Wireless communication channel access mechanism

Abstract

Apparatus, system, and method for selecting a channel access mechanism in wireless communications, particularly 3GPP NR-U. For example, an appropriate Listen-Before-Talk (LBT) channel access category (Cat) may be defined for a particular message, such as a particular DL and / or UL control message, and a particular RACH message. For other messages, the appropriate Cat may be signaled by the base station, for example, in a DCI message or SIB. Mechanisms are provided for the base station to signal specific channel access profile parameters, such as the appropriate LBT Cat, CAPC, and / or CP extension, to the UE. Mechanisms are also provided for adjusting the contention window duration.

Description

Technical Field

[0001] This application relates to wireless devices, and more particularly, to an apparatus, system, and method for selecting between available channel access mechanisms in wireless communication.

Background Art

[0002] The use of wireless communication systems is increasing rapidly. In recent years, wireless devices such as smartphones and tablet computers have become increasingly high-performance. In addition to supporting telephone functions, many mobile devices now provide access to the Internet, email, text messaging, and navigation using the global positioning system (GPS), and can run sophisticated applications that utilize these functions. In addition, there are numerous different wireless communication technologies and standards. Some examples of wireless communication standards include GSM, UMTS (e.g., related to the WCDMA or TD-SCDMA air interface), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE802.11 (WLAN or Wi-Fi), BLUETOOTH (trademark), and the like.

[0003] The ever-increasing features and functions introduced into wireless communication devices also create a continuing need to improve both wireless communication and wireless communication devices. To increase coverage and better meet the increasing demands and scope of the intended use of wireless communication, in addition to the above communication standards, there are additional wireless communication technologies under development, including fifth-generation (5G) new radio (NR) communication.

[0004] Various methods of wireless communication technology have been developed for negotiating channel access when performing wireless communication. Cellular communication technologies such as LTE-A and 5G NR are increasingly able to operate in frequency ranges traditionally used by non-cellular wireless communication technologies such as Wi-Fi. As a result, when operating in these frequency ranges, cellular communication technologies should be adapted to efficiently negotiate channel access in a way that mediates the existing channel negotiation procedures of non-cellular technologies.

[0005] Accordingly, improvements in this field are desired to support such development and design. SUMMARY OF THE INVENTION

[0006] Embodiments relate to an apparatus, system, and method for selecting a channel access mechanism in wireless communication. For example, an appropriate listen-before-talk (LBT) channel access category (Cat) can be defined for specific messages such as specific DL and / or UL control messages and specific RACH messages. For other messages, the appropriate Cat can be signaled by a base station, for example, within a DCI message or SIB. A mechanism is provided for a base station to signal specific channel access profile parameters such as an appropriate LBT Cat, CAPC, and / or CP extension to a UE. A mechanism for adjusting the contention window period is also provided.

[0007] A wireless communication device is disclosed that includes a memory for storing software instructions and a processor circuit. The processor circuit may be configured to execute the software instructions to cause the wireless communication device to receive from a base station a downlink control information (DCI) message that includes an indication of a listen-before-talk (LBT) category and an indication of cyclic prefix information. The software instructions may further cause the wireless communication device to perform an LBT procedure based on the LBT category and, in response to a successful completion of the LBT procedure, transmit a message having a cyclic prefix based on the cyclic prefix information.

[0008] In some scenarios, the indication of the LBT category may be included in a first information element (IE) of the DCI message, and the indication of the cyclic prefix information may be included in a second different IE. In other scenarios, both the indication of the LBT category and the indication of the cyclic prefix information may be included in a single IE of the DCI message.

[0009] In some scenarios, the DCI message may also include an indication of a channel access priority class (CAPC), and the LBT procedure may be further based on the CAPC.

[0010] In some scenarios, the DCI message may also include instructions for the wireless communication device to autonomously select a CAPC, and the processor circuit may be further configured to execute the software instructions to cause the wireless communication device to select a CAPC in response to receiving the DCI message, and the LBT procedure may be further based on the selected CAPC.

[0011] A wireless communication device is disclosed that includes a memory for storing software instructions and a processor circuit. The processor circuit may be configured to execute the software instructions to cause the wireless communication device to receive, from a base station, a first message that permits an uplink transmission at a specific time, the first message including an indication of a listen-before-talk (LBT) category to be used for the uplink transmission. The processor circuit may be configured to execute the software instructions to cause the wireless communication device to determine whether the specific time is within a channel occupancy time (COT) started by the base station. In response to determining that the specific time is not within the COT started by the base station, the wireless communication device may execute an LBT procedure defined by the LBT category indicated in the first message. In response to determining that the specific time is within the COT started by the base station, the wireless communication device may execute an LBT procedure defined by a second LBT category other than the LBT category indicated in the first message. In response to a successful completion of the LBT procedure, the wireless communication device may transmit an uplink transmission at the specific time.

[0012] In some scenarios, the processor circuit may be further configured to execute the software instructions to cause the wireless communication device to receive a second message indicating timing information of a COT started by the base station, and determining whether the specific time is within the COT started by the base station is based on the timing information.

[0013] In some scenarios, the LBT procedure defined by the LBT category indicated in the first message may include a random backoff, and the LBT procedure defined by the second LBT category may not include a random backoff.

[0014] In some scenarios, the LBT procedure defined by the second LBT category may enable transmission without performing a clear channel assessment.

[0015] In some scenarios, the first message can include a downlink channel information (DCI) message, an indication of the LBT category can be included in a first information element (IE) of the first message, and a second IE of the first message can include an indication of cyclic prefix information for uplink transmission. In some such scenarios, a third IE of the first message can include an indication of a channel access priority class (CAPC), and performing the LBT procedure defined by the LBT category indicated in the first message can include performing the LBT procedure defined by the CAPC. In other such scenarios, a third IE of the first message can include an instruction for the wireless communication device to autonomously select a CAPC, and the processor circuit can be further configured to execute software instructions to cause the wireless communication device to select a CAPC in response to reception of the first message, and performing the LBT procedure defined by the LBT category indicated in the first message can include performing the LBT procedure defined by the selected CAPC.

