Method and related equipment for listening first and then speaking recovery process

Abstract

A method for a listen-before-talk (LBT) recovery process for a user equipment (UE) is provided, the method comprising: performing multiple LBT fault detection processes for multiple bandwidth parts (BWPs) of a serving cell; in response to detecting continuous uplink (UL) LBT faults in the multiple BWPs through the multiple LBT fault detection processes, triggering multiple LBT recovery processes for the multiple BWPs of the serving cell, wherein each specific LBT recovery process in the multiple triggered LBT recovery processes includes triggering an LBT fault process, and the LBT fault process is used to determine the BWP that triggers the specific LBT recovery process as an invalid BWP; and in response to confirming a predefined condition in the UE, canceling all of the multiple triggered LBT recovery processes on the serving cell.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 62 / 932,198, filed on November 7, 2019, entitled “Method and apparatus to handle LBT failure recovery procedure” (hereinafter “the '198 Provisional”) and U.S. Provisional Patent Application Serial No. 62 / 934,673, filed on November 13, 2019, entitled “Method and apparatus to handle completion of LBT failure recovery procedure” (hereinafter “the '673 Provisional”). The disclosures of the '198 Provisional and the '673 Provisional are hereby incorporated by reference into this disclosure in their entirety. Technical Field

[0003] The present disclosure relates generally to wireless communications, and more particularly to a method and related apparatus for a listen-before-talk (LBT) recovery process. Background Art

[0004] With the huge growth in the number of connected devices and the rapid increase in user / network traffic, various efforts have been made to improve various aspects of wireless communications for next-generation wireless communication systems such as fifth generation (5G) new radio (NR) by improving data rates, latency, reliability, and mobility.

[0005] The 5G NR system is designed to provide flexibility and configurability to optimize network services and types to accommodate various use cases such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC).

[0006] However, as the demand for radio access continues to increase, wireless communications for next generation wireless communication systems need to be further improved. Summary of the invention

[0007] The present disclosure provides a method and related apparatus for a listen before talk (LBT) recovery process.

[0008] According to one aspect of the present disclosure, a method for a listen-before-talk (LBT) recovery process for a user equipment (UE) is provided, the method comprising: performing multiple LBT fault detection processes for multiple bandwidth parts BWP of a serving cell; in response to detecting continuous uplink UL LBT failures in the multiple BWPs through the multiple LBT fault detection processes, triggering multiple LBT recovery processes for the multiple BWPs of the serving cell, wherein each specific LBT recovery process among the multiple triggered LBT recovery processes includes triggering an LBT fault process, and the LBT fault process is used to determine the BWP that triggers the specific LBT recovery process as an invalid BWP; and in response to confirming a predefined condition in the UE, canceling all of the multiple triggered LBT recovery processes on the serving cell.

[0009] According to another aspect of the present disclosure, a UE for performing an LBT recovery process is provided, the UE comprising: a processor for executing computer-executable instructions and a non-transitory computer-readable medium coupled to the processor for storing the computer-executable instructions, wherein the computer-executable instructions instruct the processor to perform the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Various aspects of the present disclosure are best understood from the following detailed description when read with the accompanying drawings. Various features are not drawn to scale. The dimensions of various features may be arbitrarily increased or decreased for clarity of discussion.

[0011] Figure 1 It is a schematic diagram of the LBT recovery process on the primary cell (PCell) according to an embodiment of the present disclosure.

[0012] Figure 2 It is a schematic diagram of the LBT recovery process on a primary-secondary cell group (SCG) cell (PSCell) according to an embodiment of the present disclosure.

[0013] Figure 3 It is a schematic diagram of the LBT recovery process on the secondary cell (SCell) according to an embodiment of the present disclosure.

[0014] Figure 4 is a flowchart of a method for LBT recovery process according to one embodiment of the present disclosure.

[0015] Figure 5 is a block diagram of a node for wireless communication according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0016] The following description contains specific information related to exemplary embodiments of the present disclosure. The drawings and the accompanying detailed descriptions in the present disclosure are exemplary embodiments only. However, the present disclosure is not limited to these exemplary embodiments. Other variations and embodiments of the present disclosure will occur to those skilled in the art. Unless otherwise specified, identical or corresponding parts in the drawings may be represented by identical or corresponding figure numbers. In addition, the drawings and illustrations in the present disclosure are generally not drawn to scale and are not intended to correspond to actual relative sizes.

[0017] For the purpose of continuity and ease of understanding, the same features are indicated by reference numerals in the example drawings (although not in some cases). However, the features in different embodiments may differ in other aspects and should not be narrowly limited to the features shown in the drawings.

[0018] The terms "in one embodiment" and "in some embodiments" may refer to one or more of the same or different embodiments, respectively. The term "coupled" is defined as connected, whether directly or indirectly through intermediate components, and is not necessarily limited to physical connections. The term "comprising" when used means "including but not necessarily limited to"; it expressly indicates open inclusion or members of the described combinations, groups, series, and equivalents.

[0019] The term "and / or" in this article is only used to describe the association relationship of associated objects, and indicates that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. "A and / or B and / or C" can mean that at least one of A, B and C exists. In addition, the character " / " used in this article generally indicates that the previous associated object and the next associated object are in an "or" relationship.

[0020] In addition, any two or more of the following paragraphs, (sub) bullets, points, actions, behaviors, terms, alternatives, examples, or claims described in the present disclosure may be logically, reasonably, and appropriately combined to form a specific method. Any sentence, paragraph, (sub) bullet, point, action, behavior, term, or claim described in the present disclosure may be independently and separately implemented to form a specific method. Dependencies, such as, for example, "based on", "more specifically", "preferably", "in one embodiment", "in one implementation", "in an alternative", etc., refer only to one possible example in the present disclosure, which will not limit the specific method.

[0021] For the purpose of non-limiting explanation, specific details such as functional entities, technologies, protocols, standards, etc. are set forth to provide an understanding of the described technology. In other examples, detailed descriptions of well-known methods, technologies, systems, architectures, etc. are omitted to avoid obscuring the description with unnecessary details.

[0022] Those skilled in the art will immediately recognize that any (one or more) network functions or (one or more) algorithms described in this disclosure can be implemented by hardware, software, or a combination of software and hardware. The functions described may correspond to modules, which may be software, hardware, firmware, or any combination thereof. Software implementations may include computer executable instructions stored on a computer-readable medium such as a memory or other type of storage device. For example, one or more microprocessors or general-purpose computers with communication processing capabilities may be programmed with corresponding executable instructions and execute the described (one or more) network functions or (one or more) algorithms. The microprocessor or general-purpose computer may be composed of an application-specific integrated circuit (ASIC), a programmable logic array, and / or one or more digital signal processors (DSP). Although the embodiments of the present disclosure are directed to software installed and executed on computer hardware, alternative example implementations implemented as firmware or hardware or a combination of hardware and software are also within the scope of the present disclosure.

[0023] Computer readable media include, but are not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM), cassettes, magnetic tapes, disk storage, or any other equivalent media that can store computer readable instructions.

[0024] A radio communication network architecture (such as a Long Term Evolution (LTE) system, an advanced LTE (LTE-Advanced, LTE-A) system, an advanced LTE Pro system or an NR system) generally includes at least one base station (BS), at least one UE and one or more optional network elements that provide connections within the network. The UE communicates with a network (such as a core network (CN), an evolved packet core (EPC) network, an evolved universal terrestrial RAN (Evolved Universal Terrestrial RAN, E-UTRAN), a next-generation core (Next-Generation Core, NGC), a 5G core (5G Core, 5GC) or the Internet) through a radio access network (RAN) established by one or more BSs.

[0025] It should be noted that in the present disclosure, UE may include but is not limited to a mobile station, a mobile terminal or device, a user communication radio terminal. For example, a UE may be a portable radio device, including but not limited to a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a personal digital assistant (PDA) with wireless communication capabilities. The UE may be configured to receive signals over an air interface and transmit signals to one or more cells in the RAN.

[0026] The BS may include, but is not limited to, a Node B (NB) in a Universal Mobile Telecommunication System (UMTS), an evolved Node B (eNB) in LTE-A, a Radio Network Controller (RNC) in UMTS, a Base Station Controller (BSC) in a Global System for Mobile communication (GSM) / GSM Enhanced Data rates for GSM Evolution RAN (GERAN), a Next Generation eNB (ng-eNB) in an Evolved Universal Terrestrial Radio Access (E-UTRA) BS connected to a 5GC, such as a Next Generation Node B (gNB) in a 5G-RAN (or in a 5G Access Network (5G-AN)), and any other device capable of controlling radio communications and managing radio resources within a cell. The BS may be connected to a network via a radio interface to serve one or more UEs.

[0027] The base station may be configured to provide communication services according to at least the following Radio Access Technology (RAT): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, commonly referred to as 2G), GERAN, General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS, commonly referred to as 3G) based on basic Wideband-Code Division Multiple Access (W-CDMA), High-Speed ​​Packet Access (HSPA), LTE, LTE-A, evolved LTE (eLTE, which is LTE connected to 5GC), NR (commonly referred to as 5G) and / or LTE-A Pro. However, the scope of the present disclosure is not limited to these protocols.

[0028] The BS is operable to provide radio coverage to a specific geographical area using multiple cells forming a RAN. The BS supports the operation of cells. Each cell is operable to provide services to at least one UE within its radio coverage. More specifically, each cell (commonly referred to as a serving cell) provides services to serve one or more UEs within its radio coverage (e.g., each cell schedules downlink (DL) resources and optional UL resources to at least one UE within its radio coverage for DL ​​packet transmission and optional UL packet transmission). The BS can communicate with one or more UEs in a radio communication system through multiple cells. The cell can allocate sidelink (SL) resources to support proximity services (ProSe), LTE SL services, and LTE / NR vehicle to everything (V2X) services. Each cell may have a coverage area that overlaps with other cells. In the case of multi-RAT dual connectivity (MR-DC), the main cell of a main cell group (MCG) or a secondary cell group (SCG) may be referred to as a special cell (SpCell). The main cell (PCell) may refer to the SpCell of the MCG. The primary SCG cell (PSCell) may refer to the SpCell of the SCG. The MCG may refer to a set of service cells associated with a master node (MN), including the SpCell and optionally one or more secondary cells (scell). The SCG may refer to a set of service cells associated with a secondary node (SN), including the SpCell and optionally one or more SCells.

[0029] As previously discussed, the frame structure for NR supports flexible configuration to accommodate various next-generation (e.g., 5G) communication requirements, such as eMBB, mMTC, and URLLC, while meeting high reliability, high data rate, and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology described in the 3rd Generation Partnership Project (3GPP) can be used as a baseline for the NR waveform. Scalable OFDM parameter sets, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP) can also be used. In addition, two coding schemes considered for NR are: (1) Low-Density Parity-Check (LDPC) code and (2) polar code. Coding scheme adaptation can be configured based on channel conditions and / or service applications.

[0030] In addition, it is also believed that in the transmission time interval of a single NR frame, at least DL transmission data, protection period and UL transmission data should be included, where the parts of DL transmission data, protection period and UL transmission data should also be configurable, for example, based on the network dynamics of NR. In addition, SL resources can also be provided through NR frames to support ProSe services or V2X services.

[0031] NR radio access operating in unlicensed spectrum (called NR-U) was introduced in the 3GPP specification, which can coexist fairly between already deployed Wi-Fi generations and NR-U, between NR-U and LTE Licensed Assisted Access (LAA), between different NR-U systems, and so on.

