Method and apparatus for beam failure recovery configuration in a wireless communication system

Abstract

A User Equipment (UE) for performing a Beam Failure Recovery (BFR) procedure is provided. The UE includes at least one processor and at least one non-transitory computer-readable medium storing instructions that, when executed, cause the UE to receive a first Beam Failure Detection Reference Signal (BFD-RS) set associated with a first Synchronization Signal Block (SSB) and a second BFD-RS set associated with a second SSB for a serving cell. The UE receives a BFR configuration, including a first BFR-related parameter associated with the first SSB, for the serving cell. In response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, the UE determines that the second BFR-related parameter is associated with the second SSB; otherwise, the UE determines that the first BFR-related parameter is associated with both the first and second SSBs. In addition, a method and a BS are also provided.

Description

METHOD AND APPARATUS FOR BEAM FAILURE RECOVERY CONFIGURATION IN A WIRELESS COMMUNICATION SYSTEM

[0001] The present disclosure is related to wireless communication and, more specifically, to a User Equipment (UE), a Base Station (BS), and a method for beam failure recovery configuration in a wireless communication system.

[0002] Various efforts have been made to improve different aspects of wireless communication for the cellular wireless communication systems, such as the 5thGeneration (5G) New Radio (NR), by improving data rate, latency, reliability, and mobility. The 5G NR system is designed to provide flexibility and configurability to optimize network services and types, accommodating various use cases, such as enhanced Mobile Broadband (eMBB), massive Machine-Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC). As the demand for radio access continues to grow, however, there exists a need for further improvements in the next-generation wireless communication systems, such as improvements in a beam management procedure.Summery of Invention

[0003] The present disclosure is directed to a User Equipment (UE), a Base Station (BS), and a method for beam failure recovery configuration in a wireless communication system.

[0004] According to a first aspect of the present disclosure, a User Equipment (UE) for performing a Beam Failure Recovery (BFR) procedure in a wireless communication system is provided, the UE including at least one processor and at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the UE to receive, from a Base Station (BS), a first Beam Failure Detection Reference Signal (BFD-RS) set associated with a first Synchronization Signal Block (SSB) and a second BFD-RS set associated with a second SSB, for a serving cell; receive, from the BS, a BFR configuration for the serving cell, the BFR configuration including a first BFR-related parameter associated with the first SSB; in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determine that the second BFR-related parameter is associated with the second SSB; and in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determine that the first BFR-related parameter is associated with both the first SSB and the second SSB.

[0005] In some implementations of the first aspect of the present disclosure, the first BFR-related parameter includes a first Reference Signal Received Power (RSRP) threshold, and the second BFR-related parameter includes a second RSRP threshold.

[0006] In some implementations of the first aspect of the present disclosure, the first BFR-related parameter includes a first candidate beam list, and the second BFR-related parameter includes a second candidate beam list.

[0007] In some implementations of the first aspect of the first aspect of the present disclosure, a third candidate beam list associated with the first SSB is further configured in the BFR configuration, and the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: in response to the second candidate beam list associated with the second SSB is not configured in the BFR configuration, determine that the third candidate beam list is associated with both the first SSB and the second SSB.

[0008] In some implementations of the first aspect of the present disclosure, the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: determine whether the second SSB is activated or deactivated; in response to determining that the second SSB is activated, determine that the second SSB is transmitted on the serving cell; and in response to determining that the second SSB is deactivated, determine that the second SSB is not transmitted on the serving cell.

[0009] According to a second aspect of the present disclosure, a BS is provided, the BS including at least one processor and at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the BS to: transmit, to a UE, a first BFD-RS set associated with a first SSB and a second BFD-RS set associated with a second SSB, for a serving cell of the UE; and transmit, to the UE, a BFR configuration for the serving cell, the BFR configuration including a first BFR-related parameter associated with the first SSB, where the BFR configuration causes the UE to: in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determine that the second BFR-related parameter is associated with the second SSB; and in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determine that the first BFR-related parameter is associated with both the first SSB and the second SSB.

[0010] In some implementations of the second aspect of the present disclosure, the first BFR-related parameter includes a first RSRP threshold, and the second BFR-related parameter includes a second RSRP threshold.

[0011] In some implementations of the second aspect of the present disclosure, the first BFR-related parameter includes a first candidate beam list, and the second BFR-related parameter includes a second candidate beam list.

[0012] In some implementations of the second aspect of the present disclosure, a third candidate beam list associated with the first SSB is further configured in the BFR configuration, and the BFR configuration further causes the UE to: in response to the second candidate beam list associated with the second SSB is not configured in the BFR configuration, determine that the third candidate beam list is associated with both the first SSB and the second SSB.

[0013] In some implementations of the second aspect of the present disclosure, the BFR configuration further causes the UE to: determine whether the second SSB is activated or deactivated; in response to determining that the second SSB is activated, determine that the second SSB is transmitted on the serving cell; and in response to determining that the second SSB is deactivated, determine that the second SSB is not transmitted on the serving cell.

