Channel access procedure for unlicensed radio frequency spectrum bands

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may receive a configuration indicating a plurality of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for uplink communications. The UE may receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes a plurality of bits indicated in the configuration. Based on the LBT category or the channel access priority level, the user equipment may perform an LBT process on an uplink communication transmitted at a transmission starting point in one or more uplink communications. Many other aspects are provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to Indian Patent Application No. 201941032933, filed on August 14, 2019, entitled “Channel Access Process for Unlicensed Radio Frequency Spectrum Band,” Indian Patent Application No. 201941034502, filed on August 27, 2019, entitled “Channel Access Process for Unlicensed Radio Frequency Spectrum Band,” and U.S. Non-Provisional Patent Application No. 16 / 991,643, filed on August 12, 2020, entitled “Channel Access Process for Unlicensed Radio Frequency Spectrum Band,” the entire contents of which are expressly incorporated herein by application. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications, and to techniques and devices for channel access procedures for unlicensed radio frequency spectrum bands. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services, such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). 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) systems. LTE / LTE-Advanced is a collection of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] A wireless communication network may include multiple base stations (BS) that can support communications with multiple user equipment (UE). User equipment (UE) can communicate with a base station (BS) via a downlink and an uplink. A downlink (or forward link) refers to a communication link from a BS to a UE, and an uplink (or reverse link) refers to a communication link from a UE to a BS. As will be described in more detail herein, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), New Radio (NR) BS, 5G Node B, etc.

[0006] The above-mentioned multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate at municipal, national, regional and even global levels. New Radio (NR), also known as 5G, is a collection of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR aims to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards: using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM and / or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation. However, with the increasing demand for mobile broadband access, further improvements in LTE and NR technologies are needed. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0007] In some aspects, a method of wireless communication performed by a user equipment (UE) includes: receiving a configuration indicating a plurality of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level (priority class) to be used for uplink communications; receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes a plurality of bits indicated in the configuration; and performing an LBT process on an uplink communication transmitted at the transmission starting point in one or more uplink communications according to the LBT category or the channel access priority level.

[0008] In some aspects, a UE for wireless communication includes: a memory; and one or more processors operably coupled to the memory, the memory and the one or more processors being configured to: receive a configuration indicating a plurality of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications; receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes the plurality of bits indicated in the configuration; and perform an LBT process on an uplink communication transmitted at the transmission starting point in one or more uplink communications according to the LBT category or the channel access priority level.

[0009] In some aspects, a non-transitory computer-readable medium storing an instruction set for wireless communication includes: one or more instructions that, when executed by one or more processors of a UE, cause the UE to: receive a configuration indicating a plurality of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications; receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes the plurality of bits indicated in the configuration; and perform an LBT process on an uplink communication transmitted at the transmission starting point in one or more uplink communications based on the LBT category or the channel access priority level.

[0010] In some aspects, an apparatus for wireless communication includes: an apparatus for receiving a configuration indicating a plurality of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications; an apparatus for receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes the plurality of bits indicated in the configuration; and an apparatus for performing an LBT process on an uplink communication transmitted at the transmission starting point in one or more uplink communications based on the LBT category or the channel access priority level.

[0011] In some aspects, a wireless communication method performed by a UE may include: receiving a DCI indicating a physical uplink control channel (PUCCH) resource for transmitting PUCCH communications in an unlicensed radio frequency spectrum band; receiving an indication of an LBT category to be used in association with transmitting the PUCCH communications; and performing an LBT process on the PUCCH communications based on the indicated LBT category.

[0012] In some aspects, a wireless communication method performed by a UE may include: receiving an uplink grant indicating a resource set for uplink communication; allocating a first portion of data stored in a buffer of the UE and associated with one or more higher priority logical channels according to a logical channel priority rule to one or more resources of the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels; avoiding allocating a second portion of data stored in a buffer of the UE and associated with one or more lower priority logical channels according to an LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels; and sending the first portion of the data in the resource set using the channel access priority levels associated with the one or more higher priority logical channels.

[0013] In some aspects, a wireless communication method performed by a UE may include: receiving an indication of at least one of an LBT category or a channel access priority level of a transmission starting point among multiple transmission starting points associated with one or more uplink communications; and performing an LBT process on an uplink communication transmitted at the transmission starting point among the one or more uplink communications based on the LBT category or the channel access priority.

[0014] In some aspects, a wireless communication method performed by a UE may include: receiving an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; receiving an indication that the uplink grant is revoked; and avoiding transmitting uplink communications based at least in part on receiving the indication that the uplink grant is revoked.

[0015] In some aspects, a wireless communication method performed by a UE may include: receiving a DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; determining a channel access priority class (CAPC) for the uplink communication independently of the DCI; and transmitting the uplink communication using the determined CAPC with the indicated uplink resources.

[0016] In some aspects, a wireless communication method performed by a base station may include: determining a CAPC to be used for one or more downlink non-unicast messages that are not transmitted in a synchronization signal block based at least in part on a duration of the one or more downlink non-unicast messages; and transmitting the one or more downlink non-unicast messages using the determined CAPC.

[0017] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive downlink control information indicating PUCCH resources for transmitting PUCCH communications in an unlicensed radio frequency spectrum band; receive an indication of an LBT category to be used in association with transmitting the PUCCH communications; and perform an LBT procedure on the PUCCH communications according to the indicated LBT category.

[0018] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive an uplink grant indicating a resource set for uplink communication; allocate a first portion of data stored in a buffer of the UE and associated with one or more higher priority logical channels according to an LCP rule to one or more resources of the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels; avoid allocating a second portion of data stored in a buffer of the UE and associated with one or more lower priority logical channels according to the LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels; and send the first portion of the data in the resource set using the channel access priority levels associated with the one or more higher priority logical channels.

[0019] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point among a plurality of transmission starting points associated with one or more uplink communications; and perform an LBT procedure on an uplink communication transmitted at the transmission starting point among the one or more uplink communications according to the LBT category or the channel access priority level.

[0020] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; receive an indication that the uplink grant is revoked; and refrain from transmitting the uplink communications based at least in part on receiving the indication that the uplink grant is revoked.

[0021] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to receive a DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; determine a CAPC for the uplink communications independently of the DCI; and transmit the uplink communications with the indicated uplink resources using the determined CAPC.

[0022] In some aspects, a base station for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to determine a CAPC to be used for one or more downlink non-unicast messages not transmitted in a synchronization signal block based at least in part on a duration of the one or more downlink non-unicast messages; and transmit the one or more downlink non-unicast messages using the determined CAPC.

[0023] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions may cause the one or more processors to: receive downlink control information indicating PUCCH resources for transmitting PUCCH communications in an unlicensed radio frequency spectrum band; receive an indication of an LBT category to be used in association with transmitting the PUCCH communications; and perform an LBT procedure on the PUCCH communications according to the indicated LBT category.

[0024] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions may cause the one or more processors to: receive an uplink grant indicating a resource set for uplink communication; allocate a first portion of data stored in a buffer of the UE and associated with one or more higher priority logical channels according to an LCP rule to one or more resources of the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels; avoid allocating a second portion of data stored in a buffer of the UE and associated with one or more lower priority logical channels according to the LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels; and send the first portion of data in the resource set using the channel access priority level associated with the one or more higher priority logical channels.

[0025] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions may cause the one or more processors to: receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point among a plurality of transmission starting points associated with one or more uplink communications; and perform an LBT process on an uplink communication transmitted at a transmission starting point among the one or more uplink communications according to the LBT category or the channel access priority level.

[0026] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions may cause the one or more processors to: receive an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; receive an indication that the uplink grant is revoked; and avoid transmitting uplink communications based at least in part on receiving the indication that the uplink grant is revoked.

[0027] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a UE, the one or more instructions may cause the one or more processors to: receive a DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; determine a CAPC for uplink communications independently of the DCI; and transmit uplink communications with the indicated uplink resources using the determined CAPC.

[0028] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a base station, the one or more instructions may cause the one or more processors to: determine a CAPC to be used for one or more downlink non-unicast messages that are not transmitted in a synchronization signal block based at least in part on a duration of the one or more downlink non-unicast messages, and transmit the one or more downlink non-unicast messages using the determined CAPC.

[0029] In some aspects, an apparatus for wireless communications may include an apparatus for receiving downlink control information indicating PUCCH resources for transmitting PUCCH communications in an unlicensed radio frequency spectrum band; an apparatus for receiving an indication of an LBT category to be used in association with transmitting the PUCCH communications; and an apparatus for performing an LBT process on the PUCCH communications based on the indicated LBT category.

[0030] In some aspects, an apparatus for wireless communication may include an apparatus for receiving an uplink grant indicating a resource set for uplink communication; an apparatus for allocating a first portion of data stored in a buffer of the apparatus and associated with one or more higher priority logical channels according to an LCP rule to one or more resources of the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels; an apparatus for avoiding allocating a second portion of data stored in a buffer of the apparatus and associated with one or more lower priority logical channels according to the LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels; and an apparatus for sending the first portion of the data in the resource set using the channel access priority levels associated with the one or more higher priority logical channels.

[0031] In some aspects, an apparatus for wireless communications may include: an apparatus for receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point among multiple transmission starting points associated with one or more uplink communications; and an apparatus for performing an LBT process on an uplink communication transmitted at the transmission starting point among the one or more uplink communications according to the LBT category or the channel access priority.

[0032] In some aspects, an apparatus for wireless communications may include an apparatus for receiving an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; an apparatus for receiving an indication that the uplink grant is revoked; and an apparatus for refraining from transmitting uplink communications based at least in part on receiving the indication that the uplink grant is revoked.

[0033] In some aspects, an apparatus for wireless communications may include a device for receiving a DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; a device for determining a CAPC for the uplink communications independently of the DCI; and a device for transmitting the uplink communications with the indicated uplink resources using the determined CAPC.

[0034] In some aspects, an apparatus for wireless communication may include means for determining a CAPC to be used for one or more downlink non-unicast messages that are not transmitted in a synchronization signal block based at least in part on a duration of the one or more downlink non-unicast messages; and means for transmitting the one or more downlink non-unicast messages using the determined CAPC.

