Methods and apparatus related to directional-based listen before talk

Abstract

Systems and methods for directional-based listen before talk (LBT) are presented. A wireless communication device can perform one or more listen before talk (LBT) attempts on each of a plurality of beams. Each of the plurality of beams can have a respective beam direction. The wireless communication device can determine a count of failed LBT attempts for at least one of the plurality of beams.

Description

Technical Field

[0001] This disclosure generally relates to wireless communications, including but not limited to systems and methods for direction-based listen-before-talk (LBT). Background Technology

[0002] The standards organization 3GPP is currently in the process of specifying a new radio interface called 5G New Radio (5G NR) and the next-generation packet core network (NG-CN or NGC). 5G NR will have three main components: the 5G Access Network (5G-AN), the 5G Core Network (NGC), and the User Equipment (UE). To facilitate the implementation of different data services and needs, the elements of 5GC (also known as network functions) have been simplified, with some elements being software-based and others hardware-based, allowing them to be adapted as needed. Summary of the Invention

[0003] The exemplary embodiments disclosed herein are intended to address problems related to one or more difficulties existing in the prior art, and to provide additional features that will become apparent when taken in conjunction with the accompanying drawings and the following detailed description. Exemplary systems, methods, apparatuses, and computer program products are disclosed herein according to various embodiments. However, it should be understood that these embodiments are presented by way of example and not limitation, and that various modifications can be made to the disclosed embodiments by those skilled in the art who have read this disclosure, while remaining within the scope of this disclosure.

[0004] At least one aspect relates to a system, method, apparatus, or computer-readable medium. A wireless communication device can perform one or more Listen-After-Speak (LBT) attempts on each of a plurality of beams. Each of the plurality of beams may have a corresponding beam orientation. The wireless communication device can determine a count (e.g., number or other statistic) of failed LBT attempts for at least one of the plurality of beams.

[0005] In some embodiments, the wireless communication device may identify a plurality of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RS) that satisfy a first threshold. In some embodiments, the wireless communication device may identify a Physical Random Access Channel (PRACH) resource for each of the plurality of SSBs or CSI-RS. In some embodiments, the wireless communication device may identify a preamble corresponding to each of the plurality of SSBs or CSI-RS. In some embodiments, the wireless communication device may perform at least one LBT attempt for each of the identified PRACH resources. In some embodiments, the wireless communication device may identify one of a plurality of beams corresponding to one of the plurality of successful LBT attempts. In some embodiments, the wireless communication device may transmit the corresponding preamble.

[0006] In some embodiments, a wireless communication device may receive downlink control information (DCI) from a wireless communication node. In some embodiments, the DCI may include indications of multiple synchronization signal blocks (SSBs). In some embodiments, the wireless communication device may perform one or more LBT attempts on multiple beams in response to the indications of multiple SSBs. In some embodiments, the multiple beams may correspond to multiple SSBs.

[0007] In some embodiments, the wireless communication device may determine that each of at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) has a reference signal received power (RSRP) above a first threshold (e.g., equal to and / or above the first threshold). In some embodiments, the wireless communication device may determine that each of at least one SSB or CSI-RS has a received signal strength indicator (RSSI) below a second threshold (e.g., equal to and / or below the second threshold). In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts. In some embodiments, the wireless communication device may identify one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

[0008] In some embodiments, the wireless communication device may determine that each of at least one Synchronization Block (SSB) or Channel State Information Reference Signal (CSI-RS) has a Reference Signal Received Power (RSRP) above a first threshold (e.g., equal to and / or above the first threshold). In some embodiments, the wireless communication device may determine that none of at least one SSB or CSI-RS has a Received Signal Strength Indicator (RSSI) below a second threshold (e.g., equal to and / or below the second threshold). In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS based on RSSI measurements of at least one SSB or CSI-RS. In some embodiments, the wireless communication device may (from one or more LBT attempts) identify one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

[0009] In some embodiments, the wireless communication device may determine that each of at least one Synchronization Block (SSB) or Channel State Information Reference Signal (CSI-RS) has a Received Signal Strength Indicator (RSSI) below a second threshold. In some embodiments, the wireless communication device may determine that none of at least one SSB or CSI-RS has a Reference Signal Received Power (RSRP) above a first threshold. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts. In some embodiments, the wireless communication device may (from one or more LBT attempts) identify one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

[0010] In some embodiments, the wireless communication device may determine that none of at least one Synchronization Block (SSB) or Channel State Information Reference Signal (CSI-RS) has a Reference Signal Received Power (RSRP) above a first threshold (e.g., equal to and / or higher than the first threshold). In some embodiments, the wireless communication device may determine that none of at least one SSB or CSI-RS has a Received Signal Strength Indicator (RSSI) below a second threshold (e.g., equal to and / or lower than the second threshold). In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts. In some embodiments, the wireless communication device may identify one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

[0011] In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts, according to a pre-configured implementation of the wireless communication device. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts based on at least one SSB or CSI-RS having an RSRP closest to a first threshold among those at least one SSB or CSI-RS. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts based on at least one SSB or CSI-RS having an RSSI closest to a second threshold among those at least one SSB or CSI-RS.

[0012] In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts based on one or more of at least one SSB or CSI-RS having an RSRP that maximizes above a first threshold among at least one SSB or CSI-RS. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts based on one or more of at least one SSB or CSI-RS having an RSSI that maximizes above a second threshold among at least one SSB or CSI-RS. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts according to a random selection process.

[0013] In some embodiments, the wireless communication device may determine that each of at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) has a reference signal received power (RSRP) greater than a first threshold. In some embodiments, the wireless communication device may determine a count of failed LBT attempts for each of at least one SSB or CSI-RS. In some embodiments, the wireless communication device may select one or more of at least one SSB or CSI-RS to perform one or more LBT attempts based on the count of failed LBT attempts.

[0014] In some embodiments, the wireless communication device may determine a count of failed LBT attempts for each synchronization signal block (SSB) corresponding to a respective one of a plurality of beams. In some embodiments, the wireless communication device may select a first beam among the plurality of beams based on the count of failed LBT attempts. In some embodiments, the count of failed LBT attempts (in or from one or more LBT attempts) for a first SSB corresponding to the first beam may include: a maximum value of a counter before a timer expires or restarts. In some embodiments, the value of the counter may increment in response to a failed LBT attempt. In some embodiments, the timer may start or restart in response to a failed LBT attempt. In some embodiments, the counter may be set to 0 when the timer expires (e.g., reset to an initial value / default value). In some embodiments, the value of the counter may increment in response to a failed LBT attempt. In some embodiments, the timer may start or restart in response to a failed LBT attempt when the value of the counter is 0 (e.g., that value or other defined value / initial value / default value).

[0015] In some embodiments, the wireless communication device may receive indications of multiple beams from the wireless communication node via Radio Resource Control (RRC) signaling. In some embodiments, for a transmission using configuration grant, the wireless communication device may perform one or more LBT attempts on each of the multiple beams. In some embodiments, for a transmission using configuration grant, the wireless communication device may select a first beam from the multiple beams. In some embodiments, selecting the first beam may include: the wireless communication device determining that a successful LBT attempt (from one or more LBT attempts) has occurred on the first beam among the multiple beams prior to any other successful LBT attempt. In some embodiments, selecting the first beam may include: the wireless communication device determining that the count of failed LBT attempts on the first beam among the multiple beams is lower (or lower than and / or equal to) those of the other beams among the multiple beams.

[0016] In some embodiments, the wireless communication device may receive indications of multiple beams from the wireless communication node via Media Access Control-CE (MAC-CE) signaling. In some embodiments, the wireless communication device may perform one or more LBT attempts for each of the multiple beams. In some embodiments, for transmissions using uplink control channel resources, the wireless communication device may perform one or more LBT attempts. In some embodiments, for transmissions using uplink control channel resources, the wireless communication device may select a first beam from the multiple beams. In some embodiments, selecting the first beam may include: the wireless communication device determining that a successful LBT attempt occurred on the first beam among the multiple beams prior to any other successful LBT attempt. In some embodiments, selecting the first beam may include: the wireless communication device determining that the count of failed LBT attempts on the first beam among the multiple beams is lower than that of the other beams among the multiple beams.

[0017] In some embodiments, the wireless communication device may determine a count of failed LBT attempts for each of a plurality of beams. In some embodiments, the count of failed LBT attempts for a first beam may include the maximum value of a counter before a timer expires or restarts. In some embodiments, the value of the counter may increment in response to a failed LBT attempt. In some embodiments, the timer may start or restart in response to a failed LBT attempt. In some embodiments, the counter may be set to 0 when the timer expires. In some embodiments, the timer may start or restart in response to a failed LBT attempt when the counter value is 0. In some embodiments, the counter value may increment in response to a failed LBT attempt when the counter value is 0. In some embodiments, the timer may stop when the counter value reaches a threshold before the timer expires or restarts. In some embodiments, the counter may be set to 0 (e.g., reset to that value or another initial / default / defined value) when the counter value reaches a threshold before the timer expires or restarts. In some embodiments, the counter may be set to 0 when the timer expires and the counter value fails to reach the threshold. In some embodiments, the value of the counter may increment in response to a failed LBT attempt (e.g., increment by 1 or other defined value). In some embodiments, the value of the counter may be set to 0 in response to a successful LBT attempt.

[0018] In some embodiments, for wireless communication devices in the primary cell (SpCell) of a primary cell group or secondary cell group, a counter value reaching a threshold can trigger beam failure recovery. In some embodiments, when the counter value reaches the threshold, the wireless communication device in the SpCell can switch from a first bandwidth portion (BWP) to a second BWP, in which a random access procedure is performed. In some embodiments, when the counter value reaches the threshold, the wireless communication device in the SpCell can report a persistent LBT failure to the upper layer, at which point the counter value reaches the threshold in the currently active BWP. In some embodiments, for wireless communication devices in a secondary cell (SCell), a counter value reaching the threshold can trigger beam failure recovery. In some embodiments, when the counter value reaches the threshold, the wireless communication device in the SCell can report a persistent LBT failure to the wireless communication node via Media Access Control Element (MAC-CE) signaling. In some embodiments, when the counter value reaches the threshold, the wireless communication device in the SCell can switch from a first bandwidth portion (BWP) to a second BWP, in which a random access procedure is performed.

[0019] In some embodiments, the wireless communication device in the secondary cell (SCell) can determine that the first synchronization block (SSB) or channel state information reference signal (CSI-RS) has a reference signal received power (RSRP) above a first threshold. In some embodiments, the wireless communication device in the SCell can determine that the first SSB or CSI-RS has a received signal strength indicator (RSSI) below a second threshold. In some embodiments, the wireless communication device can report the identifier of the first SSB or CSI-RS to the wireless communication node.

[0020] In some embodiments, wireless communication devices in the primary cell (SpCell) of a primary or secondary cell group may transmit one or more indices to a wireless communication node via Media Access Control (MAC-CE) signaling. In some embodiments, the one or more indices may indicate one or more of a plurality of beams on which persistent LBT failures have occurred. In some embodiments, the wireless communication device may receive a subset of the plurality of beams to be monitored from the wireless communication node. In some embodiments, the wireless communication device may monitor the count of failed LBT attempts for a subset of the plurality of beams. In some embodiments, the wireless communication device may determine a subset of the plurality of beams to be monitored. In some embodiments, the wireless communication device may monitor the count (e.g., number or other statistics) of failed LBT attempts for each subset of the plurality of beams.