[0014] According to a third aspect of the present disclosure, a method performed by a UE for performing a BFR procedure in a wireless communication system is provided, the method including: receiving, from a BS, a first BFD-RS set associated with a first SSB and a second BFD-RS set associated with a second SSB, for a serving cell; receiving, from the BS, a BFR configuration for the serving cell, the BFR configuration including a first BFR-related parameter associated with the first SSB; in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determining that the second BFR-related parameter is associated with the second SSB; and in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determining that the first BFR-related parameter is associated with both the first SSB and the second SSB.

[0015] Aspects of the present disclosure are best understood from the following detailed disclosure and the corresponding figures. Various features are not drawn to scale and dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.

[0016] FIG. 1 is a schematic diagram illustrating Beam Failure Detection-Reference Signal (BFD-RS) set configuration(s) that refers to an On-Demand Synchronized Signal Block (OD-SSB), according to an example implementation of the present disclosure.

[0017] FIG. 2 is a schematic diagram illustrating configuration(s) for OD-SSB enabled Beam Failure Recovery (BFR), according to an example implementation of the present disclosure.

[0018] FIG. 3 is a schematic diagram illustrating a New-Type-1 BFR Medium Access Control (MAC) Control Element (CE), according to an example implementation of the present disclosure.

[0019] FIG. 4 is a schematic diagram illustrating a New-Type-2 BFR MAC CE, according to an example implementation of the present disclosure.

[0020] FIG. 5 is a schematic diagram illustrating a New-Type-2 BFR MAC CE, according to an example implementation of the present disclosure.

[0021] FIG. 6 is a flowchart illustrating a method / process performed by a User Equipment (UE) for performing a BFR procedure, according to an example implementation of the present disclosure.

[0022] FIG. 7 is a block diagram illustrating a node for wireless communication, according to an example implementation of the present disclosure.

[0023] Some of the abbreviations used in the present disclosure include: Abbreviation　　　　Full name 3GPP　　　　　　　　3rd Generation Partnership Project AP 　　　　　　　　Aperiodic BFD　　　　　　　　Beam Failure Detection BFR　　　　　　　　Beam Failure Recovery BWP 　　　　　　　　Bandwidth part CA　　　　　　　　Carrier Aggregation CC　　　　　　　　Component Carrier CD-SSB 　　　　Cell Defining SSB CE 　　　　　　　　Control Element CS-RNTI　　　　Configured Scheduling Radio Network Temporary Identifier C-RNTI　　　　Cell Radio Network Temporary Identifier CSI　　　　　　　　Channel State Information CSI-RS 　　　　Channel state information reference signal CSI-RSRP 　　　　CSI reference signal received power CSI-RSRQ 　　　　CSI reference signal received quality CSI-SINR 　　　　CSI signal-to-noise and interference ratio CQI 　　　　　　　　Channel quality indicator DC　　　　　　　　Dual Connectivity DCI　　　　　　　　Downlink Control Information DL　　　　　　　　Downlink DRX 　　　　　　　　Discontinuous Reception gNB　　　　　　　　Next Generation Node B HARQ　　　　　　　　Hybrid Automatic Repeat Request IE　　　　　　　　Information element L1　　　　　　　　Layer 1 L1-RSRP 　　　　Layer 1 reference signal received power L2　　　　　　　　Layer 2 L3　　　　　　　　Layer 3 LTM 　　　　　　　　L1 / L2 Triggered Mobility MAC　　　　　　　　Medium Access Control (N)ES　　　　　　　　(Network) Energy Saving NR　　　　　　　　New Radio PCell　　　　　　　　Primary Cell PDCCH　　　　Physical Downlink Control Channel PDU　　　　　　　　Protocol Data Unit PDSCH　　　　Physical Downlink Shared Channel PHY　　　　　　　　Physical (layer) PUCCH 　　　　Physical uplink control channel QCL 　　　　　　　　Quasi co-location RLC　　　　　　　　Radio Link Control RRC　　　　　　　　Radio Resource Control RS　　　　　　　　Reference Signal SCell　　　　　　　　Secondary Cell SCS　　　　　　　　SubCarrier Spacing SDU　　　　　　　　Service Data Unit SFN 　　　　　　　　System Frame Number SN　　　　　　　　Sequence Number SpCell　　　　　　　　Special Cell SPS　　　　　　　　Semi-Persistent Scheduling SP 　　　　　　　　Semi-Persistent SP-CSI-RNTI 　　　　Semi-Persistent CSI RNTI SSB　　　　　　　　Synchronization Signal Block TA 　　　　　　　　Timing Advance TS　　　　　　　　Technical Specification UE　　　　　　　　User Equipment UL　　　　　　　　Uplink

[0024] The following contains specific information related to implementations of the present disclosure. The drawings and their accompanying detailed disclosure are merely directed to implementations. However, the present disclosure is not limited to these implementations. Other variations and implementations of the present disclosure will be obvious to those skilled in the art.