[0016] In some scenarios, the first message can include a downlink channel information (DCI) message, and a first information element (IE) of the first message can include an indication of the LBT category and an indication of cyclic prefix information for uplink transmission.

[0017] The techniques described herein may be implemented in and / or used with any of several different types of devices, including but not limited to cellular telephones, tablet computers, wearable computing devices, portable media players, and various other computing devices.

[0018] The summary of this invention is intended to provide some brief overviews of the subject matter described in this document. Therefore, it should be understood that the above features are merely examples and should not be construed as in any way narrowing the scope or spirit of the subject matter described in this specification. Other features, aspects, and advantages of the subject matter described in this specification will become apparent from the following detailed description, drawings, and claims.

[0019] A better understanding of the subject matter can be obtained by considering the following detailed description of various embodiments in conjunction with the following drawings.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

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Figure 7

[0021] The features described in this specification may be subject to various modifications and alternative forms, but the specific embodiments are shown in the drawings by way of example and are described in detail herein. However, the drawings and the detailed description thereof are not intended to limit to the specific forms disclosed, but rather, the intention is to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the subject matter as defined by the appended "claims".

Embodiments for Carrying Out the Invention

[0022] Term

[0023] The following is a glossary of terms used in this disclosure.

[0024] Memory medium - Any of various types of non - transient memory devices or storage devices. The term "memory medium" is intended to include, for example, installation media such as CD - ROMs, floppy disks, or tape devices, computer system memories or random access memories such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, non - volatile memories such as flash, for example, magnetic media such as hard drives, or optical storage, registers, or other similar types of memory elements. The memory medium may include other types of non - transient memory, or combinations thereof. Additionally, the memory medium may be located in a first computer system in which the program is executed, or in a second different computer system connected to the first computer system via a network such as the Internet. In the latter instance, the second computer system can provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that can exist at different locations, for example, in different computer systems connected via a network. The memory medium may store program instructions executable by one or more processors (e.g., embodied as a computer program).

[0025] Carrier medium - A memory medium as described above, as well as physical transmission media such as buses, networks, and / or other physical transmission media that transmit signals such as electrical signals, electromagnetic signals, or digital signals.

[0026] Programmable hardware elements - include various hardware devices comprising a plurality of programmable functional blocks connected via a programmable interconnect. Examples include Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), Field Programmable Object Arrays (FPOAs), and Complex Programmable Logic Devices (CPLDs). The programmable functional blocks can range from fine-grained ones (combinational logic or look-up tables) to coarse-grained ones (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "reconfigurable logic".

[0027] Computer systems - any of various types of computing or processing systems including personal computer systems (PCs), mainframe computer systems, workstations, network devices, Internet devices, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. In general, the term "computer system" can be defined broadly to include any device (or combination of devices) having at least one processor that executes instructions from a storage medium.

[0028] User Equipment (UE) (or, "UE device") - A mobile or portable computer system or device of various types that performs wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhone (trademark), Android (trademark)-based phones), portable game devices (e.g., Nintendo DS (trademark), PlayStation Portable (trademark), Gameboy Advance (trademark), iPhone (trademark)), laptops, wearable devices (e.g., smartwatches, smart glasses), PDAs, portable Internet devices, music players, data storage devices, or other handheld devices. In general, the terms "UE" or "UE device" can be defined broadly to include any electronic, computing, and / or telecommunications device (or combination of devices) that can be easily carried by a user and is capable of wireless communication.

[0029] Wireless device - Any of various types of computer systems or devices that perform wireless communication. A wireless device can be portable (or mobile), or it may be stationary or fixed in a location. A UE is an example of a wireless device.

[0030] Communication device - Any of various types of computer systems or devices that perform communication. Communication can be wired or wireless. A communication device can be portable (or mobile), or it may be stationary or fixed in a location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0031] Base station - The term "base station" has its full ordinary meaning and includes, at a minimum, a wireless communication station installed in a fixed location and used to communicate as part of a radiotelephone system or wireless system.

[0032] Processing element - Refers to various elements or combinations of elements that are capable of performing functions within a device such as a user equipment or a cellular network device. A processing element may include, for example, a processor and associated memory, a part or circuit of an individual processor core, an entire processor core, a processor array, a circuit such as an ASIC (Application Specific Integrated Circuit), a programmable hardware element such as a Field Programmable Gate Array (FPGA), and any various combinations of the above.

[0033] Channel - A medium used to transmit information from a transmitting side (transmitter) to a receiver. Since the characteristics of a "channel" may vary according to different wireless protocols, when used in this specification, it should be noted that the term "channel" is considered to be used in accordance with the standards of the type of device to which this term refers. In some standards, the channel width can be variable (e.g., depending on device capabilities, band conditions, etc.). For example, LTE may support a scalable channel bandwidth from 1.4 MHz to 20 MHz. In contrast, a WLAN channel may have a width of 22 MHz, and a Bluetooth channel may have a width of 1 MHz. Other protocols and standards may include different channel definitions. Furthermore, some standards can define and use multiple types of channels, for example, different channels for uplink or downlink, and / or different channels for different uses such as data, control information, etc.

[0034] Band - The term "band" has the full range of its normal meaning and includes at least the portion of the spectrum (e.g., radio frequency spectrum) where channels are used for the same purpose or excluded.

[0035] Automatically - A user input causes a computer system (e.g., software executed by a computer system) or a device (e.g., circuitry, programmable hardware elements, ASICs, etc.) to perform those actions or operations without directly specifying or executing the action or operation. Thus, the term "automatically" is contrasted with actions or operations that are manually performed or specified by a user, where the user provides an input to directly execute the operation. An automatic procedure may be initiated by an input provided by the user, but the subsequent actions that are "automatically" performed are not specified by the user, i.e., the user does not "manually" perform by specifying each action to be performed. For example, a user filling out an electronic form by selecting each field and providing an input to specify information (e.g., by typing information, selecting a checkbox, selecting a radio button, etc.) is a manual entry into the form, even if the computer system must update the form in response to the user action. The form may be filled out automatically by a computer system, and the computer system (e.g., software running on the computer system) analyzes the fields of the form and fills out the form without a user input specifying the responses to the fields. As described above, the user can initiate the automatic filling of the form but is not involved in the actual filling of the form (e.g., the user is not manually specifying responses to the fields, rather the responses are automatically completed). This specification provides various examples of actions that are automatically performed in response to actions taken by the user.

