive ECW for sidelink transmission selection on unlicensed frequency bands and associated with MAC PDUs. For example, the UE (e.g., using...) Figure 10 The communication manager 1008 described herein can select one or more candidate resources within an adaptive ECW candidate resource set for sidelink transmissions on unlicensed frequency bands and associated with MAC PDUs, as described above.

[0114] like Figure 9 Further, in some aspects, process 900 may include adjusting at least one parameter of the adaptive ECW, at least in part, based on the channel access output associated with the one or more candidate resources, to determine at least one adjusted parameter (box 920). For example, the UE (e.g., using...) Figure 10 The communication manager 1008 depicted can adjust at least one parameter of the adaptive ECW, at least in part, based on the channel access output associated with the one or more candidate resources, to determine at least one adjusted parameter, as described above.

[0115] like Figure 9 Further shown, in some aspects, process 900 may include transmitting the MAC PDU using one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on at least one adjusted parameter (box 930). For example, the UE (e.g., using transmission component 1004, such as...) Figure 10 The MAC PDU can be transmitted using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on at least one adjusted parameter, as described above.

[0116] Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0117] In the first aspect, selecting the one or more candidate resources includes randomly selecting the one or more candidate resources.

[0118] In the second aspect, either alone or in combination with the first aspect, at least one parameter of the adaptive ECW includes at least one of the following: anchor time, adaptive ECW offset associated with anchor time, or adaptive ECW width.

[0119] In the third aspect, either alone or in combination with one or more of the first and second aspects, the adaptive ECW offset includes the number of symbols between the anchor time and the initial symbol corresponding to the adaptive ECW.

[0120] In the fourth aspect, either alone or in combination with one or more of the first to third aspects, the adaptive ECW width includes the number of symbols.

[0121] In the fifth aspect, either alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of channel access failure, and adjusting the at least one parameter includes increasing the adaptive ECW width based at least in part on the indication of channel access failure.

[0122] In the sixth aspect, increasing the adaptive ECW width, either alone or in combination with one or more of the first to fifth aspects, includes multiplicatively increasing the adaptive ECW width.

[0123] In the seventh aspect, either alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of successful channel access, and adjusting the at least one parameter includes reducing the adaptive ECW width based at least in part on the indication of successful channel access.

[0124] In the eighth aspect, reducing the adaptive ECW width, either alone or in combination with one or more of the first to seventh aspects, includes reducing the adaptive ECW width in a linear manner.

[0125] In the ninth aspect, either alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of channel access failure, and adjusting the at least one parameter includes increasing the adaptive ECW offset based at least in part on the indication of channel access failure.

[0126] In the tenth aspect, alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of successful channel access, and adjusting the at least one parameter includes reducing the adaptive ECW offset based at least in part on the indication of successful channel access.

[0127] In the eleventh aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to tenth aspects, includes: setting a distribution upper limit based at least in part on the channel access output, wherein the distribution upper limit is determined based on an initial adaptive ECW offset value of the adaptive ECW offset; selecting a random number from a uniform distribution between zero and the distribution upper limit; and adjusting the adaptive ECW offset based at least in part on the random number to determine an adjusted adaptive ECW offset value.

[0128] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the adjusted adaptive ECW offset value corresponds to the number of symbols offset from the anchor time, wherein the number of symbols includes the random number.

[0129] In the thirteenth aspect, alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of channel access failure, and adjusting the at least one parameter includes increasing the adaptive ECW width and adaptive ECW offset based at least in part on the indication of channel access failure.

[0130] In the fourteenth aspect, alone or in combination with one or more of the first to fourth aspects, the channel access output includes an indication of successful channel access, and adjusting the at least one parameter includes reducing the adaptive ECW width and adaptive ECW offset based at least in part on the indication of successful channel access.

[0131] In the fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the channel access output includes an indication of channel access failure, and the indication of channel access failure includes at least one of the following: failure to receive an ACK feedback message associated with ACK-based physical sidelink shared channel transmission, LBT procedure failure associated with time slot boundary, or failure to reach a specified channel occupancy time at a specified sidelink time slot.

[0132] In the sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, process 900 includes determining a candidate resource set based at least in part on sensing operations performed by the physical layer of the UE.

[0133] In the seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the candidate resource set includes a valid available resource set, wherein the valid available resource set includes a subset of the identified resources within the resource selection window.

[0134] In the eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, process 900 includes determining the effective set of available resources by excluding one or more time slots from the plurality of identified resources that do not include one or more available resources.

[0135] In the nineteenth aspect, alone or in combination with one or more of the first to eighteenth aspects, the at least one parameter of the adaptive ECW includes an anchor time, and the process 900 further includes: using a MAC layer to define the anchor time to include: a first slot index of a resource selection window associated with a candidate resource set, a slot index corresponding to a first available resource within the resource selection window, a slot index corresponding to the expected LBT completion time associated with a MAC PDU, or a maximum slot index of any combination thereof.

[0136] In the twentieth aspect, alone or in combination with one or more of the first to nineteenth aspects, process 900 includes determining the expected LBT completion time based at least in part on the CAPC of the MAC PDU.

[0137] In the twentieth aspect, alone or in combination with one or more of the first to twentieth aspects, process 900 includes using the MAC layer to request a contention window size corresponding to the CAPC of the MAC PDU from the physical layer, wherein determining the expected LBT completion time includes using the MAC layer and determining the expected LBT completion time based at least in part on the contention window size.

