Listen-before-talk technology for wireless communication systems

Abstract

Methods, systems, and devices for wireless communications are described. A wireless device, such as a UE or a base station, may implement one or more listen-before-talk (LBT) techniques. The wireless device may determine to transmit a communication on a plurality of subbands of a radio frequency spectrum band during a transmission time interval. The wireless device may identify whether a transmission time interval for a first set of subbands of the plurality of subbands is during a channel occupancy time of a base station. The wireless device may perform one or more LBT procedures based on the identification. For example, the wireless device may perform an LBT procedure selected for each subband based on identifying that the transmission time interval for the first set of subbands is during a channel occupancy time. The wireless device may transmit a communication based on a result of the LBT procedure.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, and more particularly to listen-before-talk (LBT) techniques for wireless communication systems. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems, which may be referred to as new radio (NR) systems. These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiple access (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each base station or network access node simultaneously supporting communication for multiple communication devices, which may be further referred to as user equipment (UE).

[0003] In some wireless communication systems, a wireless device (e.g., a UE or base station) can implement a listen-before-talk (LBT) process before transmitting data. The wireless device can monitor a subband to determine if it is occupied. If the subband is occupied, the wireless device can wait to transmit data later when the subband is unoccupied. However, in some cases, the wireless device may be scheduled to transmit data on multiple subbands. In such cases, conventional LBT techniques may be relatively inefficient or cause communication interference. Summary of the Invention

[0004] The described technology relates to improved methods, systems, devices, and apparatuses that support improved listen-before-talk (LBT) techniques for wireless communication systems. Generally, the described technology enables a wireless device (e.g., a UE or a base station) to perform LBT procedures for multiple subbands of a radio frequency spectrum band. For example, the UE may determine to send one or more communications (e.g., uplink messages) on a subband set during a transmission time interval (TTI). The UE may identify which subbands, if any, are included in the channel occupancy time (COT) of the base station. For example, during the COT, the base station may have medium access to a subset of the subbands (e.g., no subbands, a portion of the subband set, or the entire subband set). In some examples, the UE may perform one or more LBT procedures for the subband set. For example, the UE may perform an LBT procedure (e.g., Category 2 LBT, Category 4 LBT, etc.) based on whether the TTI of the subband is included in the COT of the base station or outside the COT of the base station. In such an example, the UE may transmit one or more communications on the subband set based on a successful outcome of one or more LBT procedures (e.g., the LBT procedure for each subband may indicate that the subband set is unoccupied). In some other examples, the UE may not perform an LBT procedure, for example, based on determining that a portion of the subband set is included in the COT and a portion of the subband set is outside the COT.

[0005] A wireless communication method performed at a user equipment terminal (UE) is described. The method may include: determining to send an uplink message to a base station on a subband set of a radio frequency spectrum band during a transmission time interval; identifying that the transmission time interval is during a COT of the base station for a first subband set in the subband set; performing, for each subband in the subband set, a LBT procedure selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station; and sending the uplink message on each subband in the subband set based on a result of the LBT procedure performed for the subband set.

[0006] An apparatus for wireless communication at a user equipment terminal (UE) is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: determine that an uplink message is to be sent to a base station on a subband set of a radio frequency spectrum band during a transmission time interval; identify that the transmission time interval is during a COT for a first subband set in the subband set; perform, for each subband in the subband set, a LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT for the base station; and send the uplink message on each subband in the subband set based on a result of the LBT process performed for the subband set.

[0007] Another apparatus for wireless communication at a UE is described. The apparatus may include means for determining to send an uplink message to a base station on a subband set of a radio frequency spectrum band during a transmission time interval; identifying that the transmission time interval is during a COT for a first subband set in the subband set; performing, for each subband in the subband set, a LBT procedure selected for each subband in the subband set based on identifying that the transmission time interval is during the COT for the base station; and sending the uplink message on each subband in the subband set based on a result of the LBT procedure performed for the subband set.

[0008] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: determine to send an uplink message to a base station on a subband set of a radio frequency spectrum band during a transmission time interval; identify that the transmission time interval is during a COT for a first subband set in the subband set; perform, for each subband in the subband set, a LBT procedure selected for each subband in the subband set based on identifying that the transmission time interval is during the COT for the base station; and send the uplink message on each subband in the subband set based on a result of the LBT procedure performed for the subband set.

[0009] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the LBT process for each subband in the subband set includes the same LBT process.

[0010] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining that a transmission time interval is during a COT period of a base station for all subbands of a subband set (where the first subband set includes the subband set), and selecting the LBT process as a Category 2 LBT process.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining that a transmission time interval is outside the COT of a base station for all subbands of a subband set (where the first subband set includes the subband set), and selecting the LBT process as a Category 4 LBT process.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an uplink message on a subband set may include operations, features, components, or instructions for identifying that a previous transmission time interval is outside the COT for a second subband set of the subband set, avoiding performing an LBT procedure on the previous transmission time interval based on identifying that the previous transmission time interval may be outside the COT, and transmitting on the subband set during the uplink message based on identifying that the transmission time interval may be during the COT of the base station for all subbands of the subband set or that the transmission time interval may be outside the COT for all subbands of the subband set.

[0013] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining that a transmission time interval is during COT for all subbands of a subband set (where the first subband set includes the subband set), and selecting the same LBT process for each subband in the subband set based on the transmission time interval being during COT for all subbands of the base station.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a first subband in the subband set based on determining that a transmission time interval is outside the COT for at least one subband in the subband set, and performing a first LBT process for the selected first subband in the subband set and performing a second LBT process for the remaining one or more subbands in the subband set.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, selecting the first subband may include operations, features, components, or instructions for randomly selecting the first subband from a set of subbands.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first LBT process includes a Category 4 LBT process, and the second LBT process includes a Category 2 LBT process.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing an LBT process for each subband in a subband set may include operations, features, components, or instructions for selecting a first subband in the subband set, selecting a first LBT process for the selected first subband based on identifying that a transmission time interval may be outside the COT for the first subband, or selecting a second LBT process for the selected first subband based on identifying that a transmission time interval may be during the COT for the first subband, and performing the second LBT process for one or more remaining subbands in the subband set, the remaining one or more subbands being different from the selected first subband.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first LBT process includes a Category 4 LBT process, and the second LBT process includes a Category 2 LBT process.

[0019] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending an uplink message on a subband set may be in response to a result of an LBT process (including a first LBT process and a second LBT process) performed on each subband in the subband set indicating that all subbands in the subband set may be idle.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing an LBT process for each subband in a subband set may include operations, features, components, or instructions for selecting a first subband of a first subband set, performing a first LBT process for the selected first subband, and performing a second LBT process for the remaining one or more subbands of the subband set.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, selecting the first subband may include operations, features, components, or instructions for randomly selecting the first subband from a first set of subbands for which a transmission time interval is during a COT of the base station.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first LBT process includes a Category 4 LBT process, and the second LBT process includes a Category 2 LBT process.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an uplink configuration for a UE from a base station, the uplink configuration indicating a set of subbands of a radio frequency spectrum band.

[0024] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving an uplink configuration may include operations, features, components, or instructions for receiving a radio resource control signal indicating an uplink configuration, a downlink control information signal indicating an uplink configuration, or a combination thereof.

[0025] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving system information from a base station, the system information indicating a result of an LBT process performed by the base station for each subband in a subband set, wherein a transmission time interval may be identified as being during a COT based on the received system information.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the system information includes a bitmap, each bit of the bitmap corresponding to a result of the LBT process for a corresponding one of the subbands in the subband set. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 and Figure 2 An example of a wireless communication system supporting a listen-before-talk (LBT) technique for the wireless communication system according to aspects of the present disclosure is shown.

[0028] 3-5 illustrate examples of timelines for supporting LBT techniques for wireless communication systems according to aspects of the present disclosure.

[0029] Figure 6 and Figure 7 A block diagram of a device supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown.

[0030] Figure 8 A block diagram of a communication manager supporting LBT technology for a wireless communication system is shown in accordance with aspects of the present disclosure.

[0031] Figure 9 A diagram of a system including a device supporting LBT technology for a wireless communication system is shown in accordance with aspects of the present disclosure.

[0032] Figure 10 and Figure 11 Shown is a flow chart illustrating a method of supporting LBT technology for a wireless communication system according to aspects of the present disclosure. DETAILED DESCRIPTION

[0033] In some wireless communication systems (e.g., New Radio Unlicensed (NR-U) systems, enhanced License Assisted Access (eLAA), etc.), a wireless device may perform a Listen Before Talk (LBT) procedure to determine whether a subband (e.g., a carrier, a channel, etc.) is unoccupied. For example, a wireless device (e.g., a user equipment (UE) or a base station) may perform energy sensing of a subband to identify whether the subband is occupied (e.g., whether another wireless device is utilizing the subband for communication). If the LBT procedure is successful (e.g., the subband is idle), the wireless device may transmit communications on the subband. Alternatively, if the LBT procedure is unsuccessful (e.g., the subband is occupied), the wireless device may avoid transmitting until a subsequent time (e.g., when the subband is idle). In some cases, the base station may perform a medium access procedure to protect a subband set used for communication. For example, the base station may perform an LBT procedure on the subband set to determine whether the subband set is occupied. In some examples, the base station may identify one or more subbands that are idle (e.g., the result of the LBT process is successful), and the base station may protect the channel for a period of time (such as a channel occupancy time (COT)). Additionally or alternatively, the base station may identify one or more subbands that are occupied (e.g., the result of the LBT process is unsuccessful), and the base station may not be able to obtain a COT for these subbands.