[0032] Configuration grants Type 1 and Type 2 are defined in the NR system. These two configuration grants are also included in NR-U. For retransmissions of HARQ processes that were originally transmitted via the configured uplink grant resources, retransmissions via the same configured uplink grant resources and retransmissions via resources scheduled via UL grants are supported.

[0033] In unlicensed spectrum, the UE can perform channel access before performing transmission to ensure that no other device occupies the channel where the transmission is intended to be performed. For channel access in NR-U, the listen-before-talk (LBT) fault detection process can be adopted as the baseline for the 5GHz band and as the starting point for the design of the 6GHz band. For the NR-U LBT fault detection process, before performing UL transmission, the UE can perform the LBT fault detection process using one of the four LBT types for different transmissions in the channel occupancy time (COT) (defined below) and different channels / signals to be transmitted. Specifically, before performing random access channel (RACH) transmission, physical uplink control channel (PUCCH) transmission, physical uplink shared channel (PUSCH) transmission and sounding reference signal (SRS) transmission, the UE can perform the LBT fault detection process by using different LBT categories.

[0034] Type 1: Transmit immediately after a short switching interval

[0035] LBT Type 1 can be used for the transmitter to transmit immediately after the switching gap within the COT. More specifically, the switching gap from reception to transmission is to accommodate the turnaround time of the transceiver and does not exceed 16μs. Note that Type 1 can also be called Type 2 UL channel access procedure.

[0036] Type 2: LBT without random fallback

[0037] For LBT Type 2, the duration for which the channel (intended to perform transmission) is detected as idle is determined before the transmitting entity transmits. Note that Type 2 may also be referred to as Type 2 UL channel access procedure.

[0038] Type 3: LBT with random backoff with a fixed-size contention window

[0039] LBT Type 3 may include the following components. The transmission entity extracts a random number N within a contention window. The size of the contention window is specified by the minimum and maximum values ​​of N. The size of the contention window is fixed. In LBT Type 3, the random number N is used to determine the duration of time that a channel is determined to be idle before the transmission entity transmits on the channel (intended to perform a transmission).

[0040] Type 4: LBT with random backoff with variable-sized contention windows

[0041] LBT Type 4 includes the following components. The transmission entity extracts a random number N within the contention window. The size of the contention window is specified by the minimum and maximum values ​​of N. The transmission entity can change the size of the contention window when the random number N is extracted. In LBT Type 4, the random number N is used to determine the duration of time that the channel is determined to be idle before the transmission entity transmits on the channel (intended to perform transmission). Please note that Type 4 can also be called Type 1 UL channel access procedure.

[0042] NR-U can operate in PCell, SCell or PSCell. In standalone mode, all cells are in unlicensed spectrum. When SCell is in unlicensed spectrum, PCell can be in licensed spectrum. NR-U SCell can be configured with UL or not. DC type operation can be configured with E-UTRAN node (connected to EPC or 5GC) as master node (MN) or with NR node.

[0043] The gNB and the UE may apply the LBT failure detection procedure (on the serving cell) before performing UL transmission (on the serving cell). When performing the LBT failure detection procedure (on the serving cell), the transmitter monitors the channel to determine whether the channel is idle or busy (on the serving cell), and performs transmission only when the channel is sensed to be idle (on the serving cell).

[0044] The LBT failure detection process can be applied to any type of UL transmission.The LBT failure detection process of a BWP / serving cell / cell group can be used to count the number of LBT failures of a BWP / serving cell / cell group.

[0045] When the UE detects continuous UL-LBT failure on the SCell, the UE may report the continuous UL LBT failure to the corresponding gNB (MN of MCG, or secondary node (SN) of SCG) (via MAC CE). When the UE detects continuous UL-LBT failure on the BWP of the SpCell, the UE may trigger the LBT recovery procedure on the SpCell. The LBT recovery procedure on the SpCell may involve switching to a new BWP on the SpCell, where no continuous UL LBT failure is detected on the new BWP, and a PRACH opportunity has been configured for the new BWP, and a random access (RA) procedure is started on the new BWP. When multiple BWPs are available for switching (for example, each of the multiple BWPs has not detected a continuous UL-LBT failure and has been configured with a PRACH opportunity), the UE may determine which one to select. On the other hand, for PSCell, if there is no available BWP for BWP switching during the LBT recovery process (for example, continuous UL-LBT failure is detected in the switched BWP), the UE can trigger the SCG radio link failure (RLF) process and report the LBT failure to the MN. For PCell, if continuous UL-LBT failure is detected, the UE can trigger the RLF process.

[0046] The UE may perform UL transmission (on the serving cell) only when no LBT failure is detected according to the LBT failure detection process (on the serving cell) (e.g., under the above-mentioned LBT type). In addition, if no LBT failure is detected for UL transmission (on the serving cell), the maximum continuous (UL) transmission time may be predetermined by the Maximum Channel Occupancy Time (MCOT) value. The UE may perform UL transmission (on the serving cell) within the period defined by the MCOT without performing the LBT failure detection process (on the serving cell).

[0047] More specifically, if the channel is detected to be idle (e.g., the UE detects that the power used to perform UL transmission is less than a predetermined / configured power threshold) within a predetermined / configured duration (e.g., via LBT type 2 / 3 / 4), the UE may determine that no LBT failure is detected. Otherwise, the UE may determine that a UL LBT failure is detected. In addition, when a UL-LBT failure is detected, the Medium Access Control (MAC) entity may receive an LBT failure indication from a physical (Physical, PHY) layer. The LBT failure indication may be used to increase an LBT counter (e.g., LBT_COUNTER).

[0048] LBT failure indication can delay UL transmission because it means that the UE must transmit or retransmit data on subsequent UL resources. Note that some UL transmissions can be initiated by the UE via contention based random access (CBRA), scheduling request (SR), configured uplink grant resources, etc. Therefore, if the UE fails to perform UL transmission due to LBT failure, the network may not know it. In addition, due to hidden nodes, the network may not be able to predict the UL channel conditions from the UE's perspective (for example, the network may not be aware of another device that also performs UL transmission near the UE). Therefore, the network may not be able to prevent the UE from suffering LBT failure in time through configuration / indication. To solve this problem, a UL LBT recovery process is introduced to handle LBT failures in NR-U systems. In order to prevent delays in UL transmissions, the LBT recovery process can be triggered by the UE for LBT failures.

[0049] Counters (such as LBT_COUNTER), timers (lbt-FailureDetectionTimer) and thresholds (such as lbt-FailureInstanceMaxCount) are used in the LBT fault detection process. In addition, LBT_COUNTER, lbt-FailureDetectionTimer and lbt-FailureInstanceMaxCount can be configured / maintained according to BWP / cell / cell group / cell group subset.

[0050] Upon (re)configuration, the LBT_COUNTER (of the serving cell) may be initially set to zero, and the UE may increase the LBT_COUNTER when a UL LBT failure is detected or an LBT failure indication is received from the PHY layer according to the LBT failure detection procedure (of the serving cell). More specifically, a UL LBT failure may be caused by any (or specific) UL transmission type. That is, the LBT_COUNTER (of the serving cell) may be increased when any (or specific) type of UL transmission cannot be performed (on the serving cell). In one embodiment, the LBT_COUNTER (of the serving cell) may be increased by 1 for each UL LBT failure detected by the UE (on the serving cell) according to the LBT failure detection procedure.

[0051] The lbt-FailureDetectionTimer (of the serving cell) may be configured by the network to the UE. The lbt-FailureDetectionTimer (of the serving cell) may be started or restarted when any (or specific) type of UL transmission cannot be performed (on the serving cell). Alternatively, the UE may (re)start the lbt-FailureDetectionTimer (of the serving cell) whenever the LBT_COUNTER (of the serving cell) increases. When the lbt-FailureDetectionTimer (of the serving cell) expires, the LBT_COUNTER (of the serving cell) may be reset (e.g., set to zero).

[0052] If the LBT_COUNTER (of the serving cell) reaches the lbt-FailureInstanceMaxCount (of the BWP of the serving cell), it means that continuous UL LBT failures are detected (in the BWP of the serving cell). Therefore, the UE can trigger the LBT recovery procedure (of the serving cell).

[0053] Figure 1 FIG. 1 is a schematic diagram showing an LBT recovery process on a PCell according to an embodiment of the present disclosure. Figure 1As shown, if continuous UL LBT failures are detected in a BWP on the PCell according to the LBT failure detection process on the PCell (e.g., the LBT_COUNTER reaches the lbt-FailureInstanceMaxCount of the corresponding BWP of the PCell) (action 102), the UE may trigger an LBT recovery process on the PCell, which involves triggering an LBT failure process for the BWP to determine that the BWP is invalid (operation 104). In addition, the UE may determine whether the LBT failure process is triggered for all BWPs with PRACH opportunities on the PCell (e.g., whether all BWPs with PRACH opportunities on the PCell are determined to be invalid) (e.g., action 106). If not, as part of the LBT recovery process, the UE may switch to a new BWP on the PCell that has a PRACH opportunity and is not determined to be invalid (e.g., action 110). In addition, an LBT failure MACCE indicating an invalid BWP / cell or a BWP / cell indicating an LBT failure may be transmitted to the network as part of the LBT recovery process on the PCell (e.g., action 110). However, if all BWPs with PRACH opportunities on the PCell are determined to be invalid (or the BWP_declaration_counter has reached the configured BWP_declaration_threshold), the UE may trigger the RLF procedure (eg, action 108).

[0054] Figure 2 FIG. 1 is a schematic diagram showing the LBT recovery process on a PSCell according to an embodiment of the present disclosure. Figure 2As shown, if continuous UL LBT failures are detected in a BWP on the PSCell according to the LBT failure detection process on the PSCell (e.g., the LBT_COUNTER reaches the lbt-FailureInstanceMaxCount of the corresponding BWP of the PSCell) (action 202), the UE may trigger an LBT recovery process on the PSCell, which involves triggering an LBT failure process for the BWP to determine that the BWP is invalid (operation 204). In addition, the UE may determine whether the LBT failure process is triggered for all BWPs with PRACH opportunities of the PSCell (e.g., whether all BWPs with PRACH opportunities of the PSCell are determined to be invalid) (e.g., action 206). If not, as part of the LBT recovery process, the UE may switch to a new BWP on the PSCell that has a PRACH opportunity and is not determined to be invalid (e.g., action 210). In addition, an LBT failure MAC CE indicating an invalid BWP / cell or a BWP / cell indicating an LBT failure may be transmitted to the network as part of the LBT recovery process on the PSCell (e.g., action 210). However, if all BWPs with PRACH opportunities on the PSCell are determined to be invalid (or the BWP_declaration_counter has reached the configured BWP_declaration_threshold), the UE may report SCG failure information to the network (eg, action 208).

[0055] In one embodiment, BWP_declaration_counter may be initially set to zero upon (re)configuration. BWP_declaration_counter may be maintained per cell (or per cell group / cell group subset) to count the number of BWPs detected under consecutive UL LBT failures for the corresponding cell. Whenever a BWP (of the serving cell) is determined to be an invalid BWP (e.g., consecutive UL LBT failures occur on the BWP of the serving cell), BWP_declaration_counter (corresponding to the serving cell) may be incremented by "1".