[0025] Unless noted otherwise, like or corresponding elements among the drawings may be indicated by like or corresponding reference numerals. Moreover, the drawings and illustrations in the present disclosure are generally not to scale and are not intended to correspond to actual relative dimensions.

[0026] For the purposes of consistency and ease of understanding, like features may be identified (although, in some examples, not illustrated) by the same numerals in the drawings. However, the features in different implementations may be different in other respects and may not be narrowly confined to what is illustrated in the drawings.

[0027] References to “one implementation,” “an implementation,” “example implementation,” “various implementations,” “some implementations,” “implementations of the present application,” etc., may indicate that the implementation(s) of the present application so described may include a particular feature, structure, or characteristic, but not every possible implementation of the present application necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase “In some implementations,” or “in an example implementation,” “an implementation,” do not necessarily refer to the same implementation, although they may. Moreover, any use of phrases like “implementations” in connection with “the present application” are never meant to characterize that all implementations of the present application must include the particular feature, structure, or characteristic, and should instead be understood to mean “at least some implementations of the present application” includes the stated particular feature, structure, or characteristic. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The term “comprising,” when utilized, means “including, but not necessarily limited to”; the term specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the equivalent.

[0028] The expression “at least one of A, B and C” or “at least one of the following: A, B and C” means “only A, or only B, or only C, or any combination of A, B and C.” The terms “system” and “network” may be used interchangeably. The term “and / or” is only an association relationship for describing associated objects and represents that three relationships may exist such that A and / or B may indicate that A exists alone, A and B exist at the same time, or B exists alone. The character “ / ” generally represents that the associated objects are in an “or” relationship.

[0029] For the purposes of explanation and non-limitation, specific details, such as functional entities, techniques, protocols, and standards, are set forth for providing an understanding of the disclosed technology. In other examples, detailed disclosure of well-known methods, technologies, systems, and architectures are omitted so as not to obscure the present disclosure with unnecessary details.

[0030] Persons skilled in the art will immediately recognize that any network function(s) or algorithm(s) disclosed may be implemented by hardware, software, or a combination of software and hardware. Disclosed functions may correspond to modules which may be software, hardware, firmware, or any combination thereof.

[0031] A software implementation may include computer executable instructions stored on a computer-readable medium, such as memory or other type of storage devices. One or more microprocessors or general-purpose computers with communication processing capability may be programmed with corresponding executable instructions and perform the disclosed network function(s) or algorithm(s).

[0032] The microprocessors or general-purpose computers may include Application-Specific Integrated Circuits (ASICs), programmable logic arrays, and / or one or more Digital Signal Processor (DSPs). Although some of the disclosed implementations are oriented to software installed and executing on computer hardware, alternative implementations implemented as firmware, as hardware, or as a combination of hardware and software are well within the scope of the present disclosure. The computer-readable medium includes but is 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), magnetic cassettes, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-readable instructions.

[0033] A radio communication network architecture such as a Long-Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, or a 5G NR Radio Access Network (RAN) typically includes at least one base station (BS), at least one User Equipment (UE), and one or more optional network elements that provide connection within a network. The UE communicates with the network such as a Core Network (CN), an Evolved Packet Core (EPC) network, an Evolved Universal Terrestrial RAN (E-UTRAN), a 5G Core (5GC), or an internet via a RAN established by one or more BSs.

[0034] A UE may include, but is not limited to, a mobile station, a mobile terminal or device, or a user communication radio terminal. The UE may be a portable radio equipment that includes, but is not limited to, a mobile phone, a tablet, a wearable device, a sensor, a vehicle, or a Personal Digital Assistant (PDA) with wireless communication capability. The UE is configured to receive and transmit signals over an air interface to one or more cells in a RAN.

[0035] The BS may be configured to provide communication services according to at least a Radio Access Technology (RAT) such as Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM) that is often referred to as 2G, GSM Enhanced Data rates for GSM Evolution (EDGE) RAN (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS) that is often 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) that is LTE connected to 5GC, NR (often referred to as 5G), and / or LTE-A Pro. However, the scope of the present disclosure is not limited to these protocols.

[0036] The BS may include, but is not limited to, a node B (NB) in the UMTS, an evolved node B (eNB) in LTE or LTE-A, a radio network controller (RNC) in UMTS, a BS controller (BSC) in the GSM / GERAN, an ng-eNB in an Evolved Universal Terrestrial Radio Access (E-UTRA) BS in connection with 5GC, a next generation Node B (gNB) in the 5G-RAN, or any other apparatus capable of controlling radio communication and managing radio resources within a cell. The BS may serve one or more UEs via a radio interface. Although the gNB is used as an example in some implementations within the present disclosure, it should be noted that the disclosed implementations may also be applied to other types of base stations.