[0034] In some examples, a base station may schedule a UE for uplink transmissions across multiple LBT subbands (e.g., unlicensed frequencies). For example, a dynamic uplink grant or configured uplink transmission may indicate the resources of a subband set (e.g., in a system with broadband operation including multiple LBT subbands). Additionally or alternatively, a UE may be scheduled or configured to transmit on multiple uplink carriers (e.g., using carrier aggregation across LBT subbands). However, the base station may fail to protect COT on each of the multiple subbands. For example, the base station may have obtained medium access (e.g., COT) for some subbands but failed to obtain medium access for other subbands. Techniques for implementing LBT procedures across multiple subbands may be required.

[0035] According to the techniques described herein, a UE may implement one or more LBT schemes for multiple subbands of a radio frequency spectrum band. The UE may determine, for example, based on an uplink configuration from a base station (e.g., radio resource control (RRC) signaling, downlink control information (DCI), etc.), to send one or more uplink messages on a subband set during a transmission time interval (TTI). In some examples, during a channel occupancy time (COT), the base station may obtain medium access to a subset of subbands (e.g., no subbands, a portion of a subband set, or the entire subband set). The base station may indicate the obtained medium access to a subset of subbands, for example, by sending system information (e.g., a bitmap indicating whether the base station has obtained a COT for each subband in the subband set).

[0036] The UE may determine which, if any, of the subbands are within the obtained medium access. For example, the UE may determine that one or more subbands are included in the COT of the TTI during which the UE wants to perform an uplink transmission. The UE may select an LBT process (e.g., a first type of LBT process or a second type of LBT process) for each subband based on this determination. A shorter LBT process may use less energy but have lower accuracy, while a longer LBT process may consume more energy and increase interference to other devices but improve accuracy. Subbands during the base station COT may allow for shorter LBT processes (e.g., due to a relatively low probability that the channel is occupied by other devices). Taking such an LBT process into account across COTs of multiple subbands may enable more efficient communication while maintaining a relatively low chance of interfering with other transmissions in the system.

[0037] Various aspects of the present disclosure are initially described in the context of wireless communication systems. Various aspects of the present disclosure are also described in the context of a timeline related to LBT technology for wireless communication systems. Various aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to LBT technology for wireless communication systems.

[0038] Figure 1 An example of a wireless communication system 100 supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, communication with low-cost and low-complexity devices, or any combination thereof.

[0039] Base stations 105 may be dispersed throughout a geographic area to form wireless communication system 100 and may be different forms of devices or devices with different capabilities. Base stations 105 and UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which a UE 115 and base station 105 may establish one or more communication links 125. A coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support communication of signals according to one or more radio access technologies.

[0040] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary, mobile, or both at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 1 Some example UEs 115 are shown in FIG. The UEs 115 described herein may be capable of communicating with various types of devices, such as Figure 1 Other UEs 115, base stations 105, or network devices (eg, core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices) are shown.

[0041] The base stations 105 can communicate with the core network 130, or with each other, or both. For example, the base stations 105 can interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 can communicate with each other via the backhaul links 120 (e.g., via X2, Xn, or other interfaces) directly (e.g., directly between the base stations 105), indirectly (e.g., via the core network 130), or both. In some examples, the backhaul links 120 can be or include one or more wireless links.

[0042] The one or more base stations 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga NodeB (any of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0043] UE 115 may include or be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where "device" may also be referred to as a unit, a station, a terminal, a client, and other examples. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, and the like, which may be implemented in various objects such as appliances, vehicles, meters, and the like.

[0044] The UE 115 described herein may be capable of communicating with various types of devices, such as Figure 1 Other UEs 115 are shown, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc.

[0045] The UE 115 and the base station 105 can wirelessly communicate with each other via one or more communication links 125 on one or more carriers. The term "carrier" can refer to a collection of radio spectrum resources with a defined physical layer structure for supporting the communication link 125. For example, a carrier used for the communication link 125 can include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels of a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel can carry acquisition signaling (e.g., synchronization signals, system information), control signaling to coordinate operations for the carrier, user data, or other signaling. The wireless communication system 100 can use carrier aggregation or multi-carrier operation to support communication with the UE 115. Depending on the carrier aggregation configuration, the UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0046] The signal waveform transmitted on the carrier may be composed of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may be composed of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the codec rate of the modulation scheme, or both). Therefore, the more resource elements received by the UE 115 and the higher the order of the modulation scheme, the higher the data rate of the UE 115 may be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may also increase the data rate or data integrity of communications with the UE 115.

[0047] One or more numerologies for a carrier may be supported, where the numerology may include subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs with the same or different numerologies. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communication by the UE 115 may be restricted to the one or more active BWPs.

[0048] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, which can be, for example, T s =1 / (Δf max ·N f ) seconds of sampling period, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported Discrete Fourier Transform (DFT) size may be indicated. Time intervals for communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0049] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). In some wireless communication systems 100, a time slot may also be divided into a plurality of mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may also contain one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0050] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0051] Physical channels can be multiplexed on a carrier according to various techniques. For example, physical control channels and physical data channels can be multiplexed on a downlink carrier using one or more time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel can be defined by a number of symbol periods and can extend across the system bandwidth of a carrier or a subset of that bandwidth. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more UEs 115 can monitor or search the control region for control information according to one or more search space sets, and each search space set can include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information in a control information format having a given payload size. A search space set can include a common search space set configured to transmit control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115.

[0052] In some examples, base stations 105 can be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0053] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE 115 can be designed to support ultra-reliable, low-latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can be supported by one or more mission-critical services such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency are used interchangeably herein.

[0054] In some examples, UE 115 may also be able to communicate directly with other UEs 115 via device-to-device (D2D) communication links 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of base station 105 or otherwise unable to receive transmissions from base station 105. In some examples, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE 115 transmits to each other UE 115 in the group. In some examples, base station 105 facilitates resource scheduling for D2D communication. In other cases, D2D communication is performed between UEs 115 without the involvement of base station 105.

[0055] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) that manages access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) that routes packets to or interconnects with external networks. The control plane entities may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the core network 130. User IP packets may be transmitted via the user plane entities, which may provide IP address allocation and other functions. The user plane entities may connect to network operator IP services 150. Operator IP services 150 may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet-switched streaming services.

[0056] Some network devices, such as base stations 105, may include subcomponents such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with the UE 115 through one or more other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., base station 105).

[0057] The wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is approximately 1 decimeter to 1 meter. UHF waves may be blocked or redirected by buildings and environmental features, but these waves can penetrate structures sufficiently for a macro cell to provide service to a UE 115 located indoors. Transmission of UHF waves can be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) compared to transmission using the lower frequencies and longer wavelengths of the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0058] The wireless communication system 100 can utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 can employ license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed radio frequency spectrum band, devices such as the base station 105 and the UE 115 can employ carrier sensing for collision detection and avoidance. In some examples, operations in the unlicensed band can be based on a combination of carrier aggregation configuration and component carriers operating in a licensed band (e.g., LAA). Operations in the unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0059] The base station 105 or UE 115 may be equipped with multiple antennas that may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels that may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array with multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panels may support radio frequency beamforming for signals transmitted via the antenna ports.

[0060] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0061] In some examples, the wireless communication system 100 may enable an LBT process (e.g., the wireless communication system may be an example of an NR-U system or an eLAA system, as well as other examples of wireless communication systems). For example, a wireless device (e.g., a base station 105 or a UE 115) may perform an LBT process to determine whether an LBT subband (e.g., an LBT carrier, an LBT channel, etc.) is unoccupied. For example, the wireless device may perform energy sensing of the subband to identify whether the subband is occupied (e.g., if another wireless device is utilizing the subband for communication). If the LBT process is successful (e.g., the subband is idle), the wireless device may transmit communications on the subband. Alternatively, if the LBT process is unsuccessful (e.g., the subband is occupied), the wireless device may avoid transmitting until a later time. In some cases, the base station 105 may perform a medium access process to protect a subband set used for communication. For example, the base station 105 may perform an LBT process on the subband set to determine whether the subband set is occupied. In some examples, base station 105 can identify one or more subbands that are idle (e.g., the result of the LBT process is successful), and the base station can protect the channel for COT. Additionally or alternatively, the base station can identify one or more subbands that are occupied (e.g., the result of the LBT process is unsuccessful), and the base station may not be able to obtain COT for these subbands.

[0062] In some examples, the base station 105 may schedule the UE 115 for uplink transmissions across multiple subbands. For example, a dynamic uplink grant or configured uplink transmission may indicate resources of a subband set (e.g., in a system with wideband operation including multiple LBT subbands). Additionally or alternatively, the UE 115 may be scheduled or configured to transmit on multiple uplink carriers (e.g., using carrier aggregation across LBT subbands). However, the base station 105 may fail to protect the COT on each of the multiple subbands. For example, the base station 105 may have obtained medium access (e.g., COT) for some subbands but failed to obtain medium access for other subbands. Techniques for implementing LBT procedures across multiple subbands may be required.

[0063] According to the techniques described herein, UE 115 may implement one or more LBT schemes for multiple subbands of a radio frequency spectrum band. UE 115 may determine to send one or more uplink messages on a subband set during a TTI, for example, based on an uplink configuration from a base station (e.g., RRC signaling, DCI, etc.). In some examples, during a COT, base station 105 may obtain medium access to a subset of subbands (e.g., no subbands, a portion of a subband set, or the entire subband set). Base station 105 may indicate the obtained medium access to a subset of subbands, for example, by sending system information (e.g., a bitmap indicating whether base station 105 has obtained COT for each subband in a subband set).

[0064] UE 115 may determine which, if any, of the subbands are within the obtained medium access. For example, UE 115 may determine that one or more subbands are included in the COT of a TTI during which UE 115 wants to perform an uplink transmission (e.g., via communication link 125). UE 115 may select an LBT process (e.g., a first type of LBT process or a second type of LBT process) for each subband based on this determination. A shorter LBT process may use less energy but have lower accuracy, while a longer LBT process may consume more energy and increase interference to other devices but improve accuracy. Subbands during the COT of base station 105 may allow for shorter LBT processes (e.g., because the probability of the channel being occupied by other devices is relatively low). Such LBT processes that take into account COTs across multiple subbands may enable more efficient communication while maintaining a relatively low chance of interfering with other transmissions in the system.