[0036] Refers to a value that is approximate - almost exact or precise. For example, approximate can refer to a value that is within 1 - 10 percent of a precise (or desired) value. However, note that the actual threshold (or tolerance) may depend on the application. For example, in some embodiments, "approximate" may mean within 0.1% of a specified or desired value, and in various other embodiments, the threshold may be, as desired, or as required by a particular application, for example, 2%, 3%, 5%, etc.

[0037] Simultaneous - Refers to parallel execution or implementation in which tasks, processes, or programs are executed such that they at least partially overlap. For example, simultaneous can be implemented using "strong" or strict parallelism in which tasks are executed in parallel (at least partially) on respective computing elements, or using "weak parallelism" in which tasks are executed in an interleaved fashion, for example, by time - slicing of execution threads.

[0038] Configured to - Various components can be described as "configured to" perform a task or group of tasks. In such a context, "configured to" is a broad description that generally means "having a structure" that performs the task(s) during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (for example, a set of electrical conductors can be configured to electrically connect one module to another module even when the two modules are not connected). In some contexts, "configured to" may be a broad description of a structure that generally means "having a circuit" that performs the task(s) during operation. Thus, a component can be configured to perform a task even when the component is not currently on. Generally, a circuit forming the structure corresponding to "configured to" may include a hardware circuit.

[0039] Various components may be described as performing tasks (singular or plural) for convenience in the description. Such descriptions should be construed as including the phrase "configured to". It is explicitly intended that the description of a component configured to perform one or more tasks does not carry out the interpretation of 35 U.S.C. § 112(f) for that component.

[0040] It should be fully understood that the use of personally identifiable information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled to minimize the risk of unintended or unauthorized access or use, and the nature of the permitted use should be clearly disclosed to the user. FIG. 1 and FIGS. 2 - Communication System

[0041] FIG. 1 shows a simplified exemplary wireless communication system according to some embodiments. Note that the system of FIG. 1 is merely an example of a possible system, and the features of the present disclosure may be implemented as desired in any of various systems.

[0042] As shown in the figure, an exemplary wireless communication system includes a base station 102A that communicates with one or more user devices 106A, 106B,..., 106N via a transmission medium. Each of the user devices may be referred to herein as a "User Equipment" (UE). Thus, the user device 106 is referred to as a UE or a UE device.

[0043] The base station (BS) 102A may be a base transceiver station (BTS) or a cell site (a "cellular base station") and may include hardware that enables wireless communication with the UEs 106A - 106N.

[0044] The communication area (or coverage area) of a base station may be referred to as a "cell". The base station 102A and the UE 106 can be configured to communicate via a transmission medium using any of various radio access technologies (RATs), such as GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), 5G New Radio (5G NR), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), which are also called radio communication technologies or telecommunication standards. Note that when the base station 102A is implemented in the context of LTE, it may alternatively be called an "eNodeB" or "eNB". When the base station 102A is implemented in the context of 5G NR, note that the base station 102A may alternatively be referred to as a "gNodeB" or "gNB".

[0045] As shown in the figure, the base station 102A can also have the function of communicating with a network 100 (e.g., among various possibilities, the core network of a cellular service provider, a telecommunication network such as a public switched telephone network (PSTN), and / or the Internet). Therefore, the base station 102A can facilitate communication between user devices and / or between a user device and the network 100. Specifically, the cellular base station 102A can provide various telecommunication capabilities, such as voice, SMS, and / or data services, to the UE 106.

[0046] Therefore, the base station 102A and other similar base stations (such as base stations 102B to 102N) operating according to the same or different cellular communication standards may be provided as a network of cells, which can provide continuous or nearly continuous overlapping services to the UEs 106A to 106N and similar devices across a geographical area via one or more cellular communication standards.

[0047] Therefore, as shown in FIG. 1, the base station 102A can function as a "serving cell" for the UEs 106A to 106N, and each UE 106 can receive signals (and in some cases be within the communication range) from one or more other cells (which may be provided by the base stations 102B to 102N and / or any other base station) that may be referred to as "adjacent cells". Such cells can also facilitate communication between user devices and / or communication between user devices and the network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells providing various other granularities of service area size. For example, the base stations 102A and 102B illustrated in FIG. 1 may be macro cells, while the base station 102N may be a micro cell. Other configurations are possible.

[0048] In some embodiments, the base station 102A may be a next-generation base station, such as a 5G New Radio (5G NR) base station, or a "gNB". In some embodiments, the gNB may be connected to an Evolved Packet Core (EPC) network and / or an NR Core (NRC) network. Additionally, a gNB cell can include one or more Transition and Reception Points (TRPs). Additionally, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs. For example, the base station 102A and one or more other base stations 102 may be able to support joint transmission so that the UE 106 can receive transmissions from multiple base stations (and / or multiple TRPs provided by the same base station).

[0049] Note that the UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE 106 may, if desired, in addition to at least one cellular communication protocol (e.g., GSM, UMTS (e.g., associated with the WCDMA or TD-SCDMA air interface), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.), be configured to communicate using a wireless network protocol (e.g., Wi-Fi) and / or a peer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.). The UE 106 may also, or alternatively, if desired, be configured to communicate using one or more global navigation satellite systems (GNSS, e.g., GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H), and / or any other wireless communication protocol. Other combinations of wireless communication standards (including three or more wireless communication standards) are also possible.

[0050] FIG. 2 shows a user equipment 106 (e.g., one of devices 106A - 106N) communicating with a base station 102, according to some embodiments. The UE 106 may be a device having cellular communication capabilities such as a mobile phone, a handheld device, a computer or tablet, or substantially any type of wireless device.