[0138] In the twentieth aspect, alone or in combination with one or more of the first to twenty-first aspects, process 900 includes using the MAC layer to request an LBT counter value PDU corresponding to the CAPC of the MAC PDU from the physical layer, wherein determining the expected LBT completion time includes using the MAC layer and at least in part based on the LBT counter value PDU to determine the expected LBT completion time.

[0139] In the twenty-third aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-two aspects, includes using a binary exponential backoff algorithm to determine the adjustment value of the at least one parameter.

[0140] In the twenty-fourth aspect, the binary exponential backoff algorithm is used, either alone or in combination with one or more of the first to twenty-third aspects, comprising: determining a minimum parameter value and a maximum parameter value of the at least one parameter; setting the at least one parameter to the minimum parameter value; and for a given iteration, setting the at least one parameter to the minimum of the maximum parameter value and twice the value of the at least one parameter corresponding to a previous iteration, based at least in part on the channel access output including an indication of channel access failure; or setting the at least one parameter to the minimum parameter value based at least in part on the channel access output including an indication of channel access success.

[0141] In the twenty-fifth aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-fourth aspects, includes: setting the at least one parameter to a maximum parameter value for multiple iterations; determining that the number of iterations satisfies an iteration threshold; and setting the at least one parameter to a minimum parameter value based at least in part on determining that the number of iterations satisfies the iteration threshold.

[0142] In the twenty-sixth aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-fifth aspects, comprises: determining a minimum parameter value and a maximum parameter value for the at least one parameter; determining an increment step size and a decrement step size; and, for a given iteration, setting the at least one parameter to the minimum of the sum of the maximum parameter value and the value of the at least one parameter corresponding to a previous iteration plus the increment step size, based at least in part on the channel access output including an indication of channel access failure; or setting the at least one parameter to the maximum of the difference between the minimum parameter value and the value of the at least one parameter corresponding to a previous iteration plus the decrement step size, based at least in part on the channel access output including an indication of channel access success.

[0143] In the twenty-seventh aspect, either alone or in combination with one or more of the first to twenty-sixth aspects, increasing or decreasing the step size corresponds to a collision rate based at least in part on the block error rate determined in the outer loop rate control procedure of the channel quality information.

[0144] In the twenty-eighth aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-seventh aspects, includes adjusting the at least one parameter at least in part based on determining that the LBT CW parameter includes the maximum LBT CW value.

[0145] In the twenty-ninth aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-eighth aspects, includes increasing the value of the at least one parameter, and the process 900 further includes setting the LBT CW value to a minimum LBT CW value based at least in part on increasing the value of the at least one parameter.

[0146] In the thirtieth aspect, adjusting the at least one parameter, either alone or in combination with one or more of the first to twenty-ninth aspects, comprises: determining that the channel access output includes an indication of channel access failure; determining that the time slot includes one or more SCI transmissions with signal strengths that meet a signal strength threshold; and increasing the value of at least one parameter corresponding to the time slot, at least in part, based on determining that the time slot includes one or more SCI transmissions with signal strengths that meet a signal strength threshold.

[0147] In one aspect, alone or in combination with one or more of the first to thirtieth aspects, process 900 includes determining that the size of the LBT CW is greater than the size of the time slot, and increasing the value of at least one parameter corresponding to the time slot includes increasing the value of at least one parameter corresponding to the time slot at least in part based on determining that the size of the LBT CW is greater than the size of the time slot.

[0148] In aspect 32, alone or in combination with one or more of aspects 1 to 31, process 900 includes selecting one or more resources for one or more HARQ transports based at least in part on adaptive ECW.

[0149] In the thirty-third aspect, selecting one or more resources for the one or more HARQ transmissions, either alone or in combination with one or more of the first to thirty-two aspects, includes: selecting a first resource for the initial HARQ transmission from a set of candidate resources within an adaptive ECW; determining an anchor time associated with the HARQ retransmission of the initial HARQ transmission based at least in part on a time slot index corresponding to the initial resource and the expected listen-before-talk completion interval; determining an adaptive ECW for relocation with respect to the anchor time associated with the initial HARQ transmission; and selecting a second resource for the HARQ retransmission from an additional set of candidate resources within the relocated adaptive ECW.

[0150] In aspect thirty-four, determining the adaptive ECW for relocation, either alone or in combination with one or more of aspects one through thirty-three, includes determining the adaptive ECW for relocation based at least in part on at least one PDB.

[0151] In the thirty-fifth aspect, alone or in combination with one or more of the first to thirty-fourth aspects, the at least one PDB includes: a first PDB associated with the initial HARQ transmission, wherein the first PDB has a first PDB value; and a second PDB associated with the HARQ retransmission, wherein the second PDB has a second PDB value lower than the first PDB value.

[0152] In the thirty-sixth aspect, alone or in combination with one or more of the first to thirty-fifth aspects, the at least one parameter of the adaptive ECW has at least one first parameter value, and the at least one additional parameter of the relocated adaptive ECW has at least one second parameter value that is less than the at least one first parameter value.

[0153] In the thirty-seventh aspect, alone or in combination with one or more of the first to thirty-sixth aspects, adjusting the at least one parameter of the adaptive ECW includes adjusting the at least one parameter of the adaptive ECW at least in part based on the CBR.

[0154] In the thirty-eighth aspect, alone or in combination with one or more of the first to thirty-seventh aspects, process 900 includes receiving a configuration indicating a mapping associated with the CBR, wherein adjusting the at least one parameter of the adaptive ECW includes adjusting the at least one parameter of the adaptive ECW at least in part based on the mapping.

[0155] In aspect thirty-nine, either alone or in combination with one or more of aspects one through thirty-eight, the configuration is carried in at least one of a system information block or a radio resource control message.