[0065] Figure 2 An example of a wireless communication system 200 supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. For example, the wireless communication system can include a base station 105-a and a UE 115-a, which can be reference Figure 1 Examples of corresponding devices described. Generally, the wireless communication system 200 illustrates an example of an LBT scheme that takes into account the COT for the base station 105-a. For example, the base station 105-a or the UE 115-a can perform one or more LBT procedures during the LBT period 210 based on whether one or more subbands 220 are included in the COT or excluded from the COT.

[0066] Base station 105-a may provide a coverage area (e.g., coverage area 110) within which UE 115-a and base station 105-a may communicate via communication link 205, which may be as described with reference to FIG. Figure 11. An example of the communication link 125 described. The communication link 205 may include one or more channels or carriers of an unlicensed spectrum. In the unlicensed spectrum, the one or more channels may span or include multiple subbands 220, which may be supported by the base station 105-a to communicate with the UE 115-a. An LBT process may be performed (e.g., by the base station 105-a or the UE 115-a) to monitor whether a given subband 220 is occupied. For example, the base station may determine that the subband 220 is unoccupied and obtain the COT for the subband 220. The base station may communicate with the UE 115-a during the COT of the subband 220. As shown, the multiple subbands 220 may include subbands 220-a, 220-b, 220-c, and 220-d, although any number of subbands may be used.

[0067] The base station 105-a may schedule the UE 115-a for communications outside of the COT for the base station 105-a. For example, before performing an LBT procedure, the base station 105-a may configure the UE 115-a with an uplink transmission (e.g., an uplink message) on the subband 220a. The UE 115-a may implement a first LBT procedure during the LBT period 210-a based on the uplink transmission being scheduled on the resource 225-a during the TTI 215 outside of the COT. For example, the UE 115-a may determine to perform a Category 4 LBT procedure before transmitting on the resource 225-a. The Category 4 LBT procedure may include a relatively long monitoring window (e.g., a relatively large energy detection period before sending an uplink transmission), which may ensure an accurate estimation of whether the subband 220-a is occupied or unoccupied by communications of another device. In some examples, the base station 105-a may send a DCI indicating a Category 4 LBT process for an uplink transmission (e.g., the DCI may indicate a physical uplink shared channel (PUSCH) transmission of a relatively large number of time slots (such as K2 time slots) from the DCI). Prior to the resources 225-a used for the scheduled uplink transmission, the base station 105-a may perform the LBT process and indicate the result of the LBT process to the UE 115-a. For example, the base station 105-a may send system information (e.g., COT information, such as a COT structure indicator (SI)) indicating the COT of the base station 105-a and whether one or more communications on the subband 220 are allowed during the COT based on the result of the LBT process at the base station 105-a.

[0068] In some examples, the result of the LBT process at the base station 105-a may be successful. In these examples, the UE 115-a may switch the LBT process performed during the LBT period 210-a to a Category 2 LBT process before sending an uplink transmission. The Category 2 LBT process may include a relatively small monitoring window (e.g., a relatively small energy detection period before sending an uplink transmission, such as 25 microseconds), which may result in more efficient communication (e.g., less power consumption, a relatively high probability of a successful LBT result, and other advantages). Alternatively, if the LBT process fails at the base station 105-a, the UE 115-a may maintain the LBT process as a Category 4 LBT process during the LBT period 210-a. In some examples, the UE 115-a may use a first LBT process (e.g., a Category 4 LBT process) for communications within the COT of the base station 105-a and a second LBT process (e.g., a Category 2 LBT process) for communications outside the COT (e.g., based on information associated with the COT received from the base station 105-a).

[0069] In some examples, the base station 105-a may schedule the UE 115-a with communications on multiple subbands 220. For example, the base station 105-a may configure uplink transmissions from the UE 115-a across the subbands 220 (e.g., via a dynamic uplink grant or a semi-persistent scheduling configuration). For example, the UE 115-a may perform carrier aggregation for uplink transmissions on multiple uplink carriers. The UE 115-a may identify resources 225 for uplink transmissions during a TTI 215 based on the configuration. The UE 115-a may perform one or more LBT procedures for uplink transmissions across the subbands 220 during the LBT period 210. For example, the UE 115-a may randomly select one of the subbands 220 to perform a first LBT procedure (e.g., Category 4 LBT during the LBT period 210-c on the subband 220-c), and the UE 115-a may perform a second LBT procedure on the remaining subbands 220 for the uplink transmission based on satisfying one or more thresholds. The one or more thresholds may include: the UE being scheduled or configured to transmit on each of the subbands 220; the uplink grant for the uplink transmission indicating the first LBT procedure (e.g., Category 4 LBT) and the same PUSCH start position across the subband set 220; the uplink transmission (or transmissions) being configured to start transmission at the same time across the subband set 220; the subband sets 220 (e.g., carriers) being grouped according to one or more different radio access technologies (e.g., Wi-Fi channel connection rules); or any combination thereof.

[0070] In some cases, the base station 105-5 may fail to secure a COT on each of the plurality of subbands 220. For example, the base station 105-a may have achieved a COT for some subbands 220 (e.g., subband 220-a and subband 220-b) and failed to gain medium access for other subbands 220 (e.g., subband 220-c and subband 220-d). A device of the wireless communication system 200 (e.g., the UE 115-a) may implement one or more LBT schemes described herein for the LBT process on the plurality of subbands 220 based on the COT of the base station 105-a.

[0071] As an illustrative example of a first LBT scheme, the base station 105-a may obtain a COT for one or more of the subbands 220. The base station 105-a may indicate the COT, the subbands included in the COT, the subbands outside the COT, or a combination thereof to the UE 115-a. For example, the base station 105-a may send system information (e.g., COT-SI) to the UE 115-a. In some examples, the system information may include a bitmap corresponding to the subbands 220. For example, the bitmap may include a bit associated with each subband 220 (e.g., a bit for subband 220-a indicating whether a TTI 215 for resource 225-a is included in the COT; a bit for subband 220-b indicating whether a TTI 215 for resource 225-b is included in the COT, etc.).

[0072] UE 115-a may identify the COT and determine whether the set of subbands 220 is included in the COT of base station 105-a. For example, UE 115-a may determine that all subbands 220 are included in the COT. In these examples, UE 115-a may use a second LBT process for each of LBT periods 210. For example, UE 115-a may perform a Category 2 LBT process in each of LBT periods 210 based on each of subbands 220 being included in the COT (e.g., base station 105-a may have obtained medium access on a channel including each of TTIs 215 and resources 225 of the uplink transmission). Such a process may enable relatively efficient communication at UE 115-a (e.g., reduced power consumption). In some other examples, UE 115-a may determine that all subbands 220 are outside the COT. In such an example, UE 115-a may perform a first LBT process (e.g., a Category 4 LBT process) for each of LBT periods 210 based on this determination. Such a process may enable relatively accurate sensing of the subbands 220, which may mitigate the possibility of interference with communications from other devices. In another example, the UE 115-a may determine that a first set of subbands 220 (e.g., subbands 220-a and 220-b) are included in the COT and a second set of subbands 220 (e.g., subbands 220-c and 220-d) are outside the COT. In such an example, the UE 115-a may not perform the LBT process, cancel transmissions during the TTI 215, or both. By avoiding performing the LBT process or avoiding transmissions during the TTI 215, the UE 115-a may ensure low processing overhead at the UE 115-a and avoid interference with other transmissions in the wireless communication system 200.

[0073] Figure 3A and Figure 3B 1 and 2. Examples of timelines 300-a and 300-b, respectively, supporting LBT techniques for wireless communication systems according to aspects of the present disclosure are shown. In some examples, timeline 300 can implement aspects of wireless communication systems 100 and 200. For example, timelines 300-a and 300-b can include LBT period 310, TTI 315, subband 320, and resource 325, which can be as described in reference to FIG. Figure 1 and Figure 2 Examples of corresponding elements described.

[0074] In general, timeline 300-a and timeline 300-b may illustrate an example of a second LBT scheme for performing one or more LBT procedures as described herein across multiple subbands 320. The second LBT scheme may enable a wireless device (e.g., UE 115 or base station 105) to identify a set of subbands 320 included in a COT of a base station and perform one or more LBT procedures during an LBT period 310 based on the inclusion of the set of subbands 320 in the COT.

[0075] The wireless device may identify communications on resources 325. For example, the wireless device may identify uplink transmissions scheduled on multiple subbands 320, such as a set of subbands 320 including subband 320-a, subband 320-b, subband 320-c, and subband 320-d during TTI 315-a. In some examples, the wireless device may determine that each subband 320 is included in a COT (e.g., the base station 105 has medium access on each subband 320 during the COT including TTI 315-a). In such an example, the wireless device may implement a second LBT procedure during each of the LBT periods 310. For example, the wireless device may monitor the subbands 320 to determine whether each subband 320 is occupied according to the second LBT process (e.g., each of the LBT periods 310-a, 310-b, 310-c, and 310-d is a relatively short monitoring duration preceding the resources 325-a, 325-b, 325-c, and 325-d). If the wireless device determines that each subband is idle (e.g., the result of the second LBT process on each subband indicates that the subband is not occupied), the wireless device may use the resources 325 to send an uplink transmission.

