Transmission Configuration Indicator (TCI) Switching Using a Listen-Before-Talk (LBT) Counter

Abstract

A system, method, apparatus, or computer-readable medium for performing Transmission Configuration Indicator (TCI) switching using a Listen-Before-Talk (LBT) counter is presented. A wireless communication device in an active TCI switching process may receive a Physical Data Shared Channel with an activation command. The wireless communication device may determine that a target TCI state does not exist in the active TCI state list of the Physical Data Shared Channel. The wireless communication device may determine whether the target TCI state is known.

Description

Technical Field

[0001] The present disclosure generally relates to wireless communication, including but not limited to systems and methods for transmission configuration indicator (TCI) switching using a listen-before-talk (LBT) counter. Background Art

[0002] The standardization organization 3rd Generation Partnership Project (3GPP) is currently specifying a new radio interface called 5G New Radio (5G NR) and a next-generation packet core network (NG-CN or NGC). 5G NR will have three main components: a 5G access network (5G-AN), a 5G core network (5GC), and a user equipment (UE). To facilitate enabling different data services and requirements, the elements of the 5GC (also called network functions) have been simplified, and some of them are software-based so that they can be adjusted as needed. Summary of the Invention

[0003] Exemplary embodiments disclosed herein are intended to address problems related to one or more problems existing in the prior art and to provide additional features that will become apparent by reference to the following detailed description in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read this disclosure that various modifications can be made to the disclosed embodiments 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 in an active transmission configuration indicator (TCI) switching process may receive a physical data shared channel with an activation command. The wireless communication device may determine that a target TCI state does not exist in the active TCI state list of the physical data shared channel. The wireless communication device may determine whether the target TCI state is known.

[0005] In some embodiments, the activation command may include a radio resource control (RRC) activation command that includes one TCI state in the active TCI state list. In some embodiments, the activation command may include a media access control control element (MAC CE) activation command.

[0006] In some embodiments, when the target TCI state is known, the wireless communication device may determine that a first counter has reached a defined limit. The first counter may count the number of listen-before-talk (LBT) failures in a Synchronization Signal Block (SSB) period. In some embodiments, the wireless communication device may increment a second counter in response to the first counter reaching the defined limit. In some embodiments, the wireless communication device may set the first counter to zero in response to the increment.

[0007] In some embodiments, when the SSB period is less than or equal to a defined duration and the second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device may indicate to a lower layer to stop activating the TCI state transition process.

[0008] In some embodiments, when the second counter exceeds one of the first threshold or the second threshold, the wireless communication device may trigger beam failure recovery. In some embodiments, the wireless communication device may switch to at least one other downlink bandwidth part (BWP) configured or indicated by the network. In some embodiments, the wireless communication device may switch to a specified BWP. In some embodiments, the wireless communication device may indicate a TCI state transition failure to the network via a Radio Resource Control (RRC) or Medium Access Control Control Element (MAC CE) message.

[0009] In some embodiments, in response to receiving a successful indication of an available SSB associated with the target TCI state, the wireless communication device may set the first counter and the second counter to zero. In some embodiments, the wireless communication device may increment the first counter in response to receiving a listen-before-talk (LBT) failure indication from a lower layer. The first counter may count the number of LBT failures in a Synchronization Signal Block (SSB) period.

[0010] In some embodiments, when the target TCI state is unknown and the activation of the TCI state transition process is associated with Quasi-Co-Location (QCL) type D, the wireless communication device may determine that a first counter has reached a defined limit. The first counter may count the number of listen-before-talk (LBT) failures in a Synchronization Signal Block (SSB) period. In some embodiments, the wireless communication device may increment a second counter in response to the first counter reaching the defined limit. In some embodiments, the wireless communication device may set the first counter to zero in response to the increment.

[0011] In some embodiments, when the SSB period is less than or equal to a defined duration and a second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device may indicate to a lower layer to stop activating the TCI state switching process. In some embodiments, in response to receiving a successful indication of available SSBs associated with a target TCI state, the wireless communication device may set the first counter and the second counter to zero.

[0012] In some embodiments, when the target TCI state is unknown and the activation of the TCI state switching process is associated with quasi-co-location (QCL) type D, the wireless communication device may increment a third counter in response to receiving a listen-before-talk (LBT) failure indication from the lower layer. The third counter may count the number of LBT failures in channel state information reference signal (CSI-RS) transmissions.

[0013] In some embodiments, when the CSI-RS period is less than or equal to a defined duration and the third counter exceeds a third threshold, or when the CSI-RS period is greater than the defined duration and the third counter exceeds a fourth threshold, the wireless communication device may indicate to a lower layer to stop activating the TCI state switching process. In some embodiments, in response to receiving a successful indication of available CSI-RSs associated with a target TCI state, the wireless communication device may set the third counter to zero.

[0014] In some embodiments, the wireless communication device may determine that a first counter has reached a defined limit, where the first counter is configured to count the number of listen-before-talk (LBT) failures in a synchronization signal block (SSB) period. In some embodiments, the wireless communication device may increment a second counter in response to the first counter reaching the defined limit. In some embodiments, the wireless communication device may set the first counter to zero in response to the increment.

[0015] In some embodiments, when the SSB period is less than or equal to a defined duration and a second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device may indicate to a lower layer to stop activating the TCI state switching process. In some embodiments, in response to receiving a successful indication of available SSBs associated with a target TCI state, the wireless communication device may set the first counter and the second counter to zero. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following describes various example embodiments of the present solution in detail with reference to the following attached drawings or diagrams. The attached drawings are provided for illustrative purposes only and describe only the example embodiments of the present solution to facilitate the reader's understanding of the present solution. Therefore, the diagrams should not be regarded as limiting the breadth, scope, or applicability of the present solution. It should be noted that these diagrams are not necessarily drawn to scale for clarity and ease of illustration.

[0017] Figure 1 FIG. shows an example cellular communication network in which the techniques disclosed herein can be implemented according to an embodiment of the present disclosure;

[0018] Figure 2 FIG. shows a block diagram of an example base station and user equipment according to some embodiments of the present disclosure;

[0019] Figure 3 FIG. shows a timing diagram of a transmission configuration indicator (TCI) handover process based on radio resource control (RRC);

[0020] Figure 4 FIG. shows a timing diagram of a transmission configuration indicator (TCI) handover process based on media access control control element (MAC-CE); and

[0021] Figure 5 FIG. shows a flowchart of using a listen-before-talk (LBT) counter for transmission configuration indicator (TCI) handover. Detailed Description of Specific Embodiments

[0022] The following describes various example embodiments of the present solution with reference to the attached drawings so that those of ordinary skill in the art can make and use the present solution. It will be apparent to those of ordinary skill in the art that various changes or modifications can be made to the examples described herein without departing from the scope of the present solution after reading this disclosure. Therefore, the present solution is not limited to the example embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein is merely an example method. Based on design preferences, the specific order or hierarchy of steps of the disclosed method or process can be rearranged while remaining within the scope of the present solution disclosure. Therefore, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or actions in a sample order and that the present solution is not limited to the specific order or hierarchy presented unless otherwise expressly stated.

[0023] The following acronyms are used throughout this disclosure:

[0024]

[0025]

[0026]

[0027] 1. Mobile Communication Technology and Environment

[0028] Figure 1 FIG. shows an example wireless communication network and / or system 100 in accordance with an embodiment of the present disclosure, in which the techniques disclosed herein may be implemented. In the following discussion, the wireless communication network 100 may 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 a base station 102 (hereinafter referred to as "BS 102", also referred to as a wireless communication node) and a user equipment 104 (hereinafter referred to as "UE 104", also referred to as a wireless communication device), which may communicate with each other via a communication link 110 (e.g., a wireless communication channel), and includes cell clusters 126, 130, 132, 134, 136, 138, and 140 that cover a geographical area 101. In Figure 1 BS 102 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 on its allocated bandwidth to provide sufficient wireless coverage to its intended users.

[0029] For example, BS102 may operate under an allocated channel transmission bandwidth to provide sufficient coverage to UE 104. BS102 and UE 104 may communicate via a downlink radio frame 118 and an uplink radio frame 124, respectively. Each radio frame 118 / 124 may be further divided into subframes 120 / 127, and the subframes 120 / 127 may include data symbols 122 / 128. In the present disclosure, BS 102 and UE 104 are described herein as non-limiting examples of "communication nodes", which may generally implement the methods disclosed herein. According to various embodiments of the present solution, such communication nodes are capable of wireless and / or wired communication.