[0056] On the other hand, BWP_declaration_threshold may be configured per cell (or per cell group / subset of cell groups). The threshold may be used to define the maximum number of BWPs (of the serving cell) that are determined to be invalid BWPs before the UE triggers the RLF procedure or reports SCG failure information as part of the LBT recovery procedure.

[0057] In one example, if the value of BWP_declaration_counter (corresponding to PCell) has reached the BWP_declaration_threshold for PCell, the UE may trigger the RLF procedure.

[0058] In one embodiment, if the value of BWP_declaration_counter (corresponding to PSCell) has reached the BWP_declaration_threshold of the PSCell, the UE may report SCG failure information.

[0059] In one example, the BWP_declaration_threshold configured for the serving cell may be configured to be equal to the number of BWPs configured with PRACH opportunities of the serving cell.

[0060] In another example, if continuous UL LBT failures are detected in the BWP on the SCell according to the LBT failure detection process on the SCell (e.g., the LBT_COUNTER reaches the lbt-FailureInstanceMaxCount of the corresponding BWP), the LBT recovery process on the SCell may involve triggering the LBT failure process on the BWP to determine that the BWP is invalid and transmitting an LBT failure MAC CE (identifying the faulty cell and / or BWP) to the network.

[0061] Figure 3 FIG. 1 is a schematic diagram showing a LBT recovery process on an SCell according to an embodiment of the present disclosure. Figure 3 As shown, after triggering the LBT failure procedure of the BWP on the SCell to determine that the BWP on the SCell is invalid (action 304), the UE can report the LBT failure MAC CE (action 306). In addition, after detecting continuous UL-LBT failures on the BWP of the SCell according to the LBT failure detection procedure on the SCell, the UE can trigger the LBT failure procedure of the BWP (e.g., determine that the BWP on the SCell is invalid) as part of the LBT recovery procedure (action 302).

[0062] In one example, a triggered LBT failure procedure may be considered pending until canceled. Subsequently, if UL resources (e.g., PUSCH) become available for transmission of an LBT failure MAC CE, the UE may generate an LBT failure MAC CE if there are triggered and pending LBT failure procedures. The generated LBT failure MAC CE may include information of the BWP and / or serving cell that triggered the LBT failure procedure (e.g., after detecting continuous UL LBT failures). Alternatively, the generated LBT failure MAC CE may include information of a serving cell with an invalid BWP.

[0063] In one example, when a MAC PDU includes an LBT failure MAC CE (and has a corresponding subheader), and the LBT failure MAC CE includes LBT information of a BWP and / or a serving cell, the LBT failure indicated for the BWP and / or serving cell before the MAC PDU is assembled may be canceled when the MAC PDU is transmitted.

[0064] In another example, when a MAC PDU is transmitted, all indicated LBT failures before the MAC PDU is assembled may be canceled, and the MAC PDU includes an LBT failure MAC CE (with a corresponding subheader), and the LBT failure MAC CE includes LBT information of all BWPs and / or serving cells. When a MAC PDU includes an LBT failure MAC CE (and has a corresponding subheader), and the LBT failure MAC CE includes LBT information of all BWPs and / or serving cells, all indicated LBT failures before the MAC PDU is assembled may be canceled when the MAC PDU is transmitted.

[0065] In one embodiment, the BWP / cell that triggers the LBT failure procedure may be determined to be an invalid BWP / cell.

[0066] In one implementation, the BWP / cell whose triggered LBT failure procedure is canceled may be determined as a valid BWP / cell.

[0067] In one embodiment, a BWP / cell determined to be an invalid BWP / cell may be equivalent to a BWP / cell that triggers the LBT fault process. On the other hand, an invalid BWP / cell that is reconsidered / determined to be a valid BWP / cell may be equivalent to canceling the BWP / cell that triggers the LBT fault process.

[0068] In one embodiment, after triggering the LBT failure procedure for the BWP / cell, the UE may determine the BWP / cell as an invalid BWP / cell. On the other hand, after canceling the triggered LBT failure procedure for the BWP / cell, the UE may determine the BWP / cell as a valid BWP / cell.

[0069] For the LBT recovery procedure on PCell or PSCell, when the UE detects continuous UL LBT failures in the BWP, the BWP may be determined by the UE to be an invalid BWP. In this case, the UE may be prohibited from switching to an invalid BWP (e.g., UE-initiated BWP switching). In other words, when the UE performs BWP switching as part of the LBT recovery procedure on PCell or PSCell, the UE may be restricted from switching to an invalid BWP. In addition, even though channel conditions may change over time, there is no condition or time to release the BWP switching prohibition. Therefore, when all BWPs configured with PRACH opportunities are determined to be invalid, the UE has no choice but to trigger the RLF procedure (for the LBT recovery procedure on PCell) or report SCG failure information (for the LBT recovery procedure on SCell), regardless of the actual channel conditions (e.g., idle or busy).

[0070] In one example, a UE is configured with BWP1 and BWP2 on the PCell, and BWP1 and BWP2 are configured with PRACH opportunities. When continuous UL LBT failure is detected in BWP1, the UE may determine BWP1 as an invalid BWP and thus switch to BWP 2 (and may initiate a RA procedure after switching to BWP2) as part of the LBT recovery procedure on the PCell. Subsequently, the UE may be restricted from switching back to BWP1 even if BWP1 is no longer occupied by any other contending device. As a result, the UE has no choice but to trigger an RLF procedure.

[0071] In order to solve the above problems, a condition-based method is disclosed, which introduces a condition for the UE to cancel the LBT failure process triggered on the BWP (for example, determining an invalid BWP as a valid BWP). Alternatively, a timer-based method is also disclosed, which allows the UE to switch to the BWP when the BWP determined to be invalid becomes valid again when the timer expires, which is part of the LBT recovery process.

[0072] Condition-based methods

[0073] As described above, if continuous UL LBT failure is detected in the BWP, the UE may trigger an LBT failure procedure for the BWP (e.g., determine the BWP as an invalid BWP). As a result, the UE neither switches to an invalid BWP nor switches to a BWP with an indicated LBT failure. However, a BWP determined by the UE to be invalid may be reconsidered as valid (e.g., the LBT failure procedure triggered at the BWP may be canceled). In addition, the value of BWP_declaration_counter, which counts the number of invalid BWPs that have been determined as serving cells, may be reset.

[0074] In one embodiment, if at least one of the following conditions is met, the UE may cancel the triggered LBT failure procedure of the BWP (eg, determine the invalid BWP as a valid BWP).

[0075] Condition 1: If a BWP switching command is received from the network, the UE determines the invalid BWP as a valid BWP

[0076] In some examples, the BWP switching command may be signaled via a downlink control information (DCI) message (eg, signaled on a PDCCH for BWP switching). In some examples, the BWP switching command may be a dynamic grant to schedule UL or DL ​​resources on another BWP.

[0077] In one embodiment, when the UE receives a BWP switching command for a serving cell, all invalid BWPs on the serving cell are reconsidered as valid BWPs and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0078] In one embodiment, when the UE receives a message indicating that the UL resources on the BWP are determined to be an invalid dynamic grant, the UE may switch to the corresponding BWP and regard the BWP as a valid BWP again.

[0079] In one embodiment, when the UE receives a dynamic grant indicating an invalid UL resource determined on a BWP, the UE may switch to the corresponding BWP and only if the BWP is pre-configured with a specific information element (IE), the BWP is considered again as a valid BWP. The IE may be, but is not limited to, configured by the gNB based on the BWP. Through the IE, when receiving an UL grant on the BWP, the gNB may explicitly indicate whether the UE can consider the invalid BWP again as a valid BWP.

[0080] Condition 2: During the RA process, the UE determines that the invalid BWP is a valid BWP

[0081] In one embodiment, when the UE initiates a RA procedure on a serving cell (eg, because a PRACH opportunity is not configured on the current BWP), the UE may switch to the BWP indicated by initialUplinkBWP if a PRACH opportunity is not configured on the current BWP of the UE's serving cell.

[0082] In one embodiment, when the UE switches to the BWP indicated by the initialUplinkBWP of the serving cell during the RA procedure, the BWP indicated by the initialUplinkBWP may be reconsidered as valid (e.g., the BWP indicated by the initialUplinkBWP is determined to be invalid due to continuous UL LBT failure detected in the BWP).

[0083] In one embodiment, when the UE switches to the BWP indicated by the initialUplinkBWP of the serving cell during the RA procedure, all invalid BWPs on the serving cell are reconsidered as valid BWPs and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0084] Condition 3: If bwp-InactivityTimer expires, the UE determines the invalid BWP as a valid BWP

[0085] In one embodiment, when the bwp-InactivityTimer associated with the active DL BWP of the serving cell expires and the UE performs a BWP switch to the BWP indicated by the defaultDownlinkBWP-Id or performs a BWP switch to the initialDownlinkBWP, all invalid BWPs on the serving cell will be re-considered as valid BWPs and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are re-considered as valid.

[0086] Condition 4: If an indication indicating that the BWP is valid or all BWPs are valid is received from the network, the UE determines that the invalid BWP is a valid BWP

[0087] In some examples, the indication may be signaled via a DCI message. In some examples, the indication may be signaled via a (DL) MAC CE. In some examples, the indication may be signaled via radio resource control (RRC) signaling.

[0088] In one embodiment, the network may indicate via DCI message / MAC CE / RRC signaling one or more BWPs that the UE should re-consider as a valid BWP. Upon receiving such an indication from the network, the UE may re-consider the corresponding BWP (as indicated by the network) as a valid BWP and / or reset the BWP_declaration_counte (corresponding to the serving cell) to "0". Note that the network may identify which BWPs are determined to be invalid by the UE (e.g., BWPs in which continuous UL LBT failures are detected by the UE) before providing an indication to the UE.

[0089] In one embodiment, the network may indicate via the type of the (DL) MAC CE one or more configured (UL) BWPs that the UE may re-consider as a valid BWP. In one example, the MAC CE includes a bitmap, each bit in the bitmap representing a BWP configured to the UE. In addition, a bit set to "0" or "1" may indicate that the UE should consider the corresponding BWP as a valid BWP.

[0090] Condition 5: If an RRC configuration message or an RRC reconfiguration message is received, the UE determines the invalid BWP as a valid BWP

[0091] In some examples, the RRC (re)configuration message may configure or reconfigure the BWP for the serving cell.

[0092] In some examples, the RRC (re)configuration message may configure or reconfigure firstActiveDownlinkBWP-Id and / or firstActiveUplinkBWP-Id for the SpCell.

[0093] In one embodiment, when the UE receives an RRC (re)configuration message to configure or reconfigure the BWP for the serving cell, the BWP may be considered valid again.

[0094] In one embodiment, when the UE receives an RRC (re) configuration message to configure or reconfigure the BWP serving a cell, all BWPs deemed invalid (e.g., in which continuous UL LBT failures are detected) may be reconsidered as valid BWPs and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0095] Condition 6: If the serving cell is activated or deactivated, the UE determines the invalid BWP as a valid BWP

[0096] In one example, when the sCellDeactivationTimer configured for the SCell expires, the SCell may be deactivated.

[0097] In one example, the SCell may be activated or deactivated by a SCell activation / deactivation MAC CE.