[0037] The BS may be operable to provide radio coverage to a specific geographical area using multiple cells forming the RAN. The BS may support the operations of the cells. Each cell may be operable to provide services to at least one UE within its radio coverage.

[0038] Each cell (may often referred to as a serving cell) may provide services to one or more UEs within the cell’s radio coverage, such that each cell schedules the DL (and optionally UL resources) to at least one UE within its radio coverage for DL (and optionally UL packet transmissions from the UE). The BS may communicate with one or more UEs in the radio communication system via the cells.

[0039] A cell may allocate sidelink (SL) resources for supporting the Proximity Services (ProSe) or Vehicle to Everything (V2X) services. Each cell may have overlapped coverage areas with other cells.

[0040] In Multi-RAT Dual Connectivity (MR-DC) cases, the primary cell of a Master Cell Group (MCG) or a Secondary Cell Group (SCG) may be referred to as a Special Cell (SpCell). A Primary Cell (PCell) may include the SpCell of an MCG. A Primary SCG Cell (PSCell) may include the SpCell of an SCG. MCG may include a group of serving cells associated with the Master Node (MN), including the SpCell and optionally one or more Secondary Cells (SCells). An SCG may include a group of serving cells associated with the Secondary Node (SN), including the SpCell and optionally one or more SCells.

[0041] As discussed above, the frame structure for NR may support flexible configurations for accommodating various next generation (e.g., 5G) communication requirements, such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC), while fulfilling high reliability, high data rate, and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology in the 3GPP may serve as a baseline for an NR waveform. The scalable OFDM numerology, such as adaptive sub-carrier spacing, channel bandwidth, and Cyclic Prefix (CP), may also be used.

[0042] Two coding schemes may be considered for NR, specifically, Low-Density Parity-Check (LDPC) code and Polar Code. The coding scheme adaption may be configured based on channel conditions and / or service applications.

[0043] At least the DL transmission data, a guard period, and UL transmission data should be included in a transmission time interval (TTI) of a single NR frame. The respective portions of the DL transmission data, the guard period, and the UL transmission data should also be configurable based on, for example, the network dynamics of NR. SL resources may also be provided in an NR frame to support ProSe services or V2X services.

[0044] Any two or more than two of the following sentences, paragraphs, (sub)-bullets, points, actions, behaviors, terms, alternatives, aspects, examples, implementations, or claims described in the present disclosure may be combined logically, reasonably, and properly to form a specific method.

[0045] Any sentence, paragraph, (sub)-bullet, point, action, behaviors, terms, alternatives, aspects, examples, or claims described in the present disclosure may be implemented independently and separately to form a specific method.

[0046] Dependency, e.g., “based on”, “more specifically”, “preferably”, “in one embodiment”, “in one alternative”, “in one example”, “in one aspect”, “in some implementations”, etc., in the present disclosure is just one possible example which would not restrict the specific method.

[0047] In some implementations, all the designs / embodiment / implementations introduced within this disclosure are not limited to be applied for dealing with the problems discussed within this disclosure. For example, the described embodiments may be applied to solve other problems that exist in the RAN of wireless communication systems. In some implementations, all of the numbers listed within the designs / embodiment / implementations introduced within this disclosure are just examples and for illustration, for example, of how the described methods are executed.

[0048] In some implementations, “a specific configuration is per UE configured” or “a specific configuration is configured for a UE” described in the present disclosure may be represented as the specific configuration, but which is not limited to be configured within a downlink Radio Resource Control (RRC) message.

[0049] In some implementations, “a specific configuration is per cell group configured” or “a specific configuration is configured for a cell group” described in the present disclosure may be represented as the specific configuration, but which is not limited to be configured within a CellGroupConfig or MAC-CellGroupConfig or PhysicalCellGroupConfig IE.

[0050] In some implementations, “a specific configuration is per serving cell configured” or “a specific configuration is configured for a serving cell” described in the present disclosure may be represented as the specific configuration, but which is not limited to be configured within a ServingCellConfigCommon or ServingCellConfig or PUSCH-ServingCellConfig or PDSCH-ServingCellConfig IE.

[0051] In some implementations, “a specific configuration is per UL Bandwidth Part (BWP) or per BWP configured” or “a specific configuration is configured for a UL BWP or for a BWP” described in the present disclosure may be represented as the specific configuration, but which is not limited to be configured within a BWP-Uplink or BWP-UplinkDedicated or BWP-UplinkCommon or PUSCH-ConfigCommon or PUSCH-Config IE.

[0052] In some implementations, “a specific configuration is per DL BWP or per BWP configured” or “a specific configuration is configured for a DL BWP or for a BWP” described in the present disclosure may be represented as the specific configuration, but which is not limited to be configured within a BWP-Downlink or BWP-DownlinkDedicated or BWP-DownlinkCommon or PDSCH-ConfigCommon or PDSCH-Config IE.