[0076] In some examples of the second LBT scheme, the wireless device may determine that at least one of the subbands 320 is outside the COT of the base station. For example, the wireless device may determine that all of subbands 320-a, 320-b, 320-c, and 320-d are outside the COT. Additionally or alternatively, the wireless device may determine that one or more subbands 320 are included in the COT (e.g., the base station has obtained medium access to resources 325-c including subband 320-c as shown in timeline 300-a and resources 325-g including subband 320-g as shown in timeline 300-b), and one or more subbands are outside the COT (e.g., the base station failed to obtain the COT for subbands 320-a, 320-b, and 320-d as shown in timeline 300-a). The wireless device may implement one or more LBT procedures based on determining that at least one of the subbands 320 is outside the COT. For example, the wireless device may select a subband 320 in the set of subbands 320 that is associated with an uplink transmission. In some examples, the selection of the subbands 320 can be randomly performed based on a determination that at least one of the subbands 320 is outside the COT. The wireless device can perform a first LBT process for the selected subband 320 and a second LBT process for the other subbands 320 associated with uplink transmissions across the set of subbands 320. Such an LBT scheme can result in more efficient communication across multiple subbands 320 (e.g., the wireless device can have a reduced probability of medium access failure).

[0077] As an illustrative example, a wireless device may select subband 320-d for performing a first LBT procedure in timeline 300-a. As shown, TTI 315-a for subband 320-c may be included in the base station's COT. Based on selecting subband 320-d, the wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure) for the duration of LBT period 310-d (e.g., a relatively long monitoring period). The wireless device may perform a second LBT procedure for the remaining subbands 320 (e.g., subbands 320 not selected for uplink transmission). For example, the wireless device may perform a Category 2 LBT procedure for the duration of LBT period 310-a for subband 320-a, the duration of LBT period 310-b for subband 320-b, and the duration of LBT period 310-c for subband 320-c. The wireless device may transmit or refrain from transmitting an uplink transmission based on the results of each LBT procedure. For example, if the wireless device determines that each of the subbands 320 is idle (e.g., the results of the LBT process on each subband 320 indicate that the subband 320 is not occupied), the wireless device may send an uplink transmission on the resource 325 during the TTI 315-a. Alternatively, if the wireless device determines that the LBT process for one or more of the subbands 320 is unsuccessful, the wireless device may wait until a subsequent TTI 315 to attempt to send an uplink transmission (e.g., the wireless device may wait until all LBT processes are idle for a given TTI 315).

[0078] As another illustrative example, the wireless device may select subband 320-g for performing a first LBT procedure in timeline 300-b. As shown, TTI 315-b for subband 320-g may be included in the base station's COT. Based on selecting subband 320-g, the wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure) for the duration of LBT period 310-g (e.g., a relatively long monitoring period). The wireless device may perform a second LBT procedure for the remaining subbands 320 (e.g., subbands 320 not selected for uplink transmission). For example, the wireless device may perform a Category 2 LBT procedure for the duration of LBT period 310-e for subband 320-e, the duration of LBT period 310-f for subband 320-f, and the duration of LBT period 310-h for subband 320-h. The wireless device may transmit or refrain from transmitting an uplink transmission based on the results of each LBT procedure. For example, if the wireless device determines that each of the subbands 320 is idle (e.g., the results of the LBT process on each subband 320 indicate that the subband 320 is not occupied), the wireless device may send an uplink transmission on the resource 325 during the TTI 315-b. Alternatively, if the wireless device determines that the LBT process on one or more of the subbands 320 is unsuccessful, the wireless device may wait until a subsequent TTI 315 to attempt to send an uplink transmission (e.g., the wireless device may wait until all LBT processes are idle for a given TTI 315).

[0079] Figure 4A and Figure 4B 1 shows an example of a timeline 400-a and a timeline 400-b supporting LBT technology for a wireless communication system according to aspects of the present disclosure. In some examples, timeline 400 can implement aspects of wireless communication systems 100 and 200, timeline 300, or any combination thereof. For example, timelines 400-a and 400-b can include LBT period 410, TTI 415, subband 420, and resource 425, which can be as described in reference to FIG. Figure 1 - Examples of corresponding elements described in Figure 3.

[0080] In general, timeline 400-a and timeline 400-b may illustrate an example of a third LBT scheme for performing one or more LBT procedures as described herein across multiple subbands 420. The third LBT scheme may enable a wireless device (e.g., UE 115 or base station 105) to identify a set of subbands 420 included in a COT of a base station and perform one or more LBT procedures during an LBT period 410 based on the inclusion of the set of subbands 420 in the COT.

[0081] The wireless device can identify communications on resources 425. For example, the wireless device can identify uplink transmissions scheduled on multiple subbands 420, such as the set of subbands 420 that includes subband 420-a, subband 420-b, subband 420-c, and subband 420-d during TTI 415-a. In some examples, the wireless device can be configured with uplink transmissions as described herein with reference to FIG.

[0082] The wireless device may identify a set of subbands 420 from among a plurality of subbands 420 included in a COT of a base station (e.g., via an indication from the base station as described with reference to FIG. 3 ). For example, the wireless device may identify that none of the subbands 420 associated with an uplink transmission are included in the COT, that all of the subbands 420 associated with the uplink transmission are included in the COT, or that a first set of subbands 420 are included in the COT and a second set of subbands 420 are outside the COT. As an illustrative example, a first set of subbands 420 included in the COT may include subband 420-c in timeline 400-a (e.g., base station 105 has medium access to subband 420-c during a COT that includes TTI 415-a). As another illustrative example, a first set of subbands 420 included in the COT may include subband 420-g in timeline 400-b (e.g., base station 105 has medium access to subband 420-g during a COT that includes TTI 415-b).

[0083] The wireless device may implement one or more LBT procedures based on identifying a set of subbands 420 from among a plurality of subbands 420 included in the COT. For example, the wireless device may select one of the subbands 420 associated with uplink transmissions as an anchor subband 420 (e.g., an anchor channel). In some examples, the wireless device may randomly select the anchor subband 420. The wireless device may perform one or more LBT procedures during the LBT period 410 based on the selected anchor subband 420. For example, the wireless device may identify whether the anchor subband 420 is included in the COT. If the anchor subband 420 is outside the COT, the wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure). Alternatively, if the anchor subband 420 is included in the COT, the wireless device may perform a second LBT procedure (e.g., a Category 2 LBT procedure).

[0084] As an illustrative example, the wireless device may select subband 420-d as the anchor subband 420 in timeline 400-a. As shown, TTI 415-a for subband 420-c may be included in the COT of the base station (e.g., resources 425-c may be included in the COT). The wireless device may determine whether the selected anchor subband 420 (e.g., subband 420-d) is within the COT of the base station. For example, the wireless device may identify that the selected anchor subband 420-d in timeline 400-a includes resources 425-d outside the COT of the base station (e.g., the base station may not be able to obtain the COT of subband 420-d during TTI 415-a). The wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure) for the duration of LBT period 410-d (e.g., a relatively long monitoring period) based on identifying that anchor subband 420-d is outside the COT. Additionally or alternatively, the wireless device may perform a second LBT procedure for the remaining subbands 420 (e.g., subbands 420 that are not selected as uplink transmissions for the anchor subband 420). For example, the wireless device may perform a Category 2 LBT procedure (e.g., a relatively short monitoring period) for the duration of the LBT period 410-a for the subband 420-a, the duration of the LBT period 410-b for the subband 420-b, and the duration of the LBT period 410-c for the subband 420-c.

[0085] As another illustrative example, the wireless device may select subband 420-g as the anchor subband 420 in timeline 400-b. As shown, TTI 415-b for subband 420-g may be included in the base station's COT (e.g., resource 425-g may be included in the COT). The wireless device may determine whether the selected anchor subband 420 (e.g., subband 420-g) is within the base station's COT. For example, the wireless device may identify that the selected anchor subband 420-g in timeline 400-b includes resource 425-d within the base station's COT (e.g., the base station may obtain the COT for subband 420-g during TTI 415-b). The wireless device may perform a second LBT procedure (e.g., a Category 2 LBT procedure) for the duration of LBT period 410-g (e.g., a relatively short monitoring period) based on identifying that anchor subband 420-g is within the COT. Additionally or alternatively, the wireless device may perform a second LBT procedure for the remaining subbands 420 (e.g., subbands 420 that are not selected as uplink transmissions for the anchor subband 420). For example, the wireless device may perform a Category 2 LBT procedure for the duration of the LBT period 410-e of the subband 420-e, the duration of the LBT period 410-f of the subband 420-f, and the duration of the LBT period 410-h of the subband 420-h.

[0086] In reference Figure 4A and Figure 4B In some examples of the third LBT scheme described, the wireless device may send or refrain from sending an uplink transmission based on the results of each LBT process. For example, if the wireless device determines that each of the subbands 420 is idle (e.g., the results of the LBT process on each subband 420 indicate that the subband 420 is not occupied), the wireless device may send an uplink transmission on the resource 425 during the TTI 415-a. Alternatively, if the wireless device determines that the LBT process on one or more of the subbands 420 is unsuccessful, the wireless device may wait until a subsequent TTI 415 to attempt to send an uplink transmission (e.g., the wireless device may wait until all LBT processes are idle for a given TTI 415).

[0087] FIG5 illustrates an example of a timeline 500-a and a timeline 500-b supporting LBT technology for a wireless communication system according to aspects of the present disclosure. In some examples, timeline 500 can implement aspects of wireless communication systems 100 and 200, timeline 300, timeline 400, or any combination thereof. For example, timelines 500-a and 500-b can include LBT period 510, TTI 515, subband 520, and resource 525, which can be as described in reference to FIG5. Figure 1 - Examples of corresponding elements described in Figure 4.

[0088] In general, timeline 500-a and timeline 500-b may illustrate an example of a fourth LBT scheme for performing one or more LBT procedures as described herein across multiple subbands 520. The fourth LBT scheme may enable a wireless device (e.g., UE 115 or base station 105) to identify a set of subbands 520 included in a COT of a base station and perform one or more LBT procedures during an LBT period 510 based on the inclusion of the set of subbands 520 in the COT.