[0156] In the fortieth aspect, alone or in combination with one or more of the first to thirty-ninth aspects, the mapping includes at least one of the following: a mapping from CBR to activation or deactivation of adaptive ECW, a mapping from CBR to at least one parameter of adaptive ECW, a mapping from CBR to the minimum parameter value of the at least one parameter of adaptive ECW, a mapping from CBR to the maximum parameter value of the at least one parameter of adaptive ECW, a binary exponential backoff associated with the at least one parameter of adaptive ECW, or a collision rate associated with the at least one parameter of adaptive ECW.

[0157] In the forty-first aspect, alone or in combination with one or more of the first to forty aspects, process 900 includes determining a first traffic priority among a plurality of traffic priorities corresponding to a MAC PDU, wherein selecting one or more candidate resources in a candidate resource set within an adaptive ECW includes: selecting the one or more candidate resources at least in part based on determining that the first traffic priority among the plurality of traffic priorities corresponds to a MAC PDU, wherein the adaptive ECW is associated with a first traffic priority, and wherein an additional adaptive ECW is associated with a second traffic priority among the plurality of traffic priorities.

[0158] In aspect 42, either alone or in combination with one or more of aspects 1 to 41, adaptive ECW is associated with a first bandwidth among a plurality of bandwidths corresponding to the candidate resource set, and additional adaptive ECW is associated with a second bandwidth among the plurality of bandwidths.

[0159] In aspect 43, alone or in combination with one or more of aspects 1 to 42, process 900 includes sending a sidelink sensing request to the physical layer of the UE using the MAC layer of the UE, wherein the sidelink sensing request indicates a resource selection window (RSW) based at least in part on an adaptive ECW.

[0160] In aspect 44, either alone or in combination with one or more of aspects 1 to 43, the sidelink sensing request indicates a first time period and a second time period, wherein the first time period includes the offset between resource selection triggering and RSW, and the second time period includes the width of RSW.

[0161] In aspect 45, alone or in combination with one or more of aspects 1 through 44, the second time period includes the budget of grouped data associated with MAC PDU.

[0162] In aspect 46, either alone or in combination with one or more of aspects 1 to 45, the sidelink sensing request indicates the RSW based at least in part on an additional adaptive ECW, wherein the adaptive ECW is associated with the initial HARQ transmission, and wherein the additional adaptive ECW is associated with a retransmission of the initial HARQ transmission.

[0163] In aspect 47, either alone or in combination with one or more of aspects 1 to 46, the sidelink sensing request indicates an additional RSW based at least in part on an additional adaptive ECW, wherein the adaptive ECW is associated with the initial HARQ transmission, and wherein the additional adaptive ECW is associated with a retransmission of the initial HARQ transmission.

[0164] In aspect 48, either alone or in combination with one or more of aspects 1 to 47, the adaptive ECW is associated with the initial HARQ transmission, and process 900 further includes sending an additional sidelink sensing request to the physical layer of the UE using the UE's MAC layer, wherein the additional sidelink sensing request indicates an additional RSW based at least in part on the additional adaptive ECW, wherein the additional adaptive ECW is associated with a retransmission of the initial HARQ transmission.

[0165] although Figure 9 An example box of process 900 is shown, but in some respects, process 900 may include... Figure 9 The boxes depicted in the diagram are compared to additional boxes, fewer boxes, different boxes, or boxes arranged differently. Additionally or alternatively, two or more boxes in process 900 can be executed in parallel.

[0166] Figure 10This is a block diagram of an example device 1000 for wireless communication. Device 1000 may be a UE, or a UE may include device 1000. In some aspects, device 1000 includes a receiving component 1002 and a transmitting component 1004, which may be in communication with each other (e.g., via one or more buses and / or one or more other components). As shown, device 1000 may use the receiving component 1002 and the transmitting component 1004 to communicate with another device 1006 (such as a UE, a base station, or another wireless communication device). As further shown, device 1000 may include a communication manager 1008 and other examples.

[0167] In some respects, Equipment 1000 can be configured to perform the combined functions described in this article. Figure 6-8 The described one or more operations. Additionally or alternatively, the apparatus 1000 may be configured to perform one or more processes described herein, such as Figure 9 The process 900. In some aspects, the device 1000 and / or Figure 10 One or more components shown may include the above combination Figure 2 One or more components of the described UE. Additionally or alternatively, Figure 10 One or more components shown can be combined as described above. Figure 2 Implemented within one or more of the described components. Additionally or alternatively, one or more components in the set of components may be implemented at least partially as software stored in memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and may be executed by a controller or processor to perform the function or operation of that component.

[0168] Receiver 1002 may receive communications (such as reference signals, control information, data communications, or combinations thereof) from device 1006. Receiver 1002 may provide the received communications to one or more other components of device 1000. In some aspects, receiver 1002 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, and other examples), and may provide the processed signal to one or more other components of device 1006. In some aspects, receiver 1002 may include combinations thereof. Figure 2 The described UE includes one or more antennas, demodulators, MIMO detectors, receiver processors, controllers / processors, memory, or combinations thereof.

[0169] The transmission component 1004 can transmit communications (such as reference signals, control information, data communications, or combinations thereof) to the device 1006. In some aspects, one or more other components of the device 1006 can generate communications and provide the generated communications to the transmission component 1004 for transmission to the device 1006. In some aspects, the transmission component 1004 can perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, etc.) on the generated communications and can transmit the processed signals to the device 1006. In some aspects, the transmission component 1004 may include combinations of the above. Figure 2 The described UE includes one or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof. In some aspects, the transmit component 1004 may coexist with the receive component 1002 in a transceiver.