[0030] Figure 2 FIG. shows a block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) in accordance with some embodiments of the present solution. System 200 may include components and elements configured to support known or conventional operating features that are not described in detail herein. In one illustrative embodiment, as described above, system 200 may be used to transmit (e.g., send and receive) data symbols in a wireless communication environment such as Figure 1 the wireless communication environment 100.

[0031] System 200 generally includes a base station 202 (hereinafter referred to as "BS202") and a user equipment 204 (hereinafter referred to as "UE204"). 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, and each module is coupled and interconnected with each other via a data communication bus 220 as needed. 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, and each module is coupled and interconnected with each other via a data communication bus 240 as needed. BS 202 communicates with UE204 via a wireless transmission link 250, and the wireless transmission link 250 can be any wireless channel or other medium suitable for data transmission as described herein.

[0032] As understood by those of ordinary skill in the art, system 200 may also include any number of modules other than Figure 2 the modules shown. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logics described in connection with the embodiments disclosed herein may 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 functions. Whether such functions are implemented in hardware, firmware, or software depends on the specific application and the design constraints imposed on the overall system. Persons familiar with the concepts described herein can implement such functions in an appropriate manner for each specific application, but such implementation decisions should not be construed as limiting the scope of the present disclosure.

[0033] According to some embodiments, the UE transceiver module 230 may herein be referred to as an "uplink" transceiver 230, which includes a radio frequency (RF) transmitter and an RF receiver, each of which includes circuitry coupled to an antenna 232. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in a time-division duplexing manner. Similarly, according to some embodiments, the BS transceiver module 210 may herein be referred to as a "downlink" transceiver 210, which includes an RF transmitter and an RF receiver, each of which includes circuitry coupled to an antenna 212. The downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in a time-division duplexing manner. The operations of the two transceiver modules 210 and 230 may be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna 232 to receive transmissions via the wireless transmission link 250 while the downlink transmitter is coupled to the downlink antenna 212. Conversely, the operations of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver is coupled to the downlink antenna 212 while the uplink transmitter is coupled to the uplink antenna 232 to receive transmissions via the wireless transmission link 250. In some embodiments, there is tight time synchronization with a minimum guard time between changes in the duplex direction.

[0034] The UE transceiver module 230 and the base station transceiver module 210 are configured to communicate via the wireless transmission link 250 and cooperate with a suitably configured RF antenna arrangement 212 / 232 that can support a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver module 210 and the base station transceiver module 210 are configured to support industry standards such as Long Term Evolution (LTE) and emerging 5G standards. However, it should be understood that the present disclosure is not necessarily limited in application to specific standards and related protocols. Instead, the UE transceiver module 230 and the base station transceiver module 210 may be configured to support alternative or additional wireless data communication protocols, including future standards or variants thereof.

[0035] According to various embodiments, BS 202 may be an evolved Node B (eNB), serving eNB, target eNB, femtocell, or picocell. In some embodiments, UE 204 may be embodied in various types of user equipment, such as a mobile phone, smartphone, personal digital assistant (PDA), tablet computer, laptop computer, wearable computing device, 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, intended to perform the functions described herein. In this way, the processor may be implemented as a microprocessor, controller, microcontroller, state machine, etc. The processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with digital signal processor cores, or any other such configuration.

[0036] In addition, the steps of the methods or algorithms described in connection with the embodiments disclosed herein may be directly embodied in hardware, firmware, software modules executed respectively by processor modules 214 and 236, or in any practical combination thereof. Memory modules 216 and 234 may 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 may be respectively coupled to processor modules 214 and 236 such that processor modules 214 and 236 can respectively read information from and write information to memory modules 216 and 234. Memory modules 216 and 234 may also be integrated into the respective processor modules 214 and 236. In some embodiments, memory modules 216 and 234 may each include a cache for storing temporary variables or other intermediate information during the execution of instructions to be executed respectively by processor modules 214 and 236. Memory modules 216 and 234 may also each include non-volatile memory for storing the instructions to be executed respectively by processor modules 214 and 236.

[0037] The network communication module 218 generally represents the hardware, software, firmware, processing logic, and / or other components of the base station 202 that implement two-way communication between the base station transceiver module 210 and other network components and communication nodes configured to communicate with the base station 202. For example, the network communication module 218 can be configured to support Internet or WiMAX traffic. In a typical deployment, without limitation, the network communication module 218 provides an 802.3 Ethernet interface such that the base station transceiver module 210 can communicate with a conventional Ethernet-based computer network. In this way, the network communication module 218 can include a physical interface for connecting to a computer network (e.g., a mobile switching center (MSC)). The terms “configured to,” “configured for,” and their conjugates, as used herein with respect to a specified operation or function, refer to a device, component, circuit, structure, machine, signal, etc. that is physically constructed, programmed, formatted, and / or arranged to perform the specified operation or function.

[0038] The Open Systems Interconnection (OSI) model (referred to herein as the “Open Systems Interconnection model”) is a conceptual and logical layout that defines the network communication used by systems (e.g., wireless communication devices, wireless communication nodes) that are open to interconnecting and communicating with other systems. The model is divided into seven sub-components or layers, each layer representing a conceptual collection of services provided to its upper and lower layers. The OSI model also defines a logical network and effectively describes computer packet transmission by using different layer protocols. The OSI model can also be referred to as the seven-layer OSI model or the seven-layer model. In some embodiments, the first layer can be the physical layer. In some embodiments, the second layer can be the Medium Access Control (MAC) layer. In some embodiments, the third layer can be the Radio Link Control (RLC) layer. In some embodiments, the fourth layer can be the Packet Data Convergence Protocol (PDCP) layer. In some embodiments, the fifth layer can be the Radio Resource Control (RRC) layer. In some embodiments, the sixth layer can be the Non-Access Stratum (NAS) layer or the Internet Protocol (IP) layer, and the seventh layer is another layer.

[0039] 2. Systems and Methods for Transmit Configuration Indicator (TCI) Switching Using a Listen-Before-Talk (LBT) Counter

[0040] In New Radio (NR), a Transmission Configuration Indicator (TCI) state can describe the Quasi-Co-Location (QCL) relationship of reference signals or Synchronization Signal Blocks (SSBs) and Control Resource Sets / Physical Downlink Shared Channels (CORESETs / PDSCHs) configured in a specific cell with a Cell ID within a specific bandwidth part having a Bandwidth Part Identifier (BWP ID). An NR UE can be configured with one or more TCI state configurations on serving cells in Multi-Radio Dual Connectivity (MR-DC) or Standalone NR. There can be one or more active TCI states in the active TCI state list, and the UE can perform an active TCI state switch under different triggering conditions, such as Radio Resource Control (RRC)-based handover, Medium Access Control (MAC) Control Element (CE)-based handover, and Downlink Control Information (DCI)-based handover.

[0041] There are two types of requirements related to TCI states:

[0042] ● Active TCI state switch latency; and

[0043] ● Active TCI state list update.

[0044] In unlicensed spectrum, Listen Before Talk (LBT) that performs a Clear Channel Assessment (CCA) check can be carried out before transmission. CCA can determine the presence or absence of other signals on the channel at least using energy detection, so as to determine whether the channel is occupied or idle respectively. If the channel is occupied, the transmission of reference signals from the base station may be blocked, resulting in a longer time to complete the active TCI state switch process at the UE. To avoid this, a maximum acceptable number of lost Discovery Reference Signal (DRS) occasions for TCI requirements can be introduced at the UE. Once the number of lost DRS occasions exceeds the defined maximum value, the UE behavior can be defined.

[0045] For the TCI state switch process based on Medium Access Control CE / Radio Resource Control (MAC CE / RRC), the UE can use the new TCI state to receive the Physical Downlink Control Channel (PDCCH) for a certain period of time. Currently, the maximum number of SS / PBCH block / Channel State Information Reference Signal (SSB / CSI-RS) occasions that are unavailable at the UE due to CCA failure is defined. When exceeding the maximum number, the UE can indicate to the lower layer to stop the active state switch process.

[0046] For RRC-based Transmission Configuration Indicator (TCI) state transitions, since the UE cannot return to the old TCI state, some recovery procedures such as beam failure can be considered. In other words, when the number of SSB / CSI-RS occasions unavailable due to Clear Channel Assessment (CCA) failure exceeds the maximum value, beam failure is triggered. In the following cases, for the SpCell (special cell), the random access procedure can be initialized. Via the Random Access Channel (RACH) procedure, the beam above the threshold can be notified to the network. For the SCell (secondary cell), Beam Failure Recovery (BFR) can be triggered. When there are available resources to accommodate the BFR MAC CE, the beam above the threshold will be notified to the network. Then, the NW (network) can indicate the new TCI state based on the received beam.