[0021] When using directional LBT, the wireless communication device (e.g., UE, terminal, or serving node) can count / compute the number of LBT failures (e.g., failed LBT attempts) for each beam. The wireless communication node (e.g., ground terminal, base station, gNB, eNB, or serving node) can indicate / specify one or more available beams for spatial reuse (SR) and / or configuration licensing. The wireless communication device can perform / implement LBT in one or more beams before performing / initiating a transmission (e.g., transmission of a random access preamble). If at least one beam results in a successful LBT attempt, the wireless communication device can perform / complete the corresponding transmission. In some embodiments, the wireless communication device can select / identify / determine at least one beam with light load based on one or more uplink LBT failure statistics (e.g., count of failed LBT attempts).

[0022] For downlink beam detection, when an out-of-sync event is identified (e.g., caused by LBT failure), the wireless communication device can count the number of downlink LBT failures. An out-of-sync event can refer to or include differences between signals / data transmitted / provided from one device and signals / data received / processed by another device. For wireless communication devices in the primary cell (SpCell) of a primary or secondary cell group, reaching or exceeding a threshold number of downlink LBT failures can trigger / cause / initiate beam failure recovery (BFR). In some embodiments, when the number of downlink LBT failures reaches or exceeds the threshold, the wireless communication device can switch to another downlink bandwidth portion (BWP). A random access procedure can be triggered / caused / initiated in response to the switch to another BWP. The corresponding uplink BWP can be configured with random access channel (RACH) resources. For wireless communication devices in the secondary cell (SCell), reaching or exceeding a threshold number of downlink LBT failures can trigger / cause / initiate BFR. Wireless communication devices can use the BFR Media Access Control element (MAC-CE) to report / indicate / specify at least one beam to the wireless communication node. If one or more downlink LBT failures are triggered, the wireless communication device can use the downlink LBT failure MAC-CE to report the downlink LBT failure. Attached Figure Description

[0023] Various exemplary embodiments of the present solution are described in detail below with reference to the figures or accompanying drawings. The drawings are provided for illustrative purposes only and depict only exemplary embodiments of the present solution to facilitate the reader's understanding of it. Therefore, the drawings should not be considered as limitations on the breadth, scope, or applicability of the present solution. It should be noted that these drawings are not necessarily drawn to scale for clarity and ease of explanation.

[0024] Figure 1 An example cellular communication network according to an embodiment of the present disclosure is described, in which the techniques disclosed herein can be implemented;

[0025] Figure 2 Block diagrams illustrating example base stations and user equipment according to some embodiments of the present disclosure are provided;

[0026] Figure 3-6 This disclosure describes various Media Access Control Element (MAC-CE) formats for reporting the results of one or more Listen-After-Speak (LBT) attempts, according to some embodiments thereof; and

[0027] Figure 7 A flowchart illustrating an example method of orientation-based LBT according to embodiments of the present disclosure is provided. Detailed Implementation

[0028] Various exemplary embodiments of this solution are described below with reference to the accompanying drawings to enable those skilled in the art to manufacture and use this solution. It will be apparent to those skilled in the art that, after reading this disclosure, various changes or modifications can be made to the examples described herein without departing from the scope of this solution. Therefore, this solution is not limited to the exemplary embodiments and applications described and illustrated herein. Furthermore, the specific order or hierarchy of steps in the methods disclosed herein is merely an exemplary approach. Based on design preferences, the specific order or hierarchy of steps in the disclosed methods or processes can be rearranged while remaining within the scope of this solution. Therefore, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or actions in a sample order, and unless otherwise expressly stated, this solution is not limited to the specific order or hierarchy presented.

[0029] The following acronyms were used throughout this publication:

[0030]

[0031]

[0032]

[0033]

[0034] 1. Mobile Communication Technology and Environment

[0035] Figure 1Example wireless communication networks and / or systems 100 according to embodiments of this disclosure are described, in which the techniques disclosed herein can be implemented. In the following discussion, wireless communication network 100 can be any wireless network such as a cellular network or a narrowband Internet of Things (NB-IoT) network, and is referred to herein as "network 100". Such an example network 100 includes: base stations 102 (hereinafter referred to as "BS 102"; also referred to as wireless communication nodes) and user equipment 104 (hereinafter referred to as "UE 104"; also referred to as wireless communication devices) that can communicate with each other via communication links 110 (e.g., wireless communication channels), and clusters of cells 126, 130, 132, 134, 136, 138, and 140 covering a geographic area 101. Figure 1 In this context, BS102 and UE 104 are included within the respective geographical boundaries of cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 may include at least one base station operating within its allocated bandwidth to provide adequate radio coverage to its intended users.

[0036] For example, BS 102 can operate within the allocated channel transmission bandwidth to provide sufficient coverage to UE 104. BS 102 and UE 104 can communicate via downlink radio frame 118 and uplink radio frame 124, respectively. Each radio frame 118 / 124 can be further divided into subframes 120 / 127, which may include data symbols 122 / 128. In this disclosure, BS 102 and UE 104 are generally described herein as non-limiting examples of "communication nodes" that can practice the methods disclosed herein. According to various embodiments of this solution, such communication nodes can be capable of wireless and / or wired communication.

[0037] Figure 2 A block diagram illustrating an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) according to some embodiments of this solution is provided. System 200 may include components and elements configured to support known or conventional operating characteristics, which need not be described in detail herein. In one illustrative embodiment, system 200 can be used in wireless communication environments (such as those described above). Figure 1 In a wireless communication environment 100, data symbols are conveyed (e.g., transmitted and received).

[0038] System 200 generally includes a base station 202 (hereinafter referred to as "BS 202") and a user equipment 204 (hereinafter referred to as "UE 204"). BS 202 includes: a BS (Base Station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each module being coupled and interconnected to each other as needed via a data communication bus 220. UE 204 includes: a UE (User Equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each module being coupled and interconnected to each other as needed via a data communication bus 240. BS 202 communicates with UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for data transmission as described herein.

[0039] As will be understood by those skilled in the art, system 200 may also include, in addition to Figure 2 Any number of modules other than those shown. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein can be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, the various illustrative components, blocks, modules, circuits, and steps are generally described in terms of their functionality. Whether this functionality is implemented as hardware, firmware, or software can depend on the specific application and design constraints imposed on the system as a whole. Those skilled in the art, upon which the concepts described herein are skilled, can implement this functionality in a suitable manner for each specific application; however, such implementation decisions should not be construed as limiting the scope of this disclosure.

[0040] According to some embodiments, UE transceiver 230, which may be referred to herein as "uplink" transceiver 230, includes a radio frequency (RF) transmitter and an RF receiver, each including circuitry coupled to antenna 232. A duplex switch (not shown) can alternately couple the uplink transmitter or receiver to the uplink antenna in a time-duplex manner. Similarly, according to some embodiments, BS transceiver 210, which may be referred to herein as "downlink" transceiver 210, includes a radio frequency (RF) transmitter and an RF receiver, each including circuitry coupled to antenna 212. A downlink duplex switch can alternately couple the downlink transmitter or receiver to downlink antenna 212 in a time-division duplex manner. The operation of the two transceiver modules 210 and 230 can be time-coordinated, such that while the downlink transmitter is coupled to downlink antenna 212, the uplink receiver circuitry is coupled to uplink antenna 232 to receive transmissions via wireless transmission link 250. Conversely, the operation of the two transceiver modules 210 and 230 can be time-coordinated, such that while the uplink transmitter is coupled to the uplink antenna 232, the downlink receiver is coupled to the downlink antenna 212 to receive transmissions via the wireless transmission link 250. In some embodiments, there is tight time synchronization with a minimum guard time between the changes in the duplex direction.

[0041] UE transceiver 230 and base transceiver 210 are configured to communicate via wireless data communication link 250 and cooperate with RF antenna arrangements 212 / 232 appropriately configured to support specific wireless communication protocols and modulation schemes. In some illustrative embodiments, UE transceiver 230 and base transceiver 210 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G standards. However, it should be understood that this disclosure is not necessarily limited to specific standards and related protocols in application. Rather, UE transceiver 230 and base transceiver 210 may be configured to support alternative or additional wireless data communication protocols, including future standards or variations thereof.

[0042] According to various embodiments, BS 202 may be, for example, an evolved Node B (eNB), a serving eNB, a target eNB, a femtocell, or a picocell. According to some embodiments, UE 204 may be embodied in various types of user equipment, such as mobile phones, smartphones, personal digital assistants (PDAs), tablets, laptops, wearable computing devices, etc. Processor modules 214 and 236 may be implemented or realized using a general-purpose processor, content-addressable memory, digital signal processor, application-specific integrated circuit, field-programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. In this way, the processor may be implemented as a microprocessor, a controller, a microcontroller, a state machine, or the like. The processor may also be implemented as a combination of computing devices, such as a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a digital signal processor core, or any other such configuration.

[0043] Furthermore, the steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be directly embodied in hardware, firmware, software modules executed by processor modules 214 and 236 respectively, or any actual combination thereof. Memory modules 216 and 234 can be implemented as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules 216 and 234 can be coupled to processor modules 210 and 230 respectively, such that processor modules 210 and 230 can read information from and write information to memory modules 216 and 234 respectively. Memory modules 216 and 234 can also be integrated into their respective processor modules 210 and 230. In some embodiments, memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during the execution of instructions executed by processor modules 210 and 230 respectively. Memory modules 216 and 234 may each include non-volatile memory for storing instructions to be executed by processor modules 210 and 230, respectively.

[0044] Network communication module 218 typically represents the hardware, software, firmware, processing logic, and / or other components of base station 202 that enable bidirectional communication between BS transceiver 210 and other network components and communication nodes configured to communicate with base station 202. For example, network communication module 218 may be configured to support Internet or WiMAX traffic. In a typical deployment, without limitations, network communication module 218 provides an 802.3 Ethernet interface, enabling base station transceiver 210 to communicate with a conventional Ethernet-based computer network. In this way, network communication module 218 may include a physical interface for connecting to a computer network (e.g., a mobile switching center (MSC)). As used herein with respect to a specified operation or function, the terms “configured for…”, “configured as…”, and their variations, refer to devices, components, circuits, structures, machines, signals, etc., physically constructed, programmed, formatted, and / or arranged to perform the specified operation or function.

[0045] The Open Systems Interconnection (OSI) model (referred to herein as the "OSI model") is a conceptual and logical layout that defines network communication used by systems (e.g., wireless communication devices, wireless communication nodes) that are open to interconnection and communication with other systems. The model is decomposed into seven sub-components or layers, each representing a set of concepts provided to the layers above and below it. The OSI model also defines logical networks and effectively describes computer packet transmission using different layer protocols. The OSI model may also be referred to as the seven-layer OSI model or the seven-layer model. In some embodiments, the first layer may be the physical layer. In some embodiments, the second layer may be the Media Access Control (MAC) layer. In some embodiments, the third layer may be the Radio Link Control (RLC) layer. In some embodiments, the fourth layer may be the Packet Data Convergence Protocol (PDCP) layer. In some embodiments, the fifth layer may be the Radio Resource Control (RRC) layer. In some embodiments, the sixth layer may be either the Non-Access Stratum (NAS) layer or the Internet Protocol (IP) layer, and the seventh layer is another layer.