[0089] The wireless device may identify communications on resources 525. For example, the wireless device may identify uplink transmissions scheduled on multiple subbands 520, such as a set of subbands 520 including subband 520-a, subband 520-b, subband 520-c, and subband 520-d during TTI 515-a. In some examples, the wireless device may determine that each subband 520 is included in a COT (e.g., the base station 105 has medium access on each subband 520 during the COT including TTI 515-a). In such an example, the wireless device may implement a second LBT process (e.g., a Category 2 LBT process) during each of the LBT periods 510. For example, the wireless device may monitor the subbands 520 to determine whether each subband 520 is occupied according to the second LBT process (e.g., each of the LBT periods 510-a, 510-b, 510-c, and 510-d is a relatively short monitoring duration preceding the resources 525-a, 525-b, 525-c, and 525-d). If the wireless device determines that each subband is idle (e.g., the result of the second LBT process on each subband indicates that the subband is not occupied), the wireless device may use the resources 525 to send an uplink transmission.

[0090] In some examples of the fourth LBT scheme, the wireless device may determine that at least one of the subbands 520 is outside the COT of the base station. For example, the wireless device may determine that all of subbands 520-a, 520-b, 520-c, and 520-d are outside the COT. Additionally or alternatively, the wireless device may determine that a first set of subbands 520 is included in the COT (e.g., the base station has obtained medium access to resources 525-c including subband 520-c as shown in timeline 500-a and resources 525-g including subband 520-g as shown in timeline 500-b), and a second set of subbands is outside the COT (e.g., the base station has failed to obtain the COT for subbands 520-a, 520-b, and 520-d as shown in timeline 500-a).

[0091] The wireless device may implement one or more LBT processes based on determining that the first set of subbands 520 is included in the COT. For example, the wireless device may select a subband 520 from the second set of subbands 520 (e.g., subbands 520 outside the COT). In some examples, the selection of the subband 520 may be performed randomly within the second set of subbands 520 outside the COT. The wireless device may perform a first LBT process (e.g., a Category 4 LBT process) for the selected subband 520 and a second LBT process (e.g., a Category 2 LBT process) for the other subbands 520 associated with uplink transmissions spanning multiple subbands 520.

[0092] As an illustrative example, the wireless device may select subband 520-d for performing a first LBT procedure in timeline 500-a. As shown, TTI 515-a for subband 520-c may be included in the COT of the base station, and TTI 515-a for subbands 520-a, 520-b, and 520-d may be outside the COT. The wireless device may randomly select subband 520-d from the subbands 520-a, 520-b, and 520-d outside the COT. The wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure) for the duration of LBT period 510-d (e.g., a relatively long monitoring period) based on selecting subband 520-d. The wireless device may perform a second LBT procedure for the remaining subbands 520 (e.g., subbands 520 not selected for uplink transmission). For example, the wireless device may perform a Category 2 LBT procedure for the duration of LBT period 510-a for subband 520-a, the duration of LBT period 510-b for subband 520-b, and the duration of LBT period 510-d for subband 520-d. The wireless device may send or refrain from sending an uplink transmission based on the results of each LBT procedure. For example, if the wireless device determines that each of the subbands 520 is idle (e.g., the results of the LBT procedure on each subband 520 indicate that the subband 520 is not occupied), the wireless device may send an uplink transmission on resource 525 during TTI 515-a. Alternatively, if the wireless device determines that the LBT procedure for one or more of the subbands 520 is unsuccessful, the wireless device may wait until a subsequent TTI 515 to attempt to send an uplink transmission (e.g., the wireless device may wait until all LBT processes are idle for a given TTI 515).

[0093] As another illustrative example, the wireless device may select subband 520-f for performing a first LBT procedure in timeline 500-a. As shown, TTI 515-a for subband 520-g may be included in the COT of the base station, and TTI 515-a for subbands 520-e, 520-f, and 520-h may be outside the COT. The wireless device may randomly select subband 520-f from among subbands 520-e, 520-f, and 520-h outside the COT. The wireless device may perform a first LBT procedure (e.g., a Category 4 LBT procedure) for the duration of LBT period 510-f (e.g., a relatively long monitoring period) based on selecting subband 520-f. The wireless device may perform a second LBT procedure for the remaining subbands 520 (e.g., subbands 520 not selected for uplink transmission). For example, the wireless device may perform a Category 2 LBT procedure for the duration of the LBT period 510-e for subband 520-e, the duration of the LBT period 510-g for subband 520-g, and the duration of the LBT period 510-h for subband 520-h. The wireless device may send or refrain from sending an uplink transmission based on the results of each LBT procedure. For example, if the wireless device determines that each of the subbands 520 is idle (e.g., the results of the LBT procedure on each subband 520 indicate that the subband 520 is not occupied), the wireless device may send an uplink transmission on the resource 525 during the TTI 515-a. Alternatively, if the wireless device determines that the LBT procedure for one or more of the subbands 520 is unsuccessful, the wireless device may wait until a subsequent TTI 515 to attempt to send an uplink transmission (e.g., the wireless device may wait until all LBT processes are idle for a given TTI 515).

[0094] Figure 6 A block diagram 600 of a device 605 supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown. The device 605 can be an example of aspects of the UE 115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 may also include one or more processors, a memory coupled to the one or more processors, and instructions stored in the memory that are executable by the one or more processors to enable the one or more processors to perform the LBT features discussed herein. Each of these components can communicate with each other (e.g., via one or more buses).

[0095] The receiver 610 may receive information associated with various information channels (e.g., control channels, data channels, and information related to LBT technology for wireless communication systems, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 605. The receiver 610 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 610 may utilize a single antenna or a collection of antennas.

[0096] The communication manager 615 may determine to send an uplink message to the base station on a subband set of a radio frequency spectrum band during a transmission time interval, identify that the transmission time interval is during a COT of the base station for a first subband set in the subband set, perform an LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station, and send the uplink message on each subband set based on a result of the LBT process performed for the subband set. The communication manager 615 may be an example of aspects of the communication manager 910 described herein.

[0097] The communication manager 615 or its subcomponents may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615 or its subcomponents may be performed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0098] The communication manager 615 or its subcomponents can be physically located in a variety of locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0099] The actions performed by the communication manager 615 described herein may be implemented to achieve one or more potential advantages. For example, performing one or more LBT procedures for multiple subbands based on determining that a first set of subbands (e.g., all subbands, no subbands, or a portion of the subbands) is included in the COT of the base station may result in relatively efficient communication. For example, such LBT procedures that consider the COT across multiple subbands may achieve more efficient communication while maintaining a relatively low chance of interfering with other transmissions in the system.

[0100] Additionally or alternatively, the communication manager 615 can be implemented to realize one or more potential advantages at the processor level. For example, the communication manager 615 can be enabled to perform a relatively more efficient LBT process (e.g., a Category 2 LBT process) for one or more of the multiple subbands used for uplink transmission. Such an LBT process can result in reduced processing overhead and power consumption at the UE's processor, increased likelihood of successful medium access, or both, among other advantages.

[0101] Transmitter 620 can transmit signals generated by other components of device 605. In some examples, transmitter 620 can be co-located with receiver 610 in a transceiver module. For example, transmitter 620 can be a reference Figure 9 Examples of aspects of the described transceiver 920. The transmitter 620 may utilize a single antenna or a collection of antennas.

[0102] Figure 7 A block diagram 700 is shown of a device 705 supporting LBT technology for a wireless communication system according to aspects of the present disclosure. The device 705 can be an example of aspects of the device 605 or UE 115 as described herein. The device 705 can include a receiver 710, a communication manager 715, and a transmitter 740. The device 705 can also include a processor. Each of these components can communicate with each other (e.g., via one or more buses).

[0103] The receiver 710 may receive information associated with various information channels (e.g., control channels, data channels, and information related to LBT technology for wireless communication systems, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 705. The receiver 710 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 710 may utilize a single antenna or a collection of antennas.

[0104] Communications manager 715 may be an example of aspects of communications manager 615 described herein. Communications manager 715 may include messaging component 720, COT component 725, LBT component 730, and uplink transmitter 735. Communications manager 715 may be an example of aspects of communications manager 910 described herein.

[0105] The message component 720 can determine to send an uplink message to the base station on a set of subbands of the radio frequency spectrum band during a transmission time interval.

[0106] The COT component 725 can identify that a transmission time interval is during a COT of the base station for a first subband set in the subband sets.

[0107] The LBT component 730 can perform, for each subband in the subband set, an LBT process selected for each subband based on identifying that the transmission time interval is during a COT of the base station.

[0108] The uplink transmitter 735 may transmit an uplink message on the subband set based on the result of the LBT process performed for each subband in the subband set.

[0109] Transmitter 740 can transmit signals generated by other components of device 705. In some examples, transmitter 740 can be co-located with receiver 710 in a transceiver module. For example, transmitter 740 can be a reference Figure 9 Examples of aspects of the described transceiver 920. The transmitter 740 may utilize a single antenna or a collection of antennas.

[0110] In some cases, the message component 720, the COT component 725, the LBT component 730, and the uplink transmitter 735 can each be a part of a process or at least a processor (e.g., a transceiver processor, a radio processor, a transmitter processor, or a receiver processor). The processor can be coupled to a memory and execute instructions stored in the memory that enable the processor to perform or facilitate the features of the message component 720, the COT component 725, the LBT component 730, and the uplink transmitter 735 discussed herein. The transceiver processor can be co-located with and / or communicate with (e.g., direct the operation of) the transceiver of the device. The radio processor can be co-located with and / or communicate with (e.g., direct the operation of) the radio of the device (e.g., NR radio, LTE radio, Wi-Fi radio). The transmitter processor can be co-located with and / or communicate with (e.g., direct the operation of) the transmitter of the device. The receiver processor can be co-located with and / or communicate with (e.g., direct the operation of) the receiver of the device.