[0047] For the maximum number of SSB / CSI-RS occasions unavailable due to CCA failure, two different states (e.g., known state and unknown state) need to be distinguished. When the target TCI state is known, if the target TCI state is not in the active TCI state list of the Physical Downlink Shared Channel (PDSCH), the number of Listen-Before-Talk (LBT) failures for the SSB associated with the target TCI state can be counted. When the target TCI state is unknown, if the TCI state transition involves (Quasi-Co-Located) QCL-TypeD and the L1 Reference Signal Received Power (L1-RSRP) measurement is based on CSI-RS, two different counters for the LBT failures of CSI-RS and SSB can be counted. When the target TCI state is unknown, if the TCI state transition involves QCL-TypeD and the L1-RSRP measurement is based on SSB, one counter for the LBT failures of SSB can be counted. When the target TCI state is unknown, if the TCI state transition involves other QCL types, the number of LBT failures of SSB can be counted. Once the counter exceeds the maximum number of LBT failures, the UE can indicate to the lower layer to stop the TCI state transition process. When a receive success indication is received, the counter can be cleared and the transition process can be terminated. In addition, for a Quasi-Co-Located (QCLed) SSB, if all transmission opportunities of an SSB within an SSB period cannot be received due to CCA failure, it can be considered as one failure of the SSB.

[0048] A. Radio Resource Control (RRC)-based Transmission Configuration Indicator (TCI) Switching

[0049] I. TCI in the Known State

[0050] When the following conditions are met (e.g., as defined in 38.133 8.10.2), the TCI state can be identified as being in the known state:

[0051] ● During the period from the last transmission of the RS resource for the L1-RSRP measurement report for the target TCI state to the completion of the activation of the TCI state switch, where the RS resource for the L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0052] ● A TCI state switch command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0053] ● Before the TCI state switch command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0054] ● The TCI state remains detectable during the TCI state switch period;

[0055] ● The SSB associated with the TCI state remains detectable during the TCI switch period; and

[0056] ● The SNR of the TCI state ≥ -3 dB.

[0057] Within one SSB period, if an LBT failure indication is received from the lower layer, LBT_COUNTER1 can be incremented by 1. LBT_COUNTER1 can be used to count the number of LBT failures within one SSB period.

[0058] When the UE receives a PDSCH carrying an RRC activation command (which includes only one TCI state from the RRC TCI state list), if the target TCI state is known, then this TCI state may not be in the active TCI state list of the PDSCH. The LBT_COUNTER1 of this SSB can reach the total transmission opportunities within a period, and LBT_COUNTER2 can be incremented by 1. LBT_COUNTER2 can be used to count the number of LBT failures of this SSB with a larger granularity. Then, LBT_COUNTER1 can be set to 0.

[0059] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER2 exceeds Threshold1, the UE can indicate to the lower layer to stop the activation of the TCI state switch process. If the SSB period is greater than 40 ms and LBT_COUNTER2 exceeds Threshold2, the UE can also indicate to the lower layer to stop the activation of the TCI state switch process.

[0060] In addition, when LBT_COUNTER2 exceeds threshold 1 or threshold 2, one of the following options can also be considered:

[0061] (1) The UE can trigger a beam failure recovery procedure. For the SpCell, the UE will initiate a random access procedure. For the SCell, the beam failure recovery procedure will be triggered.

[0062] (2) The UE can switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0063] (3) If the defaultDownlinkBWP-Id is configured, the UE can switch to the BWP indicated by the defaultDownlinkBWP-Id; otherwise, it switches to the initialDownlinkBWP.

[0064] (4) The UE sends a TCI state switch failure to the network via an RRC message or a MAC CE.

[0065] (5) For the SpCell, the UE can indicate a DL LBT failure to the upper layer. Once a DL LBT failure is received, the RRC layer can perform a radio link failure (RLF). For the SCell, the UE can deactivate the SCell.

[0066] (6) For the SpCell, the UE can indicate a DL LBT failure to the upper layer. When the UE receives a DL LBT failure and is configured with a conditional handover (CHO) configuration, the DL LBT failure can be used as a trigger condition to select a target cell to perform a handover. For the SCell, the UE can deactivate the SCell.

[0067] When the UE receives a successful indication of the first available SSB associated with the target TCI state after the UE performs RRC processing, both LBT_COUNTER1 and LBT_COUNTER2 can be set to 0. In addition, the TCI state switch process can be successfully completed.

[0068] When the UE detects that there is no SSB failure associated with the target TCI state due to a CCA failure or receives an SSB failure, the UE can send a channel access failure indication to the higher layer. When an SSB associated with the target TCI state is successfully received, a successful reception indication of the SSB can be sent to the higher layer.

[0069] II. TCI in an unknown state

[0070] When at least one of the following conditions is not met (e.g., as defined in 38.133 8.10.2), the TCI state can be identified as being in an unknown state:

[0071] ● During the period from the last transmission of the RS resource for the L1-RSRP measurement report for the target TCI state to the completion of the activation of the TCI state switch, where the RS resource for the L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0072] ● A TCI state switch command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0073] ● Before the TCI state switch command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0074] ● The TCI state remains detectable during the TCI state switch period;

[0075] ● The SSB associated with the TCI state remains detectable during the TCI switch period; and

[0076] ● The SNR of the TCI state ≥ -3 dB

[0077] If the target TCI state is unknown, the UE may receive a PDSCH carrying an RRC activation command (which includes only one TCI state in the RRC TCI state list), and may perform the following operations.

[0078] Within one SSB period, if an LBT failure indication is received from the lower layer, LBT_COUNTER1 may be incremented by 1. LBT_COUNTER1 can be used to count the number of LBT failures within one SSB period. Depending on the configuration of the target TCI state, the following three cases will be considered:

[0079] (1) The TCI state switch may involve QCL-TypeD, and the corresponding reference signal may be the SSB;

[0080] (2) The TCI state switch may involve QCL-TypeD, and the corresponding reference signal may be the CSI-RS; and

[0081] (3) The TCI state switch may involve QCL-TypeA or QCL-TypeC.

[0082] For case (1), if the target TCI state is unknown and LBT_COUNTER1 for the SSB associated with the TCI target state reaches the maximum transmission opportunity for that SSB, LBT_COUNTER2 may be incremented by 1. LBT_COUNTER2 can be used to count the number of LBT failures for that SSB with a larger granularity. Then, LBT_COUNTER1 may be set to 0.

[0083] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER2 exceeds Threshold1, the UE may indicate to the lower layer to stop activating the TCI state switching process. If the SSB period is greater than 40 ms and LBT_COUNTER2 exceeds Threshold2, the UE may also indicate to the lower layer to stop activating the TCI state switching process.

[0084] In addition, when LBT_COUNTER2 exceeds threshold 1 or threshold 2, one of the following options may also be considered:

[0085] (1) The UE may trigger a beam failure to resume the process. For the SpCell, the UE may initiate a random access process. For the SCell, the beam failure recovery process will be triggered.

[0086] (2) The UE may switch to a specific BWP. The network may select a BWP with lower load. Then the BWP may be configured for the UE by an RRC message or indicated by a MAC CE.

[0087] (3) If defaultDownlinkBWP-Id is configured, the UE may switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE may switch to initialDownlinkBWP.

[0088] (4) The UE sends a TCI state switching failure to the network via an RRC message or a MAC CE.

[0089] (5) For the SpCell, the UE may indicate DL LBT failure to the upper layer. Once receiving the DL LBT failure, the RRC layer may perform a radio link failure (RLF). For the SCell, the UE may deactivate the SCell.

[0090] (6) For the SpCell, the UE may indicate DL LBT failure to the upper layer. When the UE receives the DL LBT failure and is configured with conditional handover (CHO) configuration, the DL LBT failure may be used as an execution condition to select a target cell to perform a handover. For the SCell, the UE may deactivate the SCell.

[0091] When the UE receives a successful indication of the first available SSB associated with the target TCI state after the UE performs RRC processing, both LBT_COUNTER1 and LBT_COUNTER2 may be set to 0. In this way, the TCI state switching process can be successfully completed.

[0092] For case (2) (e.g., as depicted in Figure 3 ), if the target TCI state is unknown and an LBT failure indication for this CSI-RS is received from the lower layer, LBT_COUNTER3 can be incremented by 1. LBT_COUNTER3 can be used to count the number of LBT failures for or related to CSI-RS.