[0035] As fully described herein with reference to and illustrated by the accompanying drawings and description, various aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems.

[0036] The features and technical advantages of the examples according to the present disclosure have been outlined quite broadly above so that the detailed description below may be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples may be easily used as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent structures do not depart from the scope of the appended claims. The features of the concepts disclosed herein, their organization and methods of operation, and related advantages will be better understood from the following description when considered in conjunction with the accompanying drawings. Each of the appendices in the drawings is provided for the purpose of illustration and description and is not intended to be a definition of limiting the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to be able to understand the above features of the present disclosure in detail, a more specific description briefly summarized above can be obtained by reference to multiple aspects, some of which are shown in the accompanying drawings. However, it should be noted that the drawings only show certain typical aspects of the present disclosure and should not be considered as limiting the scope thereof, as the description may admit of other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0038] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0039] Figure 2 is a block diagram conceptually illustrating an example of a BS communicating with a UE in a wireless communication network according to various aspects of the present disclosure.

[0040] Figure 3-Figure 8 is a diagram illustrating an example of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure.

[0041] Figure 9-Figure 15 is a diagram illustrating example procedures associated with a channel access procedure for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0042] The various aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms and should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. On the contrary, these aspects are provided to make the present disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings herein, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether it is implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method, which is practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein can be embodied by one or more elements of the claims.

[0043] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms and / or the like (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and design constraints imposed on the overall system.

[0044] It should be noted that although various aspects may be described herein using terminology typically associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations, such as 5G and higher, including NR technology.

[0045] Figure 1 1 is a diagram showing a wireless network 100 in which various aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a plurality of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a BS, NRBS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0046] A BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access to UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access to UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown, BS 110a may be a macro BS of macro cell 102a, BS 110b may be a pico BS of pico cell 102b, and BS 110c may be a femto BS of femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NRBS", "gNB", "TRP", "AP", "Node B", "5GNB", and "cell" may be used interchangeably herein.

[0047] In some aspects, the cells are not necessarily stationary, and the geographic area of ​​the cells may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected to each other and / or 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 using any suitable transport network, virtual networks, etc.).

[0048] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and send data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown, relay BS 110d may communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay BS may also be referred to as a relay station, relay base station, relay, or the like.

[0049] The wireless network 100 may be a heterogeneous network including different types of 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 impacts on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0050] A network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other directly or indirectly, for example, via a wireless or wired backhaul.

[0051] UE 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be fixed or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biosensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0052] Some UEs may be considered as machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a base station, another device (e.g., a remote device), or some other entity. For example, a wireless node may provide a connection to a network (e.g., a wide area network such as the Internet or a cellular network) or provide a connection to a network via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, and / or may be implemented as narrowband Internet of Things (NB-IoT) devices. Some UEs may be considered as customer premises equipment (CPE). UE 120 may be included in a housing that houses components of UE 120 (such as processor components, memory components, etc.).

[0053] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific RAT and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0054] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using BS 110 as a medium for communicating with each other) using one or more side link channels. For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocol (e.g., which may include vehicle-to-vehicle (V2V) protocol, vehicle-to-infrastructure (V2I) protocol, etc.), mesh network, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by BS 110.

[0055] As mentioned above, providing Figure 1 As an example. Other examples may differ from the Figure 1 as described.

[0056] Figure 2 It shows that it can be Figure 1 1. Block diagram of a design 200 for a BS 110 that is one of the BSs and a UE 120 that is one of the UEs in a wireless communication network. BS 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≥1 and R≥1.

[0057] At BS110, the transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the (multiple) MCS selected for the UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols (if applicable), and may provide T output symbol streams to T modulators 232a to 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may 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 may be transmitted via antennas 234a to 234t, respectively. According to various aspects described in more detail below, position coding may be used to generate synchronization signals to transmit additional information.

[0058] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 and / or other BSs, and may provide received signals to demodulators 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0059] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., including reports of RSRP, RSSI, RSRQ, CQI, etc.) from a controller / processor 280. The transmit processor 264 may also generate reference symbols for one or more reference signals. Symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266, if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by MIMO detector 236 (if applicable), and further processed by a receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0060] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component(s) of the base station 110 may perform one or more techniques associated with a channel access process for an unlicensed radio frequency spectrum band as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component(s) of may perform or direct e.g. Fig. 9 The process of 900 Fig.10 The process of 1000 Fig.11 Process 1100, Fig.12 The process 1200 Fig.13 The process of 1300 Fig.14 The process of 1400 Fig.15 The operations of process 1500 are performed. Memories 242 and 282 may store data and program codes 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 for wireless communication. For example, when executed by one or more processors of base station 110 and / or UE 120, the one or more instructions may perform or direct, for example, Fig. 9 The process of 900 Fig.10The process of 1000 Fig.11 Process 1100, Fig.12 The process 1200 Fig.13 The process of 1300 Fig.14 The process of 1400 Fig.15 The scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink.

[0061] In some aspects, the UE 120 may include means for receiving a configuration indicating a number of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications; means for receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission start point associated with one or more uplink communications, wherein the indication includes the number of bits indicated in the configuration; means for performing an LBT procedure on an uplink communication transmitted at the transmission start point in the one or more uplink communications according to the LBT category or the channel access priority level, etc. Additionally or alternatively, the UE 120 may include means for receiving downlink control information indicating a physical uplink control channel (PUCCH) resource to be used for transmission in a PUCCH communication in an unlicensed radio frequency spectrum band; means for receiving an indication of a listen-before-talk (LBT) category to be used in association with transmitting the PUCCH communication; means for performing an LBT procedure on the PUCCH communication according to the indicated LBT category, etc. Additionally or alternatively, UE 120 may include a device for receiving an uplink grant indicating a resource set for uplink communication; a device for allocating a first portion of data stored in a buffer of UE 120 and associated with one or more higher priority logical channels according to a logical channel priority (LCP) rule to one or more resources in the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels; a device for avoiding allocating a second portion of data stored in a buffer of the UE 120 and associated with one or more lower priority logical channels according to the LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels; a device for sending the first portion of the data in the resource set using the channel access priority levels associated with the one or more higher priority logical channels, etc. Additionally or alternatively, UE 120 may include means for receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point among a plurality of transmission starting points associated with one or more uplink communications; means for performing an LBT process on an uplink communication transmitted at a transmission starting point among the one or more uplink communications according to the LBT category or the channel access priority, etc. Additionally or alternatively, UE 120 may include means for receiving an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; means for receiving an indication that an uplink grant is revoked; means for avoiding transmitting uplink communications based at least in part on receiving an indication that an uplink grant is revoked, etc.Additionally or alternatively, UE 120 may include means for receiving downlink control information (DCI) indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band; means for determining a channel access priority level (CAPC) for uplink communications independently of the DCI; means for transmitting uplink communications with the indicated uplink resources using the determined CAPC, etc. In some aspects, such means may include a combination. Figure 2 One or more components of UE 120 are depicted, 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.

[0062] In some aspects, the base station 110 may include means for determining a CAPC to be used by one or more downlink non-unicast messages not transmitted in a synchronization signal block based at least in part on a duration of the one or more downlink non-unicast messages; means for transmitting the one or more downlink non-unicast messages using the determined CAPC, etc. In some aspects, such means may include combining Figure 2 One or more components of the base station 110 are depicted, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.

[0063] As mentioned above, providing Figure 2 As an example. Other examples can be related to Figure 2 Described differently.

[0064] Some aspects described herein relate to unlicensed radio frequency spectrum bands that can be used for communications in a wireless network, such as wireless network 100. In some aspects, the unlicensed radio frequency spectrum bands can be used by base stations 110 and UEs 120 of a cellular network for long term evolution (LTE) communications and / or advanced LTE communications, and by Wi-Fi access points and Wi-Fi stations of Wi-Fi for Wi-Fi communications. Unlicensed radio frequency spectrum bands can be used in a cellular network in conjunction with or independently of licensed radio frequency spectrum bands. In some examples, an unlicensed radio frequency spectrum band can be a radio frequency spectrum band that devices may need to contend for access to because the radio frequency spectrum band is at least partially available for unlicensed use, such as Wi-Fi use.

[0065] Prior to obtaining access to and communicating on an unlicensed radio frequency spectrum band, a base station 110 or a UE 120 may perform a listen-before-talk (LBT) process to contend for access to the unlicensed radio frequency spectrum band. The LBT process, sometimes referred to as a clear channel assessment (CCA) process, may include performing a CCA to determine whether a channel of the unlicensed radio frequency spectrum band is available. When it is determined that a channel of the unlicensed radio frequency spectrum band is not available (e.g., because another device is already using a channel of the unlicensed radio frequency spectrum band), a CCA process may be performed again on the channel at a later time. In an environment where the base station 110 or the UE 120 may not be able to access a channel of the unlicensed radio frequency spectrum band due to Wi-Fi activity, an extended CCA process may be employed to increase the likelihood that the base station 110 or the UE 120 will successfully contend for access to a channel of the unlicensed radio frequency spectrum band. The extended CCA process includes performing a random number of CCA processes (from 1 to q) based on an extended CCA counter.

[0066] Regardless of whether a single CCA process is performed or multiple CCA processes are performed, each CCA process may include detecting or sensing an energy level on a channel of an unlicensed radio frequency spectrum band and determining whether the energy level is below a threshold. When the energy level is below the threshold, the CCA process is successful, and contention for access to the channel of the unlicensed radio frequency spectrum band may be successful. When the energy level exceeds the threshold, the CCA process is unsuccessful, and contention for access to the channel of the unlicensed radio frequency spectrum band may be unsuccessful.

[0067] When the CCA process or the extended CCA process is successful, transmission can be performed over a channel of an unlicensed radio frequency spectrum band. When a packet error is encountered (e.g., due to a collision of transmissions by two or more transmitting devices, or due to poor channel conditions), a hybrid automatic repeat request (HARQ)-based retransmission can be performed. In some examples, the retransmission can be modified from the original transmission using rate adaptation (e.g., based at least in part on a channel quality indicator (CQI) reported by the UE).