[0098] In one embodiment, when the serving cell is deactivated, all BWPs determined to be invalid (e.g., continuous UL LBT failures are detected in these BWPs) may be reconsidered as valid, and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0099] In one embodiment, when the serving cell is activated, all BWPs that are considered invalid (e.g., continuous UL LBT failures are detected in these BWPs) may be considered valid again, and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0". In addition, the LBT recovery process triggered on the serving cell may be canceled because the LBT failure process triggered in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are considered valid again.

[0100] In one example, when a serving cell (or BWP) is activated (or deactivated), the initial state of the BWP of the serving cell is considered valid.

[0101] Condition 7: If a specific type of RA procedure is completed successfully / unsuccessfully, the UE determines the invalid BWP as a valid BWP

[0102] Note that a specific type of RA procedure may be referred to as a UE-initiated RA procedure (eg, a UE-initiated RA procedure is considered as part of the LBT recovery procedure (eg, on a PCell or PSCell)).

[0103] In one embodiment, when continuous UL LBT failures are detected in a BWP of a PCell, an LBT recovery procedure may be triggered on the PCell, which may involve triggering an LBT failure procedure for the BWP of the PCell (e.g., determining the BWP as an invalid BWP). In addition, the LBT recovery procedure on the PCell may involve initiating an RA procedure on a new BWP configured by a PRACH opportunity, and the BWP is not determined to be invalid on the PCell. Subsequently, when the RA procedure is completed (successfully / unsuccessfully) on the new BWP, all BWPs configured on the PCell that are determined to be invalid (e.g., continuous UL LBT failures are detected in these BWPs) are re-considered valid (e.g., all BWPs become candidates for BWP switching) and / or the BWP_declaration_counter (corresponding to the PCell) may be reset to "0". In addition, since the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the PCell are re-considered valid, the LBT recovery procedure triggered on the PCell may be canceled.

[0104] In one embodiment, when continuous UL LBT failures are detected in a BWP on a PSCell, an LBT recovery procedure may be triggered on the PSCell, which may involve triggering an LBT failure procedure for the BWP (e.g., determining the BWP to be an invalid BWP). In addition, the LBT recovery procedure on the PSCell may involve initiating a RA procedure on a new BWP configured with a PRACH opportunity, and the BWP is not determined to be invalid on the PSCell. Subsequently, when the RA procedure is completed (successfully / unsuccessfully) on the new BWP, all BWPs configured on the PSCell that are determined to be invalid (e.g., continuous UL LBT failures are detected in these BWPs) are re-considered as valid (e.g., candidates for BWP switching) and / or the BWP_declaration_counter (corresponding to the PSCell) may be reset to "0". In addition, the LBT recovery procedure triggered on the PSCell may be canceled because the LBT failure procedures triggered in all BWPs on the serving cell are canceled, or all invalid BWPs on the PCell are re-considered as valid.

[0105] Note that the UE may consider detecting continuous UL LBT failures when the LBT_COUNTER reaches the lbt-FailureInstanceMaxCount for the serving cell during an ongoing RA procedure initiated on the serving cell. In this case, the UE may consider that the corresponding RA procedure was not successfully completed.

[0106] Condition 8: If timeAlignmentTimer expires, the UE determines the invalid BWP as a valid BWP

[0107] In one example, timeAlignmentTimer may be configured per timing advance group (TAG).

[0108] In one embodiment, when the timeAlignmentTimer of the TAG expires, all BWPs associated with the TAG and considered invalid (for example, continuous UL LBT failures are detected in these BWPs) may be re-considered valid, and / or the BWP_declaration_counter (corresponding to those serving cells) may be reset to "0". In addition, the LBT recovery procedure triggered on the serving cell associated with the TAG may be canceled because the triggered LBT failure procedure in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell associated with the TAG are re-considered valid.

[0109] Condition 9: If LBT Failure MAC CE is transmitted, the UE determines the invalid BWP as a valid BWP

[0110] In one embodiment, when a MAC PDU includes an LBT failure MAC CE with a corresponding subheader, and the LBT failure MAC CE includes LBT failure-related information (e.g., the identification of the BWP / service cell where continuous UL LBT failures are detected, or the identification of the service cell where continuous UL LBT failures are detected), when the MAC PDU is transmitted, the BWP identified in the LBT failure MAC CE can be reconsidered as valid.

[0111] In one embodiment, when a MAC PDU includes an LBT failure MAC CE with a corresponding subheader, and the LBT failure MAC CE includes LBT failure related information of one or more service cells with invalid BWP (e.g., identification of one or more service cells where continuous UL LBT failure is detected), when the MAC PDU is transmitted, all invalid BWPs from the one or more service cells may be considered valid again. In addition, the triggered LBT recovery process on one or more service cells may be canceled because the triggered LBT failure process in all BWPs on one or more service cells is canceled, or all invalid BWPs on one or more service cells are considered valid again.

[0112] In one embodiment, when a MAC PDU includes an LBT failure MAC CE with a corresponding subheader, and the LBT failure MAC CE includes LBT failure related information (e.g., an identifier of a BWP in which continuous UL LBT failures are detected, or an identifier of a serving cell in which continuous UL LBT failures are detected), when the MAC PDU is transmitted and an explicit (DL) HARQ ACK or an implicit HARQ ACK is received from a network (e.g., a gNB) for a transport block (TB) carrying the MAC PDU, the BWP identified in the LBT failure MAC CE may be reconsidered as valid.

[0113] In one example, the UE may consider receiving an implicit HARQ ACK from the network when a MAC PDU is transmitted over configured UL grant resources (e.g., PUSCH resources corresponding to the configured grant configuration) and a configuredGrantTimer corresponding to the HARQ process identifier (ID) of the configured UL grant resources expires.

[0114] In another example, the UE may consider receiving an implicit HARQ ACK from the network when a MAC PDU is transmitted via a dynamic UL grant resource (e.g., a PUSCH resource indicated by a dynamic uplink grant), specifically UL resource 1, and the network schedules another dynamic UL grant for a new transmission with the same HARQ process ID as UL resource 1 (e.g., using a switched new data indicator (NDI)).

[0115] Condition 10: If the LBT recovery procedure is cancelled / stopped / pending / failed / successful, the UE determines the invalid BWP as a valid BWP

[0116] In some examples, the LBT recovery process may be triggered on a PCell, PSCell, or SCell.

[0117] In some examples, the LBT recovery process can be triggered when LBT_COUNTER>=lbt-FailureInstanceMaxCount.

[0118] In one embodiment, when the LBT recovery process on the serving cell is canceled / stopped / pending / failed or is deemed to have been successfully executed, all BWPs on the serving cell that were determined to be invalid BWPs (e.g., continuous UL LBT failures were detected in these BWPs) may be re-considered as valid BWPs and / or the BWP_declaration_counter (corresponding to the serving cell) may be reset to "0".

[0119] In some examples, when a UE-initiated RA process initiated due to detection of continuous UL LBT failure is stopped due to the initiation of another RA process, the LBT recovery process on the serving cell (e.g., on the PCell / PSCell) may be stopped.

[0120] Condition 11: If a MAC reset is performed for the MAC entity corresponding to the serving cell, the UE determines the invalid BWP as a valid BWP

[0121] In some examples, a MAC reset of the MAC entity may be requested by a higher layer (eg, RRC layer). In some examples, the MAC entity may correspond to a cell group.

[0122] In one embodiment, when a MAC reset is requested by a higher layer (e.g., an RRC layer), all BWPs determined to be invalid BWPs on the corresponding cell group (e.g., continuous UL LBT failures are detected in these BWPs) may be re-considered as valid BWPs and / or BWP_declaration_counter (corresponding to the cell group) may be reset to "0". In addition, the LBT recovery process triggered on the serving cell corresponding to the cell group may be canceled because the LBT failure process triggered in all BWPs on the serving cell corresponding to the cell group is canceled, or all invalid BWPs on the serving cell corresponding to the cell group are re-considered as valid.

[0123] Condition 12: If the RLF procedure is triggered, the UE determines the invalid BWP as a valid BWP. In one example, the RLF procedure may be triggered on the PCell, where continuous UL LBT failures are detected in all BWPs configured with PRACH opportunities on the PCell.

[0124] In one embodiment, after the RLF process is triggered on the PCell, all BWPs determined to be invalid BWPs on the PCell and / or MCG and / or SCG (for example, continuous UL LBT failures are detected in these BWPs) can be re-considered as valid BWPs. In addition, the triggered LBT recovery process on the PCell and / or MCG and / or SCG can be canceled because the LBT failure process triggered in all BWPs on the PCell and / or MCG and / or SCG is canceled, or all invalid BWPs on the PCell and / or MCG and / or SCG are re-considered as valid.

[0125] Alternatively, after the RLF process is triggered on the PCell, all BWPs on the PCell and / or MCG and / or SCG may be re-considered as invalid BWPs.

[0126] In one example, after the RLF process is triggered on the PCell, the BWP_declaration_counter (corresponding to the PCell) may be reset to '0'.

[0127] Condition 13: After initiating the process of reporting SCG failure information, the UE determines that the invalid BWP is a valid BWP

[0128] In one example, the process for reporting SCG failure information can be initiated as part of the LBT recovery process on the PSCell (e.g., continuous UL LBT failure is detected in the BWP on the PSCell, and continuous UL LBT failure is detected in all BWPs configured with PRACH opportunities in the PSCell).

[0129] In one embodiment, after initiating a process to report SCG fault information (as part of the LBT recovery process on the PSCell), all BWPs determined to be invalid BWPs on the PSCell and / or SCG can be re-considered as valid BWPs. In addition, the LBT recovery process triggered on the PSCell and / or SCG can be canceled because the LBT fault process triggered in all BWPs on the PSCell and / or SCG is canceled, or all invalid BWPs on the PSCell and / or SCG are re-considered as valid.

[0130] Alternatively, as part of the LBT recovery process on the PSCell, after initiating a process to report SCG failure information, all BWPs on the PSCell and / or SCG may be re-considered as invalid BWPs.

[0131] In one embodiment, after initiating a process to report SCG failure information (as part of the LBT recovery process on the PSCell), the BWP_declaration_counter (corresponding to the PSCell) may be reset to "0".

[0132] Condition 14: If lbt-FailureDetectionTimer expires, the UE determines the invalid BWP as a valid BWP

[0133] Condition 15: When lbt-FailureDetectionTimer or lbt-FailureInstanceMaxCount is reconfigured by higher layers, the UE determines the invalid BWP as a valid BWP

[0134] Condition 16: If BWP_declaration_threshold is configured or reconfigured by higher layers, the UE determines an invalid BWP as a valid BWP

[0135] In one example, when BWP_declaration_threshold (configured for the serving cell) is configured or reconfigured by a higher layer, BWP_declaration_counter (corresponding to the serving cell) may be reset to '0'.

[0136] Condition 17: If the UE does not perform a specific RA procedure, the UE determines the invalid BWP as a valid BWP

[0137] A specific type of RA process may be referred to as a UE-initiated RA process (e.g., a UE-initiated RA process as part of an LBT recovery process on a PCell or PSCell).

[0138] In one embodiment, when the UE receives a BWP switching command for a serving cell without performing a RA procedure, all invalid BWPs on the serving cell are reconsidered as valid BWPs and / or BWP_declaration_counter (corresponding to PCell) may be reset to "0". The RA procedure may be performed as part of an LBT recovery procedure on a serving cell (e.g., PCell or PSCell). In addition, an LBT recovery procedure triggered on a serving cell may be canceled because an LBT failure procedure triggered in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0139] In one embodiment, when the UE receives a dynamic grant indicating UL resources in a BWP of a serving cell determined by the UE as an invalid serving cell when the UE did not perform a RA procedure as part of an LBT recovery procedure on the serving cell, the UE may switch to the corresponding BWP and re-consider the BWP as a valid BWP.