[0170] The communication manager 1008 can select one or more candidate resources within a candidate resource set for sidelink transmission selection in an adaptive ECW on an unlicensed frequency band and associated with a MAC PDU. The communication manager 1008 can adjust at least one parameter of the adaptive ECW, at least in part, based on the channel access output associated with the one or more candidate resources, to determine the adjusted at least one parameter. In some aspects, the communication manager 1008 may include a combination of the above. Figure 2 The described UE includes a demodulator, MIMO detector, receive processor, modulator, transmit MIMO processor, transmit processor, controller / processor, memory, or a combination thereof. The transmission component 1004 may use the one or more candidate resources or additional one or more candidate resources to transmit the MAC PDU, wherein the additional one or more candidate resources are selected at least in part based on at least one adjusted parameter.

[0171] Figure 10 The number and arrangement of components shown are provided as an example. In practice, different arrangements may exist. Figure 10 The components shown are compared to additional components, fewer components, different components, or components arranged differently. Furthermore, Figure 10 The two or more components shown can be implemented within a single component, or Figure 10 The single component shown can be implemented as multiple distributed components. Additionally or alternatively, Figure 10 The collection of components shown (e.g., one or more components) can be executed as described by Figure 10 The other set of components shown in the diagram performs one or more functions.

[0172] The following provides an overview of some aspects of this disclosure:

[0173] Aspect 1: A method of wireless communication performed by a user equipment (UE), comprising: selecting one or more candidate resources from a candidate resource set within an adaptive effective contention window (ECW) for a sidelink transmission on an unlicensed frequency band and associated with a Media Access Control (MAC) Protocol Data Unit (PDU); adjusting at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine at least one adjusted parameter; and transmitting the MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

[0174] Aspect 2: The method of aspect 1, wherein selecting the one or more candidate resources includes randomly selecting the one or more candidate resources.

[0175] Aspect 3: The method of any one of Aspect 1 or 2, wherein the at least one parameter of the adaptive ECW includes at least one of the following: anchor time, adaptive ECW offset associated with anchor time, or adaptive ECW width.

[0176] Aspect 4: The method of aspect 3, wherein the adaptive ECW offset includes the anchor time and the number of symbols between the initial symbols corresponding to the adaptive ECW.

[0177] Aspect 5: The method of any one of Aspects 3 or 4, wherein the adaptive ECW width includes the number of symbols.

[0178] Aspect 6: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of channel access failure, and wherein adjusting the at least one parameter includes increasing the adaptive ECW width at least in part based on the indication of channel access failure.

[0179] Aspect 7: The method of aspect 6, wherein increasing the adaptive ECW width includes multiplicatively increasing the adaptive ECW width.

[0180] Aspect 8: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of successful channel access, and wherein adjusting the at least one parameter includes reducing the adaptive ECW width based at least in part on the indication of successful channel access.

[0181] Aspect 9: The method of aspect 8, wherein reducing the adaptive ECW width includes linearly reducing the adaptive ECW width.

[0182] Aspect 10: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of channel access failure, and wherein adjusting the at least one parameter includes increasing the adaptive ECW offset based at least in part on the indication of channel access failure.

[0183] Aspect 11: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of successful channel access, and wherein adjusting the at least one parameter includes reducing the adaptive ECW offset based at least in part on the indication of successful channel access.

[0184] Aspect 12: The method of any one of Aspects 3-11, wherein adjusting the at least one parameter comprises: setting a distribution upper limit based at least in part on the channel access output, wherein the distribution upper limit is determined based on an initial adaptive ECW offset value of the adaptive ECW offset; selecting a random number from a uniform distribution between zero and the distribution upper limit; and adjusting the adaptive ECW offset based at least in part on the random number to determine an adjusted adaptive ECW offset value.

[0185] Aspect 13: The method of aspect 12, wherein the adjusted adaptive ECW offset value corresponds to the number of symbols of the anchor time offset, wherein the number of symbols includes a random number.

[0186] Aspect 14: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of channel access failure, and wherein adjusting the at least one parameter includes increasing the adaptive ECW width and the adaptive ECW offset based at least in part on the indication of channel access failure.

[0187] Aspect 15: The method of any one of Aspects 3-5, wherein the channel access output includes an indication of successful channel access, and wherein adjusting the at least one parameter includes reducing the adaptive ECW width and adaptive ECW offset based at least in part on the indication of successful channel access.

[0188] Aspect 16: The method of Aspect 1, wherein the channel access output includes an indication of channel access failure, and wherein the indication of channel access failure includes at least one of the following: failure to receive an acknowledgment (ACK) feedback message associated with a physical sidelink shared channel transmission based on ACK, failure of the Listen-Before-Talk (LBT) procedure associated with a time slot boundary, or failure to reach a specified channel occupancy time at a specified sidelink time slot.

[0189] Aspect 17: The method of any of Aspects 1-16 further includes: determining a candidate resource set based at least in part on sensing operations performed by the physical layer of the UE.

[0190] Aspect 18: The method of aspect 17, wherein the candidate resource set includes a valid available resource set, wherein the valid available resource set includes a subset containing a plurality of identified resources within a resource selection window.

[0191] Aspect 19: The method of aspect 18 further includes: determining the effective set of available resources by excluding one or more time slots from the plurality of identified resources that do not include one or more available resources.