[0068] Some of the techniques and apparatus described herein address various issues associated with contending for access to unlicensed radio frequency spectrum bands or other types of channels that devices contend for access to. For example, some of the techniques and apparatus described herein address issues associated with determining an LBT category to be used for an LBT process, determining a channel access priority level (CAPC) for one or more communications, and the like.

[0069] Figure 3 is a diagram illustrating an example 300 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 3 As shown, base station 110 and UE 120 may communicate with each other.

[0070] As shown in the reference numeral 305, the base station 110 can send and the UE 120 can receive downlink control information (DCI) indicating PUCCH resources for transmitting physical uplink control channel (PUCCH) communications in an unlicensed radio frequency spectrum band. For example, the DCI can indicate one or more time resources, one or more frequency resources, one or more spatial resources (e.g., beams), etc. In some aspects, the PUCCH communication can include a channel state information (CSI) report scheduled by the DCI, an acknowledgment (ACK) or negative acknowledgment (NACK) (collectively referred to as ACK / NACK) feedback of a downlink data communication scheduled by the DCI, etc.

[0071] As indicated by reference numeral 310, the base station 110 may send, and the UE 120 may receive, an indication of an LBT category to be used in association with transmitting a PUCCH communication. The LBT category may define a channel sensing duration during which devices competing for access to the channel perform a CCA procedure. The channel sensing duration may indicate a length of time during which a device detects or senses an energy level on a channel to determine whether the energy level is less than (or equal to) a threshold. If the energy level is less than (or equal to) the threshold, the LBT / CCA procedure is successful and the device transmits the communication. If the energy level is greater than (or equal to) the threshold, the CCA procedure is unsuccessful and the device may wait for a period of time (e.g., a backoff duration) before performing the CCA procedure again.

[0072] Example LBT categories include Category One (Cat 1) LBT, Category Two (Cat 2) LBT, Category Three (Cat 3) LBT, and Category Four (Cat 4) LBT. In Cat 1 LBT, also known as No LBT, no LBT process is performed before transmitting communications on the channel. In Cat 2 LBT, the channel detection duration is fixed (e.g., there is no random backoff). For example, a channel sensing duration of 16 microseconds is used for Cat 2 LBT of 16 microseconds, and a channel sensing duration of 25 microseconds is used for Cat 2 LBT of 25 microseconds. In Ca 3 LBT, the channel sensing duration is fixed (e.g., the contention window has a fixed size), and random backoff is used. In Cat 4 LBT, the channel detection duration is variable (e.g., the contention window has a variable size), and random backoff is used.

[0073] In Cat 4LBT, the channel sensing duration can vary depending on whether the device competing for access to the channel senses interference (e.g., an energy level greater than or equal to a threshold). Using the Ca 4LBT process, the device can select a minimum channel detection duration, which can be defined by the CAPC associated with the Ca 4LBT process that the device is using. For example, four different CAPCs can be associated with Cat 4LBT, with the lowest CAPC value (e.g., CAPC 0) being associated with the highest priority for Cat 4LBT (e.g., the shortest contention window size and the shortest backoff duration), and the highest CAPC value (e.g., CAPC3) being associated with the lowest priority for Cat 4LBT (e.g., the longest contention window size and the longest backoff duration). Typically, higher CAPC values ​​(e.g., higher CAPC indexes) are associated with lower priorities. In Cat 4LBT, if a device detects interference within the minimum channel detection duration for the CCA process defined by the CAPC for the Cat 4LBT process, the device can increase the channel detection duration for the next CCA process.

[0074] In some aspects, the base station 110 may indicate the LBT category in the channel occupancy time structure indication. The base station 110 may send the COT-SI (e.g., to all connected mode UEs 120 connected to the base station 110) after the base station 110 acquires the channel. The COT-SI may indicate the duration of the base station 110 accessing the channel. The duration may be selected as the channel occupancy time (COT), with the maximum duration being defined by the maximum COT. In some aspects, the COT-SI may indicate the LBT category based at least in part on whether the PUCCH resources indicated in the DCI are included in the COT indicated in the COT-SI. Additionally or alternatively, the COT-SI may indicate whether Cat 2 LBT or Cat 4 LBT is used for PUCCH communication.

[0075] For example, if the PUCCH resources indicated in the DCI are included in the COT indicated in the COT-SI, the UE 120 may use Cat 2 LBT (or a first LBT category with a shorter channel sensing duration) because during the period when the PUCCH resources appear, the possibility of a conflict is lower because the base station 110 is acquiring a channel. As another example, if the PUCCH resources indicated in the DCI are not included in the COT indicated in the COT-SI, the UE 120 may use Cat 4 LBT (or a second LBT category with a longer channel sensing duration) because during the period when the PUCCH resources appear, the possibility of a conflict is higher because the base station 110 is not acquiring a channel.

[0076] In some aspects, the base station 110 may indicate the LBT category in a DCI indicating a PUCCH resource for transmitting a PUCCH communication. For example, the DCI may include a field for indicating an LBT category such as Cat 1 LBT (e.g., no LBT), Cat 2 LBT (e.g., Cat 2 LBT of 16 microseconds or Cat 2 LBT of 25 microseconds), Cat 4 LBT (and in some aspects, a CAPC associated with Cat 4 LBT), etc.

[0077] In some aspects, the LBT category may be implicitly indicated (e.g., by a DCI). For example, in some aspects, any PUCCH communication in an unlicensed radio frequency spectrum band scheduled by a DCI may be associated with a default LBT category. In some aspects, the default LBT category is Cat 2 LBT. For example, a UE 120 may be configured to use Category 2 LBT (or another default LBT category) for any PUCCH communication scheduled in an unlicensed radio frequency spectrum band using a DCI. In this case, the base station 110 may schedule the PUCCH communication such that the PUCCH resources are included in the COT acquired by the base station 110.

[0078] As indicated by reference numeral 315, the UE 120 may perform an LBT procedure (e.g., contend for access to an unlicensed radio frequency band in order to transmit a PUCCH communication in a PUCCH resource) according to the indicated LBT category. For example, as described elsewhere herein, the UE 120 may perform an LBT procedure by sensing the channel for a channel sensing duration indicated by the LBT category. If the energy detected by the UE 120 on the channel satisfies a threshold (e.g., if the LBT procedure fails), the UE 120 may avoid transmitting PUCCH communications on the channel. If the energy detected by the UE 120 on the channel does not satisfy the threshold (e.g., if the LBT procedure succeeds), the UE 120 may transmit PUCCH communications as indicated by reference numeral 320.

[0079] When UE 120 receives an indication of the LBT category to be used for PUCCH communications scheduled using DCI on an unlicensed radio frequency spectrum band, the possibility of collisions can be reduced and delays can be reduced. For example, when UE 120 acquires a channel for COT, UE 120 typically uses Cat 4 LBT for PUCCH transmissions. However, for PUCCH communications scheduled by base station 110 using DCI, base station 110 may have already acquired a channel for COT and may instruct UE 120 to use a shorter channel sensing duration so that PUCCH communications are transmitted during the COT period when base station 110 has acquired the channel. In this way, the possibility of delays and collisions can be reduced.

[0080] As mentioned above, providing Figure 3 As an example. Other examples can be related to Figure 3 Described differently.

[0081] Figure 4 4 is a diagram illustrating an example 400 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 4 As shown, base station 110 and UE 120 may communicate with each other.

[0082] As indicated by reference numeral 405, the base station 110 may send, and the UE 120 may receive, an uplink grant indicating a set of resources for uplink communication. For example, the uplink grant (e.g., included in a DCI) may indicate one or more time resources, one or more frequency resources, one or more spatial resources (e.g., beams), etc. In some aspects, the uplink communication is an uplink data communication, such as a physical uplink shared channel (PUSCH) communication.

[0083] As indicated by reference numeral 410, UE 120 may store data for transmission in a buffer (e.g., memory) of UE 120. As further shown, the data may include a first portion of the data and a second portion of the data. The first portion of the data may be associated with one or more higher priority logical channels (shown as LCs) according to a logical channel priority rule, and the second portion of the data may be associated with one or more lower priority logical channels according to an LCP rule. For example, UE 120 may be configured with an LCP rule indicating a set of logical channels and a set of corresponding CAPCs (e.g., one CAPC per logical channel). A higher priority logical channel may be associated with a higher priority CAPC (e.g., having a lower CAPC index value), and a lower priority logical channel may be associated with a lower priority CAPC (e.g., having a higher CAPC index value).

[0084] In uplink communications, UE 120 may typically apply LCP rules to include data for all logical channels (e.g., some data from each logical channel, for each logical channel data is stored in a buffer), or data for multiple logical channels. For example, if the buffer includes high priority ultra-reliable low latency communication (URLLC) data and low priority enhanced mobile broadband (eMBB) data, UE 120 may allocate all URLLC data to uplink communications, and then may allocate eMBB data to uplink communications. However, when uplink communications are transmitted in an unlicensed radio frequency spectrum band (e.g., using LTE-LAA procedures, using autonomous uplink, etc.), UE 120 may be required to use the CAPC associated with the lowest priority data included in the uplink communications (e.g., the highest CAPC index value among all CAPC index values ​​associated with data included in the uplink communications). In this case, UE 120 may use a low priority CAPC (e.g., associated with eMBB data) to send high priority data (e.g., URLLC data), which may increase latency (e.g., due to failure of the LBT process with a longer channel sensing time indicated by the lower priority CAPC). This may cause URLLC requirements (e.g., quality of service (QoS) requirements) to not be met. Some techniques and apparatus described herein address this issue.

[0085] As indicated by reference numeral 415, the UE 120 may allocate a first portion of data associated with one or more higher priority logical channels to one or more resources in the resource set. As indicated by reference numeral 420, the UE 120 may refrain from allocating a second portion of data associated with one or more lower priority logical channels to the resource set. For example, as indicated by reference numeral 425, after allocating the first portion of data to the resource set, the UE 120 may interrupt the LCP procedure. In some aspects, the UE 120 may interrupt the LCP procedure after allocating data to a particular logical channel, after allocating data to a threshold number of logical channels, after allocating data to a logical channel having a particular priority (e.g., associated with a particular CAPC value), and the like.