[0093] If the CSI-RS period is equal to or shorter than 40 ms and LBT_COUNTER3 exceeds Threshold3, the UE may indicate to the lower layer to stop activating the TCI state switching process. If the CSI-RS period is greater than 40 ms and LBT_COUNTER3 exceeds Threshold4, the UE may also indicate to the lower layer to stop activating the TCI state switching process.

[0094] In addition, when LBT_COUNTER3 exceeds threshold 3 or threshold 4, one of the following options can also be considered:

[0095] (1) The UE may trigger a beam failure recovery process. For the SpCell, the UE will initiate a random access process. For the SCell, the beam failure recovery process can be triggered;

[0096] (2) The UE may switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0097] (3) If defaultDownlinkBWP-Id is configured, the UE may switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE may switch to the initialDownlinkBWP.

[0098] (4) The UE sends a TCI state switching failure to the network via an RRC message or a MAC CE.

[0099] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Once the DL LBT failure is received, the RRC layer may perform a radio link failure (RLF). For the SCell, the UE may deactivate the SCell.

[0100] (6) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. When the UE receives a DL LBT failure and is configured with a conditional handover (CHO) configuration, the DL LBT failure can be used as a criterion to select a target cell for handover. For the SCell, the UE may deactivate the SCell.

[0101] When the UE receives a success indication for the first available CSI-RS after the UE performs RRC processing, the UE may set LBT_COUNTER3 to 0 and consider the CSI-RS to be successfully received.

[0102] In the following, if the LBT_COUNTER1 of the SSB associated with the target TCI state reaches the maximum transmission opportunity of the SSB within a period, LBT_COUNTER4 may be incremented by 1. LBT_COUNTER4 can be used to count the number of LBT failures of SSBs with a larger granularity. Then, LBT_COUNTER1 may be set to 0.

[0103] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER4 exceeds Threshold5, the UE may indicate to the lower layer to stop activating the TCI state switching process. If the SSB period is greater than 40 ms and LBT_COUNTER4 exceeds Threshold6, the UE may also indicate to the lower layer to stop activating the TCI state switching process.

[0104] In addition, when LBT_COUNTER4 exceeds threshold 5 or threshold 6, one of the following options may also be considered:

[0105] (1) The UE may trigger a beam failure recovery process. For the SpCell, the UE will initiate a random access process. For the SCell, the beam failure recovery process will be triggered.

[0106] (2) The UE may switch to a specific BWP. The network may select a BWP with lower load. Then the BWP may be configured for the UE via an RRC message or indicated by a MAC CE.

[0107] (3) If defaultDownlinkBWP-Id is configured, the UE may switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE switches to the initialDownlinkBWP.

[0108] (4) The UE sends a TCI state switching failure to the network via an RRC message or a MAC CE.

[0109] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Once receiving the DL LBT failure, the RRC layer may perform a radio link failure (RLF). For the SCell, the UE may deactivate the SCell.

[0110] (6) For SpCell, the UE may indicate DL LBT failure to the upper layer. When the UE receives DL LBT failure and is configured with conditional handover (CHO) configuration, the DL LBT failure may be used as an execution condition to select a target cell to perform handover. For SCell, the UE may deactivate the SCell.

[0111] When the UE receives a success indication of the first available SSB after L1-RSRP measurement, both LBT_COUNTER1 and LBT_COUNTER4 may be set to 0.

[0112] For case (3), if LBT_COUNTER1 of the SSB associated with the target TCI state reaches the maximum transmission opportunity of the SSB, LBT_COUNTER5 may be incremented by 1. LBT_COUNTER5 may be used to count the number of LBT failures of SSBs with a larger granularity. Then, LBT_COUNTER1 may be set to 0.

[0113] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER5 exceeds Threshold7, the UE may indicate to the lower layer to stop the activation of the TCI state handover process. If the SSB period is greater than 40 ms and LBT_COUNTER5 exceeds Threshold8, the UE may also indicate to the lower layer to stop the activation of the TCI state handover process.

[0114] In addition, when LBT_COUNTER5 exceeds threshold 7 or threshold 8, one of the following options may also be considered:

[0115] (1) The UE may trigger a beam failure recovery process. For SpCell, the UE will initiate a random access process. For SCell, the beam failure recovery process will be triggered.

[0116] (2) The UE may switch to a specific BWP. The network may select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0117] (3) If defaultDownlinkBWP-Id is configured, the UE may switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE may switch to initialDownlinkBWP.

[0118] (4) The UE sends a TCI state handover failure to the network via an RRC message or a MAC CE.

[0119] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Upon receiving the DL LBT failure, the RRC layer may perform a Radio Link Failure (RLF). For the SCell, the UE may deactivate the SCell.

[0120] (6) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. When the UE receives the DL LBT failure and is configured with Conditional Handover (CHO) configuration, the DL LBT failure may be used as a criterion to select a target cell to perform a handover. For the SCell, the UE may deactivate the SCell.

[0121] When the UE receives a success indication for the first available SSB after RRC processing by the UE, both LBT_COUNTER1 and LBT_COUNTER5 may be set to 0. In this way, the TCI state switching process can be successfully completed.

[0122] When the UE detects that there is no SSB failure associated with the target TCI state due to CCA failure or receives an SSB failure, the UE may send a channel access failure indication to the higher layer. When the SSB associated with the target TCI state is successfully received, an SSB reception success indication may be sent to the higher layer. B. Transmission Configuration Indicator (TCI) Handover Based on Medium Access Control (MAC) Control Element (CE) I. TCI in Known State

[0123] When the following conditions are met (e.g., as defined in 38.133 8.10.2), the TCI state may be recognized as being in a known state:

[0124] ● During the period from the last transmission of the RS resource of the L1-RSRP measurement report for the target TCI state to the completion of the activation of the TCI state switch, where the RS resource for L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0125] ● A TCI state switch command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0126] ● Before the TCI state switch command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0127] ● The TCI state remains detectable during the TCI state switch period;

[0128] ● The SSB associated with the TCI state remains detectable during the TCI switch period; and

[0129] ● The SNR of the TCI state ≥ -3 dB.

[0130] Within an SSB period, if an LBT failure indication is received from the lower layer, LBT_COUNTER1 can be incremented by 1. LBT_COUNTER1 can be used to count the number of LBT failures within an SSB period.

[0131] When the UE receives a PDSCH carrying a MAC-CE activation command, if the target TCI state is known, this TCI state may not be in the active TCI state list of the PDSCH, and LBT_COUNTER1 for this SSB can reach the total transmission opportunities of this SSB within a period, and LBT_COUNTER2 can be incremented by 1. LBT_COUNTER2 can be used to count the number of LBT failures of this SSB with a larger granularity. Then, LBT_COUNTER1 can be set to 0.

[0132] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER2 exceeds Threshold1, the UE can indicate to the lower layer to abandon or stop the activation TCI state switching process and maintain the original state. When the SSB period is greater than 40 ms and LBT_COUNTER2 exceeds Threshold2, the UE can also indicate to the lower layer to stop the activation TCI state switching process and maintain the original state.

[0133] In addition, when LBT_COUNTER2 exceeds threshold 1 or threshold 2, one of the following options can also be considered:

[0134] (1) The UE can trigger a beam failure recovery process. For the SpCell, the UE will initialize a random access process. For the SCell, the beam failure recovery process can be triggered.

[0135] (2) The UE can switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0136] (3) If defaultDownlinkBWP-Id is configured, the UE can switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE can switch to initialDownlinkBWP.

[0137] (4) The UE sends a TCI state switching failure to the network via an RRC message or a MAC CE.

[0138] (5) For a SpCell, the UE may indicate DL LBT failure to the upper layer. Once receiving the DL LBT failure, the RRC layer performs radio link failure (RLF). For an SCell, the UE may deactivate the SCell.

[0139] (6) For a SpCell, the UE may indicate DL LBT failure to the upper layer. When the UE receives the DL LBT failure and is configured with conditional handover (CHO) configuration, the DL LBT failure may be used as an execution condition to select a target cell to perform handover. For an SCell, the UE may deactivate the SCell.

[0140] When the UE receives a success indication of the first available SSB associated with the target TCI state after the MAC CE command is decoded by the UE, both LBT_COUNTER1 and LBT_COUNTER2 may be set to 0. In this way, the TCI state handover process can be successfully completed.

[0141] When the UE detects that there is no SSB failure associated with the target TCI state due to CCA failure or receives an SSB failure, the UE may send a channel access failure indication to the upper layer. When the SSB associated with the target TCI state is successfully received, the reception success indication of the SSB may be sent to the upper layer.