[0051] The UE106 may include a processor configured to execute program instructions stored in a memory. By executing such stored instructions, the UE 106 may perform any of the method embodiments described herein. Alternatively, or in addition, the UE106 may include programmable hardware elements such as an FPGA (field programmable gate array) configured to perform any of the method embodiments described herein, or any part of any of the method embodiments described herein.

[0052] UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, UE 106 may be configured to communicate using NR or LTE, for example, using at least some shared radio components. As a further possibility, UE 106 may be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio, and / or using either GSM or LTE using a single shared radio. The shared radio can be connected to a single antenna for performing wireless communication, or can be connected to multiple antennas (for example, in the case of MIMO). Generally, the radio may include any combination of a baseband processor, analog RF signal processing circuitry (including, for example, filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (for example, for digital modulation and other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the above hardware. For example, UE 106 may share one or more portions of the receive and / or transmit chain among multiple wireless communication technologies such as those described above.

[0053] In some embodiments, UE 106 may include separate transmit and / or receive chains for each wireless communication protocol that UE 106 is configured to use for communication (including, for example, separate antennas and other wireless mechanism components). As a further possibility, UE 106 may include one or more radios shared among multiple wireless communication protocols, and one or more radios used exclusively by a single wireless communication protocol. For example, UE 106 may include a shared radio for communicating using either LTE or 5G NR (among various possibilities, or either LTE or 1xRTT, or either LTE or GSM), and separate radios for communicating using each of Wi-Fi and Bluetooth. Other configurations are possible. Figure 3 - Block Diagram of UE

[0054] Figure 3 shows an exemplary simplified block diagram of a communication device 106 according to some embodiments. Note that the block diagram of the communication device in FIG. 3 is merely an example of a possible communication device. According to embodiments, the communication device 106 can be, among other devices, a User Equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop computer, notebook computer, or portable computing device), a tablet, and / or a combination of devices. As shown in the figure, the communication device 106 can include a set of components 300 configured to perform core functions. For example, this set of components may be implemented as a System On Chip (SOC), and the SOC can include parts for various purposes. Alternatively, this set of components 300 may be implemented as separate components or groups of components for various purposes. The set of components 300 may be coupled (e.g., communicatively, directly or indirectly) to various other circuits of the communication device 106.

[0055] For example, the communication device 106 can include various types of memory (e.g., including NAND flash 310), an input / output interface (I / F) 320 (for connecting to, for example, input devices such as a computer system, dock, charging station, microphone, camera, keyboard, etc., and output devices such as a speaker), a display 360 that may be integrated with or external to the communication device 106, and a wireless communication circuit 330 (for, e.g., LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some embodiments, the communication device 106 can include a wired communication circuit (not shown), such as a network interface card for Ethernet, for example.

[0056] As shown in the figure, the wireless communication circuit 330 can be coupled (e.g., communicatively, directly or indirectly) to one or more antennas such as antenna(s) 335. The wireless communication circuit 330 may include a cellular communication circuit and / or a short- to medium-range wireless communication circuit, and may include, for example, multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams in a Multiple-Input Multiple Output (MIMO) configuration.

[0057] In some embodiments, as further described below, the cellular communication circuit 330 may include one or more receive chains (e.g., a first receive chain for LTE and a second receive chain for 5G NR) for multiple RATs (including dedicated processors and / or radios, and / or coupled (e.g., communicatively directly or indirectly) thereto). Additionally, in some embodiments, the cellular communication circuit 330 can include a single transmit chain that can be switched between radios dedicated to a particular RAT. For example, a first radio can be dedicated to a first RAT such as LTE and communicate with a dedicated receive chain and a shared transmit chain shared with a second radio. The second radio can be dedicated to a second RAT, e.g., 5G NR, and communicate with the dedicated receive chain and the shared transmit chain.

[0058] The communication device 106 may also include and / or be configured to be used with one or more user interface elements. The user interface elements may include a display 360 (which may be a touch screen display), a keyboard (which may be a separate keyboard or implemented as part of a touch screen display), a mouse, a microphone, and / or a speaker, one or more cameras, one or more buttons, and / or any of various other elements capable of providing information to the user and / or receiving or interpreting user input, such as any of various elements.

[0059] The communication device 106 may further include one or more smart cards 345, which include subscriber identity module (SIM) functionality, such as one or more universal integrated circuit cards (UICCs).

[0060] As shown in the figure, the SOC 300 may include a processor(s) 302 capable of executing program instructions for the communication device 106, and a display circuit 304 capable of performing graphic processing and providing a display signal to the display 360. The processor(s) 302 may be coupled to a memory management unit (MMU) 340, which receives addresses from the processor(s) 302 and converts those addresses to locations within a memory (e.g., memory 306, read only memory (ROM) 350, NAND flash memory 310), and / or to other circuits or devices such as the display circuit 304, the wireless communication circuit 330, the I / F 320, and / or the display 360. The MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, the MMU 340 may be included as part of the processor(s) 302.

[0061] As described above, the communication device 106 may be configured to communicate using wireless and / or wired communication circuits. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and techniques described herein. The processor 302 of the communication device 106 may be configured to implement some or all of the features described herein, for example, by executing program instructions stored in a storage medium (e.g., a non-transitory computer-readable storage medium). Alternatively (or in addition), the processor 302 may be configured as a programmable hardware element such as a field-programmable gate array (FPGA) or as an application-specific integrated circuit (ASIC). Alternatively (or in addition), the processor 302 of the communication device 106 may be configured to implement some or all of the features described herein in conjunction with one or more of the other components 300, 304, 306, 310, 320, 330, 340, 345, 350, 360.

[0062] In addition, as described herein, the processor 302 can include one or more processing elements. Thus, the processor 302 can include one or more integrated circuits (ICs) configured to perform the functions of the processor 302. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the processor(s) 302.