[0086] As shown by reference numeral 430, if the first portion of the data does not fill the resource set, the UE 120 may include additional information in the remainder of the resource set. In some aspects, the UE 120 may include some or all of the second portion of the data in the remainder of the resource set. In this case, even if the second portion of the data associated with the lower priority CAPC is included in the resource set, the UE 120 may transmit uplink communications using the higher priority CAPC associated with the first portion of the data as described in more detail below.

[0087] Additionally or alternatively, the UE 120 may include one or more padding bits in the remainder of the resource set. In this case, the first portion of the data plus the padding bits may fill the resource set, and the UE 120 may transmit uplink communications using a higher priority CAPC associated with the first portion of the data. Additionally or alternatively, the UE 120 may send a buffer status report (BSR) in the remainder of the resource set. The BSR may indicate that the UE 120 has additional data stored in the buffer, which may trigger the base station 110 to send an uplink grant to the UE 120 (e.g., allowing the UE 120 to send the second portion of the data). Additionally or alternatively, the UE 120 may include an indication in the remainder of the resource set that the UE has interrupted the LCP process. In some aspects, the indication may be included in a media access control (MAC) control element (CE) (collectively referred to as MAC-CE). This may trigger the base station 110 to send an uplink grant to the UE 120 (e.g., allowing the UE 120 to send the second portion of the data).

[0088] As shown by reference numeral 435, UE 120 can transmit uplink communications in a resource set using a higher priority CAPC associated with one or more higher priority logical channels. As described above, the uplink communications can include a first portion of the data assigned to the resource set. In some aspects, as described above, the uplink communications can also include padding bits, some of the second portion of the data, and / or other information. By interrupting the LCP process and / or using a higher priority CAPC (e.g., associated with the first portion of the data) instead of a lower priority CAPC (e.g., associated with the second portion of the data) to transmit the uplink communications, UE 120 can reduce delays, which can help meet QoS requirements for the first portion of the higher priority data.

[0089] In some aspects, UE 120 may perform one or more of the above operations (e.g., allocating a first portion of the data and refraining from allocating a second portion of the data, interrupting an LCP procedure, transmitting uplink communications at a priority CAPC higher than a lowest priority CAPC associated with data stored in a UE buffer, etc.) based at least in part on determining that the LCP restriction condition is satisfied. Additionally or alternatively, UE 120 may perform any other type of logical channel restriction procedure (e.g., excluding data associated with a set of logical channels from uplink communications based at least in part on an LCP priority of the set of logical channels, based at least in part on a logical channel configuration, based at least in part on a CAPC associated with the set of logical channels, etc.) based at least in part on determining that the logical channel restriction condition is satisfied.

[0090] In some aspects, the UE 120 may determine that the LCP restriction condition is satisfied based at least in part on a determination that the first portion of the data or the set of padding bits used to fill the resource set satisfies the condition relative to filling the resource set with data. For example, if the set of padding bits is less than or equal to a threshold size (e.g., includes a number of bits less than or equal to the threshold), if the set of padding bits is less than or equal to a threshold percentage of the total bits included in the resource set, etc., then the set of padding bits may be used to fill the remainder of the resource set. Similarly, if the first portion of the data is greater than or equal to a threshold size (e.g., includes a number of bits greater than or equal to the threshold), if the first portion of the data is greater than or equal to a threshold percentage of the total bits included in the resource set, etc., then the set of padding bits may be used to fill the remainder of the resource set. In some aspects, the threshold may depend on the CAPC used to transmit the uplink communication, the highest priority CAPC associated with the data in the UE buffer, etc.

[0091] Additionally or alternatively, UE 120 may determine that the LCP restriction condition is satisfied based at least in part on a determination that all data from one or more higher priority logical channels has been allocated to the resource set. For example, if all data having a priority greater than or equal to a threshold priority has been included in the resource set, a set of padding bits may be used to fill the remainder of the resource set.

[0092] Additionally or alternatively, UE 120 may determine that the LCP restriction condition is satisfied based at least in part on a determination that the size of the second data portion satisfies the condition. In some aspects, the condition is based at least in part on one or more lower priority logical channels. For example, based at least in part on the excluded data from the excluded logical channels, a set of padding bits may be used to fill the remainder of the resource set. UE 120 may use a set of padding bits whose size is based at least in part on an LCP bucket size and / or a buffer size associated with the excluded logical channels.

[0093] Additionally or alternatively, UE 120 may determine that the LCP restriction condition is satisfied based at least in part on a determination that a contention window size associated with one or more lower priority logical channels differs from a contention window size of one or more higher priority logical channels by a threshold amount. For example, if a low priority logical channel is associated with an LBT contention window size that is within a threshold size of a high priority logical channel (e.g., a highest priority logical channel for which data is transmitted) and / or within a threshold size of a contention window size defined by a CAPC for transmitting uplink communications, UE 120 may include data for the low priority logical channel in the resource set.

[0094] Additionally or alternatively, the UE 120 may determine that the LCP restriction condition is satisfied based at least in part on the LBT category indicated by the uplink grant. For example, the UE 120 may interrupt the LCP process for a first LBT category (e.g., Cat 4 LBT) and may avoid interrupting the LCP process for a second LBT category (e.g., Cat 1 LBT or Cat 2 LBT). Additionally or alternatively, the UE 120 may determine that the LCP restriction condition is satisfied based at least in part on the type of cell in which the uplink communication is to be transmitted. For example, for a frame-based equipment (FBE) cell, a category two LBT may be used, and thus the UE 120 may not perform LCP restriction for the FBE cell. In some aspects, the UE 120 may perform LCP restriction for a load-based equipment (LBE) cell.

[0095] Additionally or alternatively, UE 120 may determine that the LCP restriction condition is satisfied based at least in part on an indication to activate the LCP restriction procedure. For example, base station 110 may send an indication to UE 120 to activate or deactivate the LCP restriction procedure. In some aspects, the indication may be included in a MAC-CE. In some aspects, base station 110 may activate the LCP restriction procedure based at least in part on a determination that channel congestion and / or interference is greater than or equal to a threshold, and may deactivate the LCP restriction procedure based at least in part on a determination that channel congestion and / or interference is less than or equal to a threshold.

[0096] Additionally or alternatively, the UE 120 may determine that the LCP restriction condition is satisfied based at least in part on a determination that an interference level measured by the UE satisfies a threshold. In some aspects, the UE 120 may activate an LCP restriction procedure based at least in part on a determination that channel congestion and / or interference is greater than or equal to a threshold, and may deactivate the LCP restriction procedure based at least in part on a determination that channel congestion and / or interference is less than or equal to a threshold. Additionally or alternatively, the UE 120 may activate or deactivate an LCP restriction procedure based at least in part on a size of a contention window, a number of busy slots detected in one or more LBT processes, a network indication of congestion in a channel, and the like.

[0097] As mentioned above, providing Figure 4 As an example. Other examples can be related to Figure 4 Described differently.

[0098] Figure 5 is a diagram illustrating an example 500 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 5 As shown, base station 110 and UE 120 may communicate with each other.

[0099] As indicated by reference numeral 505, the base station 110 may send, and the UE 120 may receive, an indication of one or more LBT parameters (e.g., LBT category, CAPC, etc.) to be used for a transmission (tx) start point associated with one or more uplink communications in a plurality of transmission start points. For example, the base station 110 may send a multi-transmission time interval (multi-TTI) uplink grant indicating an LBT category and / or CAPC to be used for each transmission start point (e.g., each uplink grant indicating a different uplink resource) permitted by the multi-TTI grant. Although some operations are described herein in conjunction with transmission start points for uplink communications scheduled by multi-TTI grants, these operations may also be applied to other scenarios in which multiple transmission time points are being used in an unlicensed radio frequency spectrum band, or another type of communication system in which devices compete for channel access.

[0100] The multi-TTI uplink grant may indicate a plurality of resources granted for an uplink communication, such as for a plurality of uplink communications (e.g., each uplink communication may be transmitted in a different resource) or for a single uplink communication, where an LBT process may be performed in each of the plurality of resources. For example, if a first LBT process of a first transmission starting point (e.g., a first resource for a first uplink grant in the multi-TTI uplink grant) fails, the UE 120 may attempt a second LBT process of a second transmission starting point (e.g., a second resource for a second uplink grant in the multi-TTI uplink grant), and so on, until the UE 120 successfully transmits the uplink communication.

[0101] As indicated by reference numeral 510, the UE 120 may perform an LBT procedure (e.g., a first LBT procedure) of a first transmission starting point according to the indicated LBT parameter(s) (e.g., an indicated LBT category and / or an indicated CAPC). As indicated by reference numeral 515, the first LBT procedure may fail. As indicated by reference numeral 520, the UE 120 may perform an LBT procedure (e.g., a second LBT procedure) of a second transmission starting point according to the indicated LBT parameter(s).

[0102] In some aspects, the base station 110 may indicate (e.g., in a multi-TTI grant) that a single LBT category and / or a single CAPC will be used for all transmission start points. In this case, the UE 120 may use the same LBT category and / or the same CAPC for the first LBT process, the second LBT process, etc. In some aspects, the UE 120 may use different LBT categories and / or different CAPCs for different transmission start points or for different sets of transmission start points. For example, the UE 120 may use the LBT category and / or CAPC indicated by the base station 110 (e.g., the first LBT category or the first CAPC) for the initial LBT process at the initial transmission start point, and may use the second LBT category and / or the second CAPC for subsequent LBT processes (e.g., a single LBT process after the initial LBT process, multiple LBT processes after the initial LBT process, all LBT processes after the initial LBT process, etc.) at subsequent transmission start points. The first LBT category and / or the first CAPC may define a first channel sensing time that is shorter than the second channel sensing time defined by the second LBT category and / or the second CAPC. For example, if the LBT category indicated by the base station 110 is Cat 1 LBT (e.g., no LBT), the second LBT category may be Cat 2 LBT of 16 microseconds or Cat 2 LBT of 25 microseconds. As another example, if the LBT category indicated by the BS is Cat 2 LBT of 16 microseconds, the second LBT category may be Cat 2 LBT of 25 microseconds.

[0103] In some aspects, the indication may include a separate indication of the LBT category and / or CAPC for each transmission starting point. For example, a multi-TTI grant may include a separate indication of the LBT category and / or CAPC for each transmission starting point (e.g., in a separate field). Alternatively, the indication may indicate a first LBT category and / or a first CAPC to be used for a first set of transmission starting points, and a second LBT category and / or a second CAPC to be used for a second set of transmission starting points, which may reduce signaling overhead.