[0046] 2. Systems and methods for direction-based listen-before-speak (LBT)

[0047] In some systems (e.g., Rel-16 shared / unlicensed spectrum and / or other systems), one or more channels and / or signals (e.g., physical channels, physical signals, and / or other channels or signals) may be transmitted using one or more beams other than narrow beams in the Sub-7 GHz spectrum (or other spectrum). If channels and / or signals are transmitted using one or more beams, support for Listen-After-Speak (LBT) may be unnecessary. For frequency bands above 52.6 GHz (or other frequencies), beam-based transmission and / or reception can enable / cause power gain / increase. Power gain can overcome the limitations of millimeter-wave (mmWave) spectrum coverage.

[0048] Beam-based LBTs may have a limited / constrained directional range for signal reception. Therefore, the success of an LBT can depend on the presence of at least one potential interference in a specific direction of the LBT beam. Consequently, the success rate of beam-based LBTs may be increased / improved compared to omnidirectional LBTs (e.g., assuming the availability of alternative candidate beam directions). In certain scenarios (e.g., dense deployment scenarios), spatial reuse may be improved.

[0049] In some embodiments, transmission may be blocked when beam-based LBT is introduced. If spatial dimension LBT is used, one or more spatial dimension enhancements can be considered. The systems and methods presented herein include a novel approach for orientation-based LBT to, for example, reuse space and enhance / boost spatial dimensions by at least 25% (e.g., 35%, 45%, or other percentages).

[0050] A. Example 1: Selection of Multiple Synchronization Signal Blocks (SSBs) for Msg1

[0051] In some embodiments, beam-based LBTs can be used / enabled / applied at high frequencies (e.g., high-frequency spectrum). Similar to omnidirectional LBTs, one or more transmissions may face congestion / obstruction / blockage in beam-based LBTs. Therefore, certain enhancements (e.g., spatial dimension enhancement or other enhancements) can be considered for beam-based LBTs.

[0052] During random access, one or more preamble transmissions (e.g., RACH preamble, Physical Random Access Channel (PRACH) preamble, and / or other transmissions initiating synchronization / communication with the wireless communication node) may face congestion / obstruction / blockage. In some embodiments, multiple spatial dimension transmission opportunities may be considered to reduce / minimize LBT impact. In certain spectrum (e.g., licensed spectrum), at least one SSB can be selected / identified / designated. The wireless communication device (e.g., UE, terminal, or serving node) can select / identify / designate (random access) preambles and / or PRACH timings based on the selected SSB. In some embodiments, the lower layer (or other layer) may perform / complete one or more (random access) preamble transmissions in an uplink beam (e.g., the uplink beam corresponding to the selected SSB). For other spectrum (e.g., unlicensed spectrum), the wireless communication device may select one or more SSBs and / or Channel State Information Reference Signals (CSI-RS) that reach or exceed a threshold. For each SSB and / or CSI-RS, the wireless communication device may select subsequent available PRACH timings / resources from one or more PRACH timings. One or more PRACH timings may correspond to the selected SSB and / or CSI-RS. For each SSB and / or CSI-RS, the wireless communication device may select at least one (random access) preamble based on the selected SSB and / or CSI-RS.

[0053] In response to the completion of the selection, the wireless communication device can calculate / operate / determine the preamble transmission power and / or random access radio network temporary identifier (RA-RNTI) for each selected SSB and / or CSI-RS. The Media Access Control (MAC) layer (or other layers) can instruct / provide / specify the selected PRACH timing / resource, the corresponding RA-RNTI, the preamble index, the preamble transmission power, and / or other information for each selected SSB and / or CSI-RS to the lower layers (e.g., the physical layer).

[0054] The physical layer / lower layer (or other layer) may perform / complete beam-based LBT before transmitting / sending / broadcasting the preamble for each selected PRACH resource. If one or more LBT attempts are successful, the wireless communication device may select at least one beam with successful LBT attempts to transmit the preamble. If other ongoing LBT attempts exist, the wireless communication device may stop / pause / terminate the ongoing LBT attempts. The steps discussed herein can be used in a 4-step contention-based random access procedure, a 4-step non-contention-based random access procedure, a 2-step random access procedure, and / or other procedures.

[0055] B. Example 2: Multiple SSB selection for Msg1, Physical Downlink Control Channel (PDCCH) sequence

[0056] In some embodiments, beam-based LBTs can be used / enabled / applied at high frequencies. One or more transmissions may face congestion / obstruction / blocking / interference in beam-based LBTs. Therefore, certain enhancements to beam-based LBTs (e.g., spatial dimension enhancement or other enhancements) can be considered.

[0057] During a random access procedure, one or more preamble transmissions (e.g., RACH preamble, PRACH preamble, and / or other transmissions initiating synchronization / communication with the wireless communication node) may face congestion / obstruction / blocking / interference. In some embodiments, the availability of transmission opportunities in multiple spatial dimensions can be considered to reduce / minimize the impact of LBT. For example, the order of PDCCH (or other downlink channels) can trigger / cause / initiate a random access procedure. For a random access procedure triggered by PDCCH order, the wireless communication device can indicate / specify at least one SSB in the current specification. The wireless communication node (e.g., a ground terminal, base station, gNB, eNB, or serving node) can use downlink control information (DCI) and / or other information to indicate / specify one or more SSBs and / or one or more preamble indices corresponding to each SSB. The wireless communication node can indicate one or more SSBs and / or preamble indices to provide one or more transmission opportunities. The preamble index can provide information for identifying / selecting one or more preambles. At least one PRACH mask index can be used for one or more SSBs. The PRACH mask index can indicate / specify / identify at least one PRACH resource used for transmitting / sending / broadcasting (random access) preambles.

[0058] In some embodiments, the SSB index and / or preamble index may utilize 12 (or other number) bits. At least 6 bits may be used to indicate / specify the SSB index and / or preamble index. The wireless communication node may use a DCI (e.g., DCI_0 or other types and / or formats of DCI) to indicate at least 2 SSB indices and / or 2 preamble indices corresponding to the 2 SSB indices.

[0059] A wireless communication device can receive / acquire a DCI (or other information) indicating one or more SSBs. In response to receiving the DCI, the wireless communication device can perform a LBT (Local Bit Transmission) in one or more uplink beams. One or more uplink beams may correspond to one or more SSBs. If at least one beam has a successful LBT attempt, the wireless communication device can perform / implement / complete the preamble transmission.

[0060] a) Wireless communication node side

[0061] In some embodiments, the random access preamble index may utilize at least 1 to 6 bits according to the ra-PreambleIndex (or other index) in certain implementations (e.g., clause 5.1.2 of [8, TS38.321]). In some embodiments, the random access preamble index may utilize at least 2 to 6 bits according to the ra-PreambleIndex (or other index) in certain implementations (e.g., clause 5.1.2 of [8, TS38.321]).

[0062] The uplink (UL) and / or supplementary UL (SUL) indicators can utilize 1 (or other number) bits. In certain cases, the value of the random access preamble index can correspond to a non-all-zero value. The wireless communication device can be configured using the supplementaryUplink (or other parameter / setting) in the ServingCellConfig (or other configuration) within the cell. Therefore, the UL / SUL indicator field can specify the UL carrier in the cell to transmit PRACH (e.g., according to Table 7.3.1.1.1-1). Otherwise, this field can be reserved.

[0063] In some embodiments, the Secondary Synchronization (SS) / Physical Broadcast Channel (PBCH) index may utilize at least 1 to 6 bits. In some embodiments, the SS / PBCH index may utilize at least 2 to 6 bits. In some scenarios, the value of the random access preamble index corresponds to a non-all-zero value. Therefore, the field of the SS / PBCH index may specify the timing of the RACH used by the SS / PBCH to determine the PRACH transmission. Otherwise, this field may be reserved.

[0064] In some embodiments, the PRACH mask index may utilize at least 4 bits. In some cases, the value of the random access preamble index may correspond to a non-all-zero value. Therefore, the field of the PRACH mask index may specify or indicate the RACH timing associated with the SS / PBCH. The SS / PBCH may be indicated by the SS / PBCH index used for PRACH transmission (e.g., according to clause 5.1.1 of [8, TS38.321]). Otherwise, the field may be reserved. In some embodiments, at least 10 bits may correspond to reserved bits. Reserved bits may be used for operation in cells with shared spectrum channel access. In some embodiments, 12 bits may be used for reserved bits.

[0065] C. Example 3A: Two thresholds used for the preamble

[0066] In certain specifications, a wireless communication device may select / determine / identify at least one SSB and / or CSI-RS based on a Reference Signal Received Power (RSRP) and / or a configured threshold. The wireless communication device may select / identify / determine one or more SSBs / CSI-RSs with associated measurements / metrics above a threshold. In some embodiments, the wireless communication device may select one or more SSBs / CSI-RSs (e.g., due to hidden nodes) taking into account RSRP (e.g., L1-RSRP) and / or Received Signal Strength Indicator (RSSI). The wireless communication device may select / determine / identify one or more SSBs and / or CSI-RSs based on the RSRP and / or RSSI (e.g., RSSI / CO) of each SSB / CSI-RS. A first threshold associated with RSRP may be configured to select / identify / classify one or more SSBs and / or CSI-RSs. A second threshold associated with RSSI may be configured to select / identify / classify one or more SSBs and / or CSI-RSs. System information, Radio Resource Control (RRC) messages, and / or other messages or information may be configured with one or more thresholds.

[0067] For the transmitted SSB / CSI-RS, the wireless communication device can use system information and / or RRC messages to configure a first threshold (e.g., rsrp-thresholdSSB) and / or a second threshold (e.g., rssi-thresholdSSB). If a random access procedure is triggered, the wireless communication device can select one or more SSB / CSI-RSs with an associated RSRP that reaches or exceeds the first threshold. Among the selected SSB / CSI-RSs, the wireless communication device can select one or more SSB / CSI-RSs with an RSSI below the second threshold. In some embodiments, at least four scenarios may occur:

[0068] ● Scenario 1: One or more SSBs / CSI-RSs may have corresponding RSRPs that reach or exceed a first threshold (e.g., rsrp-thresholdSSB). One or more SSBs / CSI-RSs may have corresponding RSSIs that are below a second threshold (e.g., rssi-thresholdSSB). The wireless communication device may select at least one SSB / CSI-RS from the one or more SSBs / CSI-RSs, for example, according to one or more predefined rules or configurations. For example, the wireless communication device may select / identify one or more SSBs / CSI-RSs whose RSRPs meet or exceed the first threshold by a maximum amount. In another example, the wireless communication device may select one or more SSBs / CSI-RSs in a random / arbitrary manner.