[0140] Timer-based methods

[0141] In one embodiment, an invalid BWP timer may be applied and maintained per BWP (or per cell). The invalid BWP timer defines a period of time during which a BWP is determined by the UE to be an invalid BWP. In other words, when the invalid BWP timer is running, the corresponding BWP may be considered an invalid BWP. When the invalid BWP timer expires or the invalid BWP timer is stopped, the corresponding BWP may be re-considered as a valid BWP and / or the BWP_declaration_counter may be set to "0".

[0142] In one embodiment, an invalid BWP timer may be applied and maintained for each cell. While the timer is running, the UE may not reconsider the BWP of the cell as valid. When the timer expires, the UE may reconsider all BWPs of the cell as valid and / or the BWP_declaration_counter may be set to "0". In addition, the LBT recovery procedure triggered on the serving cell may be canceled because the LBT failure procedure triggered in all BWPs on the serving cell is canceled, or all invalid BWPs on the serving cell are reconsidered as valid.

[0143] Specifically, as part of the LBT recovery procedure on PCell / PSCell, the UE is restricted from performing UE-initiated BWP switching to an invalid BWP. In other words, if the UE performs BWP switching due to continuous UL LBT failure on PCell / PSCell, the UE may be restricted from switching to an invalid BWP.

[0144] Specifically, if the UE performs BWP switching due to continuous UL LBT failure on PCell / PSCell, the UE may switch to a valid BWP configured with a PRACH opportunity.

[0145] In addition, the Invalidate BWP timer may be initiated or re-initiated when one or more of the following conditions are met:

[0146] Condition 1: If the UE triggers the LBT recovery procedure, it can initiate or re-initiate the invalid BWP timer

[0147] In one example, if the LBT recovery process is triggered due to detection of continuous UL LBT failures in the BWP, an invalid BWP timer corresponding to the BWP may be initiated or re-initiated.

[0148] In one example, if the LBT recovery process of a cell is triggered due to detection of continuous UL LBT failure in the BWP of the cell, an invalid BWP timer corresponding to the cell may be initiated or re-initiated. When the invalid BWP timer is running, the invalid BWP timer cannot be re-initiated.

[0149] Condition 2: If the UE considers that continuous UL LBT failure is detected for the active BWP, it may initiate or re-initiate the invalid BWP timer

[0150] In one example, when the UE determines continuous UL LBT failure for an active BWP, an invalid BWP timer corresponding to the BWP may be initiated or re-initiated.

[0151] In one example, when the UE detects continuous UL LBT failure for the active BWP of a cell, an invalid BWP timer corresponding to the cell may be initiated or re-initiated. When the invalid BWP timer is running, the invalid BWP timer cannot be re-initiated.

[0152] Condition 3: If the UE detects continuous UL LBT failure in the BWP, it may initiate or re-initiate the Invalid BWP timer

[0153] In one example, when continuous UL LBT failures are detected in a BWP, an invalid BWP timer corresponding to the BWP may be initiated or re-initiated.

[0154] In one example, when continuous UL LBT failure is detected in the BWP of a cell, if the invalid BWP timer of the cell is not running, an invalid BWP timer corresponding to the cell may be initiated.

[0155] Condition 4: If the UE performs a BWP switch as part of the LBT recovery procedure (e.g., on PCell / PSCell), the Invalidate BWP timer may be initiated or re-initiated

[0156] In one example, when continuous UL LBT failure is detected in a BWP (eg, BWP1), for PCell / PSCell, the UE may switch to another BWP configured with a PRACH opportunity and initiate or re-initiate an invalid BWP timer corresponding to BWP1.

[0157] In one example, when continuous UL LBT failure is detected in the BWP of a cell, specifically BWP1, for PCell / PSCell, the UE can switch to another BWP of the cell configured with PRACH opportunities, and initiate the invalid BWP timer if the invalid BWP timer of the cell is not running.

[0158] Condition 5: If the UE initiates a RA procedure as part of the LBT recovery procedure, the Invalidate BWP timer may be initiated or re-initiated

[0159] In one example, when continuous UL LBT failure is detected in a BWP, specifically BWP1, for PCell / PSCell, the UE may switch to a new BWP configured with a PRACH opportunity and initiate a RA procedure on the new BWP. In addition, the UE may initiate or re-initiate an invalid BWP timer corresponding to BWP1 during the RA procedure.

[0160] In one example, when continuous UL LBT failure is detected in a BWP, specifically BWP1, for PCell / PSCell, the UE may switch to a new BWP of the cell configured with PRACH opportunities and initiate a RA procedure on the new BWP. In addition, if the invalid BWP timer of the cell is not running, the UE may initiate an invalid BWP timer.

[0161] In addition to the above (re)initiation conditions, whether the invalid BWP timer corresponding to the BWP is (re)initiation may be based on whether the BWP is pre-configured with a specific IE. The IE may be, but is not limited to, configured by the network based on the BWP. Through the IE, the gNB explicitly indicates whether the UE can re-consider the invalid BWP as a valid BWP when receiving an UL grant on the BWP.

[0162] The Invalid BWP Timer can be stopped when one or more of the following conditions are met:

[0163] Condition 1: If the UE receives a BWP switching command from the network, it can stop the invalid BWP timer

[0164] Specifically, the BWP switching command may be signaled via a DCI message (eg, signaled on a PDCCH for BWP switching).

[0165] Specifically, the BWP switching command may be a dynamic grant to schedule UL resources on another BWP.

[0166] In one example, when the UE receives a BWP switching command of a serving cell, a running invalid BWP timer corresponding to the serving cell is stopped.

[0167] In one example, when the UE receives a BWP switching command for a BWP, if the invalid BWP timer is running, the UE may stop the invalid BWP timer corresponding to the BWP.

[0168] Condition 2: If the UE switches BWP during the RA procedure because no PRACH opportunity is configured on the current BWP, the invalid BWP timer may be stopped

[0169] Specifically, during the RA procedure initiated on the serving cell, if no PRACH opportunity is configured on the current BWP of the UE in the serving cell, the UE may switch to the BWP indicated by initialUplinkBWP.

[0170] In one example, when the UE switches to a BWP indicated by initialUplinkBWP of a serving cell during a RA procedure, if the invalid BWP timer is running, the UE may stop the invalid BWP timer corresponding to the BWP.

[0171] In one example, when the UE switches to the BWP indicated by the initialUplinkBWP of the serving cell during the RA procedure, if the invalid BWP timer is running, all invalid BWP timers corresponding to the serving cell may be stopped.

[0172] Condition 3: When bwp-InactivityTimer expires, if the UE switches BWP, the invalid BWP timer can be stopped

[0173] In one example, when the bwp-InactivityTimer associated with an active DL BWP expires and the UE performs a BWP switch to a BWP indicated by defaultDownlinkBWP-Id or performs a BWP switch to initialDownlinkBWP, if the invalid BWP timer is running, all invalid BWP timers corresponding to the serving cell may be stopped.

[0174] Condition 4: If the UE receives an indication from the network indicating that the BWP is valid or that all BWPs are valid, the invalid BWP timer may be stopped.

[0175] In one example, the indication may be signaled via a DCI message.

[0176] In one example, the indication may be signaled via a MAC CE.

[0177] In one example, the indication may be signaled via RRC signaling.

[0178] In one example, the indication may include one or more valid BWPs (eg, BWPs that the UE may reconsider as valid BWPs).

[0179] In one embodiment, the network may indicate via DCI message / MAC CE / RRC signaling one or more BWPs that the UE may reconsider as a valid BWP. In this case, the network may identify the BWP considered invalid by the UE (e.g., a BWP in which continuous UL LBT failure is detected) before providing such an indication to the UE. When the indication is received, all invalid BWP timers corresponding to the BWP indicated by the network may be stopped if they are running.

[0180] Condition 5: If the UE receives an RRC (re)configuration message, the invalid BWP timer may be stopped

[0181] In one example, the RRC (re)configuration message may configure or reconfigure the BWP for the serving cell.

[0182] In one example, such an RRC (re)configuration message may configure or reconfigure firstActiveDownlinkBWP-Id and / or firstActiveUplinkBWP-Id for the SpCell.

[0183] In one embodiment, when the UE receives an RRC (re)configuration message to configure or reconfigure a BWP for a serving cell, the invalid BWP timer corresponding to the BWP may be stopped if it is running.

[0184] In one embodiment, if the UE receives an RRC (re)configuration message to configure or reconfigure the BWP for a serving cell, all invalid BWP timers corresponding to the serving cell may be stopped if they are running.

[0185] Condition 6: If the serving cell is activated or deactivated, the invalid BWP timer can be stopped

[0186] In one implementation, when the sCellDeactivationTimer configured for the SCell expires, the SCell may be deactivated.

[0187] In one implementation, the SCell may be activated or deactivated by a SCell activation / deactivation MAC CE.

[0188] In one embodiment, when a serving cell is deactivated, all invalid BWP timers corresponding to the serving cell may be stopped if they are running.

[0189] In one embodiment, when a serving cell (or BWP) is activated (or deactivated), the BWP_declaration_counter (corresponding to the serving cell) may be set to zero.

[0190] Condition 7: If a specific type of RA procedure is completed, the invalid BWP timer can be stopped

[0191] It should be noted that a specific type of RA process may refer to a RA process initiated by the UE (for example, a RA process initiated by the UE as part of the LBT recovery process on the PCell or PSCell).

[0192] In one embodiment, when the RA procedure initiated by the UE as part of the LBT recovery procedure (e.g., on the PCell / PSCell) is successfully completed, the UE may stop all invalid BWP timers corresponding to the cell.

[0193] Condition 8: If "timeAlignmentTimer" expires, the invalid BWP timer can be stopped

[0194] In one example, timeAlignmentTimer may be configured for each TAG.

[0195] In one example, if the timeAlignmentTimer of a TAG expires, all invalid BWP timers corresponding to the BWP associated with the TAG may be stopped if they are running.

[0196] Condition 9: If the LBT recovery process is cancelled / stopped / pending / failed or deemed successful, the invalid BWP timer can be stopped

[0197] In one example, the LBT recovery process can be triggered on PCell, PSCell and SCell.

[0198] In one example, if LBT_COUNTER>=lbt-FailureInstanceMaxCount, the LBT recovery process may be triggered.

[0199] In one embodiment, when the LBT recovery procedure on the serving cell is canceled / stopped / pending / failed or deemed successful, all invalid BWP timers corresponding to the serving cell may be stopped if they are running.

[0200] Condition 10: If lbt-FailureDetectionTimer expires, the invalid BWP timer can be stopped

[0201] Condition 11: If the upper layer reconfigures "lbt-FailureDetectionTimer" or "lbt-FailureInstanceMaxCount", the invalid BWP timer can be stopped

[0202] Specifically, the network may configure the invalid BWP timer, lbt-FailureInstanceMaxCount, BWP_declaration_threshold, or lbt-FailureDetectionTimer through RRC signaling. In one example, the invalid BWP timer, lbt-FailureInstanceMaxCount, BWP_declaration_threshold, or lbt-FailureDetectionTimer may be configured in the NRU-UplinkLbtFailureConfig IE. In addition, the NRU-UplinkLbtFailureConfig IE may be configured according to a subset of BWP / cell group / cell / cell group.