[0104] In some aspects, the indication of one or more LBT parameters (e.g., LBT category, CAPC, etc.) may include multiple bits (e.g., a certain number of bits), and the base station 110 may indicate the multiple bits included in the indication of the one or more LBT parameters. For example, the base station 110 may send a radio resource control (RRC) message to the UE 120 indicating the multiple bits to be included in the indication of the one or more LBT parameters (e.g., in a multi-TTI uplink grant or a single uplink grant). Additionally or alternatively, the RRC message may indicate a mapping between a set of bit values ​​and a corresponding set of LBT parameters (e.g., a first bit value corresponding to a first set of LBT parameters (such as a first LBT category and / or a first CAPC), a second bit value corresponding to a second set of LBT parameters (such as a second LBT category and / or a second CAPC), and so on). In this way, when the UE 120 receives a multi-TTI grant or a single uplink grant (e.g., a single TTI grant), the UE 120 will be able to interpret the bits to identify the one or more LBT parameters to be used for each transmission start point.

[0105] In some aspects, a mapping between a plurality of bits and / or bit values ​​included in an indication of one or more LBT parameters and the corresponding one or more LBT parameters may depend on the channel over which the uplink communication is transmitted. For example, different numbers of bits may be used for different channels (e.g., PUCCH, PUSCH, etc.), or different mappings between bit values ​​and the corresponding one or more LBT parameters may be used for different channels. Additionally or alternatively, a mapping between a plurality of bits and / or bit values ​​included in an indication of one or more LBT parameters and the corresponding one or more LBT parameters may depend on the type of cell in which the uplink communication is transmitted (e.g., FBE cell, LBE cell, etc.). For example, different numbers of bits may be used for different types of cells, or different mappings between bit values ​​and the corresponding one or more LBT parameters may be used for different types of cells. As another example, one or more bits indicating CAPC may be excluded from the indication of an FBE cell.

[0106] By receiving an indication of one or more LBT parameters to be used for multiple transmission start points, UE 120 can appropriately perform LBT for different transmission start points. In addition, by mapping bit values ​​to one or more LBT parameters, signaling overhead can be saved, such as by mapping only LBT parameters supported by UE 120 (e.g., according to a capability report transmitted by UE 120 to base station 110).

[0107] In some aspects, the UE 120 may modify the LBT category of one or more transmission starting points based at least in part on receiving the COT-SI. For example, if the UE 120 determines that the one or more transmission starting points are within the channel occupancy duration (e.g., COT) obtained by the base station 110, the UE 120 may modify the LBT category of the one or more transmission starting points from the first LBT category indicated by the base station 110 for the one or more transmission starting points to the second LBT category. The first LBT category may define a first channel sensing time that is longer than the second channel sensing time defined by the second LBT category. For example, the first LBT category may be Cat 4 LBT, and the second LBT category may be one of Cat 1 LBT (e.g., no LBT), 16 microseconds Cat 2 LBT, or 25 microseconds Cat 2 LBT. In another example, the first LBT category may be a category two LBT of 25 microseconds, and the second LBT category may be one of category one LBT (e.g., no LBT) or 16 microseconds Category two LBT. Alternatively, as described above, the first LBT category may define a first channel sensing time that is shorter than the second channel sensing time defined by the second LBT category. The UE 120 may determine the second LBT category based at least in part on information that the UE 120 may receive in a COT-SI message or at least in part on predefined criteria. In some aspects, the second LBT category may be a category two LBT of 25 microseconds. In some aspects, for one or more transmission start points, a second LBT category may be indicated within the COT-SI. In some aspects, the second LBT category may be determined by the UE 120 based at least in part on a slot format indicator (SFI) and / or other information included in the COT-SI.

[0108] In some aspects, after performing an uplink transmission in a first transmission starting point that occurs before the one or more transmission starting points, the UE 120 may avoid performing an LBT procedure on the one or more transmission starting points. For example, if there is no transmission gap greater than a threshold value (e.g., 16 microseconds) during the time from the first uplink transmission of the UE 120 at the first transmission starting point to the last uplink transmission of the UE 120 at the one or more transmission starting points, the UE 120 may avoid performing an LBT procedure on the one or more transmission starting points. In another example, if the priority of the CAPC associated with the one or more transmission starting points is greater than or equal to the priority of the CAPC associated with the first transmission starting point, the UE 120 may avoid performing an LBT procedure on the one or more transmission starting points. In another example, if the LBT category associated with the one or more transmission starting points is the same as the LBT category associated with the first transmission starting point, the UE 120 may avoid performing an LBT procedure on the one or more transmission starting points. In another example, if there is a transmission gap equal to 16 microseconds before a transmission start point within one or more transmission start points, the UE 120 may be required to perform a Category 2 LBT of 16 microseconds.

[0109] As mentioned above, providing Figure 5 As an example. Other examples can be related to Figure 5 Described differently.

[0110] Figure 6 6 is a diagram illustrating an example 600 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 6 As shown, base station 110 and UE 120 may communicate with each other.

[0111] As indicated by reference numeral 605, in a manner similar to that described elsewhere herein, base station 110 may transmit, and UE 120 may receive, an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band. In some aspects, the uplink grant may be transmitted in a first DCI.

[0112] As shown in reference numeral 610, after transmitting the uplink grant, the base station 110 may send and the UE 120 may receive an indication that the uplink grant is revoked. In some aspects, the indication that the uplink grant is revoked may be transmitted in a second DCI transmission (e.g., transmitted after the first DCI). For example, the indication may be a preemptive indication in a DCI transmission, which identifies a set of uplink resources (e.g., time resources, frequency resources, space resources, etc.) that are not allowed to be used by the UE 120 for uplink communication. In this case, the UE 120 may determine to avoid transmitting uplink communications based at least in part on a determination that the uplink resource set identified in the preemptive indication partially or completely overlaps with the uplink resources indicated in the uplink grant.

[0113] In some aspects, an indication that the uplink grant was revoked may be sent in the COT-SI. The COT-SI may indicate a set of occupied subbands (e.g., subbands that have been acquired by the base station 110 for COT). In this case, the UE 120 may determine to avoid transmitting uplink communications based at least in part on a determination that one or more subbands of the uplink resources indicated in the uplink grant are not included in the set of occupied subbands indicated in the COT-SI.

[0114] As shown in reference numeral 615, UE 120 may refrain from transmitting uplink communications based at least in part on receiving an indication that the uplink grant is revoked. In some aspects, base station 110 may send and UE 120 may receive a subsequent COT-SI (e.g., which may be sent after the COT-SI and / or DCI indicating that the uplink grant is revoked) that includes an indication that uplink communications associated with the previous COT-SI are allowed to be transmitted in a COT associated with the subsequent COT-SI. In this case, based at least in part on receiving an indication that uplink communications are allowed to be transmitted in a COT associated with the subsequent COT-SI, UE 120 may transmit uplink communications in the COT indicated by the subsequent COT-SI.

[0115] By allowing the cancellation of uplink grants, the base station 110 can prioritize communications with higher priority (e.g., URLLC data of a different UE 120) than the uplink communications scheduled for the UE 120 by the uplink grant. This can help meet QoS requirements while also reducing the possibility of conflicts (e.g., by canceling uplink communications from the UE 120 in favor of high priority communications of another UE 120). In addition, this can eliminate LBT processes that may fail when the base station 110 acquires fewer resources and / or subbands than the resources and / or subbands granted to the UE 120 in the uplink grant, thereby saving network resources and resources (e.g., processing resources, memory resources, battery power, etc.) of the UE 120.

[0116] As mentioned above, providing Figure 6 As an example. Other examples may differ from the Figure 6 as described.

[0117] Figure 7 is a diagram illustrating an example 700 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 7 As shown, base station 110 and UE 120 may communicate with each other.

[0118] As indicated by reference numeral 705, in a manner similar to that described elsewhere herein, the base station 110 may transmit, and the UE 120 may receive, a DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band.

[0119] As indicated by reference numeral 710, the UE 120 may determine a CAPC for uplink communications independent of the DCI. For example, the UE 120 may determine a CAPC for uplink communications regardless of the CAPC indicated in the DCI, may determine a CAPC for uplink communications if the DCI does not indicate a CAPC for uplink communications, may determine a CAPC for uplink communications if the DCI does not indicate a valid CAPC to be used for uplink communications, and so on. In some aspects, the base station 110 may send an indication to the UE 120 to instruct the UE 120 to determine the CAPC independent of the DCI. In some aspects, the UE 120 may determine a CAPC associated with uplink data to be transmitted by the UE 120 in an uplink communication (e.g., based at least in part on a priority of the uplink data, a logical channel associated with the uplink data, a CAPC configured for the logical channel, and so on), and may use the CAPC when transmitting the uplink communications.

[0120] In some aspects, base station 110 may indicate a valid CAPC value (e.g., one of Type 1 to Type 4) to allow base station 110 to share channel occupancy initiated by UE 120 for transmitting uplink communications. In this case, UE 120 may use the CAPC value indicated by base station 110. In another example, base station 110 may indicate an invalid CAPC value to allow UE 120 to autonomously determine the CAPC for uplink communications (e.g., using one or more of the techniques described above).

[0121] In some aspects, the base station 110 may indicate the CAPC for the uplink grant only if Cat 2 LBT is indicated for the uplink grant (e.g., only if the base station 110 determines and / or indicates that Cat 2 LBT will be used for the uplink grant). Based at least in part on the indicated CAPC and the CAPC of the data included in the uplink grant, the UE 120 may determine whether to perform an uplink transmission. If Cat 4 LBT is indicated for the uplink grant, the base station 110 may not be required to indicate the CAPC for the uplink grant (e.g., may avoid indicating the CAPC). In this case, as described above, the UE 120 may autonomously determine the CAPC for the uplink grant. In this case, the bits required to indicate the CAPC may be reserved (e.g., if the Cat 4 LBT indication is not jointly encoded within the CAPC indication, the CAPC bits may be reserved), or an invalid CAPC value may be indicated (e.g., if the Cat 4 LBT indication is jointly encoded within the CAPC indication, the CAPC bits may indicate an unused value).