[0053] In some implementations, the term “transmitted” used in all implementations may be defined as when a corresponding Medium Access Control (MAC) Control Element (CE) / MAC Packet Data Unit (PDU) / Layer 1 (L1) signaling / higher layer signaling is started to be transmitted, completely transmitted, or already delivered to the corresponding Hybrid Automatic Repeat Request (HARQ) process / buffer for transmission. In some implementations, the term “transmitted” may also be defined as when the HARQ-ACK feedback (e.g., response from the gNB) of the MAC PDU carrying the MAC CE / MAC PDU / L1 signaling / higher layer signaling is received. In some implementations, the term “transmitted” may also be defined as when the corresponding MAC CE / MAC PDU is built.

[0054] In some implementations, the “HARQ-ACK feedback” may be implemented as a Downlink Control Information (DCI) format 0_0, 0_1, or some other format of DCI received by the UE from the gNB on the Physical Downlink Control Channel (PDCCH). The received DCI may include a New Data Indicator (NDI) which is set to a specific value (e.g., set to 1), and the DCI may also indicate a HARQ process ID which is the same as the HARQ process ID applied by or indicated to be used for the HARQ process of the MAC PDU (e.g., carrying the Beam Failure Recovery Request (BFRQ) MAC CE) transmission.

[0055] The PDCCH may be transmitted by the gNB to the UE. In other words, the PDCCH may be received by the UE from the gNB. The Physical Downlink Shared Channel (PDSCH) may be transmitted by the gNB to the UE. In other words, the PDSCH may be received by the UE from the gNB. The Physical Uplink Shared Channel (PUSCH) may be transmitted by the UE to the gNB. In other words, the Physical Uplink Control Channel (PUCCH) may be received by the gNB from the UE.

[0056] A PDSCH / PDSCH / PUSCH transmission may span multiple of symbols in time domain. A time duration of a PDSCH / PDSCH / PUSCH (transmission) may imply a time interval that starts from the beginning of the first symbol of the PDSCH / PDSCH / PUSCH (transmission) and ends at the end of the last symbol of the PDSCH / PDSCH / PUSCH (transmission).

[0057] In the present disclosure, “by specific Physical layer signaling” may be “by a specific format of DCI,” “by a specific field of a DCI,” “by (a) specific field(s) of a DCI, and the field(s) is / are set to (a) specific value(s),” or “by a DCI with Cyclic Redundancy Check (CRC) bits scrambled with a specific Radio Network Temporary Identifier (RNTI)”.

[0058] In the present disclosure, “a timer” may be configured by RRC which is indicated by the gNB. The UE may be configured with an initial value of the timer and the unit of the value may be frame / sub-frame / milli second / sub-milli second / slot / symbol. The timer may be started and / or restarted by the UE. The timer may be started and / or restarted by the UE when some specific condition is satisfied.

[0059] Examples of some selected terms in the present disclosure are provided as follows.

[0060] Cell: A radio network object that may be uniquely identified by a UE from a (cell) identification that is broadcasted over a geographical area from one Universal Terrestrial Radio Access Network (UTRAN) Access Point. A Cell may be either Frequency Division Duplex (FDD) or Time Division Duplex (TDD) mode.

[0061] Dedicated Signalling: Signalling sent on the Dedicated Control Channel (DCCH) logical channel between the network and a single UE.

[0062] Field: The individual contents of an Information Element (IE) may be referred to as fields.

[0063] Information Element: A structural element containing single or multiple fields may be referred to as an IE.

[0064] PDCCH: In the downlink, the gNB may dynamically allocate resources to UEs at least via the Cell Radio Network Temporary Identifier (C-RNTI) / Modulation and Coding Scheme Cell Radio Network Temporary Identifier (MCS-C-RNTI) / Configured Scheduling Radio Network Temporary Identifier (CS-RNTI) on PDCCH. A UE may always monitor the PDCCH in order to find possible assignments when the UE’s downlink reception is enabled (activity governed by Discontinuous Reception (DRX) when configured). When Carrier Aggregation (CA) is configured, the same C-RNTI may apply to all serving cells.

[0065] PDSCH / PUSCH: The PDCCH may be used to schedule DL transmissions on PDSCH and UL transmissions on PUSCH.

[0066] Primary Cell (PCell): The Master Cell Group (MCG) cell, operating on the primary frequency, in which the UE either performs the initial connection establishment procedure or initiates the connection re-establishment procedure.

[0067] Secondary Cell (SCell): For a UE configured with CA, an SCell may provide additional radio resources on top of a Special Cell.

[0068] Serving Cell: For a UE in RRC Connected (RRC_CONNECTED) state not configured with CA or Dual Connectivity (DC), there may be only one serving cell including the Primary Cell. For a UE in RRC_CONNECTED state configured with CA or DC, the term “serving cells” may be used to denote the set of cells including the Special Cell(s) and all Secondary Cells.

[0069] Special Cell: For DC operation, the term Special Cell may refer to the PCell of the MCG or the Primary Secondary Cell (PSCell) of the SCG. Otherwise, the term Special Cell may refer to the PCell.