[0111] Figure 8A block diagram 800 is shown of a communication manager 805 that supports LBT technology for a wireless communication system in accordance with aspects of the present disclosure. The communication manager 805 can be an example of aspects of the communication manager 615, the communication manager 715, or the communication manager 910 described herein. The communication manager 805 can include a messaging component 810, a COT component 815, an LBT component 820, an uplink transmitter 825, an LBT selection component 830, a subband selection component 835, a configuration component 840, and a system information component 845. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0112] The message component 810 can determine to send an uplink message to a base station on a set of subbands of a radio frequency spectrum band during a transmission time interval.

[0113] The COT component 815 can identify that a transmission time interval is during the COT of the base station for a first subband set in the subband set. In some examples, the COT component 815 can determine that a transmission time interval is during the COT of the base station for all subbands in the subband set, where the first subband set includes the subband set. In some examples, the COT component 815 can determine that a transmission time interval is outside the COT of the base station for all subbands in the subband set, where the first subband set includes the subband set.

[0114] In some examples, the COT component 815 can identify that a previous transmission time interval was outside of the COT for a second subband set in the subband set. In some examples, a transmission time interval is determined to be during the COT for all subbands in the subband set, wherein the first subband set includes the subband set.

[0115] The LBT component 820 can perform the LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station. In some examples, the LBT component 820 can avoid performing the LBT process on the previous transmission time interval based on identifying that the previous transmission time interval is outside the COT. In some examples, the LBT component 820 can perform a first LBT process on the first selected subband in the subband set and a second LBT process on the remaining one or more subbands in the subband set.

[0116] In some examples, the LBT component 820 may perform a second LBT process on one or more remaining subbands of the subband set, the remaining one or more subbands being different from the selected first subband. In some examples, the LBT component 820 may perform a first LBT process on the selected first subband. In some examples, the LBT component 820 may perform a second LBT process on the remaining one or more subbands in the subband set. In some cases, the LBT process for each subband of the subband set comprises the same LBT process. In some cases, the first LBT process comprises a Category 4 LBT process, and the second LBT process comprises a Category 2 LBT process.

[0117] The uplink transmitter 825 may transmit an uplink message on the subband set based on the results of the LBT process performed on each subband in the subband set. In some examples, the uplink transmitter 825 may transmit on the subband set during the uplink message based on identifying that a transmission time interval for all subbands in the subband set is during the COT of the base station, or that a transmission time interval for all subbands in the subband set is outside the COT of the base station. In some examples, the uplink transmitter 825 may transmit the uplink message on the subband set in response to the results of the LBT process (including the first LBT process and the second LBT process) performed on each subband in the subband set indicating that all subbands in the subband set are idle.

[0118] The LBT selection component 830 can select the LBT process as a Category 2 LBT process. In some examples, the LBT selection component 830 can select the LBT process as a Category 4 LBT process. In some examples, the LBT selection component 830 can select the same LBT process for each subband in the subband set based on the transmission time interval being during the COT period of the base station for all subbands.

[0119] In some examples, LBT selection component 830 can select a first LBT process for the selected first subband based on identifying that the transmission time interval is outside the COT for the first subband, or select a second LBT process for the selected first subband based on identifying that the transmission time interval is during the COT for the first subband. In some examples, LBT selection component 830 can randomly select the first subband from a set of first subbands for which the transmission time interval is during the COT of the base station. In some cases, the first LBT process comprises a Category 4 LBT process, and the second LBT process comprises a Category 2 LBT process.

[0120] In some examples, subband selection component 835 may select a first subband from the subband set. In some examples, subband selection component 835 may randomly select the first subband from the subband set. In some examples, subband selection component 835 may select the first subband from the subband set based on determining that a transmission time interval is outside the COT for at least one subband of the subband set. In some cases, the first LBT process comprises a Category 4 LBT process, and the second LBT process comprises a Category 2 LBT process.

[0121] Configuration component 840 may receive an uplink configuration for the UE from a base station, the uplink configuration indicating a subband set of a radio frequency spectrum band. In some examples, configuration component 840 may receive a radio resource control signal indicating the uplink configuration, a downlink control information signal indicating the uplink configuration, or a combination thereof.

[0122] The system information component 845 can receive system information from a base station, the system information indicating a result of an LBT process performed by the base station for each subband in the subband set, wherein the transmission time interval is identified as being during the COT based on the received system information. In some cases, the system information includes a bitmap, each bit of the bitmap corresponding to a result of the LBT process for a corresponding one of the subbands in the subband set.

[0123] In some cases, the message component 810, the COT component 815, the LBT component 820, the uplink transmitter 825, the LBT selection component 830, the subband selection component 835, the configuration component 840, and the system information component 845 can each be a processor or at least a portion of a processor (e.g., a transceiver processor, a radio processor, a transmitter processor, or a receiver processor). The processor can be coupled to a memory and execute instructions stored in the memory that enable the processor to perform or facilitate the features of the message component 810, the COT component 815, the LBT component 820, the uplink transmitter 825, the LBT selection component 830, the subband selection component 835, the configuration component 840, and the system information component 845 discussed herein.

[0124] Figure 9A diagram of a system 900 including a device 905 supporting LBT technology for a wireless communication system according to various aspects of the present disclosure is shown. The device 905 may be an example of the device 605, device 705, or UE 115 as described herein or include a component of the device 805, device 905, or UE 115. The device 905 may include components for two-way voice and data communication, including components for sending and receiving communications, including a communication manager 910, an I / O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components may communicate electronically via one or more buses (e.g., bus 945).

[0125] The communication manager 910 can determine that an uplink message is to be sent to the base station on a subband set of the radio frequency spectrum band during a transmission time interval, identify that the transmission time interval is during the COT of the base station for a first subband set in the subband set, perform an LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station, and send the uplink message on the subband set based on a result of the LBT process performed for each subband in the subband set.

[0126] I / O controller 915 can manage input and output signals for device 905. I / O controller 915 can also manage peripheral devices that are not integrated into device 905. In some cases, I / O controller 915 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 915 can utilize an operating system, such as or another well-known operating system. In other cases, I / O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 915 may be implemented as part of a processor. In some cases, a user may interact with device 905 via I / O controller 915 or via hardware components controlled by I / O controller 915.

[0127] As described above, the transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links. For example, the transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0128] In some cases, a wireless device may include a single antenna 925. However, in some cases, a device may have more than one antenna 925, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0129] The memory 930 may include random access memory (RAM) and read-only memory (ROM). The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 930 may also contain, among other things, a basic input / output system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0130] The processor 940 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 940 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks supporting LBT technology for a wireless communication system).

[0131] The code 935 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 935 may be stored in a non-transitory computer-readable medium such as system memory or other types of memory. In some cases, the code 935 may not be directly executable by the processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0132] Figure 10 1. A flow chart illustrating a method 1000 for supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown. The operations of the method 1000 may be implemented by a UE 115 or components thereof as described herein. In some examples, the operations of the method 1000 may be implemented by a UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0133] At 1005, the UE may determine to send an uplink message to the base station on a subband set of a radio frequency spectrum band during a transmission time interval. The operations of 1005 may be performed according to the methods described herein. In some examples, aspects of the operations of 1005 may be as described with reference to Figures 6 to 9 Describes the message component execution.

[0134] At 1010, the UE may identify that a transmission time interval is during a COT of the base station for a first subband set in the subband set. The operations of 1010 may be performed according to the methods described herein. In some examples, aspects of the operations of 1010 may be as described with reference to Figures 6 to 9 Describes the implementation of the COT components.

[0135] At 1015, the UE may perform an LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station. The operations of 1015 may be performed according to the methods described herein. In some examples, aspects of the operations of 1015 may be as described with reference to Figures 6 to 9 Describes the LBT component implementation.

[0136] At 1020, the UE may send an uplink message on the subband set based on the results of the LBT process performed for each subband in the subband set. The operations of 1020 may be performed according to the methods described herein. In some examples, aspects of the operations of 1020 may be as described with reference to Figures 6 to 9 The uplink transmitter implementation is described.

[0137] Figure 11 1. A flow chart illustrating a method 1100 for supporting LBT technology for a wireless communication system according to aspects of the present disclosure is shown. The operations of the method 1100 may be implemented by a UE 115 or components thereof as described herein. In some examples, the operations of the method 1100 may be implemented by a UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0138] At 1105, the UE may receive system information from the base station that indicates, for each subband in the subband set, a result of the LBT process performed by the base station. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be as described with reference to Figures 6 to 9 Describes the system information component implementation.

[0139] At 1110, the UE may determine to send an uplink message to the base station on a set of subbands of a radio frequency spectrum band during a transmission time interval. The operations of 1110 may be performed according to the methods described herein. In some examples, aspects of the operations of 1110 may be performed as described in reference to Figures 6 to 9 Describes the message component execution.

[0140] At 1115, the UE may identify, based on the received system information, that a transmission time interval is during the COT of the base station for the first subband set in the subband set. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be as described with reference to Figures 6 to 9 Describes the implementation of the COT components.

[0141] At 1120, the UE may perform an LBT process selected for each subband in the subband set based on identifying that the transmission time interval is during the COT of the base station. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be as described with reference to Figures 6 to 9 Describes the LBT component implementation.

[0142] At 1125, the UE may send an uplink message on the subband set based on the results of the LBT process performed for each subband in the subband set. The operations of 1125 may be performed according to the methods described herein. In some examples, aspects of the operations of 1125 may be as described with reference to Figures 6 to 9 The uplink transmitter implementation is described.

[0143] It should be noted that the methods described herein describe possible implementations, that operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0144] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and the terminology of LTE, LTE-A, LTE-A Pro, or NR may be used throughout much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described are applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0145] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout this specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0146] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration).

[0147] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or a combination of any of these. Features that implement the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented in different physical locations.