[0069] ● Scenario 2: One or more SSBs / CSI-RS may have a corresponding RSRP that reaches or exceeds a first threshold. One or more SSBs / CSI-RS may have a corresponding RSSI that reaches or exceeds a second threshold (e.g., none of the one or more SSBs has an RSSI below the second threshold). The wireless communication device can identify / designate SSBs / CSI-RS with RSRPs that reach or exceed the first threshold. The wireless communication device can select at least one SSB / CSI-RS from the identified SSBs / CSI-RS using associated RSSI measurements and / or according to one or more predefined rules or configurations. For example, the wireless communication device can select one or more SSBs / CSI-RS whose RSSI exceeds the second threshold by a maximum amount. In another example, the wireless communication device can select one or more SSBs / CSI-RS in a random / arbitrary manner.

[0070] ●Scenario 3: One or more SSB / CSI-RS may have a corresponding RSSI (e.g., RSSI / CO) below the second threshold. One or more SSB / CSI-RS may have a corresponding RSRP below the first threshold. Therefore, at least one SSB / CSI-RS can be selected according to the implementation of the wireless communication device and / or one or more predefined rules or configurations. For example, the wireless communication device can select at least one SSB / CSI-RS with an RSRP closest to / closest to the first threshold. In another example, the wireless communication device can select one or more SSB / CSI-RS in a random / arbitrary manner.

[0071] ●Scenario 4: All SSB / CSI-RS may have a corresponding RSRP below the first threshold. All SSB / CSI-RS may have a corresponding RSSI reaching or exceeding the second threshold. In some embodiments, at least one SSB / CSI-RS may be selected according to the implementation of the wireless communication device and / or according to one or more predefined rules or configurations. For example, the wireless communication device may select at least one SSB / CSI-RS with an RSRP closest to / nearest the first threshold. In another example, the wireless communication device may select one or more SSB / CSI-RS in a random / arbitrary manner.

[0072] In some embodiments, one or more SSB / CSI-RS can be selected / determined / identified using the selection principles / criteria / rules / configurations disclosed herein. The wireless communication device can perform one or more LBT attempts based on the selected SSB / CSI-RS. If at least one beam results in a successful LBT attempt, the wireless communication device can use at least one beam to perform a preamble transmission. In response to performing a preamble transmission, the wireless communication device can stop / pause other ongoing LBT attempts. In some embodiments, the wireless communication node can configure thresholds associated with RSSI using System Information Block Type 1 (SIB1), RRC reconfiguration, and / or other information.

[0073] D. Example 3B: SSB selection based on LBT failure results

[0074] In certain specifications, wireless communication devices may select / determine one or more SSB / CSI-RSs based on RSRP and / or at least one configured threshold. The wireless communication device may select one or more SSB / CSI-RSs having a corresponding RSRP that meets and / or exceeds the threshold. In some embodiments, the wireless communication device may select one or more SSB / CSI-RSs based on UL LBT failure outcome statistics (e.g., the count of failed LBT attempts, e.g., corresponding to each SSB / CSI-RS / beam).

[0075] When a random access procedure is triggered / initiated, one or more SSBs / CSI-RSs may have an RSRP that reaches or exceeds a first threshold (e.g., rsrp-ThresholdSSB). The wireless communication device may use UL LBT failure statistics (e.g., a beam-specific LBT failure count for each SSB / CSI-RS / beam) to select at least one SSB / CSI-RS. The wireless communication device may select / identify one or more SSBs / CSI-RSs with low load (e.g., SSBs / CSI-RSs with low failure counts).

[0076] E. Example 4: LBT Failure Statistics Based on (or per) Directional Beam (per SSB)

[0077] In certain shared spectrum (e.g., unlicensed spectrum), uplink transmissions can use / implement LBT failure detection / recovery. Wireless communication devices can count / calculate / track the number of LBT failures for uplink transmissions (e.g., the number of failed LBT attempts). Wireless communication devices can count / calculate / use the number of LBT failures for each directional beam to select / identify / determine / use beams with light loads (e.g., beams with low failure counts). For example, for SR and / or configured licensed transmissions, if one or more beams are indicated / designated, the wireless communication device can select / identify / use at least one light-load beam.

[0078] a. MAC layer

[0079] In some embodiments, the wireless communication device may use a counter and / or a timer to count / determine / calculate the number of UL LBT failures (e.g., the number of failed LBT attempts). The wireless communication device may count the number of UL LBT failures for each beam (e.g., the number of failed LBT attempts for each SSB corresponding to at least one beam). At least one of the following two methods may be considered / used / implemented:

[0080] ● Method 1: For each beam, the wireless communication device can receive / obtain an LBT failure indication (e.g., a failed LBT attempt) from one or more lower layers. If an LBT failure indication is received, a counter can be incremented (e.g., to a value of 1) and / or a timer can be started / restarted. Once the timer expires, the counter is reset (e.g., set to 0 or another initial / default / defined value). In this method, the timer can be started / restarted on each failed LBT attempt. Unless another failed LBT attempt occurs (e.g., before expiration), the timer can run its entire process / duration (e.g., until expiration).

[0081] ● Method 2: For each beam, the wireless communication device can receive / obtain an LBT failure indication from one or more lower layers. If an LBT failure indication is received, the counter can be incremented (e.g., to a value of 1 or other default / defined value). If the counter is equal to zero and an LBT failure indication is received, the timer can be started / initialized. Once the timer expires, the counter is reset (e.g., set to 0 or other initial / default / defined value). In this method, the timer can run its entire process / duration (e.g., until expiration) before restarting the timer (e.g., running its entire process / duration again).

[0082] b. Physical layer / lower layer

[0083] Wireless communication devices may fail to access one or more channels before the expected / scheduled UL transmission to the wireless communication node. If a wireless communication device fails to access a channel, Layer 1 (or another layer) may notify / inform / indicate the channel access failure for each beam to one or more upper layers (e.g., the MAC layer).

[0084] F. Example 5: Configuration Authorization Selection Based on LBT Failure Results

[0085] For configuration grant transmissions, wireless communication nodes can use RRC messages (or other messages) to indicate / specify one or more transmission beams. Wireless communication devices can receive / obtain indications of one or more transmission beams via RRC messages. In some embodiments, omnidirectional LBT can be performed / used / implemented / enabled. If omnidirectional LBT is performed and at least one LBT attempt fails, none of the one or more beams can be used. When directional LBT is used / performed, each beam can result in / correspond to a separate LBT outcome (e.g., a failed LBT attempt or a successful LBT attempt). A separate LBT outcome can be associated with a separate beam. Therefore, one or more transmission beams can be indicated / specified for a specific configuration grant.

[0086] A wireless communication node can instruct / specify / provide / determine one or more transmission beams for configuring authorization. At least one of the following two methods can be used / considered / implemented:

[0087] ●Method 1: The wireless communication device may perform at least one LBT attempt in one or more beams. If at least one beam / attempt results in a successful LBT attempt, the wireless communication device may use at least one beam to perform at least one configuration grant transmission. The wireless communication device may determine that a successful LBT attempt occurred on a first beam (e.g., which is subsequently selected for preamble transmission) prior to any other successful LBT attempt.

[0088] ●Method 2: The wireless communication device can use the UL LBT failure count to select / identify / determine at least one lightly loaded beam (e.g., a beam with a low failure count), for example, for preamble transmission. Therefore, the wireless communication device can select / identify / identify at least one beam whose LBT attempt failure count is lower than that of other beams.

[0089] These methods can reduce / minimize the impact of LBT on configuration grant transmission. In some embodiments, the wireless communication node can configure one or more Sound Reference Signal (SRS) resource indications. The wireless communication node can send / transmit SRS indications (or other indications) to the wireless communication device. The wireless communication node can use RRC signaling (or other types of signaling) to configure and / or send one or more SRS resource indications.

[0090] G. Example 6: SR resource selection based on LBT failure results

[0091] In some specifications, a wireless communication device can identify / specify at least one available beam for each uplink control channel (e.g., Physical Uplink Control Channel (PUCCH) or other uplink channel) resource. The wireless communication device can utilize MAC-CE signaling (or other types of signaling) to receive an indication that at least one beam is available. The wireless communication node can send / transmit / broadcast this indication via MAC-CE signaling (or other types of signaling). In some embodiments, omnidirectional LBT can be performed / used / implemented / enabled. If omnidirectional LBT is performed and there is at least one failed LBT attempt, none of the one or more beams are available. When directional LBT is used / performed, each beam can result in / correspond to a separate LBT outcome (e.g., a failed LBT attempt or a successful LBT attempt). A separate LBT outcome can be associated with a separate beam. Therefore, one or more transmission beams can be indicated / specified for each uplink control channel resource (e.g., PUCCH resource).

[0092] Wireless communication nodes can use MAC-CE (or other types of signaling) to indicate / specify / provide / determine one or more transmission beams for SR. At least one of the following two methods can be used / considered / implemented:

[0093] ●Method 1: The wireless communication device may perform at least one LBT attempt in one or more beams. If at least one beam results in a successful LBT attempt, the wireless communication device may select at least one beam to perform at least one uplink channel resource transmission. The wireless communication device may determine that the successful LBT attempt occurred on the first beam (which is subsequently selected for use) prior to other successful LBT attempts.

[0094] ●Method 2: The wireless communication device can use the UL LBT failure count to select / identify / determine at least one beam with a light load (e.g., a beam with a low failure count). Therefore, the wireless communication device can select / identify / identify at least one beam whose LBT attempt failure count is lower than that of other beams.

[0095] These methods can reduce / reduce the impact of LBT on configuration authorization transport.

[0096] H. Example 7: Downlink (DL) LBT Failure

[0097] In some specifications, one or more serving cells may use / implement beam failure detection / recovery. For one or more SpCells, a beam failure counter may reach or exceed a threshold. In some embodiments, reaching or exceeding a threshold may trigger / cause / initiate a random access procedure. For one or more SCells, beam failure recovery (BFR) may be triggered. If BFR is triggered, the wireless communication device may report / notify / designate at least one SSB / CSI-RS with an RSRP that has reached or exceeded rsrp-ThresholdBF (or other threshold). The candidateBeamRSSCellList (or other list) of the BFR MAC-CE may include at least one SSB / CSI-RS.

[0098] In certain spectrum areas (e.g., shared spectrum), SSB / CSI-RS may face congestion / blockage due to LBT failures (e.g., LBT failure attempts). In some embodiments, BFR triggering / initiation may occur earlier than expected.

[0099] In some protocols (e.g., RAN4), certain agreements may be described as follows:

[0100] ●Out-of-Synchronization (OOS) assessment period based on SSB:

[0101] ○ For estimating the signal-to-interference-to-noise ratio (SINR) EST ≤X dB, OOS assessment period:

[0102] ■Option 1: May remain unchanged.

[0103] ■Option 2: May have the following fixed sample size expansion:

[0104] ●L = for max(T) SSB ,T DRX The defined value is ≤40.

[0105] ●L = For 40 <max(T DRX ,T SSB The defined value is ≤320.

[0106] ●L = for T DRX The defined value of >320

[0107] ○ Regarding SINR EST >X dB can define or predetermine the OOS assessment period.