[0122] In some aspects, if the determined CAPC is different from the signaled CAPC indicated in the DCI, the UE 120 may use the determined CAPC instead of the signaled CAPC. In this case, the determined CAPC may override the signaled CAPC. In some aspects, the UE 120 may use a higher priority CAPC of the determined CAPC and the signaled CAPC. In this case, if the determined CAPC is associated with a higher priority than the signaled CAPC, the UE 120 may use the determined CAPC. Conversely, if the signaled CAPC is associated with a higher priority than the determined CAPC, the UE 120 may use the signaled CAPC. Using a higher priority CAPC may reduce communication delays.

[0123] Alternatively, UE 120 may use a lower priority CAPC of the determined CAPC and the signaled CAPC. In this case, if the determined CAPC is associated with a lower priority than the signaled CAPC, UE 120 may use the determined CAPC. Conversely, if the signaled CAPC is associated with a lower priority than the determined CAPC, UE 120 may use the signaled CAPC. Using a lower priority CAPC may increase fairness in the unlicensed radio frequency spectrum band by allowing other devices to access the channel.

[0124] As shown in reference numeral 715, UE 120 may transmit uplink communications with the indicated uplink resources using the determined CAPC. For example, UE 120 may perform an LBT process based at least in part on the determined CAPC (e.g., using one or more parameters defined by the CAPC when performing the LBT process). As described elsewhere herein, UE 120 may perform an LBT process by sensing the channel within a channel sensing duration indicated by the CAPC. If the energy detected by UE 120 on the channel meets a threshold (e.g., if the LBT process fails), UE 120 may avoid transmitting uplink communications on the channel. If the energy detected by UE 120 on the channel does not meet a threshold (e.g., if the LBT process is successful), UE 120 may transmit uplink communications.

[0125] In some cases, base station 110 may indicate a CAPC for a DCI based at least in part on a buffer status report transmitted by UE 120 to base station 110. The buffer status report may indicate a type of data and / or data priority stored in a buffer of UE 120, which base station 110 may use to select a CAPC. However, in some cases, the data stored in the buffer of UE 120 may change, and base station 110 may select a CAPC that reflects a previous state of the buffer. In such cases, by allowing UE 120 to determine the CAPC independently of the DCI and / or base station 110 indication, the CAPC may more accurately reflect the data stored in the buffer of UE 120.

[0126] As mentioned above, providing Figure 7 As an example. Other examples may differ from the Figure 7 as described.

[0127] Figure 8 8 is a diagram illustrating an example 800 of a channel access process for an unlicensed radio frequency spectrum band in accordance with various aspects of the present disclosure. Figure 8 As shown, base station 110 and UE 120 may communicate with each other.

[0128] As shown in reference numeral 805, the base station 110 may determine a CAPC for one or more downlink communications. In some aspects, the one or more downlink communications may be non-unicast messages (e.g., broadcast messages, multicast messages, group messages, etc.). Additionally or alternatively, the one or more downlink communications may be downlink communications that are not transmitted in a synchronization signal block (SSB). In some aspects, the one or more downlink communications may include a paging message, a random access response message, a downlink random access message, etc.

[0129] As further shown, the base station 110 may determine the CAPC based at least in part on the duration of one or more downlink communications. In some aspects, the one or more downlink communications may include a physical downlink control channel (PDCCH) communication and / or a physical downlink shared channel (PDSCH) communication that may be scheduled by the PDCCH communication. In this case, the duration may include a time period from the start of the PDCCH communication to the end of the corresponding PDSCH communication scheduled by the PDCCH communication.

[0130] In some aspects, one or more downlink communications may include multiple communications (eg, multiple PDSCH communications or messages), such as in a traffic burst. In this case, the duration may include a time period from the start of the multiple communications to the end of the multiple communications.

[0131] In some aspects, base station 110 may select a CAPC that defines a maximum COT greater than or equal to the duration. For example, if the duration is 2 milliseconds or less, base station 110 may select a CAPC with a maximum COT of 2 milliseconds. In some aspects, base station 110 may select a CAPC with a maximum COT that is closest to the duration and greater than or equal to the duration. In some aspects, base station 110 may select a higher priority CAPC for a shorter duration and may select a lower priority CAPC for a longer duration.

[0132] In some aspects, base station 110 may always select the highest priority CAPC (e.g., from a set of supported CAPCs) for one or more downlink communications. In some aspects, base station 110 may always select the lowest priority CAPC (e.g., from a set of supported CAPCs) for one or more downlink communications. In some aspects, when one or more downlink communications (e.g., one or more downlink non-unicast messages) are multiplexed with other communications (e.g., other data), base station 110 may select the lowest priority (or highest priority) CAPC (e.g., a CAPC associated with a highest priority logical channel or a lowest priority logical channel) from the set of CAPCs associated with the data to be multiplexed.

[0133] As shown at reference numeral 810, the base station 110 may transmit one or more downlink communications using the determined CAPC. In this manner, the base station 110 may select a CAPC that is consistent with the priority of the one or more downlink communications and / or the duration of the one or more downlink communications to avoid acquiring a channel for longer than the time required for transmission of the one or more downlink communications. In this way, the channel may be used for other transmissions, thereby improving spectral efficiency.

[0134] As mentioned above, providing Figure 8As an example. Other examples may differ from the Figure 8 as described.

[0135] Fig. 9 9 is a diagram illustrating an example process 900 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 900 is an example of operations in which a UE (eg, UE 120, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0136] like Fig. 9 As shown, in some aspects, process 900 may include receiving downlink control information indicating physical uplink control channel (PUCCH) resources for transmitting PUCCH communications in an unlicensed radio frequency spectrum band (block 910). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive downlink control information indicating PUCCH resources for transmitting PUCCH communications in an unlicensed radio frequency spectrum band.

[0137] like Fig. 9 As further shown in FIG. 9 , in some aspects, process 900 may include receiving an indication of a listen-before-talk (LBT) category to be used in association with transmitting PUCCH communications (block 920). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, and / or the like) may receive an indication of a LBT category to be used in association with transmitting PUCCH communications.

[0138] like Fig. 9 As further shown in FIG. 9 , in some aspects, process 900 may include performing an LBT procedure on the PUCCH communication according to the indicated LBT category (block 930). For example, as described above, the UE (e.g., using the receive processor 258, the transmit processor 264, the controller / processor 280, the memory 282, etc.) may perform an LBT procedure on the PUCCH communication according to the indicated LBT category.

[0139] Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0140] In a first aspect, the LBT category is indicated by a Channel Occupancy Time Structure Indication (COT-SI).

[0141] In a second aspect, alone or in combination with the first aspect, the LBT category is indicated by whether the PUCCH resource is included in the channel occupancy time indicated in the COT-SI.

[0142] In a third aspect, alone or in combination with one or more of the first and second aspects, if PUCCH resources are included in the channel occupancy time indicated in the COT-SI, the LBT category is category 2.

[0143] In a fourth aspect, alone or in combination with one or more of the first to third aspects, if PUCCH resources are not included in the channel occupancy time indicated in the COT-SI, the LBT category is category 4.

[0144] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the LBT category is indicated in the downlink control information.

[0145] In a sixth aspect, either alone or in combination with one or more of the first to fifth aspects, based at least in part on PUCCH communications scheduled by downlink control information, an LBT category is implicitly indicated as a default LBT category.

[0146] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the UE is configured to use Cat 2 LBT for any PUCCH communication scheduled in an unlicensed radio frequency spectrum band using DCI.

[0147] although Fig. 9 Example blocks of process 900 are shown, but in some aspects, process 900 may include Fig. 9 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in process 900. Additionally or alternatively, two or more of the blocks of process 900 may be executed in parallel.

[0148] Fig.10 1 is a diagram illustrating an example process 1000 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 1000 is an example of operations in which a UE (eg, UE 120, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0149] like Fig.10 As shown, in some aspects, process 1000 may include receiving an uplink grant indicating a set of resources for uplink communication (block 1010). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive an uplink grant indicating a set of resources for uplink communication.

[0150] like Fig.10As further shown, in some aspects, process 1000 may include allocating a first portion of data stored in a buffer of the UE and associated with one or more higher priority logical channels according to a logical channel prioritization (LCP) rule to one or more resources in the resource set, wherein the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels (block 1020). For example, as described above, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may allocate a first portion of data stored in a buffer of the UE and associated with one or more higher priority logical channels according to the LCP rule to one or more resources of the resource set. In some aspects, the one or more higher priority logical channels are associated with one or more higher priority channel access priority levels.

[0151] like Fig.10 As further shown in FIG. 1 , in some aspects, process 1000 may include refraining from allocating a second portion of data stored in a buffer of the UE and associated with one or more lower priority logical channels according to an LCP rule to the resource set, wherein the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels (block 1030). For example, as described above, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may refrain from allocating a second portion of data stored in a buffer of the UE and associated with one or more lower priority logical channels according to the LCP rule to the resource set. In some aspects, the one or more lower priority logical channels are associated with one or more lower priority channel access priority levels.

[0152] like Fig.10 As further shown in FIG. 1 , in some aspects, process 1000 may include transmitting a first portion of data in a resource set using a channel access priority level associated with one or more higher priority logical channels (block 1040). For example, as described above, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may transmit a first portion of data in a resource set using a channel access priority level associated with one or more higher priority logical channels.

[0153] Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0154] In a first aspect, process 1000 includes interrupting an LCP process after allocating a first portion of data to the set of resources.

[0155] In a second aspect, alone or in combination with the first aspect, the one or more lower priority logical channels are associated with a lower priority channel access priority than a channel access priority for transmission in the resource set.

[0156] In a third aspect, alone or in combination with one or more of the first and second aspects, process 1000 includes transmitting a first portion of data and a set of padding bits to fill the set of resources.

[0157] In a fourth aspect, alone or in combination with one or more of the first to third aspects, process 1000 includes transmitting a first portion of data in a resource set and a buffer status report to indicate that the UE has data stored in a buffer.

[0158] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, process 1000 includes transmitting a first portion of data in a resource set and an indication to indicate that the UE has interrupted the LCP procedure.