[0142] II. TCI in an unknown state

[0143] When at least one of the following conditions is not met (e.g., as defined in 38.133 8.10.2), the TCI state may be identified as being in an unknown state:

[0144] ● During the period from the last transmission of the RS resource of the L1-RSRP measurement report for the target TCI state to the completion of the activation of the TCI state handover, where the RS resource for the L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0145] ● A TCI state handover command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0146] ● Before the TCI state handover command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0147] ● The TCI state remains detectable during the TCI state handover period;

[0148] ● The SSB associated with the TCI state remains detectable during the TCI handover period; and

[0149] ●The SNR of the TCI state ≥ -3 dB

[0150] When the UE receives the PDSCH carrying the MAC-CE activation command, if the target TCI state is unknown, the following operations can be performed.

[0151] Within an SSB period, if an LBT failure indication is received from the lower layer, LBT_COUNTER1 is incremented by 1. LBT_COUNTER1 can be used to count the number of LBT failures within an SSB period. Depending on the configuration of the target TCI state, the following three cases will be considered:

[0152] (1) The TCI state transition may involve QCL-TypeD, and the corresponding reference signal may be the SSB;

[0153] (2) The TCI state transition may involve QCL-TypeD, and the corresponding reference signal may be the CSI-RS; and

[0154] (3) The TCI state transition may involve QCL-TypeA or QCL-TypeC.

[0155] For case (1), if the target TCI state is unknown and LBT_COUNTER1 for the SSB associated with the TCI target state reaches the maximum transmission opportunity of the SSB, LBT_COUNTER2 can be incremented by 1. LBT_COUNTER2 can be used to count the number of LBT failures of the SSB with a larger granularity. Then, LBT_COUNTER1 can be set to 0.

[0156] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER2 exceeds Threshold1, the UE can indicate to the lower layer to stop activating the TCI state transition process and maintain the original state. When the SSB period is greater than 40 ms and LBT_COUNTER2 exceeds Threshold2, the UE can also indicate to the lower layer to stop activating the TCI state transition process and maintain the original state.

[0157] In addition, when LBT_COUNTER2 exceeds threshold 1 or threshold 2, one of the following options can also be considered:

[0158] (1) The UE can trigger the beam failure recovery process. For the SpCell, the UE can initiate the random access process. For the SCell, the beam failure recovery process can be triggered.

[0159] (2) The UE can switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0160] (3) If defaultDownlinkBWP-Id is configured, the UE can switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, it switches to the initialDownlinkBWP.

[0161] (4) The UE sends a TCI state switch failure to the network via an RRC message or a MAC CE.

[0162] (5) For the SpCell, the UE can indicate a DL LBT failure to the upper layer. Once a DL LBT failure is received, the RRC layer performs a radio link failure (RLF). For the SCell, the UE can deactivate the SCell.

[0163] (6) For the SpCell, the UE can indicate a DL LBT failure to the upper layer. When the UE receives a DL LBT failure and is configured with a conditional handover (CHO) configuration, the DL LBT failure can be used as an execution condition to select a target cell for handover. For the SCell, the UE can deactivate the SCell.

[0164] When the UE receives a successful indication of the first available SSB associated with the target TCI state after the MAC CE command is decoded by the UE, both LBT_COUNTER1 and LBT_COUNTER2 can be set to 0. In this way, the TCI state switch process can be successfully completed.

[0165] For case (2), (for example, as Figure 4 depicted in), if the target TCI state is unknown and an LBT failure indication for this CSI-RS is received from the lower layer, LBT_COUNTER3 can be incremented by 1. LBT_COUNTER3 can be used to count the number of LBT failures for the CSI-RS / CSI-RS.

[0166] If the CSI-RS period is equal to or shorter than 40 ms and LBT_COUNTER3 exceeds Threshold3, the UE can indicate to the lower layer to stop activating the TCI state switch process. If the CSI-RS period is greater than 40 ms and LBT_COUNTER3 exceeds Threshold4, the UE can also indicate to the lower layer to stop activating the TCI state switch process and maintain the original state.

[0167] When the UE receives a success indication for the first available CSI-RS after the MAC CE command is decoded by the UE, the UE may set LBT_COUNTER3 to 0 and consider the CSI-RS successfully received.

[0168] In the following, if the LBT_COUNTER1 of the SSB associated with the target TCI state reaches the maximum transmission opportunity of the SSB within a period, LBT_COUNTER4 may be incremented by 1. LBT_COUNTER4 can be used to count the number of LBT failures of the SSB with a larger granularity. Then, LBT_COUNTER1 may be set to 0.

[0169] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER4 exceeds Threshold5, the UE may indicate to the lower layer to stop activating the TCI state switching process. If the SSB period is greater than 40 ms and LBT_COUNTER4 exceeds Threshold6, the UE may also indicate to the lower layer to stop activating the TCI state switching process and maintain the original state.

[0170] In addition, when LBT_COUNTER2 exceeds threshold 5 or threshold 6, one of the following options may also be considered:

[0171] (1) The UE may trigger a beam failure recovery process. For the SpCell, the UE will initiate a random access process. For the SCell, the beam failure recovery process will be triggered.

[0172] (2) The UE may switch to a specific BWP. The network may select a BWP with lower load. Then the BWP may be configured for the UE via an RRC message or indicated by a MAC CE.

[0173] (3) If defaultDownlinkBWP-Id is configured, the UE may switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE switches to the initialDownlinkBWP.

[0174] (4) The UE sends a TCI state switching failure to the network via an RRC message or a MAC CE.

[0175] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Upon receiving the DL LBT failure, the RRC layer performs a radio link failure (RLF). For the SCell, the UE may deactivate the SCell.

[0176] (6) For a SpCell, the UE can indicate a DL LBT failure to the upper layer. When the UE receives a DL LBT failure and is configured with conditional handover (CHO) configuration, the DL LBT failure can be used as an execution condition to select a target cell to perform a handover. For an SCell, the UE can deactivate the SCell.

[0177] When the UE receives a success indication of the first available SSB after L1-RSRP measurement, both LBT_COUNTER1 and LBT_COUNTER4 can be set to 0.

[0178] For case (3), if LBT_COUNTER1 of the SSB associated with the target TCI state reaches the maximum transmission opportunity of the SSB, LBT_COUNTER5 can be incremented by 1. LBT_COUNTER5 can be used to count the number of LBT failures of SSBs with a larger granularity. Then, LBT_COUNTER1 can be set to 0.

[0179] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER5 exceeds Threshold7, the UE can indicate to the lower layer to stop activating the TCI state handover process and maintain the original state. If the SSB period is greater than 40 ms and LBT_COUNTER5 exceeds Threshold8, the UE can also indicate to the lower layer to stop activating the TCI state handover process and maintain the original state.

[0180] In addition, when LBT_COUNTER2 exceeds threshold 7 or threshold 8, one of the following options can also be considered:

[0181] (1) The UE can trigger a beam failure recovery process. For a SpCell, the UE can initiate a random access process. For an SCell, the beam failure recovery process will be triggered.

[0182] (2) The UE can switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0183] (3) If defaultDownlinkBWP-Id is configured, the UE can switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE can switch to initialDownlinkBWP.

[0184] (4) The UE sends a TCI state handover failure to the network via an RRC message or a MAC CE.

[0185] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Once a DL LBT failure is received, the RRC layer may perform a Radio Link Failure (RLF). For the SCell, the UE may deactivate the SCell.

[0186] (6) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. When the UE receives a DL LBT failure and is configured with Conditional Handover (CHO) configuration, the DL LBT failure may be used as a criterion to select a target cell to perform a handover. For the SCell, the UE may deactivate the SCell.

[0187] When the UE receives a success indication for the first available SSB after the MAC CE command is decoded by the UE, both LBT_COUNTER1 and LBT_COUNTER5 may be set to 0.

[0188] When the UE detects that there is no SSB failure associated with the target TCI state due to CCA failure or receives an SSB failure, the UE may send a channel access failure indication to the upper layer. When the SSB associated with the target TCI state is successfully received, a receive success indication of the SSB may be sent to the upper layer. C. Transmission Configuration Indicator (TCI) using a timer

[0189] When the TCI state switching process is successfully completed (e.g., the RRC-based or MAC-CE-based TCI handover is in a known state or an unknown state), if no PDCCH is received, the LBT failure statistics may not terminate for a long time. And since the TCI state switching has been completed, the statistics may be meaningless. Therefore, a timer may be introduced to avoid this situation. The following is divided into two cases for distinction:

[0190] (1) When the TCI state is unknown, the TCI state switching involves QCL-TypeD, and the corresponding reference signal is CSI-RS. Two different statistics (e.g., two different counters) may be used.