[0108] ○X = [-7dB]

[0109] ○SINR EST This can correspond to the estimated signal-to-interference-noise ratio (SINR) at the wireless communication device side.

[0110] ■Option 1: Estimated filtered SINR during the evaluation period

[0111] ■Option 2: Current SSB SINR estimate

[0112] ■Option 3: The last available SSB SINR,

[0113] ■Other options are not excluded

[0114] In some embodiments, the SINR may reach or exceed a certain threshold. If the SINR reaches or exceeds this threshold, the wireless communication device can identify / determine / identify one or more causes of OOS. For example, OOS may be caused / triggered by one or more LBT failure attempts, poor channel quality, congestion, and / or other OOS causes. The wireless communication device can identify / identify one or more causes of OOS. In response to determining the cause of OOS, the wireless communication device can identify and count beam failures caused by failed LBT attempts for each beam. In other words, the wireless communication device can determine the count of failed LBT attempts for each beam. The wireless communication device can count beam failures individually (e.g., from those failures caused by reasons other than failed LBT attempts) to avoid triggering / initiating / causing BFR earlier than desired. The beam failure count (or the count of failed LBT attempts) can be used to calculate / determine statistics for one or more LBT failures (e.g., DL LBT failures).

[0115] LBT failure statistics can be calculated / determined using at least one of the following methods:

[0116] ●Method 1: Some methods may utilize / use a counter and / or a timer. In some embodiments, the wireless communication device may receive / obtain at least one LBT failure indication (or other indicator). In response to receiving this indication, the timer may start / restart and / or the counter may increment / increment by a value (e.g., value 1). In response to / at each failed LBT attempt, the timer may start or restart. Therefore, unless another failed LBT attempt occurs (e.g., before the timer expires), the timer may run its entire process / duration (e.g., until the timer expires). Once the timer expires, the counter sets its value to 0 (e.g., reset to the defined / initial value).

[0117] ●Method 2: Some methods may utilize / use counters and / or timers. In some embodiments, the wireless communication device may receive / obtain an indication of LBT failure from one or more lower layers. If the wireless communication device receives this indication and the counter value is zero, the timer may be started / initialized. In response to receiving / obtaining the indication, the counter may increment / increment by a value (e.g., value 1 or other default / defined value). If the counter reaches or exceeds a certain threshold while the timer is running its process, the wireless communication device may perform one or more operations (e.g., as described below). If the counter reaches or exceeds the threshold while the timer is running its process, the timer may be stopped / restarted and / or the counter may be set to zero (e.g., reset or reinitialized to a defined / initial value). If the timer expires and the counter fails to reach or exceed the threshold, the counter is set to zero.

[0118] ●Method 3: Some methods may utilize / use a counter. In some embodiments, the number of consistently failed LBTs can be identified / indicated / counted / calculated (e.g., the number of candidate beams declared / verified / acknowledged / determined as LBT failures when certain conditions and / or thresholds are met). The wireless communication device can receive / obtain an indication of an LBT failure from one or more lower layers. If the wireless communication device receives / obtains this indication, the counter can increment / increment by a value (e.g., value 1). In response to receiving an indication of an LBT success, the counter can set its value to zero (e.g., set to 0). If the counter reaches or exceeds a threshold, at least one of the following processes can be performed.

[0119] For wireless communication devices in SpCell, if a counter (e.g., a DL LBT failure counter) reaches or exceeds a threshold, at least one of the following conditions may be considered:

[0120] ●Scenario 1: In some embodiments, a BFR can be caused / triggered / initiated. If a BFR is triggered, the wireless communication device can perform a random access procedure. If a BFR is triggered, the wireless communication device can use RACH (or other resources) to report / notify / designate / indicate at least one available beam to the wireless communication node.

[0121] ● Scenario 2: If a counter (e.g., a DL LBT failure counter) reaches or exceeds a threshold, the wireless communication device can switch / change to a DL Bandwidth Part (BWP). A DL BWP can be associated with a ULBWP configured with RACH resources (or other resources). In response to switching to another BWP, a random access procedure can be initiated in the BWP. In some embodiments, one or more LBT failures can be triggered in one or more DL BWPs. If one or more LBT failures are triggered, the wireless communication device can report / indicate / specify a persistent LBT failure to at least one upper layer.

[0122] ●Scenario 3: For wireless communication devices in SpCell, a counter (e.g., a DL LBT failure counter) may reach or exceed a threshold in the currently active BWP. If the counter reaches or exceeds the threshold,

[0123] The wireless communication device can then indicate / specify a persistent LBT failure to one or more upper layers.

[0124] A persistent LBT failure (e.g., provided / specified / indicated by the MAC layer or other layers) can trigger / cause a radio link failure (RLF). The wireless communication device can then perform an RRC reconstruction procedure (or other procedures).

[0125] For wireless communication devices in SCell, if a counter (e.g., DL LBT failure counter) reaches or exceeds a threshold, at least one of the following conditions may be considered:

[0126] ●Scenario 1: In some embodiments, a BFR can be caused / triggered / initiated. The wireless communication device can report at least one SSB / CSI-RS with an RSRP that reaches or exceeds the rsrp-ThresholdBFR (or other threshold). At least one SSB / CSI-RS can be included / provided / specified in the candidateBeamRSSCellList (or other list).

[0127] ●Scenario 2: In some embodiments, a counter (e.g., a DL LBT failure counter) may reach or exceed a threshold. If the counter reaches or exceeds the threshold, a consistent LBT failure can be triggered. The wireless communication device can report / notify / transmit the LBT failure to the wireless communication node (e.g., by using a new MAC-CE or other signaling).

[0128] ●Scenario 3: In some embodiments, a counter (e.g., a DL LBT failure counter) may reach or exceed a threshold. If the counter reaches or exceeds the threshold, the wireless communication device can switch / change to the DL BWP to perform a random access procedure. The DL BWP may be associated with a UL BWP configured with RACH resources (or other resources). If the wireless communication device switches to another BWP, a random access procedure can be performed.

[0129] Now refer to Figure 3 This describes the MAC-CE format used to report the results of one or more LBT attempts. For SCell and / or SpCell, entirely new / specific MAC-CEs can be defined to report LBT failures to the wireless communication node. A MAC-CE can be referred to as the LBT Failure MAC-CE. Figure 3 The example format of the LBT failure MAC-CE is described below. The LBT failure MAC-CE can correspond to an octet format (e.g., Oct 1). The octet of the MAC-CE can correspond to a single line with 8 fields. The LBT failure MAC-CE can report / indicate / specify an LBT failure of at least one serving cell. Each serving cell can correspond to one field of the LBT failure MAC-CE (e.g., C0, C1, C2, and / or other fields). For example, if a persistent LBT failure is triggered in a serving cell (e.g., serving cell 0), the value of the corresponding field of the MAC-CE (e.g., C0) can be set to 1 (or another value). Otherwise, the value of the corresponding field (e.g., C0) can be set to 0 (or another value). At least one field of the LBT failure MAC-CE can correspond to at least one serving cell. The fields of the LBT failure MAC-CE can be organized / reported / indicated using one or more sequences. For example, the fields can be organized using the following order / sequence (from left to right): C0, C1, C2, C3, C4, C5, C6, C7.

[0130] Now refer to Figure 4 This describes the MAC-CE format used to report the results of one or more LBT attempts. For one or more SCells and / or SpCells, a completely new / specific / defined MAC-CE can be defined to report LBT failures to the wireless communication node. In some embodiments, the MAC-CE may be referred to as the LBT Failure MAC-CE. Figure 4The example format of the LBT failure MAC-CE is described below. The LBT failure MAC-CE can correspond to a four (or other numeric) octet format (e.g., Oct 1, Oct 2, Oct 3, and / or Oct 4). Each octet of the MAC-CE can correspond to a single line with eight fields. The four-octet format can concatenate / aggregate / combine results from one or more serving cells into a single MAC-CE. An LBT failure MAC-CE with a four-octet format can report / indicate / specify the LBT failure status of one or more serving cells. Each serving cell can correspond to a field of the LBT failure MAC-CE (e.g., C0, C1, C2, and / or other fields). For example, if a persistent LBT failure is triggered (and not canceled) in a serving cell (e.g., serving cell 1), the value of the corresponding field in the MAC-CE (e.g., C1) can be set to 1 (or another value). Otherwise, the value of the corresponding field (e.g., C1) can be set to 0 (or another value).

[0131] In some embodiments, when the highest ServCellIndex (or other index) of the serving cell of a MAC entity is less than 8, the LBT failure MAC-CE can use a single octet bitmap. If the highest ServCellIndex of the serving cell of a MAC entity is greater than or equal to 8, the LBT failure MAC-CE can use a four-octet format. In some embodiments, the wireless communication node can configure / determine / specify a threshold for analyzing / comparing LBT failure counts. The wireless communication node can configure the threshold using RRC configuration (or other configurations). For each SCell, a beam can be selected from the candidate beam list using another threshold.

[0132] I. Example 8: Beam failure problem of SCell

[0133] In some embodiments, beam failure can be triggered in a wireless communication device within an SCell. If beam failure is triggered, the wireless communication device can report / specify / determine the index of the SSB / CSI-RS. The SSB / CSI-RS may have an RSRP that reaches or exceeds a first threshold (e.g., rsrp-ThresholdBFR). The MAC-CE's candidateBeamRSSCellList (or other list) may include / specify the SSB / CSI-RS. When using / enabling / implementing directional LBT, the interference for each beam may differ. Therefore, the information provided by the RSSI of each beam can be considered / evaluated. An RRC message (or other message) can configure a second threshold for the RSSI. If beam failure is triggered in a wireless communication device within an SCell, the wireless communication device can report / specify / indicate an SSB / CSI-RS with an RSRP that reaches or exceeds the first threshold and an RSSI that is below the second threshold. The wireless communication device can report the identifier of the SSB / CSI-RS. For each SCell, a beam can be selected from the candidate beam list using another threshold.

[0134] J. Example 9: Beam-based LBT failure detection

[0135] In certain spectrum areas (e.g., shared spectrum), uplink transmissions can use / enable LBT failure detection / recovery. If the number of LBT failures used for uplink transmissions reaches or exceeds a threshold, a persistent (or acknowledged) LBT failure can be triggered. When using / enabling / enabling beam-based LBTs in high frequencies, the LBT state for each beam may differ. Therefore, a separate quantity can specify the number of beam-based LBT failures (e.g., LBT failure attempts for each beam).

[0136] a. MAC layer

[0137] Each beam can be associated with an individual number of LBT failures. The number of LBT failures for each beam can be compared to a threshold. If the number of LBT failures reaches or exceeds the threshold, a persistent LBT failure can be triggered. For wireless communication devices in SpCell, a persistent LBT failure can be triggered during the activation of a BWP. If a persistent LBT failure is triggered, the wireless communication device can switch / change to another BWP with RACH resources (or other resources). The wireless communication device can switch to another BWP to perform a random access procedure. If all BWPs with RACH resources have been tried, the MAC layer can indicate / notify the upper layer of the persistent LBT failure. For wireless communication devices in SCell, the wireless communication device can indicate / specify / provide / determine one or more indices to the wireless communication node. One or more indices can indicate / specify one or more beams on which a persistent LBT failure has occurred.