[0063] Furthermore, as described herein, the wireless communication circuit 330 may include one or more processing elements. In other words, one or more processing elements can be included in the wireless communication circuit 330. Thus, the wireless communication circuit 330 can include one or more integrated circuits (ICs) configured to perform the functions of the wireless communication circuit 330. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the wireless communication circuit 330. FIG. 4 - Block Diagram of a Base Station

[0064] FIG. 4 shows an exemplary block diagram of a base station 102 according to some embodiments. Note that the base station in FIG. 4 is merely an example of a possible base station. As shown in the figure, the base station 102 may include a processor(s) 404 capable of executing program instructions for the base station 102. The processor(s) 404 may also be coupled to a Memory Management Unit (MMU) 440, which is configured to receive addresses from the processor(s) 404 and translate these addresses to locations in a memory (e.g., memory 460 and Read Only Memory (ROM) 450) or other circuits or devices.

[0065] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to the telephone network to a plurality of devices, such as UE device 106, as described above in FIGS. 1 and 2.

[0066] The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as the core network of a cellular service provider. The core network may be able to provide mobility-related services and / or other services to a plurality of devices, such as UE device 106. In some cases, the network port 470 may be able to couple to a telephone network via the core network, and / or the core network may be able to provide a telephone network (e.g., between other UE devices served by a cellular service provider).

[0067] In some embodiments, base station 102 may be a next-generation base station, e.g., a 5G New Radio (5G NR) base station, or a "gNB". In such embodiments, base station 102 may be connected to an Evolved Packet Core (EPC) network and / or an NR Core (NRC) network. Additionally, base station 102 may be considered a 5G NR cell and may include one or more Transition and Reception Points (TRPs). Additionally, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs.

[0068] Base station 102 may include at least one antenna 434 and, possibly, multiple antennas. At least one antenna 434 may be configured to operate as a radio transceiver and may be further configured to communicate with UE device 106 via radio 430. Antenna 434 communicates with radio 430 via communication chain 432. Communication chain 432 may be a receive chain, a transmit chain, or both. Radio 430 may be configured to communicate via various wireless communication standards including, but not limited to, 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0069] Base station 102 may be configured to perform wireless communication using multiple wireless communication standards. In some instances, base station 102 may include multiple radios, which may enable base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, base station 102 may include an LTE radio for performing communication according to LTE and a 5G NR radio for performing communication according to 5G NR. In such a case, base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. As another possibility, base station 102 may include a multi-mode radio, which may be capable of performing communication according to any of a plurality of wireless communication technologies (e.g., 5G NR and LTE, 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0070] As will be further described hereinafter in this specification, BS 102 may include hardware and software components for implementing or supporting the implementation of the features described in this specification. The processor 404 of base station 102 may be configured to implement or support the implementation of some or all of the methods described in this specification, for example, by executing program instructions stored in a storage medium (e.g., a non-transitory computer-readable storage medium). Alternatively, processor 404 may be configured as a programmable hardware element such as a Field Programmable Gate Array (FPGA), or as an Application Specific Integrated Circuit (ASIC), or as a combination thereof. Alternatively (or in addition), processor 404 of BS 102 may be configured to implement or support the implementation of some or all of the features described in this specification in conjunction with one or more of the other components 430, 432, 434, 440, 450, 460, 470.

[0071] In addition, as described herein, the processor(s) 404 may include one or more processing elements. Thus, the processor(s) 404 can include one or more integrated circuits (ICs) configured to perform the functions of the processor(s) 404. Additionally, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the processor(s) 404.

[0072] Furthermore, as described herein, the radio 430 may include one or more processing elements. Thus, the radio 430 can include one or more integrated circuits (ICs) configured to perform the functions of the radio 430. Additionally, each integrated circuit can include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the radio 430. Selection of Channel Access Category

[0073] In some wireless access technologies, multiple channel access categories may be defined for uplink (UL) and / or downlink (DL) transmissions. For example, in the case of 5G NR operating in unlicensed spectrum (NR-U), multiple channel access categories including listen-before-talk (LBT) category 1 (Cat-1), Cat-2, and Cat-4 are defined. Cat-4 is defined as LBT with an exponential random backoff having a variable-sized sensing period, where the sensing period (also known as the contention window) is the length of time during which a clear channel assessment (CCA) is performed. Cat-2 is defined as LBT without random backoff, and the sensing period is limited to either 16 microseconds or 25 microseconds. Cat-1 is defined to enable immediate transmission, for example, without performing CCA. One or more of the defined categories may include further variations. For example, Cat-4 is defined to include four different options for a channel access priority class (CAPC) that may be selected based on the priority of the data carried in the message.

[0074] When accessing a channel using an LBT procedure (e.g., starting a channel occupancy time (COT)), a UE such as UE106 uses various factors to determine which channel access category to use, and different factors may be used for different messages and / or channels. For example, different factors may be used for various DL or UL control channels and / or for RACH-related channels such as PRACH / MSG-3 in a 4-step RACH and / or MsgA in a 2-step RACH.

[0075] As a first example, UE 106 can use different LBT channel access categories for different uplink control messages. For example, when starting the COT for a particular type of UL control message associated with a DL downlink control information (DCI) format, UE 106 may use the LBT category indicated in the associated DCI such as DCI 1_0 or DCI 1_1. Such types of UL control messages may include an aperiodic sounding reference symbol (SRS) trigger or a physical uplink control channel (PUCCH) message associated with a DL DCI such as a HARQ-ACK message or an aperiodic channel state information (CSI) report. In contrast, when starting the COT for a UL control message not associated with a DL DCI format, UE 106 can use a particular predetermined LBT category such as Cat-4 having the highest priority class (lowest value). Such messages may include, for example, a particular type of PUCCH message such as periodic CSI feedback via the PUCCH or periodic SRS.

[0076] As a second example, for DL control channel transmission (e.g., transmission including only DL control channel messages), BS102 may use an LBT category determined based on the selected CAPC value. In some scenarios, this may first include the selection of CAPC by base station 102. In other scenarios, CAPC may be selected based on DL traffic QoS requirements. For example, in 5G NR, different packet flows can be classified, marked with different Quality of Service (QoS) Flow Identifiers (QFIs), and mapped to different 5G QoS Indicator (5GI) values in the range of 1 to 85. The 5GI value may have a predefined one-to-one mapping to a defined CAPC value. Thus, BS102 can select a CAPC for channel access based on the 5GI associated with the packet flow on the PDSCH. In still other scenarios, CAPC may be selected based on a Buffer Status Report (BSR) (e.g., the most recent BSR). For example, when transmitting DCI for scheduling UL transmission, BS102 can select one CAPC value for channel access based on the most recent / up-to-date BSR status across different 5GI queues, which can be reported to BS102 by UE106.