[0148] Computer-readable media include both non-transitory computer storage media and communication media, and communication media include any media that promotes the transfer of a computer program from one place to another. Non-transitory storage media can be any available media that can be accessed by a general or special-purpose computer. As an example and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage devices, or can be used to carry or store required program code components in the form of instructions or data structures and any other non-transitory media that can be accessed by a general or special-purpose computer or a general or special-purpose processor. Moreover, any connection is properly referred to as a computer-readable medium. For example, if software is sent from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwaves, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are included in the definition of computer-readable media. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0149] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items terminated by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0150] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the specification applies to any similar component having the same first reference number, regardless of the second or subsequent reference numbers.

[0151] The description presented herein in conjunction with the accompanying drawings describes exemplary configurations and does not represent all examples that can be implemented or within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "superior to other examples." The detailed description includes specific details to provide an understanding of the technology. However, these technologies can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0152] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: determining to transmit an uplink message to a network device on a plurality of sub-bands of a radio frequency spectrum band during a transmission time interval; identifying that the transmission time interval is during a channel occupancy time of the network device for a first set of subbands in the plurality of subbands; performing, for each of the plurality of subbands, a listen-before-talk procedure selected by the UE for each subband based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for the first set of subbands; randomly selecting the first subband from the plurality of subbands based at least in part on determining that the transmission time interval is outside the channel occupancy time for at least one subband of the plurality of subbands; performing a first listen-before-talk process for a selected first subband of the plurality of subbands; performing a second listen-before-talk process for the remaining one or more subbands of the plurality of subbands, wherein the first listen-before-talk process is different from the second listen-before-talk process; and The uplink message is sent on the plurality of subbands based at least in part on a result of the listen-before-talk process performed for each of the plurality of subbands.

2. The method according to claim 1, wherein The first sub-band is selected from the plurality of sub-bands and is outside the channel occupancy time.

3. The method according to claim 1, wherein The listen-before-talk process for each subband of the plurality of subbands comprises a same listen-before-talk process.

4. The method according to claim 3, further comprising: determining that the transmission time interval is during the channel occupancy time of the network device for all subbands of the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 2 listen-before-speak process.

5. The method according to claim 3, further comprising: determining that the transmission time interval is outside the channel occupancy time of the network device for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 4 listen-before-speak process.

6. The method according to claim 1, wherein Sending the uplink message on the multiple subbands includes: identifying that a previous transmission time interval is outside the channel occupancy time for a second set of subbands in the plurality of subbands; refraining from performing the listen-before-talk procedure on a previous transmission time interval based at least in part on identifying that the previous transmission time interval is outside the channel occupancy time; and During the uplink message, transmitting on the multiple subbands is performed based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for all of the multiple subbands or that the transmission time interval is outside the channel occupancy time of the network device for all of the multiple subbands.

7. The method according to claim 1, further comprising: determining that the transmission time interval is during the channel occupancy time for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as A same listen-before-talk procedure is selected for each of the plurality of subbands based at least in part on the transmission time interval being during the channel occupancy time of the network device for all of the subbands.

8. The method according to claim 1, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

9. The method according to claim 1, wherein: Performing the listen-before-talk process for each of the plurality of subbands includes: selecting a first subband from the plurality of subbands; selecting a first listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is outside the channel occupancy time for the first subband, or selecting a second listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is during the channel occupancy time for the first subband; and The second listen-before-talk process is performed on one or more remaining subbands of the plurality of subbands, the one or more remaining subbands being different from the selected first subband.

10. The method according to claim 9, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

11. The method according to claim 9, wherein: Sending the uplink message on the plurality of subbands is responsive to a result of the listen-before-talk procedure performed for each of the plurality of subbands indicating that all of the plurality of subbands are idle, the listen-before-talk procedure including the first listen-before-talk procedure and the second listen-before-talk procedure.

12. The method according to claim 1, wherein Performing the listen-before-talk process for each of the plurality of subbands includes: selecting a first subband in the first subband set; performing a first listen-before-talk process for the selected first subband; and A second listen-before-talk process is performed for the remaining one or more subbands of the plurality of subbands.

13. The method according to claim 12, wherein: Selecting the first sub-band includes: The first subband is randomly selected from the set of first subbands for which the transmission time interval is during the channel occupancy time of the network device.

14. The method according to claim 12, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

15. The method according to claim 1, further comprising: An uplink configuration for the UE is received from the network device, the uplink configuration indicating the plurality of subbands of the radio frequency spectrum band.

16. The method according to claim 15, wherein Receiving the uplink configuration includes: A radio resource control signal indicating the uplink configuration, a downlink control information signal indicating the uplink configuration, or a combination thereof is received.

17. The method according to claim 1, further comprising: System information is received from the network device, the system information indicating a result of a listen-before-talk procedure performed by the network device for each of the plurality of subbands, wherein identifying the transmission time interval is during the channel occupancy time based at least in part on the received system information.

18. The method according to claim 17, wherein: The system information includes a bitmap, each bit of the bitmap corresponding to a result of the listen-before-talk process for a corresponding one of the plurality of subbands.

19. An apparatus for performing wireless communication at a user equipment (UE), comprising: processor, a memory coupled to the processor; as well as instructions, stored in the memory and executable by the processor, to cause the apparatus to: determining to transmit an uplink message to a network device on a plurality of sub-bands of a radio frequency spectrum band during a transmission time interval; identifying that the transmission time interval is during a channel occupancy time of the network device for a first set of subbands in the plurality of subbands; performing, for each of the plurality of subbands, a listen-before-talk procedure selected by the UE for each subband based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for the first set of subbands; randomly selecting the first subband from the plurality of subbands based at least in part on determining that the transmission time interval is outside the channel occupancy time for at least one subband of the plurality of subbands; performing a first listen-before-talk process for a selected first subband of the plurality of subbands; performing a second listen-before-talk process for the remaining one or more subbands of the plurality of subbands, wherein the first listen-before-talk process is different from the second listen-before-talk process; and The uplink message is sent on the plurality of subbands based at least in part on a result of the listen-before-talk process performed for each of the plurality of subbands.

20. The device according to claim 19, wherein The first sub-band is selected from the plurality of sub-bands and is outside the channel occupancy time.

21. The apparatus according to claim 19, wherein The listen-before-talk process for each subband of the plurality of subbands comprises a same listen-before-talk process.

22. The device according to claim 21, wherein The instructions are further executable by the processor to cause the apparatus to: determining that the transmission time interval is during the channel occupancy time of the network device for all subbands of the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 2 listen-before-speak process.

23. The device according to claim 21, wherein The instructions are further executable by the processor to cause the apparatus to: determining that the transmission time interval is outside the channel occupancy time of the network device for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 4 listen-before-speak process.

24. The apparatus according to claim 19, wherein The instructions are further executable by the processor to send the uplink message on the plurality of subbands by the processor performing the following operations: identifying that a previous transmission time interval is outside the channel occupancy time for a second set of subbands in the plurality of subbands; refraining from performing the listen-before-talk procedure on a previous transmission time interval based at least in part on identifying that the previous transmission time interval is outside the channel occupancy time; as well as During the uplink message, transmitting on the multiple subbands is performed based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for all of the multiple subbands or that the transmission time interval is outside the channel occupancy time of the network device for all of the multiple subbands.

25. The apparatus according to claim 19, wherein The instructions are further executable by the processor to cause the apparatus to: determining that the transmission time interval is during the channel occupancy time for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as A same listen-before-talk procedure is selected for each of the plurality of subbands based at least in part on the transmission time interval being during the channel occupancy time of the network device for all of the subbands.

26. The apparatus according to claim 19, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

27. The apparatus according to claim 19, wherein The instructions are further executable by the processor to perform a listen-before-talk process for each of the plurality of subbands by the processor performing the following operations: selecting a first subband from the plurality of subbands; selecting a first listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is outside the channel occupancy time for the first subband, or selecting a second listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is during the channel occupancy time for the first subband; as well as The second listen-before-talk process is performed on one or more remaining subbands of the plurality of subbands, the one or more remaining subbands being different from the selected first subband.

28. The apparatus according to claim 27, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

29. The apparatus according to claim 27, wherein Sending the uplink message on the plurality of subbands is responsive to a result of the listen-before-talk procedure performed for each of the plurality of subbands indicating that all of the plurality of subbands are idle, the listen-before-talk procedure including the first listen-before-talk procedure and the second listen-before-talk procedure.

30. The apparatus according to claim 19, wherein The instructions are further executable by the processor to perform a listen-before-talk process for each of the plurality of subbands by the processor performing the following operations: selecting a first subband in the first subband set; performing a first listen-before-talk process for the selected first subband; as well as A second listen-before-talk process is performed for the remaining one or more subbands of the plurality of subbands.

31. The device according to claim 30, wherein The instructions are further executable by the processor to select the first subband by performing, by the processor: The first subband is randomly selected from the set of first subbands for which the transmission time interval is during the channel occupancy time of the network device.

32. The apparatus according to claim 30, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

33. The apparatus of claim 19, wherein: The instructions are further executable by the processor to cause the apparatus to: An uplink configuration for the UE is received from the network device, the uplink configuration indicating the plurality of subbands of the radio frequency spectrum band.

34. The apparatus according to claim 33, wherein The instructions are further executable by the processor to receive the uplink configuration by the processor performing the following operations: A radio resource control signal indicating the uplink configuration, a downlink control information signal indicating the uplink configuration, or a combination thereof is received.

35. The apparatus of claim 19, wherein The instructions are further executable by the processor to cause the apparatus to: System information is received from the network device, the system information indicating a result of a listen-before-talk procedure performed by the network device for each of the plurality of subbands, wherein identifying the transmission time interval is during the channel occupancy time based at least in part on the received system information.

36. The apparatus of claim 35, wherein: The system information includes a bitmap, each bit of the bitmap corresponding to a result of the listen-before-talk process for a corresponding one of the plurality of subbands.