[0138] Now refer to Figure 5 and Figure 6 This describes an example of a MAC-CE format used to report the results of one or more LBT attempts. For a wireless communication device in an SCell, the device can report / notify one or more beam indices to the wireless communication node. One or more beam indices may correspond to one or more beams on which a persistent LBT failure has been triggered. In some specifications, the LBT failure MAC-CE may indicate / specify one or more indices of the serving cell on which an LBT failure has been triggered. Some formats of the LBT failure MAC-CE may not meet one or more requirements (e.g., the LBT failure MAC-CE may include one or more beam indices). New / defined / specific LBT failure MAC-CE formats may indicate / specify / provide one or more serving cell indices and / or one or more beam indices. The MAC-CE format may indicate / specify the serving cell index and / or beam index on which an LBT failure has occurred.

[0139] For wireless communication devices in SpCell, the device can report / notify / send one or more beam indices to the wireless communication node. One or more beam indices can indicate / specify the beam that triggered the LBT failure. The device can use the LBT failure MAC-CE to indicate / specify one or more beam indices. The LBT failure MAC-CE can provide / specify one or more beam indices and / or one or more serving cell indices (e.g., C7, C6, C5, and / or other fields corresponding to the serving cell indices). One or more serving cell indices can specify the serving cell on which the LBT failure has been triggered.

[0140] LBT failure MAC-CE can concatenate / aggregate / combine serving cell indexes and beam indices into a single MAC-CE. If the highest ServCellIndex of the serving cell of the MAC entity is less than 8, LBT failure MAC-CE can use... Figure 5 The publicly available format. If the highest ServCellIndex of the serving cell of the MAC entity is greater than or equal to 8, then LBT fails. MAC-CE can be used. Figure 6 The LBT failure MAC-CE uses an octet format to report / indicate serving cell indexes. If the highest ServCellIndex of the serving cell of the MAC entity is greater than or equal to 8, the LBT failure MAC-CE can use a four-octet format. Each serving cell index can correspond to a field in the LBT failure MAC-CE (e.g., C0, C1, C2, and / or other fields). For example, if a persistent LBT failure is triggered (and not eliminated) in a serving cell with a certain serving cell index (e.g., serving cell 0), the value of the corresponding field in the MAC-CE (e.g., C0) can be set to 1 (or another value). Otherwise, the value of the corresponding field (e.g., C0) can be set to 0 (or another value). If the field corresponding to a specific cell index is set to 1, the LBT failure MAC-CE can include one or more beam indices.

[0141] In some embodiments, when the highest ServCellIndex (or other index) of the MAC entity's SCell is less than 8, the LBT failure MAC-CE can use a single octet bitmap. If the highest ServCellIndex of the MAC entity's serving cell is greater than or equal to 8, the LBT failure MAC-CE can use a four-octet format.

[0142] K. Example 10: Detection Beams Configured in a Network

[0143] In certain spectrum areas (e.g., rel-16 shared spectrum), uplink transmissions can use / enable LBT failure detection / recovery. In some embodiments, the number of LBT failures for uplink transmissions can be compared to a certain threshold. Reaching or exceeding the threshold number of LBT failures can trigger persistent LBT failures. When beam-based LBTs are used / enabled / enabled in high frequencies, the LBT state for each beam may differ. Therefore, a separate quantity can specify the number of beam-based LBT failures (e.g., LBT failure attempts for each beam).

[0144] In some embodiments, the wireless communication node can configure the wireless communication device to report / indicate / count / calculate the total failure count for two (or more) beam directions. In some embodiments, the wireless communication node can divide N beam directions into M groups. The wireless communication device can report / count the total failure count for each of the M groups.

[0145] In some embodiments, a wireless communication node may send / transmit a subset of multiple beams to a wireless communication device. The wireless communication device may monitor / count failed LBT attempts for the subset of beams. For example, the wireless communication device may receive / obtain two uplink beams from the wireless communication node. The wireless communication device may monitor the count of failed LBT attempts for the two uplink beams (e.g., the total failure count for the two uplink beams).

[0146] For wireless communication devices in SpCell, the number of failed UL LBT attempts for each beam may reach or exceed a threshold. If the number of failed UL LBT attempts reaches or exceeds the threshold, the wireless communication device may switch / change to a UL BWP with RACH resources. In some embodiments, a persistent LBT failure may be triggered in one or more UL BWPs. The UL BWP may be configured with PRACH timing on the same carrier in the serving cell. If a persistent LBT failure is triggered, the wireless communication device may indicate / notify the persistent LBT failure to at least one upper layer. For wireless communication devices in SCell, the number of failed UL LBT attempts for each beam may reach or exceed a threshold. If the number of failed UL LBT attempts reaches or exceeds the threshold, a persistent UL LBT failure may be triggered. The wireless communication device may report / notify the persistent UL LBT failure to the wireless communication node using MAC-CE (or other types of signaling). In some embodiments, the wireless communication node may configure one or more SSB / CSI-RS to monitor UL LBT failures at the wireless communication device. The wireless communication node may configure the SSB / CSI-RS using RRC messages (or other messages).

[0147] L. Example 11: Selection of Wireless Communication Devices

[0148] In certain spectrum areas (e.g., rel-16 shared spectrum), uplink transmissions can use / enable LBT failure detection / recovery. In some embodiments, the number of LBT failures for uplink transmissions can be compared to a certain threshold. Reaching or exceeding the threshold number of LBT failures can trigger persistent LBT failures. When beam-based LBTs are used / enabled / enabled in high frequencies, the LBT state for each beam may differ. Therefore, a separate quantity can specify the number of beam-based LBT failures (e.g., LBT failure attempts for each beam).

[0149] In some embodiments, the wireless communication device may select / identify / determine a subset of beams (e.g., at least two beams) to monitor uplink interference. The wireless communication device may select a subset of beams to monitor the count of failed LBT attempts for each subset of beams. For a wireless communication device in a SpCell, the number of failed UL LBT attempts for each beam may reach or exceed a certain threshold. If the number of failed UL LBT attempts reaches or exceeds the threshold, the wireless communication device may switch / change to a UL BWP with RACH resources. In some embodiments, a persistent LBT failure may be triggered in one or more UL BWPs. The UL BWPs may be configured with PRACH timing on the same carrier in the serving cell. If a persistent LBT failure has been triggered, the wireless communication device may indicate / specify / notify / report the persistent failure to at least one upper layer.

[0150] For wireless communication devices in an SCell, the number of failed UL LBT attempts for each beam may reach or exceed a certain threshold. If the number of failed UL LBT attempts reaches or exceeds the threshold, a persistent LBT failure can be triggered. The wireless communication device can report the persistent failure to the wireless communication node. The wireless communication device can use MAC-CE signaling (or other types of signaling) to report the persistent failure.

[0151] M. A method for direction-based listen-before-speak (LBT)

[0152] Figure 7 A flowchart illustrating method 750 for direction-based listen-before-speak (LBT) is provided. Method 750 can be used in conjunction with... Figure 1-6 The method may be implemented using any components and devices described in detail herein. In general, method 750 may include performing LBT (752) on each of a plurality of beams. Method 750 may include determining a count of failed LBT attempts for at least one beam (754).

[0153] Referring now to operation (752), in some embodiments, the wireless communication device may perform LBT on each of a plurality of beams. The wireless communication device may perform / conduct / enforce one or more LBT attempts on each of the plurality of beams. Each of the respective beams may have or correspond to at least one beam direction. In some embodiments, the wireless communication device may identify / designate one or more synchronization signal blocks (SSBs) and / or channel state information reference signals (CSI-RS). Measurements or other aspects of the identified SSBs and / or CSI-RS (e.g., RSRP, RSSI) may be compared with a first threshold. The identified SSBs and / or CSI-RS may satisfy / reach or exceed the first threshold. For each of the plurality of SSBs and / or CSI-RS, the wireless communication device may identify / designate a Physical Random Access Channel (PRACH) resource and / or preamble (e.g., RACH preamble, PRACH preamble, and / or initiate other transmissions for synchronization / communication with the wireless communication node). The PRACH resource and / or preamble may correspond to / be associated with at least one SSB and / or CSI-RS.

[0154] In response to the identification of PRACH resources and / or preambles, the wireless communication device can calculate / operate / determine the preamble transmission power and / or random access radio network temporary identifier (RA-RNTI) for each identified SSB and / or CSI-RS. The MAC layer (or other layers) can instruct / provide / specify the selected PRACH timing / resource, the corresponding RA-RNTI, the preamble index, the preamble transmission power, and / or other information for each identified SSB and / or CSI-RS to lower layers. For each identified PRACH resource, the wireless communication device can perform / conduct at least one LBT attempt. In some embodiments, at least one of a plurality of beams can correspond to at least one of multiple successful LBT attempts. The wireless communication device can identify at least one beam to transmit / transmit / broadcast the corresponding preamble.

[0155] Referring now to operation (754), in some embodiments, the wireless communication device may determine / calculate / operate a count of failed LBT attempts for at least one of a plurality of beams. In some embodiments, the wireless communication node may send / transmit / broadcast downlink control information (DCI) and / or other information to the wireless communication device. The wireless communication device may receive / obtain a DCI that includes an indication of a plurality of SSBs. The DCI may indicate / specify one or more SSBs and / or one or more preamble indices corresponding to each SSB. In response to receiving / obtaining the indication, the wireless communication device may perform one or more LBT attempts for the plurality of beams. The plurality of beams may correspond to a plurality of SSBs.

[0156] In some embodiments, one or more SSBs and / or CSI-RS may have corresponding Reference Received Power (RSRP) and / or Received Signal Strength Indicator (RSSI). The wireless communication device may determine that each of the one or more SSBs and / or CSI-RS has an RSRP that reaches or exceeds (e.g., equal to and / or higher than) a first threshold. The wireless communication device may determine that each of the one or more SSBs and / or CSI-RS has an RSSI that is lower than (e.g., less than and / or equal to) a second threshold. The wireless communication device may use system information and / or RRC messages (or other messages) to configure the first threshold (e.g., rsrp-thresholdSSB) and / or the second threshold (e.g., rssi-thresholdSSB). The wireless communication device may select / identify at least one of the one or more SSBs and / or CSI-RS (e.g., having an RSRP greater than or equal to the first threshold and / or an RSSI lower than the second threshold). In some embodiments, the wireless communication device may select at least one SSB and / or CSI-RS in a random / arbitrary manner. The wireless communication device may perform / conduct one or more LBT attempts on the selected SSBs and / or CSI-RS. In response to performing an LBT attempt, the wireless communication device can identify at least one of a plurality of beams corresponding to a successful LBT attempt. The wireless communication device can use the identified beam (e.g., corresponding to a successful LBT attempt) to send / transmit / broadcast a (random access) preamble.