[0077] As a third example, UE106 can use different LBT channel access categories for different channels in RACH procedures such as PRACH transmission and RACH message-3 (Msg-3).

[0078] Specifically, in some implementations, the PRACH channel access category can be determined at least in part based on the device type of the UE 106, such as whether the UE 106 is operating as a load-based device (LBE) or a frame-based device (FBE). An FBE device can attempt to access the channel according to a defined frame structure and thus can perform CCA in a fixed time window within each frame period. If the channel is unavailable, the FBE device can be kept quiet until the next frame period. In contrast, an LBE device can utilize a non-time-fixed transmit / receive structure but is instead driven by requests. An LBE device can perform the necessary CCA. If the channel is unavailable, the LBE device can perform an extended CCA with an extended sensing period. For the PRACH procedure, an FBE device may use the LBT category indicated by the BS 102, for example, in a system information block (SIB) such as SIB1 or other suitable messages. Specifically, since the FBE device performs CCA within a fixed sensing period, the BS 102 can select an LBT category for the FBE PRACH procedure that is more aggressive than Cat-4 in some scenarios. In contrast, an LBE device may be limited to using a specific less aggressive LBT category (e.g., Cat-4 with the highest priority class) for PRACH transmission. In the case of a contention-free RACH procedure, such an LBE device may also use the LBT category indicated by the BS 102, for example, in the corresponding DCI 1_0 or other suitable messages.

[0079] Additionally or alternatively, the LBT category for Msg-3 in the RACH procedure can be determined at least in part based on whether Msg-3 is multiplexed with another MAC-PDU. Specifically, the UE106 can generally multiplex multiple MAC-PDUs before transmission if multiple MAC-PDUs are available for transmission. When starting the COT to transmit the RACH Msg-3, the UE106 may be limited to using a particular less aggressive LBT category (e.g., LBT Cat-4) if the UE106 does not have another MAC-PDU to multiplex with Msg-3. However, if the UE106 multiplexes one or more other MAC-PDUs with Msg-3, the UE106 can select the LBT category based on those other MAC-PDU(s). For example, if the UE102 selects (e.g., is permitted to use) a more aggressive category to start the COT for the other MAC-PDU(s), the UE106 can select a more aggressive category (e.g., Cat-2 or Cat-1).

[0080] Alternatively, the LBT category for Msg-3 can be signaled by the BS102. For example, the LBT category for Msg-3 can be indicated in DCI 1_0 scrambled with a random access radio network temporary identifier (RA-RNTI) that carries the DL allocation for the reception of the RACH response (RAR) message (e.g., Msg-2). As another example, the LBT category for Msg-3 can be included in the payload of the RAR MAC-PDU, such as in the UL grant within the RAR MAC-PDU. Signaling mechanism for UL transmission

[0081] In NR-U, either a UE such as UE106 or a BS such as BS102 can start a COT in various scenarios. When the COT is started, the transmitting device can transmit one or more transmissions (e.g., bursts) within the COT, and the bursts are separated by gaps during which the transmitting device is not transmitting. A gap having a specific period can be created using, for example, timing advance, cyclic prefix (CP) extension, or DL shortening, or one or more of the UL transmission periods by one or more OFDM symbols.

[0082] In some scenarios, the COT can be shared with another device. For example, a BS-started COT can include (e.g., start) a DL transmission that includes a UL grant for a time within the same COT. Accordingly, UE106 can transmit a UL transmission at a specified time within the COT.

[0083] As described above, NR-U supports multiple categories of LBT (e.g., Cat 1, Cat-2, 25-microsecond Cat-2, Cat-4). In some scenarios, the category of LBT used can depend at least in part on the gap period between transmissions. For example, in some scenarios, UE106 can transmit within a BS-started COT using Cat-1 (i.e., without LBT) if the gap after the end of the previous transmission is 16 microseconds or less, but can use Cat-2 if the gap is 16 microseconds or 25 microseconds. However, in some cases, UE106 may not be able to recognize the COT structure (e.g., whether the scheduled / granted transmission is within a BS-started COT) or the gap period (e.g., 16 microseconds, 25 microseconds, or larger). This can limit UE106's ability to determine the LBT type.

[0084] To ensure that UE106 remains aligned with BS102, BS102 may indicate various channel access profile parameters to UE106. Such signaling can be performed in various ways involving a trade-off between signaling flexibility and signaling overhead.

[0085] As an example, the LBT category, CP extension configuration, and CAPC can be signaled in a single uplink scheduling DCI using separate information element (IE) fields.

[0086] LBT category: In some implementations, a 2-bit information element (IE) field may be included within the DCI, and the IE field has different states with a one-to-one association with different LBT categories. For example, the value "00" can indicate "Cat-1", the value "01" can indicate "Cat-2 with a 16 microsecond sensing gap", the value "10" can indicate "Cat-2 with a 25 microsecond sensing gap", and the value "11" can indicate "Cat-4". In some implementations, the size of the LBT category field may be configurable according to the category type enabled by the network.

[0087] CP extension (CPE): In some implementations, a 2-bit IE field can be used to indicate CPE, for example, as shown in Table 1.

Table 1

[0088] In some implementations, if a subset of the rows in Table 1 is configured for the UE using RRC signaling, the field size can be further reduced to 1 bit. For example, for a given subcarrier spacing (e.g., 15 kHz), the RRC signaling can restrict the selection to only the first 2 rows shown in the table. Thus, the two available options can be indicated with a 1-bit IE.

[0089] Channel Access Priority Class (CAPC): In some implementations, a 2-bit IE field can be used to indicate one of four available values (e.g., "1, 2, 3, 4").