[0192] Aspect 20: The method of any one of Aspects 1-19, wherein the at least one parameter of the adaptive ECW includes an anchor time, and wherein the method further includes: using a MAC layer to define the anchor time to include: a first slot index of a resource selection window associated with a candidate resource set, a slot index corresponding to a first available resource within the resource selection window, a slot index corresponding to an expected listen-before-talk (LBT) completion time associated with a MAC PDU, or a maximum slot index of any combination thereof.

[0193] Aspect 21: The method of aspect 20 further includes: determining the expected LBT completion time based at least in part on the channel access priority class (CAPC) of the MAC PDU.

[0194] Aspect 22: The method of aspect 21 further includes: requesting a contention window size corresponding to the CAPC of the MAC PDU from the physical layer using the MAC layer, wherein determining the expected LBT completion time includes using the MAC layer and determining the expected LBT completion time based at least in part on the contention window size.

[0195] Aspect 23: The method of any of Aspects 21 or 22 further includes: requesting an LBT counter value PDU corresponding to the CAPC of the MAC PDU from the physical layer using the MAC layer, wherein determining the expected LBT completion time includes using the MAC layer and determining the expected LBT completion time based at least in part on the LBT counter value PDU.

[0196] Aspect 24: The method of any one of Aspects 1-23, wherein adjusting the at least one parameter includes using a binary exponential backoff algorithm to determine the adjustment value of the at least one parameter.

[0197] Aspect 25: The method of aspect 24, wherein the binary exponential backoff algorithm includes: determining a minimum parameter value and a maximum parameter value of the at least one parameter; setting the at least one parameter to the minimum parameter value; and for one iteration, setting the at least one parameter to the minimum of the maximum parameter value and twice the value of the at least one parameter corresponding to the previous iteration, based at least in part on the channel access output including an indication of channel access failure; or setting the at least one parameter to the minimum parameter value based at least in part on the channel access output including an indication of channel access success.

[0198] Aspect 26: The method of aspect 25, wherein adjusting the at least one parameter includes: setting the at least one parameter to a maximum parameter value for multiple iterations; determining that the number of iterations satisfies an iteration threshold; and setting the at least one parameter to a minimum parameter value based at least in part on determining that the number of iterations satisfies the iteration threshold.

[0199] Aspect 27: The method of any one of Aspects 1-26, wherein adjusting the at least one parameter comprises: determining a minimum parameter value and a maximum parameter value of the at least one parameter; determining an increase step size and a decrease step size; and for a given iteration, setting the at least one parameter to the minimum of the sum of the maximum parameter value and the value of the at least one parameter corresponding to a previous iteration and the increase step size, based at least in part on the channel access output including an indication of channel access failure; or setting the at least one parameter to the maximum of the difference between the minimum parameter value and the value of the at least one parameter corresponding to a previous iteration and the decrease step size, based at least in part on the channel access output including an indication of channel access success.

[0200] Aspect 28: The method of aspect 27, wherein increasing or decreasing the step size corresponds to a collision rate based at least in part on the block error rate determined in the outer loop rate control procedure of the channel quality information.

[0201] Aspect 29: The method of any one of Aspects 1-28, wherein adjusting the at least one parameter includes adjusting the at least one parameter based at least in part on determining the Listen Before Talk (LBT) contention window (CW) parameter, including the maximum LBT CW value.

[0202] Aspect 30: The method of any one of Aspects 1-29, wherein adjusting the at least one parameter includes increasing the value of the at least one parameter, and wherein the method further includes setting the Listen-Before-Speak (LBT) contention window (CW) value to a minimum LBT CW value based at least in part on increasing the value of the at least one parameter.

[0203] Aspect 31: The method of any one of Aspects 1-30, wherein adjusting the at least one parameter comprises: determining that the channel access output includes an indication of channel access failure; determining that the time slot includes one or more side link control information (SCI) transmissions with signal strengths that meet a signal strength threshold; and increasing the value of at least one parameter corresponding to the time slot based at least in part on determining that the time slot includes one or more SCI transmissions with signal strengths that meet a signal strength threshold.

[0204] Aspect 32: The method of aspect 31 further includes: determining that the size of the Listen-Before-Speak (LBT) contention window (CW) is greater than the size of the time slot, and wherein increasing the value of at least one parameter corresponding to the time slot includes increasing the value of at least one parameter corresponding to the time slot at least in part based on determining that the size of the LBT CW is greater than the size of the time slot. Increasing the value of at least one parameter corresponding to the time slot includes increasing the value of at least one parameter corresponding to the time slot at least in part based on determining that the size of the LBT CW is greater than the size of the time slot.

[0205] Aspect 33: The method of any of Aspects 1-32 further includes: selecting one or more resources for one or more Hybrid Automatic Repeat Request (HARQ) transports, at least in part based on adaptive ECW.

[0206] Aspect 34: The method of aspect 33, wherein selecting one or more resources for the one or more HARQ transmissions comprises: selecting a first resource for the initial HARQ transmission from a set of candidate resources within an adaptive ECW; determining an anchor time associated with the HARQ retransmission of the initial HARQ transmission based at least in part on a time slot index corresponding to the initial resource and the expected listen-before-talk completion interval; determining an adaptive ECW for relocation with respect to the anchor time associated with the initial HARQ transmission; and selecting a second resource for the HARQ retransmission from an additional set of candidate resources within the relocated adaptive ECW.

[0207] Aspect 35: The method of aspect 34, wherein determining the adaptive ECW for relocation includes determining the adaptive ECW for relocation based at least in part on at least one packet delay budget (PDB).