[0070] SSB Frequency: A frequency referring to the position of Resource Element (RE) #0 (subcarrier #0) of Resource Block (RB) #10 of the Synchronization Signal (SS) block.

[0071] Timer: RRC / Packet Data Convergence Protocol (PDCP) / Radio Link Control (RLC) / MAC entity may set up one or more Timers for individual purposes, for example, triggering some UL signalling retransmission or limiting some UL signalling retransmission period. A Timer may be running once the Timer is started, until the Timer is stopped or until the Timer expires; otherwise, the Timer may be not running. A Timer may be started if the Timer is not running or may be restarted if the Timer is running. A Timer may be always started or restarted from the Timer’s initial value. The initial value may be, but is not limited to be, configured by the gNB via DL RRC signalling or may be a pre-defined or pre-determined value addressed in some specification.

[0072] Network energy saving is of great importance for environmental sustainability, to reduce environmental impact (e.g., greenhouse gas emissions), and for operational cost savings. As 5G is becoming pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates (e.g., XR), networks may be denser, use more antennas, larger bandwidths, and more frequency bands. The environmental impact of 5G may need to stay under control, and novel solutions to improve network energy savings may need to be developed.

[0073] The 3GPP Release 18 (Rel-18) work on network energy savings for NR led to the specification of some of the techniques that were found beneficial, primarily for RRC_CONNECTED, user specific signals and channels, and low load scenarios. The techniques specified in Rel-18 include SSB-less SCell operation for inter-band CA for Frequency Range 1 (FR1) and co-located cells. Enhancements were also made to the cell DTX / DRX mechanism, including the alignment of cell DTX / DRX and UE DRX in RRC_CONNECTED mode, and inter-node information exchange on cell DTX / DRX. Rel-18 further provided techniques in spatial and power domains to enable efficient adaptation of spatial elements as well as efficient adaptation of power offset values between PDSCH and CSI-RS. Additional mechanisms were specified to prevent legacy UEs from camping on cells adopting the Rel-18 NES techniques. Conditional Handover (CHO) procedure enhancement(s) were included, along with inter-node beam activation and enhancements on restricting paging in a limited area. The corresponding Radio Resource Management (RRM) / Radio Frequency (RF) core requirements were also defined.

[0074] Moreover, longer periods of cell inactivity (e.g., without SSB transmission) may achieve network energy saving. In other words, SSB on a cell may be transmitted in an on-demand manner. Hence, in 3GPP Release 19 (Rel-19), one of objectives is to specify procedures and signaling method(s) to support on-demand SSB (OD-SSB) SCell operation for UEs in connected mode configured with CA, for both intra- / inter-band CA. More specifically, the potential support for OD-SSB-based Beam Failure Detection (BFD) and Beam Failure Recovery (BFR) are discussed. In the present disclosure, configurations of reference signals for BFD and the related BFD / BFR procedure will be described.

[0075] To enable On-Demand Synchronization Signal Block (OD-SSB) based Beam Failure Detection (BFD) and Beam Failure Recovery (BFR), the following aspects may be addressed. In some implementations, the present disclosure may describe how a network (NW) configures a BFD Reference Signal (BFD-RS) set containing the OD-SSB. In some implementations, the BFD procedure and the BFR procedure may be addressed when both a BFD-RS set containing an Always-On SSB (AO-SSB) and a BFD-RS set containing the OD-SSB are configured for a serving cell. In some implementations, the BFD operation and the BFR operation may be addressed when an OD-SSB configuration or an OD-SSB status changes. In some implementations, a new BFR MAC Control Element (MAC CE) format for the OD-SSB based BFD and the OD-SSB based BFR may be introduced.

[0076] SSB configuration

[0077] In some implementations, once a cell (e.g., PCell or SCell) is configured, the network may configure the UE with one or more SSB-related parameters used / applied for the cell, where the parameters may specify how the cell transmits the SSB transmission in a specific pattern. Consequently, the UE may try to perform an SSB based (e.g., L1 / L3) measurement according to the pattern and report the corresponding measurement result(s) to the network. The SSB related parameters may be included in a cell configuration (e.g., SCellConfig IE).

[0078] In some implementations, the SSB related parameters may include at least one of the following parameters: 　　　　- physCellId: The physical cell identity of the cell at which the SSB is being transmitted. 　　　　- absoluteFrequencySSB: Frequency of the SSB to be used for this serving cell (e.g., ARFCN value). 　　　　- ssb-PositionsInBurst: Indication of the time domain positions of the transmitted SSBs (e.g., SSB burst / set) in a half frame with SSBs. The first / leftmost bit may correspond to SSB index 0, the second bit may correspond to SSB index 1, and so on. Value 0 in the bitmap may indicate that the corresponding SSB is not transmitted while value 1 may indicate that the corresponding SSB is transmitted. This field may be absent when absoluteFrequencySSB is absent, otherwise the field is mandatory present. 　　　　- ssbSubcarrierSpacing: Subcarrier spacing of SSB. 　　　　- ssb-periodicityServingCell: The SSB periodicity in millisecond (ms). If the field is absent, the UE applies the value ms5 (e.g., 5 ms).