[0203] Specifically, the unit of the invalid BWP timer may be milliseconds, time slots, symbols, etc.

[0204] Interaction between RA process and UL LBT failure

[0205] In one embodiment, when continuous UL LBT failures are detected in the BWP of the serving cell during a RA procedure initiated on the serving cell (e.g., LBT_COUNTER reaches lbt-FailureInstanceMaxCount of the BWP of the serving cell), this means that continuous UL LBT failures are detected (on the serving cell). In this case, the RA procedure may be considered to be completed unsuccessfully. In addition, the MAC entity may indicate the RA problem to the RRC layer. Subsequently, the RRC layer may set the failureType to randomAccessProblem. Therefore, the UE may transmit an RRC message (e.g., an SCG Failure Information message) including the failureType to the gNB.

[0206] BWP switching and LBT recovery process

[0207] When the UE performs UE-initiated BWP switching, the UE may switch to a BWP that is determined to be an invalid BWP (eg, continuous UL LBT failure is detected in the BWP). To avoid UE-initiated BWP switching to an invalid BWP, some conditions are required.

[0208] In one example, when the BWP inactivity timer expires (and the UE operates in TDD mode), a UE-initiated BWP switching may be performed.

[0209] In one example, if the UE's current BWP is not configured with a PRACH opportunity, a UE-initiated BWP switch may be performed during the RA procedure.

[0210] In one embodiment, the BWP inactivity timer may be stopped when one or more of the following conditions are met:

[0211] Condition 1: If the LBT recovery process is triggered

[0212] In one embodiment, when continuous UL LBT failures are detected in the BWP of a serving cell (eg, SpCell or SCell) (eg, LBT_COUNTER reaches the lbt-FailureInstanceMaxCount of the corresponding BWP), the LBT recovery process may be triggered for the serving cell.

[0213] Condition 2: If "NRU-UplinkLbtFailureConfig" is configured

[0214] Specifically, the invalid BWP timer, lbt-FailureInstanceMaxCount, BWP_declaration_threshold or lbt-FailureDetectionTimer can be configured in NRU-UplinkLbtFailureConfig.

[0215] Condition 3: If the specific BWP has been determined by the UE as an invalid BWP

[0216] In one embodiment, the specific BWP may be the BWP indicated by initialUplinkBWP.

[0217] In one example, the specific BWP may be a BWP in the same frequency range as the DL BWP indicated by the defaultDownlinkBWP, and the UE operates in TDD mode.

[0218] In one example, the specific BWP may be a BWP in the same frequency range as the DL BWP indicated by initialDownlinkBWP, and the UE operates in TDD mode.

[0219] Condition 4: If the invalid BWP timer is running

[0220] Condition 5: If BWP_declaration_counter is not "0"

[0221] In one example, if the BWP inactivation timer expires, the UE does not switch its DL BWP.

[0222] In another example, the UE may not switch to a default BWP / initial BWP that is considered an invalid BWP even if a timer of BWP inactivity expires.

[0223] Completing the LBT recovery process

[0224] The UE (or MAC entity) may be configured with an LBT failure detection procedure (per serving cell) and an LBT recovery procedure (per serving cell). By counting the LBT failure indications of all UL transmissions from the lower layers (e.g., PHY layer) to the MAC entity, continuous UL LBT failures may be detected per the BWP of the serving cell (as part of the LBT recovery procedure of the serving cell).

[0225] When the UE detects continuous UL LBT failures in the BWP of SpCell according to the LBT failure detection process of SpCell (for example, when the LBT_COUNTER reaches the lbt-FailureInstanceMaxCount of the corresponding BWP of SpCell), the UE may trigger the LBT recovery process on the SpCell.

[0226] In one embodiment, the UE can only perform one LBT recovery process at a time. For example, if the first serving cell detects continuous UL LBT failure, the UE may trigger the LBT recovery process of the serving cell. At the same time, if the second serving cell detects continuous UL LBT failure, the UE may not trigger another LBT recovery process (i.e., the LBT recovery process on the second serving cell).

[0227] In other embodiments, the LBT recovery process may be triggered according to the serving cell. For example, if the first serving cell detects continuous UL LBT failure, the UE may trigger the first LBT recovery process, and if the second serving cell detects continuous UL LBT failure, the UE may trigger the second LBT recovery process. More specifically, the first LBT recovery process and the second LBT recovery process may be performed simultaneously.

[0228] Subsequently, the UE may determine / consider that the LBT recovery procedure is completed or cancelled if one or more or any combination of the following conditions are met:

[0229] Condition 1: The RA process initiated as part of the LBT recovery process on the SpCell is successfully executed.

[0230] In one example, if the LBT recovery process on the SpCell is triggered by the UE, the UE may initiate a RA process as part of the LBT recovery process. Subsequently, if the RA process is successfully completed, the UE may consider the LBT recovery process completed or cancelled.

[0231] Condition 2: If LBT Failure MAC CE is transmitted

[0232] In one example, the UE may transmit an LBT Failure MAC CE as part of the LBT recovery procedure on the SpCell.

[0233] In one example, the LBT Failure MAC CE may identify the BWP and / or cell where continuous UL LBT failure is detected.

[0234] In one example, the LBT Failure MAC CE may identify the BWP and / or cell that triggered the LBT Failure procedure.

[0235] In one example, the LBT failure MAC CE may be transmitted via UL resources allocated on the serving cell where the LBT recovery procedure is not triggered, or may be transmitted via any available UL resources without restriction.

[0236] In one example, the LBT failure MAC CE may include LBT information (e.g., BWP ID and / or cell ID) of all (or part of) BWPs (or serving cells) indicating the LBT failure before assembling the MAC PDU carrying the LBT failure MAC CE (and with corresponding subheaders).

[0237] When the UE instructs the multiplexing and assembly process to generate an LBT failure MAC CE, the UE may perform a multiplexing and assembly process (including a logical channel prioritization process). During the multiplexing and assembly process, the UE may multiplex the generated MAC CE and / or MAC SDU in the MAC PDU. The UE may then transmit the MAC PDU (e.g., via UL-SCH resources). More specifically, MAC PDU assembly may occur at any point in time between UL grant reception and actual transmission of the corresponding MAC PDU.

[0238] In one example, when the UE triggers the LBT recovery procedure on the SpCell, the UE may transmit an LBT failure MAC CE as part of the LBT recovery procedure on the SpCell. Subsequently, if the LBT failure MAC CE is transmitted (and the MAC CE includes an LBT failure indicated (on all cells) before assembling the MAC PDU carrying the LBT failure MAC CE), the UE may consider the LBT recovery procedure on the SpCell to be completed or canceled.

[0239] Condition 3: If a positive response corresponding to the transmitted LBT Failure MAC CE is received from the network

[0240] In one example, the positive response may be explicitly indicated from the network or implicitly received by the UE. If the UE receives a positive response, it means that the network successfully receives the LBT failure MAC CE from the UE. Specifically, the UE may transmit the LBT failure MAC CE as part of the LBT recovery process on the SpCell.

[0241] In one example, the LBT failure MAC CE may be transmitted on the first UL resource via the first HARQ process (if the UL resources are available for new transmissions and the first UL resources may accommodate the LBT failure MAC CE with the corresponding subheader due to logical channel priority). After transmitting the first UL resource via the first HARQ process, the UE may receive a positive response to the first HARQ process from the network, where the positive response may be a PDCCH (addressed to the C-RNTI) indicating a UL grant for a new transmission (for LBT failure MAC CE transmission) for the HARQ process.

[0242] In one example, the positive response may be explicit DL HARQ feedback (eg, explicit DL HARQ ACK) from the network indicating that the HARQ process of the UL transmission including the LBT failure MAC CE was successfully received.

[0243] In one example, the UE may implicitly receive a positive response when receiving a (dynamic) UL grant for a new transmission (e.g., using a switched NDI), and the (dynamic) UL grant corresponds to the same HARQ process ID as the UL resources that transmitted the LBT failure MAC CE.

[0244] In one example, when a specific timer expires, the UE may implicitly receive a positive response. For example, when a LBT failure MAC CE is transmitted, a specific timer may be initiated or re-initiated.

[0245] In one embodiment, when the LBT failure MAC CE is transmitted on the configured UL granted resources (e.g., corresponding to the PUSCH resources configured with the configured grant), the UE that transmits the LBT failure MAC CE may implicitly receive a positive response. For example, when the configuredGrantTime of the HARQ process of the configured UL granted resources (e.g., corresponding to the PUSCH resources configured with the configured grant) used to transmit the LBT failure MAC CE expires.

[0246] Specifically, the configuration authorization configuration may be, but is not limited to, configuration authorization type 1 / configuration authorization type 2 configuration.

[0247] In one embodiment, if the LBT failure MAC CE is transmitted on Msg 3 (e.g., transmitted on RAR scheduled PUSCH resources, which corresponds to a RA procedure initiated as part of the LBT recovery procedure), the positive response can be an explicit HARQ ACK from the network, for example, when the ra-ContentionResolutionTimer is running, the PDCCH is addressed to the C-RNTI indicated by the network (containing the UL grant for the new transmission).

[0248] In one embodiment, if the LBT recovery procedure on the SpCell is triggered by the UE, the UE may transmit an LBT failure MAC CE. Subsequently, the UE may consider the LBT recovery procedure completed or cancelled upon receiving a positive response (e.g., implicit or explicit ACK) corresponding to the transmitted LBT failure MAC CE.

[0249] When the UE detects continuous UL LBT failures in the BWP of the SCell according to the LBT failure detection procedure for the SCell, the LBT recovery procedure on the SCell may be triggered by the UE (e.g., the LBT_COUNTER reaches lbt-FailureInstanceMaxCount for the corresponding BWP of the SCell). Subsequently, the UE may determine that the LBT recovery procedure has been completed or cancelled if one or more of the following conditions are met:

[0250] Condition 1: If LBT Failure MAC CE is transmitted

[0251] In one example, the LBT Failure MAC CE may include an identifier of a BWP that detected continuous UL LBT failures, or an identifier of a serving cell that detected continuous UL LBT failures.

[0252] In one example, the LBT failure MAC CE may include LBT information (e.g., BWP ID and / or cell ID) of all (or part of) BWPs (or serving cells) indicating the LBT failure before assembling the MAC PDU carrying the LBT failure MAC CE (and with corresponding subheaders).

[0253] In one example, the LBT failure MAC CE may be transmitted via UL resources allocated on the serving cell where the LBT recovery procedure is not triggered, or may be transmitted via any available UL resources without restriction.

[0254] If the UE indicates a multiplexing and assembly process to generate an LBT failure MAC CE, the UE may perform a multiplexing and assembly process (including a logical channel prioritization process). During the multiplexing and assembly process, the UE may multiplex the generated MAC CE and / or MAC SDU in the MAC PDU. The UE may then transmit the MAC PDU (e.g., via UL SCH resources). More specifically, MAC PDU assembly may occur at any point in time between UL grant reception and actual transmission of the corresponding MAC PDU.

[0255] In one example, if the LBT recovery procedure on the SCell is triggered by the UE, the UE may transmit an LBT failure MAC CE as part of the LBT recovery procedure. Subsequently, if the LBT failure MAC CE is transmitted (and the MAC CE includes all LBT failures triggered (on the SCell) before the assembly of the MAC PDU carrying the LBT failure MAC CE), the UE may consider the LBT recovery procedure on the SCell to be completed.