[0208] Aspect 36: The method of aspect 35, wherein the at least one PDB includes: a first PDB associated with the initial HARQ transmission, wherein the first PDB has a first PDB value; and a second PDB associated with the HARQ retransmission, wherein the second PDB has a second PDB value lower than the first PDB value.

[0209] Aspect 37: The method of aspect 36, wherein the at least one parameter of the adaptive ECW has at least one first parameter value, and wherein at least one additional parameter of the relocated adaptive ECW has at least one second parameter value less than the at least one first parameter value.

[0210] Aspect 38: The method of any one of Aspects 1-37, wherein adjusting the at least one parameter of the adaptive ECW includes adjusting the at least one parameter of the adaptive ECW at least in part based on the Channel Busy Ratio (CBR).

[0211] Aspect 39: The method of aspect 38 further includes: receiving a configuration indicating a mapping associated with the CBR, wherein adjusting the at least one parameter of the adaptive ECW includes adjusting the at least one parameter of the adaptive ECW at least in part based on the mapping.

[0212] Aspect 40: The method of aspect 39, wherein the configuration is carried in at least one of a system information block or a radio resource control message.

[0213] Aspect 41: The method of any one of Aspects 39 or 40, wherein the mapping includes at least one of the following: a mapping from CBR to activation or deactivation of adaptive ECW, a mapping from CBR to at least one parameter of adaptive ECW, a mapping from CBR to the minimum parameter value of the at least one parameter of adaptive ECW, a mapping from CBR to the maximum parameter value of the at least one parameter of adaptive ECW, a binary exponential backoff associated with the at least one parameter of adaptive ECW, or a conflict rate associated with the at least one parameter of adaptive ECW.

[0214] Aspect 42: The method of any of Aspects 1-41 further includes: determining a first traffic priority among a plurality of traffic priorities that corresponds to a MAC PDU, wherein selecting one or more candidate resources in a candidate resource set within an adaptive ECW includes: selecting the one or more candidate resources at least in part based on determining that the first traffic priority among the plurality of traffic priorities corresponds to a MAC PDU; wherein the adaptive ECW is associated with the first traffic priority, and wherein an additional adaptive ECW is associated with a second traffic priority among the plurality of traffic priorities.

[0215] Aspect 43: The method of any one of Aspects 1-42, wherein the adaptive ECW is associated with a first bandwidth of a plurality of bandwidths corresponding to a candidate resource set, and wherein the additional adaptive ECW is associated with a second bandwidth of the plurality of bandwidths.

[0216] Aspect 44: The method of any of Aspects 1-43 further includes: sending a sidelink sensing request to the physical layer of the UE using the MAC layer of the UE, wherein the sidelink sensing request is at least partially based on an adaptive ECW to indicate at least one of a resource selection window (RSW) or a sensing window.

[0217] Aspect 45: The method of aspect 44, wherein the sidelink sensing request indicates a first time period and a second time period, wherein the first time period includes an offset between resource selection trigger and RSW, and wherein the second time period includes the width of RSW.

[0218] Aspect 46: The method of aspect 45, wherein the second time period includes a budget of grouped data associated with the MAC PDU.

[0219] Aspect 47: The method of any one of Aspects 44-46, wherein the sidelink sensing request indicates the RSW at least in part based on an additional adaptive ECW, wherein the adaptive ECW is associated with the initial hybrid automatic repeat request (HARQ) transmission, and wherein the additional adaptive ECW is associated with the retransmission of the initial HARQ transmission.

[0220] Aspect 48: The method of any one of Aspects 44-47, wherein the sidelink sensing request indicates an additional RSW based at least in part on an additional adaptive ECW, wherein the adaptive ECW is associated with an initial hybrid automatic repeat request (HARQ) transmission, and wherein the additional adaptive ECW is associated with a retransmission of the initial HARQ transmission.

[0221] Aspect 49: The method of any one of Aspects 44-48, wherein the adaptive ECW is associated with the initial Hybrid Automatic Repeat Request (HARQ) transmission, and wherein the method further includes sending an additional sidelink sensing request to the physical layer of the UE using the MAC layer of the UE, wherein the additional sidelink sensing request indicates an additional RSW based at least in part on the additional adaptive ECW, wherein the additional adaptive ECW is associated with a retransmission of the initial HARQ transmission.

[0222] Aspect 50: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform methods as described in one or more of aspects 1-49.

[0223] Aspect 51: An apparatus for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors being configured to perform methods as described in one or more aspects of aspects 1-49.

[0224] Aspect 52: An apparatus for wireless communication, comprising at least one means for performing one or more of the methods described in aspects 1-49.

[0225] Aspect 53: A non-transient computer-readable medium storing code for wireless communication, said code including instructions executable by a processor to perform one or more of the methods described in aspects 1-49.

[0226] Aspect 54: A non-transient computer-readable medium storing a set of instructions for wireless communication, the set of instructions including one or more instructions which, when executed by one or more processors of a device, cause the device to perform the methods described in one or more of aspects 1-49.

[0227] The foregoing disclosure provides explanations and descriptions, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the foregoing disclosure or may be obtained through practice.

[0228] As used herein, the term "component" is intended to be broadly interpreted as hardware and / or a combination of hardware and software. "Software" should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and / or functions, whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms. As used herein, processors are implemented using hardware and / or a combination of hardware and software. It will be apparent that the systems and / or methods described herein can be implemented in various forms of hardware and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited in any way. Thus, the operation and behavior of these systems and / or methods are described herein without reference to any specific software code—it is understood that software and hardware can be designed to implement these systems and / or methods, at least in part, based on the descriptions herein.