[0079] For example, the SSB related parameters provided in the SCellConfig IE may include: 　　　　- ServingCellConfigCommon; 　　　　　　　　- DLConfigCommon; 　　　　　　　　　　　　- frequencyInfoDL; 　　　　　　　　　　　　　　　　- absoluteFrequencySSB; 　　　　　　　　- ssb-PositionsInBurst; 　　　　　　　　- ssbSubcarrierSpacing; 　　　　　　　　- ssb-periodicityServingCell.

[0080] For example, the ssb-PositionsInBurst may be represented as below. ssb-PositionsInBurst CHOICE { 　　　　shortBitmap BIT STRING (SIZE (4)), 　　　　mediumBitmap BIT STRING (SIZE (8)), 　　　　longBitmap BIT STRING (SIZE (64)) }

[0081] When the SSB related parameters above are configured for specifying a SSB pattern for a cell, the UE may assume (e.g., determine) SSB is always transmitted on the cell in the SSB pattern, where this type of SSB may be referred to as Always-On SSB (AO-SSB).

[0082] In some implementations, the UE may be configured with a separate set of SSB related parameters above for specifying a specific SSB transmission pattern for a cell. The UE may assume SSB is not always transmitted by the cell with the SSB pattern, and this type of SSB may be referred to as On-Demand SSB (OD-SSB). Specifically, when the SSB related parameters are configured for OD-SSB transmission for a cell, OD-SSB (transmission) may be activated / deactivated in a dynamic manner (e.g., indicated / pre-configured by the network). If OD-SSB (transmission) is activated, the UE may assume OD-SSB is transmitted by the cell with the specified SSB pattern. If OD-SSB (transmission) is deactivated, the UE may assume OD-SSB is not transmitted by the cell with the specified SSB pattern.

[0083] In some implementations, in addition to the SSB related parameters above, the UE may be further configured with at least one of the following parameters for OD-SSB on a cell: 　　　　- A list of SSB transmission periodicities. This IE may indicate multiple SSB periodicities for OD-SSB for a cell. The value may be 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or 160 ms. 　　　　- A field to indicate the initial SSB periodicity when OD-SSB is activated. 　　　　- Time domain location information (e.g., SFN, half frame index). 　　　　- Activation status of OD-SSB for a cell. This IE may indicate whether OD-SSB is activated upon reception of configuration of OD-SSB via RRC signaling. For example, if this field is configured / present upon reception of OD-SSB configuration, the UE may assume OD-SSB is activated; otherwise, the UE may assume OD-SSB is deactivated. 　　　　- NumberN: This IE may indicate the number N of OD-SSB bursts to be transmitted after OD-SSB is activated / indicated. After OD-SSB is transmitted N times, the UE may assume OD-SSB for the cell is deactivated. 　　　　- OD-SSB-activeTimer: The UE may start this timer once OD-SSB for the cell is indicated to be activated. The UE may assume OD-SSB bursts will be transmitted during the timer is running. Once the timer expires, the UE may assume OD-SSB for the cell is deactivated.

[0084] In some implementations, the parameters above for configuring OD-SSB for a cell may be configured within an OD-SSB dedicated configuration IE as the example shown below, where the IE may be included in a serving cell configuration. ServingCellConfig ::= SEQUENCE { 　　　　servingCellMO　　　　MeasObjectId　　　　OPTIONAL,　　　　-- Cond MeasObject 　　　　od-SSBConfig　　　　SSBConfig　　　　OPTIONAL } SSBConfig { 　　　　absoluteFrequencySSB　　　　ARFCN-ValueNR　　　　OPTIONAL, 　　　　ssbSubcarrierSpacing　　　　　　　　SubcarrierSpacing　　　　OPTIONAL 　　　　ssb-PositionsInBurst CHOICE { 　　　　　　　　shortBitmap　　　　　　　　BIT STRING (SIZE (4)), 　　　　　　　　mediumBitmap　　　　BIT STRING (SIZE (8)), 　　　　　　　　longBitmap　　　　　　　　BIT STRING (SIZE (64)) 　　　　}　　　　OPTIONAL, 　　　　ssb-periodicityServingCell　　　　ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160}　　　　OPTIONAL 　　　　ssb-periodicitiesList 　　　　initial-ssb-periodicity 　　　　OD-SSB-status　　　　　　　　{On} 　　　　NumberN　　　　　　　　　　　　{1, 2, ..., n} 　　　　OD-SSB-activeTimer }

[0085] For a cell supporting OD-SSB operation, depending on whether AO-SSB is configured, the cell may be identified as one of the following cases: 　　　　- Case 1: No AO-SSB is configured for the cell. In other words, only OD-SSB is configured for the cell. 　　　　- Case 2: AO-SSB is configured and periodically transmitted by the cell. In other words, both AO-SSB and OD-SSB are configured for the cell.