[0191] (2) For other cases, only one statistic may be needed.

[0192] For case (1) and case (2), two different timers may be introduced. When the UE receives an RRC-based or MAC CE-based TCI state switch, the corresponding timer may be started according to different cases. Once the maximum number of LBT failures exceeds the threshold within the timer, the UE may indicate to the lower layer to stop the TCI state switching. If the timer expires, the counter used to count the LBT failures may be cleared, and the TCI state switching process is considered to be successfully completed.

[0193] For case (1), when the CSI-RS is successfully received, a successful indication may be required to notify the higher layer. Then, the counter of the CSI-RS can be cleared. The UE can continue to count the number of LBT failures for the SSB. For case (2), since a timer is used, a successful indication may not be required.

[0194] D. Transmission Configuration Indicator (TCI) using an indicator

[0195] When the UE receives a TCI state switch based on RRC or MAC CE, the UE can indicate to the lower layer the LBT result of reporting the target TCI state and the result of successful reception of the SSB / CSI-RS. Once the UE receives a successful indication (e.g., the SSB or CSI-RS is successful during the TCI switch), the UE can indicate to the lower layer to stop reporting. If the counter of the number of LBT failures of the SSB / CSI-RS exceeds the threshold, the UE can indicate to the lower layer to stop the TCI state switch process.

[0196] If the UE receives a start reporting indication, the UE can send the LBT result of the target TCI state and the result of successful reception of the SSB / CSI-RS to the higher layer. Once the UE receives a stop TCI state switch indication, the UE can stop sending. In addition, if the UE receives a stop reporting indication, the UE will also stop sending.

[0197] E. Transmission Configuration Indicator (TCI) using a timer and the MAC layer

[0198] When the following conditions are met (e.g., as defined in 38.133 8.10.2), the TCI state can be recognized as being in a known state:

[0199] ● During the period from the last transmission of the RS resource for the L1-RSRP measurement report for the target TCI state to the completion of the activation of the TCI state switch, where the RS resource for the L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0200] ● The TCI state switch command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0201] ● Before the TCI state switch command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0202] ● The TCI state remains detectable during the TCI state switch period;

[0203] ● The SSB associated with the TCI state remains detectable during the TCI switching period; and

[0204] ● The SNR of the TCI state ≥ -3 dB.

[0205] When the UE receives a PDSCH carrying an RRC activation command (which only includes one TCI state in the RRC TCI state list) and the target TCI state is not in the active TCI state list of the PDSCH, a timer can be started.

[0206] Within one SSB period, if an LBT failure indication is received from the lower layer, LBT_COUNTER1 can be incremented by 1. LBT_COUNTER1 can be used to count the number of LBT failures within one SSB period.

[0207] When the LBT_COUNTER1 of this SSB reaches the total transmission opportunity within one period, LBT_COUNTER2 can be incremented by 1. LBT_COUNTER2 can be used to count the number of LBT failures of this SSB with finer granularity. Then, LBT_COUNTER1 can be set to 0.

[0208] If the SSB period is equal to or shorter than 40 ms and LBT_COUNTER2 exceeds Threshold1, the timer can stop and the UE can indicate to the lower layer to stop the active TCI state switching process. When the SSB period is greater than 40 ms and LBT_COUNTER2 exceeds Threshold2, the timer can stop and the UE can also indicate to the lower layer to stop the active TCI state switching process.

[0209] In addition, when LBT_COUNTER2 exceeds threshold 1 or threshold 2, one of the following options can also be considered:

[0210] (1) The UE can trigger a beam failure recovery process. For the SpCell, the UE will initiate a random access process. For the SCell, the beam failure recovery process can be triggered.

[0211] (2) The UE can switch to a specific BWP. The network can select a BWP with lower load. Then the BWP is configured for the UE via an RRC message or indicated by a MAC CE.

[0212] (3) If defaultDownlinkBWP-Id is configured, the UE can switch to the BWP indicated by defaultDownlinkBWP-Id; otherwise, the UE can switch to initialDownlinkBWP.

[0213] (4) The UE may send a TCI state transition failure to the network via an RRC message or a MAC CE.

[0214] (5) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. Once receiving the DL LBT failure, the RRC layer performs a radio link failure (RLF). For the SCell, the UE may deactivate the SCell.

[0215] (6) For the SpCell, the UE may indicate a DL LBT failure to the upper layer. When the UE receives the DL LBT failure and is configured with a conditional handover (CHO) configuration, the DL LBT failure may be used as a condition to select a target cell to perform a handover. For the SCell, the UE may deactivate the SCell.

[0216] When the timer expires, both LBT_COUNTER1 and LBT_COUNTER2 may be set to 0. In this way, the TCI state transition process can be successfully completed. When the UE detects that there is no SSB failure associated with the target TCI state due to a CCA failure or receives an SSB failure, the UE may send a channel access failure indication to the higher layer.

[0217] F. Process of using a listen-before-talk (LBT) counter for transmission configuration indicator (TCI) handover

[0218] Reference Figure 5 , depicts a flowchart of a process or method 500 for using an LBT counter for TCI handover. The method 500 may be implemented or executed by any component detailed herein, such as BS102, UE 104, and cells 126, 130, 132, 134, 136, 138, and 140, etc. Briefly, a wireless communication device (e.g., UE 104) may receive a physical downlink shared channel (PDSCH) with an activation command (505). The wireless communication device may determine whether the target TCI state is not in the active TCI state list (510). If it is determined that the target TCI state exists, the wireless communication device may exit the TCI state transition (515). If it is determined that the target TCI state does not exist, the wireless communication device may determine whether the target TCI state is known (520). When the target TCI state is known, the wireless communication device may set the LBT counter for the known TCI state (525). The wireless communication device may perform the TCI handover process for the known TCI state (530). On the contrary, when the target TCI state is unknown, the wireless communication device may set the LBT counter for the unknown TCI state (535). The wireless communication device may perform the TCI handover process for the unknown TCI state (540).

[0219] More specifically, a wireless communication device (e.g., UE 104) may retrieve, identify, or receive a Physical Downlink Shared Channel (PDSCH) (505) with an activation command. The wireless communication device may be in an active TCI handover process. The TCI state may define the quasi-co-location (QCL) relationship of the reference signal or Synchronization Signal Block (SSB) of a specific cell within a bandwidth path with a Control Resource Set (CORESET) or a Physical Downlink Shared Channel (PDSCH). Under the active TCI handover process, the wireless communication device may select an active Bandwidth Part (BWP) according to the target TCI state. The wireless communication device may retrieve, identify, or receive a PDSCH with an activation command. In some embodiments, the activation command may identify, correspond to, or include a Radio Resource Control (RRC) activation command. The RRC activation command may identify, define, or include at least one TCI state in an activation TCI state list. In some embodiments, the activation command may identify, correspond to, or include a Medium Access Control Control Element (MAC-CE) activation command.

[0220] The wireless communication device may identify or determine whether the target TCI state does not exist in the activation TCI state list (510). In some embodiments, the wireless communication device may parse the activation TCI state list to search, identify, or determine whether there is a target TCI state. When the target TCI state is not found in the activation TCI state list, the wireless communication device may identify or determine that the target TCI state exists in the activation TCI state list. If it is determined that the target TCI state exists, the wireless communication device may exit the TCI state handover process (515). On the other hand, when the target TCI is found in the activation TCI state list, the wireless communication device may identify or determine that the TCI state does not exist in the activation TCI state list.

[0221] If it is determined that the target TCI state does not exist, the wireless communication device may identify or determine whether the target TCI state is known (520). The TCI state handover process may depend on whether the target TCI is known or unknown. This determination may be based on, for example, the following conditions:

[0222] ● During the period from the last transmission of the RS resource for the L1-RSRP measurement report for the target TCI state to the completion of the active TCI state handover, where the RS resource for the L1-RSRP measurement is the RS in the target TCI state or QCLed to the target TCI state;

[0223] ● A TCI state handover command is received within 1280 ms after the last transmission of the RS resource for beam reporting or measurement;

[0224] ● Before the TCI state switching command, the UE has sent at least 1 L1-RSRP report for the target TCI state;

[0225] ● The TCI state remains detectable during the TCI state switching period;

[0226] ● The SSB associated with the TCI state remains detectable during the TCI switching period; and

[0227] ● The SNR of the TCI state ≥ -3 dB.