37. An apparatus for performing wireless communication at a user equipment (UE), comprising: means for determining to transmit an uplink message to a network device on a plurality of sub-bands of a radio frequency spectrum band during a transmission time interval; means for identifying that the transmission time interval is during a channel occupancy time of the network device for a first set of subbands among the plurality of subbands; means for performing, for each of the plurality of subbands, a listen-before-talk procedure selected by the UE for each subband based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for the first set of subbands; means for randomly selecting the first subband from the plurality of subbands based at least in part on determining that the transmission time interval is outside the channel occupancy time for at least one subband of the plurality of subbands; means for performing a first listen-before-talk procedure for a selected first subband of the plurality of subbands; means for performing a second listen-before-talk procedure for one or more remaining subbands of the plurality of subbands, wherein the first listen-before-talk procedure is different from the second listen-before-talk procedure; as well as means for transmitting the uplink message on the plurality of subbands based at least in part on a result of the listen-before-talk procedure performed for each of the plurality of subbands.

38. The apparatus according to claim 37, wherein The first sub-band is selected from the plurality of sub-bands and is outside the channel occupancy time.

39. The apparatus of claim 37, wherein: The listen-before-talk process for each subband of the plurality of subbands comprises a same listen-before-talk process.

40. The apparatus of claim 39, further comprising: means for determining that the transmission time interval is during the channel occupancy time of the network device for all subbands of the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as Means for selecting the listen-before-talk procedure as a category 2 listen-before-talk procedure.

41. The apparatus of claim 39, further comprising: means for determining that the transmission time interval is outside the channel occupancy time of the network device for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as Means for selecting the listen-before-talk procedure as a category 4 listen-before-talk procedure.

42. The apparatus of claim 37, wherein: The means for sending the uplink message on the plurality of subbands comprises: means for identifying that a previous transmission time interval was outside of said channel occupancy time for a second set of subbands in said plurality of subbands; means for avoiding performing the listen-before-talk procedure for a previous transmission time interval based at least in part on identifying that the previous transmission time interval is outside the channel occupancy time; and and means for transmitting on the plurality of subbands during the uplink message based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for all of the plurality of subbands or that the transmission time interval is outside the channel occupancy time of the network device for all of the plurality of subbands.

43. The apparatus of claim 37, further comprising: means for determining that the transmission time interval is during the channel occupancy time for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as means for selecting a same listen-before-talk procedure for each of the plurality of subbands based at least in part on the transmission time interval being during the channel occupancy time of the network device for all of the subbands.

44. The apparatus of claim 37, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

45. The apparatus of claim 37, wherein The means for performing a listen-before-talk procedure for each of the plurality of subbands comprises: means for selecting a first subband of the plurality of subbands; means for selecting a first listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is outside the channel occupancy time for the first subband, or selecting a second listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is during the channel occupancy time for the first subband; and means for performing the second listen-before-talk procedure for one or more remaining subbands of the plurality of subbands, the one or more remaining subbands being different from the selected first subband.

46. ​​The apparatus of claim 45, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

47. The apparatus of claim 45, wherein: Sending the uplink message on the plurality of subbands indicates that all of the plurality of subbands are idle in response to a result of a listen-before-talk procedure performed for each of the plurality of subbands, the listen-before-talk procedure including the first listen-before-talk procedure and the second listen-before-talk procedure.

48. The apparatus of claim 37, wherein The means for performing a listen-before-talk procedure for each of the plurality of subbands comprises: means for selecting a first subband in said first set of subbands; means for performing a first listen-before-talk procedure for the selected first sub-band; and Means for performing a second listen-before-talk procedure for the remaining one or more subbands of the plurality of subbands.

49. The apparatus according to claim 48, wherein The means for selecting the first sub-band comprises: Means for randomly selecting the first subband from the set of first subbands for which the transmission time interval is during the channel occupancy time of the network device.

50. The apparatus of claim 48, wherein The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

51. The apparatus of claim 37, further comprising: Means for receiving an uplink configuration for the UE from the network device, the uplink configuration indicating the plurality of subbands of the radio frequency spectrum band.

52. The apparatus of claim 51, wherein The means for receiving the uplink configuration comprises: Means for receiving a radio resource control signal indicating the uplink configuration, a downlink control information signal indicating the uplink configuration, or a combination thereof.

53. The apparatus of claim 37, further comprising: means for receiving system information from the network device, the system information indicating a result of a listen-before-talk procedure performed by the network device for each of the plurality of subbands, wherein identifying the transmission time interval is during the channel occupancy time based at least in part on the received system information.

54. The apparatus of claim 53, wherein: The system information includes a bitmap, each bit of the bitmap corresponding to a result of the listen-before-talk process for a corresponding one of the plurality of subbands.

55. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to: determining to transmit an uplink message to a network device on a plurality of sub-bands of a radio frequency spectrum band during a transmission time interval; identifying that the transmission time interval is during a channel occupancy time of the network device for a first set of subbands in the plurality of subbands; performing, for each of the plurality of subbands, a listen-before-talk procedure selected by the UE for each subband based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for the first set of subbands; randomly selecting the first subband from the plurality of subbands based at least in part on determining that the transmission time interval is outside the channel occupancy time for at least one subband of the plurality of subbands; performing a first listen-before-talk process for a selected first subband of the plurality of subbands; performing a second listen-before-talk process for the remaining one or more subbands of the plurality of subbands, wherein the first listen-before-talk process is different from the second listen-before-talk process; and The uplink message is sent on the plurality of subbands based at least in part on a result of the listen-before-talk process performed for each of the plurality of subbands.

56. The non-transitory computer readable medium of claim 55, wherein: The first sub-band is selected from the plurality of sub-bands and is outside the channel occupancy time.

57. The non-transitory computer readable medium of claim 55, wherein: The listen-before-talk process for each subband of the plurality of subbands comprises a same listen-before-talk process.

58. The non-transitory computer readable medium of claim 57, wherein: The instructions are further executable to: determining that the transmission time interval is during the channel occupancy time of the network device for all subbands of the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 2 listen-before-speak process.

59. The non-transitory computer readable medium of claim 57, wherein: The instructions are further executable to: determining that the transmission time interval is outside the channel occupancy time of the network device for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as The listen-before-speak process is selected as category 4 listen-before-speak process.

60. The non-transitory computer readable medium of claim 55, wherein: The instructions for transmitting the uplink message on the plurality of subbands are executable to: identifying that a previous transmission time interval is outside the channel occupancy time for a second set of subbands in the plurality of subbands; refraining from performing the listen-before-talk procedure on a previous transmission time interval based at least in part on identifying that the previous transmission time interval is outside the channel occupancy time; as well as During the uplink message, transmitting on the multiple subbands is performed based at least in part on identifying that the transmission time interval is during the channel occupancy time of the network device for all of the multiple subbands or that the transmission time interval is outside the channel occupancy time of the network device for all of the multiple subbands.

61. The non-transitory computer readable medium of claim 55, wherein: The instructions are further executable to: determining that the transmission time interval is during the channel occupancy time for all subbands in the plurality of subbands, wherein the first subband set includes the plurality of subbands; as well as A same listen-before-talk procedure is selected for each of the plurality of subbands based at least in part on the transmission time interval being during the channel occupancy time of the network device for all of the subbands.

62. The non-transitory computer readable medium of claim 55, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

63. The non-transitory computer readable medium of claim 55, wherein: The instructions for performing a listen-before-talk process for each of the plurality of subbands are executable to: selecting a first subband from the plurality of subbands; selecting a first listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is outside the channel occupancy time for the first subband, or selecting a second listen-before-talk procedure for the selected first subband based at least in part on identifying that the transmission time interval is during the channel occupancy time for the first subband; as well as The second listen-before-talk process is performed on one or more remaining subbands of the plurality of subbands, the one or more remaining subbands being different from the selected first subband.

64. The non-transitory computer readable medium of claim 63, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

65. The non-transitory computer readable medium of claim 63, wherein: Sending the uplink message on the plurality of subbands indicates that all of the plurality of subbands are idle in response to a result of a listen-before-talk procedure performed for each of the plurality of subbands, the listen-before-talk procedure including the first listen-before-talk procedure and the second listen-before-talk procedure.

66. The non-transitory computer readable medium of claim 55, wherein: The instructions for performing a listen-before-talk process for each of the plurality of subbands are executable to: selecting a first subband in the first subband set; performing a first listen-before-talk process for the selected first subband; as well as A second listen-before-talk process is performed for the remaining one or more subbands of the plurality of subbands.

67. The non-transitory computer readable medium of claim 66, wherein: The instructions for selecting the first subband are further executable to: The first subband is randomly selected from the set of first subbands for which the transmission time interval is during the channel occupancy time of the network device.

68. The non-transitory computer readable medium of claim 66, wherein: The first listen-before-talk process comprises a category 4 listen-before-talk process, and the second listen-before-talk process comprises a category 2 listen-before-talk process.

69. The non-transitory computer readable medium of claim 55, wherein: The instructions are further executable to: An uplink configuration for the UE is received from the network device, the uplink configuration indicating the plurality of subbands of the radio frequency spectrum band.

70. The non-transitory computer readable medium of claim 69, wherein: The instructions for receiving the uplink configuration are further executable to: A radio resource control signal indicating the uplink configuration, a downlink control information signal indicating the uplink configuration, or a combination thereof is received.

71. The non-transitory computer readable medium of claim 55, wherein: The instructions are further executable to: System information is received from the network device, the system information indicating a result of a listen-before-talk procedure performed by the network device for each of the plurality of subbands, wherein identifying the transmission time interval is during the channel occupancy time based at least in part on the received system information.

72. The non-transitory computer readable medium of claim 71, wherein: The system information includes a bitmap, each bit of the bitmap corresponding to a result of the listen-before-talk process for a corresponding one of the plurality of subbands.

73. A computer program product comprising computer readable instructions which, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 18.

Images