[0256] More specifically, if there are multiple LBT recovery procedures in progress, the UE may consider the LBT recovery procedure to be completed based on whether the LBT information (e.g., BWP ID and / or cell ID) in the cell for which the BWP and / or LBT recovery procedures are triggered is included in the LBT failure MACCE.

[0257] Condition 2: If a positive response corresponding to the transmitted LBT Failure MAC CE is received from the network

[0258] In one example, the positive response may be explicitly indicated from the network or implicitly received by the UE. If the UE receives a positive response, it indicates that the network has successfully received the LBT Failure MAC CE transmitted by the UE as part of the LBT recovery procedure on the SCell.

[0259] In one example, the LBT failure MAC CE may be transmitted on the first UL resource via the first HARQ process (if the UL resource is available for new transmission and the first UL resource may accommodate the LBT failure MAC CE with the corresponding subheader due to logical channel priority). After transmitting the first UL resource via the first HARQ process, the UE may receive a positive response to the first HARQ process from the network, wherein the positive response may be a PDCCH (addressed to the C-RNTI) indicating a UL grant for a new transmission of the HARQ process (for LBT failure MAC CE transmission).

[0260] In one example, the positive response may be explicit DL HARQ feedback (eg, explicit DL HARQ ACK) from the network indicating that the HARQ process of the UL transmission including the LBT failure MAC CE was successfully received.

[0261] In one example, the UE may implicitly receive a positive response when receiving a (dynamic) UL grant for a new transmission (e.g., using a switched NDI), where the (dynamic) UL grant corresponds to the same HARQ process ID as the UL resource over which the LBT failure MAC CE was transmitted.

[0262] In one example, when a specific timer expires, the UE may implicitly receive a positive response. For example, when a LBT failure MAC CE is transmitted, a specific timer may be initiated or re-initiated.

[0263] In one example, when the LBT Failure MAC CE is transmitted on the configured UL granted resources (e.g., corresponding to the PUSCH resources configured with the configured grant), the UE that transmits the LBT Failure MAC CE may implicitly receive a positive response. For example, when the configuredGrantTimer of the HARQ process of the configured UL granted resources (e.g., corresponding to the PUSCH resources configured with the configured grant) used to transmit the LBT Failure MAC CE expires.

[0264] Specifically, the configuration authorization configuration may be, but is not limited to, configuration authorization type 1 / configuration authorization type 2 configuration.

[0265] In one example, when the LBT Failure MAC CE is transmitted on Msg 3 (e.g., transmitted on PUSCH resources scheduled by the RAR), the positive response can be an explicit HARQ ACK from the network indicated by the network when the ra-ContentionResolutionTimer runs (e.g., a PDCCH addressed to the C-RNTI contains an UL grant for a new transmission).

[0266] In one example, when the UE triggers the LBT recovery procedure on the SCell, the UE may transmit an LBT failure MAC CE. Subsequently, the UE may consider completing or canceling the LBT recovery procedure on the SCell upon receiving a positive response (e.g., implicit or explicit ACK) corresponding to the transmitted LBT failure MAC CE.

[0267] More specifically, if there are multiple LBT recovery procedures in progress, the UE may consider the LBT recovery procedure for the BWP and / or serving cell based on whether a positive response to the LBT failure MAC CE including the LBT information of the BWP and / or serving cell is received.

[0268] Condition 3: If BWP switching is performed on the SCell where continuous UL LBT failure is detected

[0269] In one example, upon receiving a PDCCH indicating a DL assignment or UL grant from the network, the UE may switch to the BWP.

[0270] In one example, when the bwp-InactivityTimer expires, the UE may switch BWP.

[0271] In one example, the UE may switch to a BWP during the RA procedure (if no PRACH opportunity is configured for an active BWP).

[0272] In one example, if the LBT recovery procedure on the SCell is triggered by the UE (e.g., the UE detects continuous UL LBT failures in the BWP of the SCell), the UE may consider completing or canceling the LBT recovery procedure when the UE performs a BWP switch on the SCell. Note that the UE may reset the LBT_COUNTER when performing a BWP switch.

[0273] Condition 4: If UL transmission is performed (successfully) on the SCell that triggered the LBT recovery process.

[0274] In one example, UL transmission may be performed on UL resources (eg, PUSCH resources) indicated via RAR, dynamic UL grant (eg, PDCCH), configuration grant, etc.

[0275] In one example, the UL resource may be a RACH resource, a PUCCH resource and / or a PUSCH resource. The UL resource may be scheduled by dynamic grant (eg, by PDCCH) and / or by RRC configuration (eg, configuring grant type 1 / configuring grant type 2 or pre-configured in RRC configuration).

[0276] In one example, if the UE's MAC entity does not receive an LBT failure indication from the PHY layer (for UL transmission), or if the MAC entity receives an LBT success indication from the PHY layer (for UL transmission), the UE may consider the UL transmission to be successfully performed.

[0277] In one example, if the LBT recovery procedure on the SCell is triggered by the UE (e.g., the UE detects continuous UL LBT failures in the BWP of the SCell), the UE may consider the LBT failure detection procedure completed or canceled when UL transmission is (successfully) performed on the SCell.

[0278] Note that when the UE considers the LBT recovery procedure (for BWP and / or serving cell (e.g., SpCell or SCell)) to be completed, the UE may reset LBT_COUNTER (corresponding to BWP and / or serving cell) and / or reset BWP_declaration_counter (corresponding to BWP and / or serving cell).

[0279] In one example, when the BWP_declaration_counter is reset, the UE may cancel the triggered LBT failure procedure for the BWP and / or serving cell.

[0280] Conditions for resetting LBT_COUNTER

[0281] The LBT_COUNTER (corresponding to the BWP and / or serving cell) may be reset if one or more of the following conditions are met:

[0282] Condition 1: After / when the LBT fault process is triggered (by the corresponding BWP and / or serving cell)

[0283] In one example, if the LBT failure procedure is triggered for the BWP and / or the serving cell, the LBT_COUNTER corresponding to the BWP and / or the serving cell may be reset. In addition, the serving cell may be a SpCell and / or a SCell.

[0284] In one example, when consecutive UL LBT failures are detected in the BWP and / or serving cell (eg, if LBT_COUNTER>=lbt-FailureInstanceMaxCount), an LBT failure procedure may be triggered for the BWP and / or serving cell.

[0285] More specifically, LBT_COUNTER is set to "0".

[0286] Condition 2: UL resources are available for transmission (on the corresponding BWP and / or serving cell)

[0287] In one example, the UL resources may be indicated via RAR, dynamic UL grant (eg, PDCCH), configuration grant, etc.

[0288] In one example, if the UL resources are sufficient to accommodate the LBT failure MAC CE (and the corresponding sub-header), the UL resources may be considered available.

[0289] In one example, UL resources may be considered available if UL resources are allowed to be used to transmit an LBT failure MAC CE.

[0290] In one example, if UL resources are allocated on a serving cell and / or BWP where no continuous UL LBT failure is detected, or UL resources are allocated on a serving cell and / or BWP where an LBT recovery process is triggered, the UL resources may be considered available.

[0291] In one example, when the UE receives UL resources on the serving cell and the UL resources are available for transmitting the LBT failure MAC CE, the UE may reset the LBT_COUNTER corresponding to the BWP and / or serving cell that triggered the LBT failure procedure.

[0292] Condition 3: If the MAC entity indicates the multiplexing and assembly process to generate an LBT Failure MAC CE

[0293] In one example, the LBT failure MAC CE may include LBT information of all (or part of) BWPs (or serving cells) indicating LBT failure before assembling the MAC PDU containing the LBT failure MAC CE (and with the corresponding subheader).

[0294] In one example, when the MAC entity indicates the multiplexing and assembly process to generate an LBT failure MAC CE, and the MAC CE includes LBT information of all BWPs or service cells indicating LBT failure before assembling the MAC PDU containing the MAC CE (and with corresponding subheaders), the UE can reset the LBT_COUNTER corresponding to the BWP and / or service cell indicating LBT failure before the MAC PDU assembly.

[0295] Condition 4: Cancel the triggered LBT fault process

[0296] In one example, when the UE cancels the LBT failure procedure triggered on one or more serving cells, the UE may reset the LBT_COUNTER corresponding to these serving cells.

[0297] In one example, when the UE cancels the LBT recovery procedure triggered on one or more serving cells, the UE may reset the LBT_COUNTER corresponding to these serving cells.

[0298] In one example, when the UE cancels the triggered LBT failure procedure of the serving cell (e.g., the UE cancels the triggered LBT failure procedure of all BWPs of the serving cell and / or reconsiders all invalid BWPs of the serving cell as valid BWPs), the UE may reset the LBT_COUNTER corresponding to the serving cell.

[0299] Condition 5: A positive response corresponding to the transmitted LBT Failure MAC CE is received from the network

[0300] In one example, when the UE receives a positive response from the network corresponding to the transmitted LBT Failure MAC CE (for BWP and / or serving cell), the UE may reset the LBT_COUNTER (corresponding to those BWP and / or serving cell).

[0301] Figure 4 4 is a flow chart of a method 400 for an LBT recovery process according to an embodiment of the present disclosure. In action 402, the UE may perform multiple LBT fault detection processes for multiple BWPs of a serving cell. In action 404, in response to detecting continuous UL LBT faults in multiple BWPs through multiple LBT fault detection processes, the UE may trigger multiple LBT recovery processes for multiple BWPs of the serving cell, and each specific LBT recovery process in the multiple triggered LBT recovery processes may include triggering an LBT fault process, and the LBT fault process is used to determine the BWP that triggers the specific LBT recovery process as an invalid BWP. In action 406, in response to confirming a predefined condition in the UE, all multiple triggered LBT recovery processes on the serving cell are canceled.

[0302] Note that the conditions for the UE to cancel the triggered LBT recovery procedure for the serving cell may include at least one of the following:

[0303] (1) The UE receives a PDCCH indicating that the UE performs a BWP switch on the serving cell;

[0304] (2) A PDCCH instructing the UE to perform BWP switching on the serving cell is received by the UE, and the UE does not perform a RA procedure on the serving cell;

[0305] (3) The UE receives an RRC configuration or reconfiguration message for configuring or reconfiguring BWP switching on the serving cell;

[0306] (4) The UE performs a MAC reset on the MAC entity corresponding to the serving cell;

[0307] (5) The serving cell is deactivated or activated;

[0308] (6) a RA procedure for a specific LBT recovery procedure on the serving cell is performed by the UE, and the RA procedure is successfully completed on the serving cell; and

[0309] (7) An LBT failure MAC CE is transmitted by the UE, and the LBT failure MAC CE indicates at least one cell that triggers at least one LBT recovery procedure, the at least one cell including a serving cell that triggers multiple triggered LBT recovery procedures.

[0310] (8) All triggered LBT fault procedures on the serving cell have been cancelled (eg, LBT fault procedures triggered on all BWPs of the serving cell have been cancelled).

[0311] (9) All invalid BWPs on the serving cell have been considered valid again.