[0228] When all conditions are met, the wireless communication device can identify or determine that the TCI state is known. On the contrary, when at least one of the conditions is not met, the wireless communication device can identify or determine that the TCI state is unknown.

[0229] When the target TCI state is known, the wireless communication device can configure, modify, or otherwise set the LBT counter (e.g., LBT_COUNTER1, LBT_COUNTER2, etc.) (525) for which the TCI state is known. The LBT counter can be used to track or count the number of LBT failures within one SSB period or during CSI-RS-based L1-RSRP measurements. In some embodiments, the wireless communication device can identify or determine whether a first counter (e.g., LBT_COUNTER1) has reached a defined limit. The first counter can be used to count the number of LBT failures within the SSB period. The defined limit can correspond to the total number of transmission opportunities during the SSB period and the value of the first counter at which a second counter (e.g., LBT_COUNTER2) is updated or incremented. When it is determined that the first counter has not reached the defined limit, the wireless communication device can maintain the second counter. Otherwise, when it is determined that the first counter has reached the defined limit, the wireless communication device can update or increment the second counter. The second counter can also be used to count the number of LBT failures with a different granularity compared to the first counter within the SSB period. As the second counter is incremented, the wireless communication device can set the first counter to zero.

[0230] A wireless communication device may perform a TCI handover procedure (530) where the TCI state is known. During the execution of the TCI handover procedure, the wireless communication device may compare one or more counters (e.g., LBT_COUNTER1, LBT_COUNTER2, etc.) with one or more thresholds (e.g., Threshold1 and Threshold2). In some embodiments, the comparison of the counter with the threshold may be related to the SSB period. In some embodiments, the wireless communication device may determine, identify, or receive a success indicator of the available SSB associated with the target TCI state. The success indicator may correspond to the successful completion of the TCI handover procedure and may be received when both counters are within the defined thresholds. In some embodiments, upon receiving the success indicator, the wireless communication device may set the first counter and the second counter to predefined values (e.g., zero or empty).

[0231] In some embodiments, the wireless communication device may communicate or indicate to a lower layer (e.g., the physical layer) to stop activating the TCI state handover procedure based on the comparison. When the SSB period is less than or equal to a defined duration and the second counter exceeds a first threshold (e.g., Threshold1), the wireless communication device may indicate to the lower layer to stop activating the TCI state handover procedure. The first threshold may define the value of the second counter at which to stop activating the TCI state handover procedure when the SSB period is less than or equal to the defined duration (e.g., 30 - 50 ms). When the SSB period is greater than the defined duration and the second counter exceeds a second threshold (e.g., Threshold2), the wireless communication device may also indicate to the lower layer to stop activating the TCI state handover procedure. The second threshold may define the value of the second counter at which to stop activating the TCI state handover procedure when the SSB period is greater than the defined duration. Otherwise, the wireless communication device may avoid indicating to the lower layer to stop activating the TCI handover procedure and continue the process.

[0232] In some embodiments, a wireless communication device may convey or indicate a TCI state transition failure based on a comparison of a counter with a threshold. When a second counter exceeds a first threshold or a second threshold, the wireless communication device may initiate or trigger a beam failure to resume the TCI state transition process. A beam failure recovery may be triggered to find new resources. In some embodiments, when the second counter exceeds either threshold, the wireless communication device may change or otherwise switch to at least one other downlink (DL) bandwidth part (BWP) configured by the network. In some embodiments, when the second counter exceeds either threshold, the wireless communication device may change or switch to a specified BWP. The BWP is specified by a BWP identifier (e.g., defaultDownlinkBWP-Id or initialDownlinkBWP). In some embodiments, the wireless communication device may indicate the TCI state transition failure to the network via an RRC or MAC-CE message. The TCI state transition failure may indicate a failure to complete the TCI state transition process. In some embodiments, the wireless communication device may indicate a DL LBT failure to an upper layer (e.g., the RRC or MAC layer) to perform a radio link failure (RLF) of the SpCell or deactivate the SCell of the SCell. In some embodiments, the wireless communication device may indicate a DL LBT failure to an upper layer (e.g., the RRC or MAC layer). Upon receiving a DL LBT failure and a configuration with conditional handover (CHO) configured, the wireless communication device may select a target cell to perform a handover of the SpCell or deactivate the SCell for the SCell.

[0233] Conversely, when the target TCI state is unknown, the wireless communication device may set an LBT counter (535) for the TCI state unknown. The LBT counter may be used to track or count the number of LBT failures within one SSB period or during CSI-RS based L1-RSRP measurements. In some embodiments, the wireless communication device may update or otherwise increment a first counter (e.g., LBT_COUNTER1) in response to receiving an LBT failure indication from a lower layer (e.g., the physical layer). The first counter may be used to count the number of LBT failures within an SSB period. In some embodiments, when activating a TCI state transition process associated with QCL type D, the wireless communication device may update or increment a third counter (e.g., LBT_COUNTER3) in response to receiving an LBT failure indicator from a lower layer. The third counter may be used to count the number of LBT failures in CSI-RS transmissions.

[0234] In some embodiments, when the activation of the TCI state transition process is associated with quasi co-location (QCL) type D, a wireless communication device may identify or determine whether a first counter has reached a defined limit. The first counter may be used to count the number of LBT failures within an SSB period. The defined limit may correspond to the total number of transmission opportunities during the SSB and the value of the first counter at which a second counter (e.g., LBT_COUNTER2) is updated or incremented. When it is determined that the first counter has not reached the defined limit, the wireless communication device may maintain the second counter. Otherwise, when it is determined that the first counter has reached the defined limit, the wireless communication device may update or increment the second counter. The second counter may also be used to count the number of LBT failures with a different granularity compared to the first counter within the SSB period. As the second counter is incremented, the wireless communication device may set the first counter to zero.

[0235] The wireless communication device may perform a TCI transition process (540) with an unknown TCI state. During the execution of the TCI transition process, the wireless communication device may compare one or more counters (e.g., LBT_COUNTER1, LBT_COUNTER2, etc.) with one or more thresholds (e.g., Threshold1 and Threshold2). In some embodiments, the comparison of the counter with the threshold may be related to the SSB period. In some embodiments, the wireless communication device may determine, identify, or receive a success indicator for the available SSB associated with the target TCI state. The success indicator may correspond to the successful completion of the TCI transition process and may be received when both counters are within the defined thresholds. In some embodiments, the wireless communication device may set the first counter and the second counter to predefined values (e.g., zero or empty) in response to receiving the success indicator. In some embodiments, the wireless communication device may determine, identify, or receive a success indicator for the success indicator of the available CSI-RS associated with the target TCI state. The success indicator may correspond to the successful completion of the TCI transition process and may be received when a third counter is within the defined threshold. In some embodiments, the wireless communication device may set the third counter to a predefined value (e.g., zero or empty) in response to receiving the success indicator.

[0236] In some embodiments, a wireless communication device may communicate or indicate to a lower layer (e.g., the physical layer) based on a comparison. When the SSB period is less than or equal to a defined duration and a second counter exceeds a first threshold (e.g., Threshold1), the wireless communication device may indicate to the lower layer to stop activating the TCI state switching process. The first threshold may define the value of the second counter at which the activation of the TCI state switching process stops when the SSB period is less than or equal to the defined duration (e.g., 30 - 50 ms). When the SSB period is greater than the defined duration and the second counter exceeds a second threshold (e.g., Threshold2), the wireless communication device may also indicate to the lower layer to stop activating the TCI state switching process. The second threshold may define the value of the second counter at which the activation of the TCI state switching process stops when the SSB period is greater than the defined duration. Otherwise, the wireless communication device may avoid indicating to the lower layer to stop activating the TCI switching process and continue the process.

[0237] In some embodiments, when the CSI-RS transmission period is less than or equal to a defined duration and a third counter exceeds a third threshold (e.g., Threshold3), the wireless communication device may indicate to the lower layer to stop activating the TCI state switching process. The third threshold may define the value of the third counter at which the activation of the TCI state switching process stops when the CSI-RS transmission period is less than or equal to the defined duration (e.g., 30 - 50 ms). When the CSI-RS transmission period is greater than the defined duration and the third counter exceeds a fourth threshold (e.g., Threshold4), the wireless communication device may also indicate to the lower layer to stop activating the TCI state switching process. The fourth threshold may define the value of the third counter at which the activation of the TCI state switching process stops when the CSI-RS transmission period is less than or equal to the defined duration (e.g., 30 - 50 ms). Otherwise, the wireless communication device may avoid indicating to the lower layer to stop activating the TCI switching process and continue the process.