[0229] As used in this article, depending on the context, a threshold can refer to a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0230] Although specific combinations of features are described in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of aspects. In fact, many of these features can be combined in ways not specifically described in the claims and / or not disclosed in the specification. Although each dependent claim listed below may be directly subordinated to only one claim, the disclosure of aspects includes each dependent claim being combined with each other claim in this set of claims. As used herein, the phrase “at least one of” refers to any combination of these items, including single members. By way of example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination having multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0231] The elements, actions, or instructions used herein should not be construed as critical or necessary unless explicitly stated otherwise. Furthermore, as used herein, the articles “a” and “a certain” are intended to include one or more items and may be used interchangeably with “one or more.” Additionally, as used herein, the article “the” is intended to include one or more items referenced in conjunction with the article “the” and may be used interchangeably with “one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items) and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Moreover, as used herein, the terms “have,” “contain,” “include,” etc., are intended to be open-ended terms. Furthermore, the phrase “based on” is intended to mean “at least partially based on” unless otherwise explicitly stated. Moreover, as used herein, the term “or” is intended to be inclusive when used in a sequence and may be used interchangeably with “and / or” unless otherwise explicitly stated (e.g., in combination with “either of” or “only one of”).

Claims

1. A user equipment (UE) for wireless communication, comprising: Memory; as well as One or more processors coupled to the memory, the one or more processors being configured to: An adaptive effective contention window (ECW) is applied to multiple identified resources within a resource selection window (RSW) to determine a set of candidate resources within the adaptive ECW; For sidelink transmissions on unlicensed frequency bands and associated with Media Access Control (MAC) Protocol Data Units (PDUs), select one or more candidate resources from the candidate resource set within the adaptive ECW; At least one parameter of the adaptive ECW is adjusted based, at least in part, on channel access output associated with the one or more candidate resources to determine at least one adjusted parameter, wherein the channel access output includes an indication of successful channel access or an indication of channel access failure, and wherein the UE is configured to adjust the at least one parameter by: The adaptive ECW is increased for channel access failures and decreased for channel access successes. as well as The MAC PDU is transmitted using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

2. The UE of claim 1, wherein, in order to select the one or more candidate resources, the one or more processors are configured to randomly select the one or more candidate resources.

3. The UE of claim 1, wherein the at least one parameter of the adaptive ECW includes at least one of the following: Anchor time, The adaptive ECW offset associated with the anchor time, or Adaptive ECW width.

4. The UE of claim 3, wherein the adaptive ECW offset includes the number of symbols between the anchor time and the initial symbol corresponding to the adaptive ECW.

5. The UE of claim 3, wherein the adaptive ECW width includes the number of symbols.

6. The UE of claim 3, wherein the channel access output includes an indication of channel access failure, and In order to adjust the at least one parameter, the one or more processors are configured to increase the adaptive ECW width at least in part based on an indication of a channel access failure.

7. The UE of claim 6, wherein, in order to increase the adaptive ECW width, the one or more processors are configured to multiplicatively increase the adaptive ECW width.

8. The UE of claim 3, wherein the channel access output includes an indication of successful channel access, and In order to adjust the at least one parameter, the one or more processors are configured to reduce the adaptive ECW width at least in part based on an indication of successful channel access.

9. The UE of claim 8, wherein, in order to reduce the adaptive ECW width, the one or more processors are configured to linearly reduce the adaptive ECW width.

10. The UE of claim 3, wherein when the channel access output includes an indication of channel access failure, in order to adjust the at least one parameter, the one or more processors are configured to increase the adaptive ECW offset at least in part based on the indication of channel access failure.

11. The UE of claim 3, wherein when the channel access output includes an indication of successful channel access, in order to adjust the at least one parameter, the one or more processors are configured to reduce the adaptive ECW offset at least in part based on the indication of successful channel access.

12. The UE of claim 3, wherein, in order to adjust the at least one parameter, the one or more processors are configured to: The distribution upper limit is set at least in part based on the channel access output, wherein the distribution upper limit is determined based on the initial adaptive ECW offset value of the adaptive ECW offset; Random numbers are selected from a uniform distribution between zero and the upper limit of the distribution; and The adaptive ECW offset is adjusted at least in part based on the random number to determine the adjusted adaptive ECW offset value.

13. The UE of claim 12, wherein the adjusted adaptive ECW offset value corresponds to the number of symbols offset from the anchor time, wherein the number of symbols includes the random number.

14. The UE of claim 3, wherein when the channel access output includes an indication of channel access failure, in order to adjust the at least one parameter, the one or more processors are configured to increase the adaptive ECW width and the adaptive ECW offset at least in part based on the indication of channel access failure.

15. The UE of claim 3, wherein when the channel access output includes an indication of successful channel access, in order to adjust the at least one parameter, the one or more processors are configured to reduce the adaptive ECW width and the adaptive ECW offset at least in part based on the indication of successful channel access.

16. The UE of claim 1, wherein the channel access output includes an indication of channel access failure, and wherein the indication of channel access failure includes at least one of the following: Unable to receive an ACK feedback message associated with physical side link shared channel transmission based on ACK. The Listen-Before-Speak (LBT) procedure associated with the time slot boundary failed, or The specified channel occupancy time could not be reached at the specified sidelink time slot.

17. The UE of claim 1, wherein, in order to adjust the at least one parameter, the one or more processors are configured to adjust the at least one parameter at least in part based on determining that the Listen-Before-Speak (LBT) contention window (CW) parameter includes the maximum LBT CW value.