[0312] During the LBT recovery process, the UE may transmit to the network an LBT failure MAC CE indicating one or more serving cells that have indicated an LBT failure. The LBT failure MAC CE may be transmitted on the serving cell or another serving cell where the LBT failure process is not triggered. The LBT failure MAC CE may indicate that the LBT failure process is triggered for the BWP. In addition, in response to no LBT failure process being triggered for another BWP on the serving cell, and the other BWP being configured with PRACH resources, the UE may switch from the BWP to another BWP on the serving cell, and / or may initiate a RA process for another BWP on the serving cell.

[0313] Note that if the serving cell is a SpCell, the UE may initiate a RA procedure for a triggered LBT recovery procedure in another BWP on the serving cell.

[0314] In one example, the serving cell may be a SpCell including at least one of a PCell or a PSCell, or the serving cell is a SCell.

[0315] In one embodiment, the UE may transmit an LBT failure MAC CE to the network, the LBT failure MAC CE indicating that an LBT failure has been triggered on the serving cell. In addition, if the serving cell is a SpCell, the LBT failure MAC CE may be transmitted on the same cell (e.g., if the LBT failure process is triggered on the SpCell, the LBT failure MAC CE may be transmitted on the SpCell).

[0316] In one embodiment, the UE may transmit an LBT failure MAC CE to the network, indicating that an LBT failure has been triggered on the serving cell. In addition, if the serving cell is an SCell, the LBT failure MAC CE may be transmitted on another cell that does not indicate an LBT failure (for example, if an LBT failure process is triggered on an SCell, the LBT failure MAC CE may be transmitted on another cell that does not indicate an LBT failure).

[0317] In one embodiment, if the serving cell is a SpCell, the UE may switch from a BWP to another BWP on the serving cell.

[0318] In one embodiment, if the serving cell is a SpCell, the UE may initiate a RA procedure for another BWP on the serving cell.

[0319] In addition, in response to the cancellation of all multiple triggered LBT recovery procedures, the UE may reset the LBT counter (e.g., LBT_COUNTER) corresponding to the serving cell. When an LBT failure is detected on the serving cell through one of the multiple LBT failure detection procedures, the UE may increase the LBT counter (e.g., LBT_COUNTER). In one example, when all the multiple triggered LBT recovery procedures are canceled, the UE may set the LBT counter to 0.

[0320] Figure 5 is a block diagram of a node 500 for wireless communication according to an embodiment of the present disclosure.

[0321] like Figure 5 As shown, the node 500 may include a transceiver 520, a processor 526, a memory 528, one or more presentation components 534, and at least one antenna 536. The node 500 may also include a radio frequency (RF) band module, a BS communication module, a network communication module, and a system communication management module, an input / output (I / O) port, an I / O component, and a power supply ( Figure 5 Each of these components can communicate directly or indirectly via one or more buses 540. Node 500 can be Figure 4 A UE or BS is shown in the figure that performs the functions disclosed in this document.

[0322] The transceiver 520 includes a transmitter 522 (with a transmitting circuit) and a receiver 524 (with a receiving circuit), and can be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 520 can be configured to transmit in different types of subframes and time slots, including but not limited to available, unavailable and flexibly available subframe and time slot formats. The transceiver 520 can be configured to receive data and control channels.

[0323] Node 500 may include various computer-readable media. Computer-readable media may be any media accessible by node 500, and include volatile (and non-volatile) media, removable (and non-removable) media. Computer-readable media may include computer storage media and communication media. Computer storage media include volatile (and non-volatile) and removable (and non-removable) media implemented in any method or technology for storing information such as computer-readable instructions.

[0324] Computer storage media may include RAM, ROM, EPROM, EEPROM, flash memory (or other storage technology), CD-ROM, Digital Versatile Disk (DVD) (or other optical disk storage), cassettes, magnetic tapes, disk storage (or other magnetic storage devices), etc. Computer storage media do not include propagated data signals. Communication media can generally contain computer readable instructions, data structures, process modules or other data in a modulated data signal such as a carrier wave or other transport mechanism, and include any information delivery media. The term "modulated data signal" may represent a signal whose one or more characteristics are set or changed in a manner that encodes the information in the signal. Communication media may include wired media such as a wired network or a direct wired connection, and wireless media such as acoustic, RF, infrared or other wireless media. Any combination of the disclosed media should also be included in the scope of computer readable media.

[0325] The memory 528 may include computer storage media in the form of volatile and / or non-volatile memory. The memory 528 may be removable, non-removable, or a combination thereof. For example, the memory 528 may include a solid-state memory, a hard drive, an optical drive, etc. Figure 5 As shown, the memory 528 may store computer-readable and / or computer-executable instructions 532 (e.g., software code) that are configured to cause the processor 526 (e.g., processing circuit) to perform various disclosed functions when executed. Alternatively, the instructions 532 may not be directly executable by the processor 526, but may be configured to cause the node 500 (e.g., when compiled and executed) to perform various disclosed functions.

[0326] The processor 526 may include an intelligent hardware device, a central processing unit (CPU), a microcontroller, an ASIC, etc. The processor 526 may include a memory. The processor 526 may process data 530 and instructions 532 received from the memory 528, as well as information through the transceiver 520, the baseband communication module, and / or the network communication module. The processor 526 may also process information to be transmitted to the transceiver 520 to be transmitted to the network communication module via the antenna 536 to be transmitted to the CN.

[0327] One or more presentation components 534 can present data to a person or other device. Presentation component 534 may include a display device, a speaker, a printing component, a vibration component, etc.

[0328] It is apparent from this disclosure that various techniques may be used to implement the concepts of this disclosure without departing from the scope of these concepts. Although these concepts have been described with specific reference to certain embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the scope of these concepts. Therefore, this disclosure will be considered illustrative and not restrictive in all respects. It should be understood that the present application is not limited to the specific embodiments disclosed, and it is possible to rearrange, modify, and replace these embodiments without departing from the scope of this disclosure.

Claims

1. A method for a listen-before-talk (LBT) recovery process for a user equipment (UE), the method comprising: Perform LBT fault detection process for the serving cell; In response to detecting a continuous uplink ULLBT failure in a first bandwidth part BWP through the LBT failure detection process, triggering an LBT recovery process for the first BWP of the serving cell, wherein the triggered LBT recovery process includes triggering an LBT failure process, wherein the LBT failure process is used to determine the first BWP as an invalid BWP; as well as in response to confirming a predefined condition in the UE, cancelling the triggered LBT recovery procedure of the first BWP on the serving cell, The LBT recovery process also includes: In the case where the serving cell is a special cell SpCell, transmitting an LBT failure media access control MAC control element CE indicating that the LBT failure procedure for the serving cell is triggered to a network on the serving cell; In the case where the serving cell is a secondary cell SCell, the LBT failure MAC CE is transmitted to a network on another serving cell, and no LBT failure process is triggered on the other serving cell; In a case where the serving cell is the SpCell, in response to no LBT failure procedure being triggered for a second BWP, switching from the first BWP of the serving cell to the second BWP, the second BWP being configured with a physical random access channel PRACH resource; and In a case where the serving cell is the SpCell, a random access procedure is initiated on the second BWP of the serving cell.

2. The method according to claim 1, characterized in that The predefined condition includes one of the following: A physical downlink control channel PDCCH is received by the UE, the PDCCH instructing the UE to perform BWP switching on the serving cell; The PDCCH is received by the UE, the PDCCH indicating that the UE performs the BWP switching on the serving cell, and the UE does not perform a second random access procedure on the serving cell; A radio resource control (RRC) configuration or reconfiguration message is received by the UE, wherein the RRC configuration or reconfiguration message configures or reconfigures the BWP switching on the serving cell; A MAC reset for a MAC entity corresponding to the serving cell is performed by the UE; The serving cell is deactivated or activated; A random access procedure for the LBT recovery procedure on the serving cell is performed by the UE, and the random access procedure is successfully completed on the serving cell; as well as The LBT failure MAC CE is transmitted by the UE, and the LBT failure MAC CE indicates at least one cell that triggers the LBT recovery process, and the at least one cell includes the serving cell that triggers the LBT recovery process.

3. The method according to claim 1, further comprising: In response to the cancellation of the triggered LBT recovery procedure, resetting the LBT counter corresponding to the serving cell; as well as When an LBT failure is detected on the serving cell through the LBT failure detection procedure, the UE increases the LBT counter.

4. The method according to claim 3, characterized in that Resetting the LBT counter includes setting the LBT counter to 0 when the triggered LBT recovery process is canceled.

5. The method according to claim 1, characterized in that: The serving cell is the SpCell including at least one of a primary cell PCell or a primary-secondary cell group cell PSCell, or the serving cell is the SCell.

6. A user equipment UE for performing a listen-before-speak (LBT) recovery process, the UE comprising: a processor configured to execute computer executable instructions; as well as A non-transitory computer readable medium coupled to the processor to store computer executable instructions, wherein the computer executable instructions instruct the processor to: Perform LBT fault detection process for the serving cell; In response to detecting a continuous uplink ULLBT failure in a first bandwidth part BWP through the LBT failure detection process, triggering an LBT recovery process for the first BWP of the serving cell, wherein the triggered LBT recovery process includes triggering an LBT failure process, wherein the LBT failure process is used to determine the first BWP as an invalid BWP; as well as in response to confirming a predefined condition in the UE, cancelling the triggered LBT recovery procedure of the first BWP on the serving cell, The LBT recovery process also includes: In the case where the serving cell is a special cell SpCell, transmitting an LBT failure media access control MAC control element CE indicating that the LBT failure procedure for the serving cell is triggered to a network on the serving cell; In the case where the serving cell is a secondary cell SCell, the LBT failure MAC CE is transmitted to a network on another serving cell, and no LBT failure process is triggered on the other serving cell; In a case where the serving cell is the SpCell, in response to no LBT failure procedure being triggered for a second BWP, switching from the first BWP of the serving cell to the second BWP, the second BWP being configured with a physical random access channel PRACH resource; and In a case where the serving cell is the SpCell, a random access procedure is initiated on the second BWP of the serving cell.

7. The UE according to claim 6, characterized in that The predefined condition includes one of the following: A physical downlink control channel PDCCH is received by the UE, the PDCCH instructing the UE to perform BWP switching on the serving cell; The PDCCH is received by the UE, the PDCCH indicating that the UE performs the BWP switching on the serving cell, and the UE does not perform a second random access procedure on the serving cell; A radio resource control (RRC) configuration or reconfiguration message is received by the UE, wherein the RRC configuration or reconfiguration message configures or reconfigures the BWP switching on the serving cell; A MAC reset for a MAC entity corresponding to the serving cell is performed by the UE; The serving cell is deactivated or activated; A random access procedure for the LBT recovery procedure on the serving cell is performed by the UE, and the random access procedure is successfully completed on the serving cell; as well as The LBT failure MAC CE is transmitted by the UE, and the LBT failure MAC CE indicates at least one cell that triggers the LBT recovery process, and the at least one cell includes the serving cell that triggers the LBT recovery process.

8. The UE of claim 6, wherein the computer executable instructions further instruct the processor to: In response to the cancellation of the triggered LBT recovery procedure, resetting the LBT counter corresponding to the serving cell; and When an LBT failure is detected on the serving cell through the LBT failure detection procedure, the UE increases the LBT counter.

9. The UE according to claim 8, characterized in that When the triggered LBT recovery process is canceled, resetting the LBT counter includes setting the LBT counter to 0.

10. The UE according to claim 6, characterized in that: The serving cell is the SpCell including at least one of a primary cell PCell or a primary-secondary cell group cell PSCell, or the serving cell is the SCell.

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