[0090] In some scenarios, the signaling overhead can be reduced based on known conditions. For example, during the BS-initiated COT, UE106 can only use Cat-1 or Cat-2 with a sensing gap of 16 microseconds. Therefore, the signaling of grants within the BS-initiated COT can omit the explicit indication of the category. Instead of relying on the explicit indication, UE106 can determine the category based on the gap period of the scheduled UL transmission. For example, when UE106 detects the occurrence of the BS-initiated COT, if the gap period <X (e.g., 16 microseconds), it can use Cat-1 within the COT, otherwise it can use Cat-2 for a 16-microsecond period.

[0091] As another example, to reduce the signaling overhead of DCI, for example, as shown in Table 2, a combined coding scheme for LBT category, CP extension, and CAPC can be used.

Table 2

[0092] In some implementations, additional values in the CAPC IE field (e.g., in addition to "1,2,3,4") may be used to indicate that UE106 needs to autonomously select a CAPC value. For example, this may enable UE106 to select a CAPC based on, for example, UE-side buffer status and / or traffic type that is unknown to BS102. For example, in response to determining that the buffer contains a large amount of data, UE106 can select a higher priority class than it would if the buffer contained a smaller amount of data. Similarly, in response to determining that the UL traffic is of a non-delay-tolerant type, UE106 can select a higher priority class than it would for a more delay-tolerant traffic type.

[0093] In some implementations, UE106 may be configured to use an LBT category other than the category indicated by BS102 in some scenarios. FIG. 5 shows one such scenario.

[0094] As shown, BS102 can transmit a UL grant 510 to UE106 at a first time t 1 For example, the UL grant 510 may be included in a UL grant DCI (e.g., DCI format 0). The UL grant 510 can permit a UL transmission 520 at a later time t 4 In some scenarios, the UL transmission 520 may include a PUSCH and / or a PUCCH. The UL grant 510 (or the DCI in which it is included) may include an indication of the first LBT category to be used by UE102 when performing the UL transmission 520, for example, according to any of the foregoing embodiments. For example, the UL grant 510 may indicate that UE102 should use Cat-4 when performing the UL transmission 520.

[0095] A second time t 2BS106 can send DCI530 (e.g., group common DCI (GC-DCI)) to UE106, which may include shared information and / or timing information for the subsequent BS-started COT540. For example, DCI530 may include shared information indicating that UL transmission is permitted within COT540. BS120 can start COT540 following DCI530 at time t 3 and.

[0096] In response to receiving DCI530, UE160 can determine that the shared information indicates that UL transmission is permitted within COT540 and / or that the permitted UL transmission 520 is scheduled within COT540. Accordingly, UE160 can autonomously determine to use an LBT category other than that indicated by UL grant 510. For example, in response to determining that UL transmission 520 occurs within the BS-started COT540, the UE can use LBT Cat-1 or Cat-2 (e.g., having either a 16-microsecond or 25-microsecond sensing period) for UL transmission 520. After satisfying the LBT procedure according to the selected category, UE160 can send UL transmission 520.

[0097] In other scenarios, UE160 can determine that UL transmission 520 does not occur within the BS-started COT (or does not occur within any COT). Accordingly, UE160 can send UL transmission 520 using the LBT category indicated by UL grant 510.

[0098] The scenario in FIG. 5 is an example, and in other scenarios, it should be understood that UE160 can determine to send UL transmission using an LBT category other than the category indicated by BS102 based on other factors not related to whether UL transmission occurs within a COT. Adjustment of contention window

[0099] As described above, some LBT procedures (e.g., NR-U LBT Cat-4) can utilize a variable-sized sensing period (or contention window). In some implementations, the sensing period can be adjusted in various ways.

[0100] As a first example, the contention window can be adjusted based on the HARQ-ACK ratio Z. For example, in some implementations, if Z exceeds a particular pre-defined threshold (e.g., 80%), the contention window can be increased to the next higher permitted value. Otherwise, the contention window can remain the same.

[0101] However, NR-U can support code block group (CBG)-based transmission, where a transport block (TB) can be divided into multiple groups of code blocks and ACK / NACK is reported for each CBG. This allows for a lower retransmission rate since each CBG can be considered individually for retransmission rather than requiring the entire TB to be retransmitted if some are not received. However, Z represents the HARQ-ACK ratio for the entire TB rather than for individual CBGs. Thus, Z can be calculated based on virtual TB level HARQ-ACK (V-T-HARQ-ACK).

[0102] A first example of calculating Z based on V-T-HARQ-ACK is shown in FIG. 6A. As shown, the HARQ-ACK value can be obtained for multiple CBGs of a single PDSCH transmission, and a logical AND operation of all corresponding individual HARQ-ACKs is performed to generate V-T-HARQ-ACK. As shown in FIG. 6A, this results in V-T-HARQ-ACK = ACK when ACKs are received for all CBGs within the multiple CBGs, and V-T-HARQ-ACK = NACK when no ACK is received for any CBG (e.g., when a NACK is received). In other implementations, a logical OR operation of all corresponding individual HARQ-ACKs is performed to generate V-T-HARQ-ACK. This results in V-T-HARQ-ACK = ACK when an ACK is received from any CBG within the multiple CBGs, and V-T-HARQ-ACK = NACK only when no ACK is received for any CBG. In either case, V-T-HARQ-ACK can be treated as a single HARQ-ACK for calculating the value of Z.

[0103] A second example of calculating Z based on V-T-HARQ-ACK is shown in FIG. 6B. Similar to FIG. 6A, the HARQ-ACK value can be obtained for multiple CBGs of a single PDSCH transmission. However, in FIG. 6B, V-T-HARQ-ACK can be set to a decimal value calculated as the ratio of NACKs to the total number of CBGs within the multiple CBGs (e.g., the total number of CBGs during a PDSCH transmission). As shown in FIG. 6B, when ACKs are received for each CBG within a set of four CBGs, V-T-HARQ-ACK = 0 / 4 = 0. However, when an ACK is not received for one of the CBGs (e.g., when a NACK is received), V-T-HARQ-ACK = 1 / 4 = 0.25. The decimal value of V-T-HARQ-ACK can be treated as a single HARQ-ACK for calculating the value of Z.