[0157] In some embodiments, the wireless communication device may determine that each of at least one SSB and / or CSI-RS has an RSRP that reaches or exceeds (e.g., equal to and / or higher than) a first threshold. The wireless communication device may determine that none of the at least one SSB and / or CSI-RS has an RSSI below (e.g., less than and / or equal to) a second threshold. The wireless communication device may select / identify one or more of the at least one SSB and / or CSI-RS. The wireless communication device may perform one or more LBT attempts on the selected SSB and / or CSI-RS. The wireless communication device may select / identify one or more of the at least one SSB and / or CSI-RS based on RSSI measurements. For example, the wireless communication device may select one or more SSBs / CSI-RS with an RSSI exceeding a maximum amount of the second threshold. In another example, the wireless communication device may select one or more SSBs / CSI-RS in a random / arbitrary manner. The RSSI measurement may correspond to at least one SSB and / or CSI-RS. In response to performing an LBT attempt, the wireless communication device may identify at least one beam from a plurality of beams corresponding to a successful LBT attempt. Wireless communication devices can use the identified beam to send / transmit a preamble (e.g., corresponding to a successful LBT attempt).

[0158] In some embodiments, each of at least one SSB and / or CSI-RS may have an associated RSSI and / or RSRP. The wireless communication device may determine that each of at least one SSB and / or CSI-RS has an RSSI below (e.g., less than and / or equal to) a second threshold. The wireless communication device may determine that none of at least one SSB and / or CSI-RS has an RSRP that reaches or exceeds a first threshold. The wireless communication device may select / identify one or more of at least one SSB and / or CSI-RS. In some embodiments, one or more SSBs and / or CSI-RS may be selected according to the implementation of the wireless communication device and / or according to one or more rules or configurations. For example, the wireless communication device may select one or more SSBs and / or CSI-RS whose RSRP is closest to / closest to the first threshold. The wireless communication device may perform one or more LBT attempts on the selected SSBs and / or CSI-RS. In response to performing an LBT attempt, the wireless communication device may identify at least one beam from a plurality of beams corresponding to a successful LBT attempt. The wireless communication device may use the identified beam to transmit / transmit a preamble (e.g., a random access preamble or other transmission).

[0159] In some embodiments, the wireless communication device may determine that none of at least one SSB and / or CSI-RS has an RSRP that reaches or exceeds a first threshold. In some embodiments, the wireless communication device may determine that none of at least one SSB and / or CSI-RS has an RSSI below a second threshold. The wireless communication device may select / identify one or more of at least one SSB and / or CSI-RS. In some embodiments, one or more SSBs and / or CSI-RS may be selected according to the implementation of the wireless communication device. For example, the wireless communication device may select at least one SSB and / or CSI-RS whose RSRP is closest to / closest to the first threshold. In another example, the wireless communication device may select one or more SSBs / CSI-RS in a random / arbitrary manner. The wireless communication device may perform one or more LBT attempts on the selected SSBs and / or CSI-RS. In response to performing an LBT attempt, the wireless communication device may identify at least one beam from a plurality of beams corresponding to a successful LBT attempt. The wireless communication device may use the identified beam to send / transmit a preamble. In response to performing a preamble transmission, the wireless communication device may stop / pause other ongoing LBT attempts.

[0160] In some embodiments, the wireless communication device can select / identify one or more of at least one SSB and / or CSI-RS. The wireless communication device can perform / make one or more LBT attempts on the selected SSB and / or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS according to a pre-configured implementation of the wireless communication device. The wireless communication device can select the SSB and / or CSI-RS based on the RSRP of the selected SSB and / or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS whose RSRP is closest to a first threshold. The selected SSB and / or CSI-RS whose RSRP is closest to the first threshold can be among at least one SSB and / or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS whose RSRP meets or exceeds the first threshold to the maximum extent. The selected SSB and / or CSI-RS whose RSRP exceeds the first threshold to the maximum extent can be among at least one SSB and / or CSI-RS.

[0161] The wireless communication device can select an SSB and / or CSI-RS based on the RSSI of the selected SSB and / or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS whose RSSI is closest to a second threshold. The selected SSB and / or CSI-RS whose RSSI is closest to the second threshold can be among at least one SSB or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS whose RSSI exceeds the second threshold to the greatest extent possible. The selected SSB and / or CSI-RS whose RSSI exceeds the second threshold to the greatest extent possible can be among at least one SSB and / or CSI-RS. The wireless communication device can select the SSB and / or CSI-RS according to a random / arbitrary selection process.

[0162] In some embodiments, each of at least one SSB and / or CSI-RS may have / correspond to at least one RSRP. The RSRP may be compared to a first threshold. The wireless communication device may determine that the RSRP of each of at least one SSB and / or CSI-RS reaches or exceeds the first threshold. In some embodiments, the wireless communication device may determine / calculate a count (e.g., LBT failure statistics) of failed LBT attempts for each of at least one SSB or CSI-RS. The wireless communication device may use the count of failed LBT attempts to select / identify / determine one or more of at least one SSB and / or CSI-RS. For example, the wireless communication device may select / identify one or more SSBs and / or CSI-RS with low load (e.g., SSBs / CSI-RS with low failed LBT attempt counts). The wireless communication device may perform / conduct one or more LBT attempts on the selected SSB and / or CSI-RS.

[0163] In some embodiments, the wireless communication device can determine / calculate / operate / track a count (e.g., LBT failure statistics) of failed LBT attempts for one or more SSBs. Each of the one or more SSBs may correspond to a specific beam among a plurality of beams. In response to determining this count, the wireless communication device can select / identify a first beam among the plurality of beams. The wireless communication device can use the count of failed LBT attempts to select the first beam among the plurality of beams. For example, the wireless communication device can count / calculate / use the number of failed LBT attempts for each beam to select / identify / determine / use a beam with a light load (e.g., a beam with a low count of failed LBT attempts).

[0164] In some embodiments, the count of failed LBT attempts may include the maximum value of a counter before the timer expires or restarts. The count of failed LBT attempts may enumerate / indicate / specify the number of failed LBT attempts for the first SSB corresponding to the first beam. In response to the occurrence of a failed LBT attempt, the value of the counter may be incremented (e.g., increased by a value of 1 or other defined value). In response to the occurrence of a failed LBT attempt, the timer may be started or restarted. Once the timer has run its entire process / duration (e.g., the timer expires), the counter may be changed / set / reset to a value of 0 (or other defined value). Unless another failed LBT attempt occurs, the timer may run its entire process / duration (e.g., until expiration). In some embodiments, the value of the counter may be incremented in response to a failed LBT attempt. If the value of the counter is 0, the timer may be started or restarted in response to a failed LBT attempt. Therefore, unless the value of the counter is 0, the timer may run its entire process / duration before restarting.

[0165] In some embodiments, a wireless communication device may receive / obtain indications of multiple beams from a wireless communication node. The wireless communication node may send / transmit / broadcast this indication via Radio Resource Control (RRC) signaling (or other types of signaling). For transmissions using configuration authorization, the wireless communication device may perform one or more LBT attempts. The wireless communication device may perform one or more LBT attempts for each of the multiple beams. The wireless communication device may use configuration authorization to select / identify a first beam from the multiple beams for transmission. In some embodiments, the wireless communication device may determine that a successful LBT attempt has occurred. A successful LBT attempt may occur on the first beam among the multiple beams. The wireless communication device may determine that a successful LBT attempt occurred before any other successful LBT attempt. In some embodiments, the first beam among the multiple beams may have a count of failed LBT attempts. The wireless communication device may determine that the count of failed LBT attempts is lower than / less than those of the other beams among the multiple beams. For example, the wireless communication device may select at least one beam with a lighter / fewer / lower load than other beams. The wireless communication device may use the count of failed LBT attempts to determine the load of each beam.

[0166] In some embodiments, a wireless communication device may receive / obtain indications of multiple beams from a wireless communication node. The wireless communication node may send / transmit this indication via Media Access Control-CE (MAC-CE) signaling (or other types of signaling). The wireless communication device may use uplink control channel resources (e.g., PUCCH) to perform one or more LBT attempts. The wireless communication device may perform one or more LBT attempts for each of the multiple beams. The wireless communication device may use uplink control channel resources to select / identify a first beam from the multiple beams for transmission. In some embodiments, the wireless communication device may determine that a successful LBT attempt has occurred. A successful LBT attempt may occur on the first beam among the multiple beams. The wireless communication device may determine that a successful LBT attempt occurred before any other successful LBT attempt. In some embodiments, the first beam among the multiple beams may have a count of failed LBT attempts. The wireless communication device may determine that the count of failed LBT attempts is lower than / less than those of the other beams among the multiple beams. For example, the wireless communication device may select at least one beam with a lighter / fewer / lower load than other beams. The wireless communication device may use the count of failed LBT attempts to determine the load of each beam.

[0167] In some embodiments, the wireless communication device may determine a count (e.g., DL LBT statistics) of failed LBT attempts for each of a plurality of beams. The count of failed LBT attempts for a first beam may include: the maximum value of a counter before a timer expires or restarts. In response to a failed LBT attempt, the value of the counter may be incremented (e.g., increased by 1). In response to a failed LBT attempt, the timer may be started or restarted. Once the timer has completed its entire duration (e.g., the timer expires), the counter may be changed / set to a value of 0. Therefore, unless a failed LBT attempt occurs, the timer may run its entire duration until expiration. If the counter value is 0, the timer may be started or restarted in response to a failed LBT attempt. If the counter value is 0, the counter may be incremented (e.g., increased by 1) in response to a failed LBT attempt.

[0168] In some embodiments, the value of the counter may reach or exceed a threshold before the timer expires and / or restarts. If the value of the counter reaches the threshold, the timer may stop / pause its process. If the value of the counter reaches the threshold, the counter may change / set / reset to a value of 0 (or other defined value). If the value of the counter fails to reach the threshold, the counter may change to a value of 0 (or other defined value). In response to a failed LBT attempt, the value of the counter may increment / increment (e.g., increase by a value of 1 or other defined value). For example, in response to a successful LBT attempt, the value of the counter may become 0.

[0169] In some embodiments, the value of the counter may reach or exceed a threshold. If the value of the counter reaches the threshold, beam failure recovery may be triggered / initiated / caused by the wireless communication device in the SpCell. If the value of the counter reaches the threshold, the wireless communication device may switch / change from the first BWP to the second BWP. The wireless communication device may perform a random access procedure in the second BWP. If the value of the counter reaches the threshold, persistent LBT failure may be reported / notified to the upper layer used by the wireless communication device in the SpCell. Persistent LBT failure may be reported when the value of the counter reaches or exceeds the threshold in the currently active BWP. If the value of the counter reaches the threshold, beam failure recovery may be triggered / initiated / caused by the wireless communication device in the SCell. If the value of the counter reaches the threshold, persistent LBT failure may be reported / notified to the wireless communication node used by the wireless communication device in the SCell. Persistent LBT failure may be reported via MAC-CE signaling (or other types of signaling). If the value of the counter reaches the threshold, the wireless communication device may switch / change from the first BWP to the second BWP. The wireless communication device may perform a random access procedure in the second BWP.