[0159] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, process 1000 includes determining to allocate a first portion of the data to the resource set and avoiding allocating a second portion of the data to the resource set based at least in part on at least one of the following: determining that the first portion of the data or a set of padding bits used to fill the resource set satisfies a condition regarding filling the resource set with data, determining that all data from one or more higher priority logical channels has been allocated to the resource set, determining that a size of the second portion of the data satisfies a condition based at least in part on one or more lower priority logical channels, determining that a contention window size associated with one or more lower priority logical channels differs from a contention window size of one or more higher priority logical channels by a threshold amount, a listen-before-talk category indicated by an uplink grant, an indication of activating an LCP restriction process, determining that an interference level measured by a UE satisfies a threshold, or a combination thereof.

[0160] although Fig.10 An example block diagram of process 1000 is shown, but in some aspects, process 1000 may include Fig.10 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in process 1000. Additionally or alternatively, two or more of the blocks of process 1000 may be executed in parallel.

[0161] Fig.11 1 is a diagram illustrating an example process 1100, for example, performed by a UE, in accordance with various aspects of the present disclosure. Example process 1100 is an example of operations in which a UE (eg, UE 120, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0162] like Fig.11 As shown, in some aspects, process 1100 may include receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point in a plurality of transmission starting points associated with one or more uplink communications (block 1110). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point in a plurality of transmission starting points associated with one or more uplink communications.

[0163] like Fig.11 As further shown in FIG. 1 , in some aspects, process 1100 may include performing an LBT procedure on an uplink communication transmitted at a transmission start point among the one or more uplink communications according to an LBT category or a channel access priority level (block 1120). For example, as described above, the UE (e.g., using the receive processor 258, the transmit processor 264, the controller / processor 280, the memory 282, and / or the like) may perform an LBT procedure on an uplink communication transmitted at a transmission start point among the one or more uplink communications according to an LBT category or a channel access priority level.

[0164] Process 1100 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0165] In a first aspect, the indication is received in a multi-transmission time interval (multi-TTI) uplink grant scheduling multiple transmission starting points for one or more uplink communications.

[0166] In a second aspect, alone or in combination with the first aspect, the LBT category is a single LBT category for all transmission start points.

[0167] In a third aspect, alone or in combination with one or more of the first and second aspects, the LBT category is a first LBT category associated with a first channel sensing time, which is used for an initial LBT process at an initial transmission start point, and the UE is configured to use a second LBT category associated with a second channel sensing time for a subsequent LBT process performed on a subsequent transmission start point, and the second channel sensing time is longer than the first channel sensing time.

[0168] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the first LBT category is no LBT, and the second LBT category is Cat 2 LBT of 16 microseconds or Cat 2 LBT of 25 microseconds.

[0169] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the first LBT category is a Cat 2 LBT of 16 microseconds, and the second LBT category is a Cat 2 LBT of 25 microseconds.

[0170] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the indication comprises a separate indication of the LBT category for each transmission start point.

[0171] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the indication indicates a first LBT category to be used for a first set of transmission starting points and a second LBT category to be used for a second set of transmission starting points.

[0172] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the indication comprises a plurality of bits, and the plurality of bits are indicated in a radio resource control message.

[0173] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, a mapping between a set of bit values ​​and a corresponding set of LBT categories or channel access priority levels is indicated in a radio resource control message.

[0174] In a tenth aspect, either alone or in combination with one or more of aspects one to nine, at least one of the mappings between a set of multiple bits or multiple bit values ​​in an indication and a set of corresponding LBT categories or channel access priority levels is based at least in part on a channel in which the uplink communication is to be transmitted.

[0175] In an eleventh aspect, either alone or in combination with one or more of the first to tenth aspects, at least one of the mappings between a set of multiple bits or multiple bit values ​​included in an indication and a set of corresponding LBT categories or channel access priority levels is based at least in part on the type of cell in which the uplink communication is to be transmitted.

[0176] although Fig.11 An example block diagram of process 1100 is shown, but in some aspects, process 1100 may include Fig.11 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in the process 1100. Additionally or alternatively, two or more of the blocks of process 1100 may be executed in parallel.

[0177] Fig.12 1 is a diagram illustrating an example process 1200, for example, performed by a UE, in accordance with various aspects of the present disclosure. Example process 1200 is an example of operations in which a UE (eg, UE 120, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0178] like Fig.12 As shown, in some aspects, process 1200 may include receiving an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band (block 1210). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive an uplink grant indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band.

[0179] like Fig.12 As further shown, in some aspects, process 1200 may include receiving an indication that an uplink grant is revoked (block 1220). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive an indication that an uplink grant is revoked.

[0180] like Fig.12 As further shown, in some aspects, process 1200 may include refraining from transmitting uplink communications based at least in part on receiving an indication that an uplink grant is revoked (block 1230). For example, as described above, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may refrain from transmitting uplink communications based at least in part on receiving an indication that an uplink grant is revoked.

[0181] Process 1200 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0182] In a first aspect, the indication is a pre-empt indication transmitted in downlink control information that identifies a set of uplink resources that are not allowed to be used by the UE for uplink communications.

[0183] In a second aspect, either alone or in combination with the first aspect, process 1200 includes determining to avoid transmitting uplink communications based at least in part on a determination that a set of uplink resources identified in a preemption indication partially or completely overlaps uplink resources indicated in an uplink grant.

[0184] In a third aspect, alone or in combination with one or more of the first and second aspects, the indication is comprised in a channel occupancy time structure indication (COT-SI) indicating a set of occupied subbands.

[0185] In a fourth aspect, either alone or in combination with one or more of the first to third aspects, process 1200 includes determining to avoid transmitting uplink communications based at least in part on a determination that one or more subbands of uplink resources indicated in an uplink grant are not included in a set of occupied subbands indicated in a COT-SI.

[0186] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, process 1200 includes: receiving a COT-SI that includes an indication that uplink communications associated with a previous COT-SI are allowed to be transmitted within a channel occupancy time associated with the COT-SI; and transmitting uplink communications within the channel occupancy time based at least in part on receiving the indication that uplink communications are allowed to be transmitted within the channel occupancy time associated with the COT-SI.

[0187] although Fig.12 An example block diagram of process 1200 is shown, but in some aspects, process 1200 may include Fig.12 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in the process 1200. Additionally or alternatively, two or more of the blocks of process 1200 may be executed in parallel.

[0188] Fig.13 1 is a diagram illustrating an example process 1300, for example, performed by a UE, in accordance with various aspects of the present disclosure. Example process 1300 is an example of operations in which a UE (eg, UE 120, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0189] like Fig.13 As shown, in some aspects, process 1300 may include receiving downlink control information (DCI) indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band (block 1310). For example, as described above, the UE (e.g., using receive processor 258, controller / processor 280, memory 282, etc.) may receive DCI indicating uplink resources for transmitting uplink communications in an unlicensed radio frequency spectrum band.

[0190] like Fig.13 As further shown, in some aspects, process 1300 may include determining a channel access priority level (CAPC) for uplink communications independent of the DCI (block 1320). For example, as described above, the UE (e.g., using controller / processor 280, memory 282, etc.) may determine a channel access priority level (CAPC) for uplink communications independent of the DCI.

[0191] like Fig.13As further shown in FIG. 1 , in some aspects, process 1300 may include transmitting uplink communications with the indicated uplink resources using the determined CAPC (block 1330). For example, as described above, the UE (e.g., using transmit processor 264, controller / processor 280, memory 282, etc.) may transmit uplink communications with the indicated uplink resources using the determined CAPC.

[0192] Process 1300 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.

[0193] In a first aspect, a CAPC is determined based at least in part on a CAPC associated with uplink data to be transmitted in an uplink communication.

[0194] In a second aspect, alone or in combination with the first aspect, the DCI indicates a first CAPC, and the determined CAPC is a second CAPC that overrides the first CAPC.

[0195] In a third aspect, either alone or in combination with one or more of the first and second aspects, a second CAPC is associated with a higher priority than the first CAPC, and the UE uses the second CAPC based at least in part on a determination that a CAPC associated with uplink data to be transmitted in an uplink communication is associated with a higher priority than the first CAPC.

[0196] In a fourth aspect, alone or in combination with one or more of the first to third aspects, a second CAPC is associated with a lower priority than the first CAPC, and the UE uses the second CAPC based at least in part on a determination that a CAPC associated with uplink data to be transmitted in an uplink communication is associated with a lower priority than the first CAPC.

[0197] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, a CAPC for uplink communication is determined independently of the DCI based at least in part on an indication from a base station that the UE is to determine the CAPC independently of the DCI.

[0198] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the DCI does not indicate a valid CAPC to be used for uplink communications.

[0199] although Fig.13 An example block diagram of process 1300 is shown, but in some aspects, process 1300 may include Fig.13Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in the process 1300. Additionally or alternatively, two or more of the blocks of process 1300 may be executed in parallel.

[0200] Fig.14 is a diagram illustrating an example process 1400, performed, for example, by a BS, in accordance with various aspects of the present disclosure. Example process 1400 is an example of operations in which a base station (eg, base station 110, etc.) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0201] like Fig.14 As shown, in some aspects, process 1400 may include determining a channel access priority level (CAPC) to be used for one or more downlink non-unicast messages that are not transmitted in a synchronization information block based at least in part on a duration of the one or more downlink non-unicast messages (block 1410). For example, as described above, a base station (e.g., using controller / processor 240, memory 242, etc.) may determine a channel access priority level (CAPC) to be used for one or more downlink non-unicast messages that are not transmitted in a synchronization information block based at least in part on a duration of the one or more downlink non-unicast messages.

[0202] like Fig.14 As further shown, in some aspects, process 1400 may include transmitting one or more downlink non-unicast messages using the determined CAPC (block 1420). For example, as described above, the base station (e.g., using transmit processor 220, controller / processor 240, memory 242, etc.) may transmit one or more downlink non-unicast messages using the determined CAPC.

[0203] Process 1400 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0204] In a first aspect, the duration comprises a time period from the start of a physical downlink control channel (PDCCH) communication to the end of a corresponding physical downlink shared channel (PDSCH) communication scheduled by the PDCCH communication.