[0104] As a second example of adjusting the contention window, in some implementations, the contention window for UL transmission in a 2-step or 4-step RACH procedure can be dynamically adjusted for a given priority class. As described above, LBT Cat-4 can utilize any of four channel access priority classes (CAPC). FIG. 7 shows an exemplary method of adjusting the contention window. The method of FIG. 7 can be performed by a UE such as UE106 or by some of its parts such as radio communication circuit 330.

[0105] At 702, UE106 can access the channel using Cat-4 LBT for either PRACH or Msg-A transmission.

[0106] At 702, UE106 can determine whether it has received an appropriate response within a defined window. For example, in a 2-step RACH procedure, UE106 can determine whether it has successfully received Msg-B from BS102 within a pre-defined RAR window. As another example, in a 4-step RACH procedure, UE106 can determine whether it has successfully received RAR or Msg-4 from BS102 within the RAR window.

[0107] At 704, in response to determining that an appropriate response has not been received within the defined window, UE106 can, at 706, increase the contention window CW for the corresponding priority class p p to the next higher permitted value.

[0108] At 704, in response to determining that an appropriate response has been received within the defined window, UE106 can, at 708, reset CW p to the minimum value CW min.p reset.

[0109] Embodiments of the present disclosure may be implemented in any of various forms. For example, some embodiments can be realized as a computer-implemented method, a computer-readable storage medium, or a computer system. Other embodiments may be realized using one or more custom-designed hardware devices such as an ASIC. Still other embodiments may be realized using one or more programmable hardware elements such as an FPGA.

[0110] In some embodiments, a non-transitory computer-readable storage medium may be configured such that the non-transitory computer-readable storage medium stores program instructions and / or data, and when the program instructions are executed by a computer system, the computer system is caused to execute a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0111] In some embodiments, a device (e.g., UE106 or BS102, or some of their components such as wireless communication circuit 330 or modem 520) may be configured to include a processor (or a set of processors) and a storage medium, the storage medium stores program instructions, the processor is configured to read and execute the program instructions from the storage medium, and the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets). The device may be realized in any of various forms.

[0112] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art if the above disclosure is fully understood. The following claims are intended to be construed to embrace all such variations and modifications.

Claims

1. A wireless communication device, comprising: a memory storing software instructions; executing the software instructions to cause the wireless communication device to receive, from a base station, a first message that permits uplink transmission at a specific time, the first message including an indication of a listen-before-talk (LBT) category used for the uplink transmission; receive, from the base station, a second message different from the first message indicating timing information of a channel occupancy time (COT) started by the base station; determine, based on the timing information, whether the specific time is within the COT started by the base station; execute an LBT procedure defined by the LBT category indicated in the first message in response to determining that the specific time is not within the COT started by the base station; autonomously determine a second LBT category other than the LBT category indicated in the first message in response to determining that the specific time is within the COT started by the base station, and execute an LBT procedure defined by the second LBT category; cause the uplink transmission to be transmitted at the specific time in response to successful completion of the LBT procedure; a processor circuit configured as such; The wireless communication device, wherein the first message includes a downlink control information (DCI) message, and a first information element (IE) of the first message includes the indication of the LBT category and an indication of cyclic prefix information for the uplink transmission.

2. The wireless communication device according to claim 1, wherein the LBT procedure defined by the LBT category indicated in the first message includes random backoff, and the LBT procedure defined by the second LBT category does not include random backoff.

3. The wireless communication device according to claim 1, wherein the LBT procedure defined by the second LBT category enables transmission without performing a clear channel assessment.

4. The first information element (IE) of the first message includes an indication of a channel access priority class (CAPC), and executing the LBT procedure defined by the LBT category indicated in the first message includes executing the LBT procedure defined by the CAPC. The wireless communication device according to claim 1.

5. The first information element (IE) of the first message includes an instruction for the wireless communication device to autonomously select a channel access priority class (CAPC), and the processor circuit executes the software instruction to cause the wireless communication device to further configured to cause the CAPC to be selected in response to receiving the first message, and executing the LBT procedure defined by the LBT category indicated in the first message includes executing the LBT procedure defined by the selected CAPC. The wireless communication device according to claim 1.

6. A non-transitory computer-readable medium storing software instructions, which, when executed by a processor of a wireless communication device, cause the wireless communication device to receive, from a base station, a first message permitting an uplink transmission at a specific time, the first message including an indication of a listen-before-talk (LBT) category used for the uplink transmission, receive, from the base station, a second message different from the first message indicating timing information of a channel occupancy time (COT) started by the base station, determine, based on the timing information, whether the specific time is within the COT started by the base station, execute the LBT procedure defined by the LBT category indicated in the first message in response to determining that the specific time is not within the COT started by the base station, autonomously determine a second LBT category other than the LBT category indicated in the first message in response to determining that the specific time is within the COT started by the base station, and execute the LBT procedure defined by the second LBT category. configured to cause the uplink transmission to be sent at the specific time in response to successful completion of the LBT procedure configured as A non-transitory computer-readable medium, wherein the first message includes a downlink control information (DCI) message, and a first information element (IE) of the first message includes an indication of the LBT category and an indication of cyclic prefix information for the uplink transmission. **Claim 7** The non-transitory computer-readable medium according to claim 6, wherein the LBT procedure defined by the LBT category indicated in the first message includes a random backoff, and the LBT procedure defined by the second LBT category does not include a random backoff. **Claim 8** The non-transitory computer-readable medium according to claim 6, wherein the LBT procedure defined by the second LBT category enables transmission without performing a clear channel assessment. **Claim 9** The non-transitory computer-readable medium according to claim 6, wherein the first information element (IE) of the first message includes an indication of a channel access priority class (CAPC), and performing the LBT procedure defined by the LBT category indicated in the first message includes performing the LBT procedure defined by the CAPC. **Claim 10** The first information element (IE) of the first message includes an instruction for the wireless communication device to autonomously select a channel access priority class (CAPC), and the software instruction further configures the wireless communication device to select a CAPC in response to receiving the first message, and performing the LBT procedure defined by the LBT category indicated in the first message includes performing the LBT procedure defined by the selected CAPC. The non-transitory computer-readable medium according to claim 6.

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