[0170] In some embodiments, the wireless communication device in the SCell can evaluate / analyze the RSRP and / or RSSI of a first SSB and / or CSI-RS. The wireless communication device can determine that the RSRP of the first SSB and / or CSI-RS reaches or exceeds a first threshold. The wireless communication device can determine that the RSSI of the first SSB and / or CSI-RS is below a second threshold. The first and / or second thresholds can be specified / configured via RRC signaling (or other types of signaling). In response to this determination, the wireless communication device can report / specify / indicate the identifier of the first SSB and / or CSI-RS to the wireless communication node. For example, the wireless communication device can report the index of the SSB (or CSI-RS) whose RSRP and / or RSSI reach or exceed their respective thresholds (e.g., the first and / or second thresholds).

[0171] In some embodiments, a wireless communication device in SpCell can send / transmit / broadcast one or more indices to a wireless communication node. The wireless communication device can transmit one or more indices via MAC-CE signaling (or other types of signaling). The wireless communication device can use a new format of MAC-CE (e.g., LBT failure MAC-CE format) to send / transmit one or more indices. One or more indices can indicate / specify / provide one or more of a plurality of beams on which a sustained LBT failure has occurred.

[0172] In some embodiments, a wireless communication device may receive / obtain a subset of multiple beams (e.g., at least two beams) from a wireless communication node. The wireless communication device may monitor / analyze the received subset of beams. The wireless communication device may monitor / determine / analyze the count of failed LBT attempts for the subset of multiple beams. For example, the wireless communication device may monitor the total count of failed attempts for the subset of multiple beams (e.g., the number of combinations of individual failed attempts for each beam in the subset). In some embodiments, the wireless communication device may determine the subset of multiple beams to be monitored. The wireless communication device may monitor the count of failed LBT attempts for each set of multiple beams. For example, the wireless communication device may monitor the individual count of failed LBT attempts for each beam included in the subset.

[0173] Although various embodiments of the present solution have been described above, it should be understood that they are presented by way of example only and not by way of limitation. Similarly, various figures may depict example architectures or configurations, provided to enable those skilled in the art to understand the example features and functionality of the present solution. However, such persons will understand that the present solution is not limited to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Furthermore, as those skilled in the art will understand, one or more features of one embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of this disclosure should not be limited by any of the illustrative embodiments described above.

[0174] It should also be understood that any reference to elements in this document using names such as “first”, “second”, etc., does not generally limit the number or order of those elements. Rather, these names may be used herein as a convenient means of distinguishing between two or more elements or instances of elements. Therefore, reference to the first and second elements does not imply that only two elements are used, or that the first element must precede the second element in some way.

[0175] Furthermore, those skilled in the art will understand that information and signals can be represented using any of a variety of different technologies and processes. For example, data, instructions, commands, information, signals, bits, and symbols, which may be referenced in the above description, can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0176] Those skilled in the art will also understand that any of the various illustrative logic blocks, modules, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementation, analog implementation, or a combination thereof), firmware, various forms of program or design code in conjunction with instructions (which may be referred to herein as "software" or "software module"), or any combination of these technologies. To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above in general terms of their functionality. Whether this functionality is implemented as hardware, firmware, software, or a combination of these technologies depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art can implement the described functionality in various ways for each specific application, but such implementation decisions do not necessarily lead to a departure from the scope of this disclosure.

[0177] Furthermore, those skilled in the art will understand that the various illustrative logic blocks, modules, devices, components, and circuits described herein may be implemented within or executed by integrated circuits (ICs), including general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, or any combination thereof. Logic blocks, modules, and circuits may also include antennas and / or transceivers for communicating with various components within a network or device. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices for performing the functions described herein, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors combined with a DSP core, or any other suitable configuration.

[0178] If implemented in software, the functionality can be stored as one or more instructions or code on a computer-readable medium. Therefore, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media include both computer storage media and communication media, with communication media including any medium that enables the transfer of computer programs or code from one place to another. Storage media can be any available medium accessible to a computer. By way of example and non-limiting intent, such computer-readable media can include: RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer.

[0179] In this document, the term "module" as used herein refers to software, firmware, hardware, and any combination of such elements for performing the associated functions described herein. Furthermore, for the purposes of discussion, various modules are described as discrete modules; however, it will be apparent to those skilled in the art that two or more modules can be combined to form a single module that performs the associated functions according to embodiments of this solution.

[0180] Additionally, in embodiments of this solution, memory or other storage devices and communication components may be employed. It will be understood that, for clarity, the above description has referred to embodiments of this solution with reference to different functional units and processors. However, it will be apparent that any suitable functional distribution among different functional units, processing logic elements, or domains may be used without departing from this solution. For example, functionality described as to be performed by a separate processing logic element or controller may be performed by the same processing logic element or controller. Therefore, references to specific functional units are merely references to suitable means for providing said functionality, and not indications of a strict logical or physical structure or organization.

[0181] Various modifications to the embodiments described herein will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the embodiments shown herein, but should be accorded the broadest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A wireless communication method, comprising: One or more Listen-After-Speak (LBT) attempts are performed on each of a plurality of beams in the wireless communication device, each of the plurality of beams having a corresponding beam direction; and The wireless communication device determines the count of failed LBT attempts for each of the plurality of beams; The wireless communication device selects a first beam from the plurality of beams based on the count of failed LBT attempts, wherein the count of failed LBT attempts for the first beam is lower than the count of failed LBT attempts for the other beams in the plurality of beams, wherein the count of failed LBT attempts for the first beam includes the maximum value of the counter before the timer expires or restarts, and wherein beam failure recovery is triggered when the count of failed LBT attempts for any of the plurality of beams reaches a predetermined threshold.

2. The method according to claim 1, comprising: The wireless communication device identifies multiple synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RS) that satisfy a first threshold. The wireless communication device identifies a Physical Random Access Channel (PRACH) resource and a preamble corresponding to the SSB or CSI-RS for each of the plurality of SSBs or CSI-RS. The wireless communication device performs at least one LBT attempt for each of the identified PRACH resources; and The wireless communication device identifies one of a plurality of beams corresponding to one of the multiple successful LBT attempts to transmit the corresponding preamble.

3. The method according to claim 1, comprising: The wireless communication device receives downlink control information (DCI) from the wireless communication node, and the downlink control information (DCI) includes indications of multiple synchronization signal blocks (SSBs). and In response to the indications of the plurality of SSBs, the wireless communication device performs one or more LBT attempts on the plurality of beams corresponding to the plurality of SSBs.

4. The method according to claim 1, comprising: The wireless communication device determines at least one synchronization signal block SSB or channel state information reference signal CSI-RS, each having a reference signal received power RSRP above a first threshold and a received signal strength indicator RSSI below a second threshold. The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts; and The wireless communication device identifies one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

5. The method according to claim 1, comprising: The wireless communication device determines that: each of at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) has a reference signal received power (RSRP) above a first threshold, and none of the at least one SSB or CSI-RS has a received signal strength indicator (RSSI) below a second threshold; The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts based on RSSI measurements of the at least one SSB or CSI-RS. and The wireless communication device identifies one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

6. The method according to claim 1, comprising: The wireless communication device determines that: each of at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) has a received signal strength indicator (RSSI) below a second threshold, and none of the at least one SSB or CSI-RS has a reference signal received power (RSRP) above a first threshold; The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts; and The wireless communication device identifies one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

7. The method according to claim 1, comprising: The wireless communication device determines that: at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) does not have a reference signal received power (RSRP) above a first threshold and a received signal strength indicator (RSSI) below a second threshold; The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts; and The wireless communication device identifies one of a plurality of beams corresponding to a successful LBT attempt to transmit a preamble.

8. The method according to any one of claims 4 to 7, comprising: The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts based on at least one of the following: The pre-configured implementation of the wireless communication device. One or more of the at least one SSB or CSI-RS have the RSRP closest to the first threshold among those of the at least one SSB or CSI-RS. One or more of the at least one SSB or CSI-RS have the RSSI closest to the second threshold among those of the at least one SSB or CSI-RS. One or more of the at least one SSB or CSI-RS have an RSRP that exceeds the first threshold to the greatest extent among those of the at least one SSB or CSI-RS. One or more of the at least one SSB or CSI-RS have an RSSI that exceeds the second threshold to the greatest extent among those of the at least one SSB or CSI-RS, or Random selection process.

9. The method according to claim 1, comprising: The wireless communication device determines that each of at least one synchronization signal block (SSB) or channel state information reference signal (CSI-RS) has a reference signal received power (RSRP) above a first threshold. The wireless communication device determines the count of failed LBT attempts for each of the at least one SSB or CSI-RS; and The wireless communication device selects one or more of the at least one SSB or CSI-RS to perform one or more LBT attempts based on the count of failed LBT attempts.

10. The method according to claim 1, comprising: The wireless communication device determines the count of failed LBT attempts for each synchronization signal block SSB corresponding to one of the plurality of beams.

11. The method according to claim 10, wherein, The count of failed LBT attempts for the first SSB corresponding to the first beam includes: the maximum value of the counter before the timer expires or restarts, where, In response to a failed LBT attempt, the counter value increments and the timer starts or restarts. When the timer expires, the counter is set to 0, or... In response to a failed LBT attempt, the counter value is incremented, and in response to a failed LBT attempt when the counter value is 0, the timer starts or restarts.

12. The method according to claim 1, comprising: The wireless communication device receives the indications of the plurality of beams from the wireless communication node via Radio Resource Control (RRC) signaling; The wireless communication device performs one or more LBT attempts for each of the plurality of beams for transmissions using the configuration license.

13. The method according to claim 1, comprising: The wireless communication device receives the indications of the plurality of beams from the wireless communication node via the Media Access Control (MAC-CE) signaling element; The wireless communication device performs one or more LBT attempts on each of the plurality of beams for transmissions using uplink control channel resources.

14. The method according to claim 1, wherein: In response to a failed LBT attempt, the counter value increments and the timer starts or restarts. When the timer expires, the counter is set to 0. or In response to a failed LBT attempt when the counter value is 0, the timer starts or restarts and the counter value increments, where: When the counter value reaches the threshold before the timer expires or restarts, the timer stops and the counter is set to 0. When the timer expires and the counter value has not reached the threshold, the counter is set to 0; or In response to a failed LBT attempt, the counter value is incremented, and in response to a successful LBT attempt, the counter value is set to 0.

15. The method according to claim 1, comprising: The wireless communication device in the secondary cell SCell determines that the first synchronization signal block SSB or channel state information reference signal CSI-RS has a reference signal received power RSRP above a first threshold and a received signal strength indicator RSSI below a second threshold; and The wireless communication device reports the identifier of the first SSB or CSI-RS to the wireless communication node.

16. The method of claim 1, comprising: The wireless communication equipment in the primary cell SpCell of the primary cell group or the secondary cell group transmits one or more indices to the wireless communication node via the Media Access Control (MAC-CE) signaling element. The one or more indices indicate one or more of the plurality of beams on which a sustained LBT failure has occurred.

17. The method of claim 1, comprising: The wireless communication device receives a subset of the plurality of beams to be monitored from the wireless communication node.

18. A non-transitory computer-readable medium storing instructions that, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 17.

19. A wireless communication device, comprising: A memory and at least one processor, the at least one processor being configured to read instructions from the memory to perform the method according to any one of claims 1 to 17.

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