[0205] In a second aspect, alone or in combination with the first aspect, the one or more downlink non-unicast messages include a plurality of messages, and the duration includes a time period from a start of the plurality of messages to an end of the plurality of messages.

[0206] In a third aspect, alone or in combination with one or more of the first and second aspects, a higher priority CAPC is determined for one or more downlink non-unicast messages of shorter duration, and a lower priority CAPC is determined for one or more downlink non-unicast messages of longer duration.

[0207] although Fig.14 An example block diagram of process 1400 is shown, but in some aspects, process 1400 may include Fig.14 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in the process 1400. Additionally or alternatively, two or more of the blocks of process 1400 may be executed in parallel.

[0208] Fig.15 1 is a diagram illustrating an example process 1500, performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 1500 is an example of operations in which a UE (eg, UE 120) performs a channel access procedure for an unlicensed radio frequency spectrum band.

[0209] like Fig.15 As shown, in some aspects, process 1500 may include receiving a configuration indicating a number of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications (block 1510). For example, as described above, the UE (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, controller / processor 280, and / or memory 282) may receive a configuration indicating a number of bits to be used in an indication of at least one of an LBT category or a channel access priority level to be used for uplink communications.

[0210] like Fig.15 As further shown in FIG. 1 , in some aspects, process 1500 may include receiving an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes a plurality of bits indicated in a configuration (block 1520). For example, as described above, the UE (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, controller / processor 280, and / or memory 282) may receive an indication of at least one of an LBT category or a channel access priority level to be used for a transmission starting point associated with one or more uplink communications, wherein the indication includes a plurality of bits indicated in a configuration.

[0211] like Fig.15As further shown in FIG. 1 , in some aspects, process 1500 may include performing an LBT procedure on an uplink communication transmitted at a transmission start point among the one or more uplink communications according to an LBT category or a channel access priority level (block 1530). For example, as described above, the UE (e.g., using antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller / processor 280, and / or memory 282) may perform an LBT procedure on an uplink communication transmitted at a transmission start point among the one or more uplink communications according to an LBT category or a channel access priority level.

[0212] Process 1500 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0213] In a first aspect, the configuration indicates a mapping between a set of bit values ​​and a corresponding set of LBT categories or channel access priority levels.

[0214] In a second aspect, alone or in combination with the first aspect, the configuration is included in a radio resource control message.

[0215] In a third aspect, alone or in combination with one or more of the first and second aspects, the transmission starting point is one of a plurality of transmission starting points associated with the one or more uplink communications.

[0216] In a fourth aspect, alone or in combination with one or more of the first to third aspects, an indication is received in a multi-transmission time interval (multi-TTI) uplink grant scheduling multiple transmission starting points for one or more uplink communications.

[0217] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the LBT category is a single LBT category for all transmission start points indicated in a multi-TTI uplink grant.

[0218] although Fig.15 An example block diagram of process 1500 is shown, but in some aspects, process 1500 may include Fig.15 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in process 1500. Additionally or alternatively, two or more of the blocks of process 1500 may be executed in parallel.

[0219] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the various aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of these aspects.

[0220] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0221] As used herein, satisfying a threshold may refer to a value greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0222] Obviously, the systems and / or methods described herein can be implemented in various forms of hardware, firmware, and / or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited in these respects. Therefore, the operation and behavior of the systems and / or methods described herein are not referenced to specific software code - it should be understood that software and hardware can be designed to implement systems and / or methods based at least in part on the description herein.

[0223] Even if a particular combination of features is cited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically described in the claims and / or is not disclosed in the specification. Although each dependent claim listed below can directly rely on only one claim, the disclosure of various aspects includes each dependent claim and each other claim in the claim set. The phrase "at least one" mentioned in the list of items refers to any combination of those items, including single members. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and any combination with multiples of the same element (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, Cc and cCc, or any other sorting of a, b and c).

[0224] Unless explicitly described, the elements, actions or instructions used herein should not be interpreted as critical or essential. In addition, as used herein, the article "a" is intended to include one or more items and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and can be used interchangeably with "one or more". When only one item is intended to be used, the phrase "only one" or similar language is used. In addition, as used herein, the terms "have", "have", "have" and / or similar terms are intended to be open terms. In addition, the phrase "based on" is intended to mean "based at least in part on", unless otherwise explicitly stated.

Claims

1. A wireless communication method performed by a user equipment (UE), comprising: receiving, via a first message, a configuration indicating a number of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for uplink communications; receiving, via a second message different from the first message, an indication of at least one of an LBT category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits indicated in the configuration; as well as An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

2. The method of claim 1, wherein the configuration indicates a mapping between a set of bit values ​​and a set of corresponding LBT categories or channel access priority levels. The method of claim 1 , wherein the first message comprises a radio resource control message.

4. The method of claim 1, wherein the indication is received in a multi-transmission time interval (multi-TTI) uplink grant that schedules the multiple transmission starting points for the one or more uplink communications.

5. The method of claim 4, wherein the LBT category is a single LBT category for all transmission start points indicated in the multi-TTI uplink grant.

6. A wireless communication method performed by a user equipment (UE), comprising: receiving, via a first message, an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits, and wherein the plurality of bits are indicated in a second message different from the first message; as well as An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

7. The method of claim 6, wherein the indication is received in a multi-transmission time interval (multi-TTI) uplink grant that schedules the multiple transmission starting points for the one or more uplink communications.

8. The method of claim 6, wherein the LBT category is a single LBT category for all transmission starting points.

9. The method of claim 6, wherein the second message comprises a radio resource control message.

10. The method of claim 9, wherein a mapping between a set of bit values ​​and a corresponding set of LBT categories or channel access priority levels is indicated in the radio resource control message.

11. The method of claim 6, wherein the LBT category is a first LBT category associated with a first channel sensing time, the first channel sensing time being used for an initial LBT process at an initial transmission start point, and wherein the UE is configured to use a second LBT category associated with a second channel sensing time for a subsequent LBT process performed on a subsequent transmission start point, wherein the second channel sensing time is longer than the first channel sensing time.

12. The method of claim 11, wherein the first LBT category is no LBT and the second LBT category is a Category 2 LBT of 16 microseconds or a Category 2 LBT of 25 microseconds.

13. The method of claim 11, wherein the first LBT category is a Category 2 LBT of 16 microseconds and the second LBT category is a Category 2 LBT of 25 microseconds.

14. The method of claim 6, wherein the indication comprises a separate indication of the LBT category for each transmission starting point.

15. The method of claim 6, wherein the indication indicates a first LBT category to be used for a first set of transmission starting points and a second LBT category to be used for a second set of transmission starting points.

16. A method according to claim 6, wherein at least one of the mappings between multiple bits in the indication, or a set of values ​​of the multiple bits and a set of corresponding LBT categories or channel access priority levels is based at least in part on the channel in which the uplink communication is to be transmitted.

17. A method according to claim 6, wherein at least one of the mappings between multiple bits in the indication, or a set of values ​​of the multiple bits and a set of corresponding LBT categories or channel access priority levels is based at least in part on the type of cell in which the uplink communication is to be transmitted.

18. A user equipment (UE) for performing wireless communication, comprising: Memory; as well as One or more processors, coupled to the memory, configured to: receiving, via a first message, a configuration indicating a number of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for uplink communications; receiving, via a second message different from the first message, an indication of at least one of an LBT category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits indicated in the configuration; as well as An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

19. The UE of claim 18, wherein the configuration indicates a mapping between a set of bit values ​​and a set of corresponding LBT categories or channel access priority levels.

20. The UE of claim 18, wherein the first message comprises a radio resource control message.

21. The UE of claim 18, wherein the indication is received in a multi-transmission time interval (multi-TTI) uplink grant that schedules the multiple transmission starting points for the one or more uplink communications.

22. The UE of claim 21, wherein the LBT category is a single LBT category for all transmission start points indicated in the multi-TTI uplink grant.

23. A user equipment (UE) for performing wireless communication, comprising: Memory; as well as One or more processors, coupled to the memory, configured to: receiving, via a first message, an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits, and wherein the plurality of bits are indicated in a second message different from the first message; as well as An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

24. The UE of claim 23, wherein the indication is received in a multi-transmission time interval (multi-TTI) uplink grant that schedules the multiple transmission starting points for the one or more uplink communications.

25. The UE of claim 23, wherein the LBT category is a single LBT category for all transmission starting points.

26. The UE of claim 23, wherein the second message comprises a radio resource control message.

27. The UE of claim 26, wherein a mapping between a set of bit values ​​and a corresponding set of LBT categories or channel access priority levels is indicated in the radio resource control message.

28. The UE of claim 23, wherein the LBT category is a first LBT category associated with a first channel sensing time, the first channel sensing time being used for an initial LBT process at an initial transmission starting point, and wherein the UE is configured to use a second LBT category associated with a second channel sensing time for a subsequent LBT process performed on a subsequent transmission starting point, wherein the second channel sensing time is longer than the first channel sensing time.

29. An apparatus for wireless communication, comprising: means for receiving, via a first message, a configuration indicating a number of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for uplink communications; means for receiving, via a second message different from the first message, an indication of at least one of an LBT category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits indicated in the configuration; as well as A means for performing an LBT process on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

30. An apparatus for wireless communication, comprising: means for receiving, via a first message, an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits, and wherein the plurality of bits are indicated in a second message different from the first message; as well as A component for performing an LBT process on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

31. A non-transitory computer-readable storage medium having stored thereon instructions for wireless communication at a user equipment (UE), the instructions being executable by a processor to: receiving, via a first message, a configuration indicating a number of bits to be used in an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for uplink communications; receiving, via a second message different from the first message, an indication of at least one of an LBT category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits indicated in the configuration; as well as An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

32. A non-transitory computer-readable storage medium having stored thereon instructions for wireless communication at a user equipment (UE), the instructions being executable by a processor to: receiving, via a first message, an indication of at least one of a listen-before-talk (LBT) category or a channel access priority level to be used for a plurality of transmission starting points associated with one or more uplink communications, wherein the indication comprises a plurality of bits, and wherein the plurality of bits are indicated in a second message different from the first message; and An LBT process is performed on an uplink communication transmitted at a transmission starting point among the multiple transmission starting points among the one or more uplink communications according to the LBT category or the channel access priority level.

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