[0238] Although various embodiments of the present solution have been described above, it should be understood that they are presented by way of example and not limitation. Similarly, the various figures may depict example architectures or configurations provided to enable a person of ordinary skill in the art to understand the example features and functions of the present solution. However, such a person will understand that the present solution is not limited to the example architectures or configurations shown, but that the present solution may be implemented using a variety of alternative architectures and configurations. Additionally, as will be understood by a person of ordinary skill in the art, one or more features of one embodiment may be combined with one or more features of another embodiment described herein. Accordingly, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments.

[0239] It should also be understood that any reference herein to elements by names such as “first,” “second,” etc., generally does not limit the number or order of those elements. Instead, these names may be used herein as a convenient means of distinguishing between two or more elements or instances of elements. Thus, a reference to first and second elements does not mean that only two elements may be employed, or that the first element must be located in front of the second element in some manner.

[0240] Additionally, a person of ordinary skill in the art will understand that any of a variety of different technologies and techniques may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, and symbols, such as may be referenced in the above description, may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0241] A person of ordinary skill in the art will further understand that any of the various illustrative logical blocks, modules, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementations, analog implementations, or combinations thereof), firmware, various forms of design code or programs containing instructions (for convenience, referred to herein as “software” or “software modules”), or any combination of these technologies. To clearly illustrate this interchangeability of hardware, firmware, and software, the various illustrative components, blocks, modules, circuits, and steps have generally been described above in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends upon the particular application and the design constraints imposed on the overall system. The skilled person may implement the described functionality in various ways for each particular application, but such implementation decisions will not result in a departure from the scope of the present disclosure.

[0242] In addition, those of ordinary skill in the art will understand that the various illustrative logical blocks, modules, devices, components, and circuits described herein can be implemented within or performed by an integrated circuit (IC), which can include: a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include an antenna and / or a transceiver to communicate with various components within a network or within a device. The general-purpose processor can be a microprocessor, but alternatively, the processor can be any conventional processor, controller, or state machine. The processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

[0243] If the functions are implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium. The computer-readable medium includes both computer storage media and communication media, and the communication media includes any medium that can transfer a computer program or code from one place to another. The storage media can be any available medium accessible by a computer. By way of example and not limitation, such computer-readable medium can include RAM, ROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0244] In this document, the term "module" as used herein refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for the purposes of discussion, the various modules are described as discrete modules; however, it will be apparent to those of ordinary skill in the art that two or more modules can be combined to form a single module that performs the associated functions according to an embodiment of the present solution.

[0245] Additionally, a memory or other storage device, as well as a communication component, may be employed in embodiments of the present solution. It should be understood that, for clarity, the above description has described embodiments of the present solution with reference to different functional units and processors. However, it will be apparent that any suitable functional distribution between different functional units, processing logic elements, or domains may be used without departing from the present solution. For example, functions illustrated as being performed by separate processing logic elements or controllers may be performed by the same processing logic element or controller. Thus, the reference to a particular functional unit is only a reference to the appropriate means for providing the described functionality, rather than indicating a strict logical or physical structure or organization.

[0246] Various modifications to the embodiments described in this disclosure will be readily 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 the disclosure. Therefore, the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A method, comprising: A wireless communication device receives a physical data sharing channel with an activation command during an activation transmission configuration indicator (TCI) handover process; The wireless communication device determines that a target TCI state does not exist in the activation TCI state list of the physical data sharing channel; The wireless communication device determines whether the target TCI state is known; When the target TCI state is known, the wireless communication device sets a first counter for counting the number of listen-before-talk (LBT) failures within a synchronization signal block (SSB) period and a second counter for counting the number of LBT failures with a different granularity compared to the first counter in the SSB period; When the target TCI state is unknown, the wireless communication device sets an LBT counter for counting the number of LBT failures within one SSB period or during CSI-RS-based L1-RSRP measurements.

2. The method according to claim 1, wherein The activation command includes a radio resource control (RRC) activation command, which includes one TCI state in the activation TCI state list.

3. The method according to claim 1, wherein, The activation command includes a media access control control element (MACCE) activation command.

4. The method according to claim 1, wherein When the target TCI state is known, the wireless communication device sets the first counter and the second counter, including: The wireless communication device determines that the first counter has reached a defined limit; In response to the first counter reaching the defined limit, the wireless communication device increments the second counter; and In response to the increment, the wireless communication device sets the first counter to zero.

5. The method according to claim 4, comprising: When the SSB period is less than or equal to a defined duration and the second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device indicates to a lower layer to stop the activation TCI state handover process.

6. The method according to claim 4, comprising, when the second counter exceeds one of the first threshold or the second threshold: The wireless communication device triggers beam failure recovery; The wireless communication device switches to a downlink bandwidth part (BWP) indicated by the network; The wireless communication device switches to a specified BWP; The wireless communication device indicates a TCI state handover failure to the network via a radio resource control (RRC) or media access control control element (MAC CE) message.

7. The method according to claim 4, comprising: In response to receiving a successful indication of an available SSB associated with the target TCI state, the wireless communication device sets the first counter and the second counter to zero.

8. The method according to claim 1, wherein, When the target TCI state is unknown, the wireless communication device sets an LBT counter for counting the number of LBT failures within one SSB period or during CSI-RS-based L1-RSRP measurements, including: In response to receiving a listen-before-talk (LBT) failure indication from a lower layer, the wireless communication device increments a first counter configured to count the number of LBT failures in a synchronization signal block (SSB) period.

9. The method according to claim 1, wherein When the target TCI state is unknown, the wireless communication device sets an LBT counter for counting the number of LBT failures within one SSB period or during CSI-RS based L1-RSRP measurements, including: When the target TCI state is unknown and the activated TCI state switching process is associated with quasi co-location (QCL) type D: The wireless communication device determines that a first counter has reached a defined limit, where the first counter is configured to count the number of listen-before-talk (LBT) failures in a synchronization signal block (SSB) period; In response to the first counter reaching the defined limit, the wireless communication device increments a second counter; and In response to the increment, the wireless communication device sets the first counter to zero.

10. The method according to claim 9, comprising: When the SSB period is less than or equal to a defined duration and the second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device instructs the lower layer to stop the activated TCI state switching process.

11. The method according to claim 10, comprising: In response to receiving a successful indication of an available SSB associated with the target TCI state, the wireless communication device sets the first counter and the second counter to zero.

12. The method according to claim 1, wherein When the target TCI state is unknown, the wireless communication device sets an LBT counter for counting the number of LBT failures within one SSB period or during CSI-RS based L1-RSRP measurements, including: When the target TCI state is unknown and the activated TCI state switching process is associated with quasi co-location (QCL) type D: In response to receiving a listen-before-talk (LBT) failure indication from a lower layer, the wireless communication device increments a third counter configured to count the number of LBT failures in channel state information reference signal (CSI-RS) transmissions.

13. The method according to claim 12, comprising: When the CSI-RS period is less than or equal to a defined duration and the third counter exceeds a third threshold, or when the CSI-RS period is greater than the defined duration and the third counter exceeds a fourth threshold, the wireless communication device instructs the lower layer to stop the activated TCI state switching process.

14. The method according to claim 13, comprising: In response to receiving a successful indication of an available CSI-RS associated with the target TCI state, the wireless communication device sets the third counter to zero.

15. The method according to claim 14, comprising: The wireless communication device determines that a first counter has reached a defined limit, where the first counter is configured to count the number of listen-before-talk (LBT) failures in the synchronization signal block (SSB) period; In response to the first counter reaching the defined limit, the wireless communication device increments a second counter; and In response to the increment, the wireless communication device sets the first counter to zero.

16. The method according to claim 15, comprising: When the SSB period is less than or equal to a defined duration and the second counter exceeds a first threshold, or when the SSB period is greater than the defined duration and the second counter exceeds a second threshold, the wireless communication device instructs a lower layer to stop the activation TCI state transition process.

17. The method according to claim 16, comprising: In response to receiving a successful indication of an available SSB associated with the target TCI state, the wireless communication device sets the first counter and the second counter to zero.

18. A computer-readable storage medium storing instructions that, when executed by one or more processors, enable the one or more processors to perform the method according to any one of claims 1-17.

19. An apparatus, comprising: One or more processors; and A memory storing executable instructions that, when executed by the one or more processors, cause the one or more processors to perform the method according to any one of claims 1-17.

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