18. The UE of claim 1, wherein, in order to adjust the at least one parameter, the one or more processors are configured to increase the value of the at least one parameter; and The one or more processors are further configured to set the Listen-Before-Speak (LBT) contention window (CW) value to a minimum LBT CW value, at least in part based on increasing the value of the at least one parameter.

19. The UE of claim 1, wherein, in order to adjust the at least one parameter of the adaptive ECW, the one or more processors are configured to adjust the at least one parameter of the adaptive ECW at least in part based on the channel busy ratio (CBR).

20. The UE of claim 19, wherein the one or more processors are further configured to receive a configuration indicating a mapping associated with the CBR. In order to adjust at least one parameter of the adaptive ECW, the one or more processors are configured to adjust at least one parameter of the adaptive ECW at least in part based on the mapping.

21. The UE of claim 20, wherein the mapping comprises at least one of the following: The mapping from the CBR to the activation or deactivation of the adaptive ECW. The mapping from the CBR to the adaptive ECW of at least one parameter. The mapping from the CBR to the minimum parameter value of at least one parameter of the adaptive ECW. Mapping from the CBR to the maximum parameter value of at least one parameter of the adaptive ECW Binary exponential backoff associated with at least one parameter of the adaptive ECW, or The conflict rate associated with at least one parameter of the adaptive ECW.

22. The UE of claim 1, wherein the one or more processors are further configured to send a sidelink sensing request to the physical layer of the UE using the MAC layer of the UE, wherein the sidelink sensing request is at least partially based on the adaptive ECW to indicate at least one of a resource selection window (RSW) or a sensing window.

23. The UE of claim 22, wherein the sidelink sensing request indicates a first time period and a second time period. The first time period includes the offset between the resource selection trigger and the RSW, and The second time period includes the width of the RSW.

24. The UE of claim 23, wherein the second time period includes a packet data budget associated with the MAC PDU.

25. The UE of claim 22, wherein the sidelink sensing request is at least in part based on an additional adaptive ECW to indicate the RSW. The adaptive ECW is associated with the initial Hybrid Automatic Repeat Request (HARQ) transmission, and The additional adaptive ECW is associated with the retransmission of the initial HARQ transmission.

26. The UE of claim 22, wherein the sidelink sensing request is at least in part based on an additional adaptive ECW to indicate an additional RSW. The adaptive ECW is associated with the initial Hybrid Automatic Repeat Request (HARQ) transmission, and The additional adaptive ECW is associated with the retransmission of the initial HARQ transmission.

27. The UE of claim 22, wherein the adaptive ECW is associated with an initial Hybrid Automatic Repeat Request (HARQ) transmission, and The one or more processors are further configured to send an additional sidelink sensing request to the physical layer of the UE using the MAC layer of the UE, wherein the additional sidelink sensing request indicates an additional RSW based at least in part on an additional adaptive ECW. The additional adaptive ECW is associated with the retransmission of the initial HARQ transmission.

28. A method for wireless communication performed by a user equipment (UE), comprising: An adaptive effective contention window (ECW) is applied to multiple identified resources within a resource selection window (RSW) to determine a set of candidate resources within the adaptive ECW; For sidelink transmissions on unlicensed frequency bands and associated with Media Access Control (MAC) Protocol Data Units (PDUs), select one or more candidate resources from the candidate resource set within the adaptive ECW; At least one parameter of the adaptive ECW is adjusted based at least in part on the channel access output associated with the one or more candidate resources to determine the adjusted at least one parameter, wherein the channel access output includes an indication of successful channel access or an indication of channel access failure, and wherein the UE is configured to adjust the at least one parameter by increasing the adaptive ECW for channel access failure and decreasing the adaptive ECW for channel access success. as well as The MAC PDU is transmitted using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

29. A non-transient computer-readable medium storing an instruction set for wireless communication, the instruction set comprising: One or more instructions that, when executed by one or more processors of a user equipment (UE), cause the UE to perform the following operations: An adaptive effective contention window (ECW) is applied to multiple identified resources within a resource selection window (RSW) to determine a set of candidate resources within the adaptive ECW; For sidelink transmissions on unlicensed frequency bands and associated with Media Access Control (MAC) Protocol Data Units (PDUs), select one or more candidate resources from the candidate resource set within the adaptive ECW; At least one parameter of the adaptive ECW is adjusted based, at least in part, on channel access output associated with the one or more candidate resources to determine at least one adjusted parameter, wherein the channel access output includes an indication of successful channel access or an indication of channel access failure, and wherein the UE is configured to adjust the at least one parameter by: The adaptive ECW is increased for channel access failures and decreased for channel access successes. as well as The MAC PDU is transmitted using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

30. A device for wireless communication, comprising: A means for applying an adaptive effective contention window (ECW) to multiple identified resources within a resource selection window (RSW) to determine a set of candidate resources within the adaptive ECW; A means for selecting one or more candidate resources from the candidate resource set within the adaptive ECW for sidelink transmissions on unlicensed frequency bands and associated with Media Access Control (MAC) Protocol Data Units (PDUs); A means for adjusting at least one parameter of the adaptive ECW based at least in part on a channel access output associated with the one or more candidate resources to determine at least one adjusted parameter, wherein the channel access output includes an indication of successful channel access or an indication of failed channel access, and wherein the means is configured to adjust the at least one parameter by increasing the adaptive ECW for failed channel access and decreasing the adaptive ECW for successful channel access. as well as A means for transmitting the MAC PDU using the one or more candidate resources or additional one or more candidate resources, wherein the additional one or more candidate resources are selected at least in part based on the adjusted at least one parameter.

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