[0086] For Case 2 (e.g., when AO-SSB and OD-SSB are both configured), the SSB frequency location (e.g., configured by the absoluteFrequencySSB field) of OD-SSB may be the same as or different from the SSB frequency location of AO-SSB. Moreover, SSB indices (e.g., configured by the ssb-positionsInBurst field) for AO-SSB and SSB indices for OD-SSB may be the same or different.

[0087] In some implementations, when OD-SSB is configured with the same frequency as AO-SSB, the ssb-positionsInBurst field for OD-SSB may be the same as the ssb-positionsInBurst field configured (within the servingCellConfigCommon IE) for AO-SSB.

[0088] In some implementations, when OD-SSB is configured with the same frequency (e.g., subcarrier location) as AO-SSB, if the ssb-PositionsInBurst field for OD-SSB is absent, the UE may refer to the ssb-postionsInBurst field for AO-SSB to identify SSB indices for OD-SSB.

[0089] In some implementations, when OD-SSB is configured with the different frequency as AO-SSB, the ssb-positionsInBurst field for OD-SSB may be the same or different than the ssb-positionsInBurst field configured (e.g., within the servingCellConfigCommon IE) for AO-SSB. Moreover, if the ssb-PositionsInBurst field for OD-SSB is absent, the UE may refer to the ssb-postionsInBurst field for AO-SSB to identify SSB indices for OD-SSB.

[0090] In some implementations, AO-SSB adaptation may be introduced. Specifically, when a cell is configured with AO-SSB while OD-SSB is not configured by the cell, the UE may be further configured with one or more AO-SSB transmission periodicities. The UE may be indicated a change of AO-SSB transmission periodicity via L1 / L2 / L3 signaling (e.g., RRC / MAC CE / DCI). The signaling may indicate that one of the configured AO-SSB transmission periodicities is to be applied. In such a case, AO-SSB with periodicity adaptation may be referred to as OD-SSB, and all implementations for OD-SSB in the present disclosure may be applied to this scenario.

[0091] The network may configure OD-SSB for an SCell depending on different deployment scenarios, as shown in Table 1 below.

[0092] Case 1: No AO-SSB is configured for the cell, only OD-SSB is configured for the cell.

[0093] Case 2a: Both AO-SSB and OD-SSB are configured for the cell, and the AO-SSB and the OD-SSB are configured on different frequency. In addition, the AO-SSB and the OD-SSB may have the same or different SSB indices (e.g., beams).

[0094] Case 2b: Both AO-SSB and OD-SSB are configured for the cell. The AO-SSB and the OD-SSB are configured on the same frequency but may have different SSB indices (e.g., elements in ssbPositionsInBurst are different). This may allow having different transmitted beams between the OD-SSB and the AO-SSB. For example, the SSB indices of the OD-SSB may be a subset of the SSB indices of the AO-SSB.

[0095] Case 2c: Both AO-SSB and OD-SSB are configured for the cell. The AO-SSB and the OD-SSB are configured on the same frequency and may have the same SSB indices (e.g., elements in ssbPositionsInBurst are identical, if the AO-SSB and the OD-SSB are both configured the ssbPositionsInBurst IE). Moreover, the periodicities of the AO-SSB and the OD-SSB may be configured to be different.

[0096] OD-SSB (De)activation

[0097] When the UE is configured with OD-SSB for a cell, in addition to an RRC-based activation / deactivation (e.g., indicated by the activation status IE), the UE may be indicated that OD-SSB is activated / deactivated for the cell via L1 / L2 signaling, where the L1 / L2 signaling may be transmitted by a PCell, PSCell or a SCell. In some implementations, the UE may receive a MAC CE which indicates OD-SSB transmission is activated on one or more cell(s). The MAC CE may also indicate the NumberN IE and / or the OD-SSB transmission periodicity to be applied. Moreover, the MAC CE may indicate OD-SSB activation / deactivation status, the NumberN IE, and / or the applied SSB periodicity of multiple SCells.

[0098] In some implementations, the MAC CE may be transmitted only via a special cell and the MAC CE is an inter-cell / intra-cell signaling on a first serving cell to indicate the OD-SSB activation / deactivation of the first serving cell itself or another serving cell(s). In some implementations, the MAC CE which includes OD-SSB activation / deactivation status of MCG may be transmitted only via PCell or the serving cells belong to MCG. In addition, the MAC CE which includes OD-SSB activation / deactivation status of SCG may be transmitted only via PSCell or the serving cells belong to SCG.

[0099] Moreover, after OD-SSB is activated for a cell, the UE may be indicated OD-SSB is deactivated on the cell via L1 / L2 signaling, where the signaling may be RRC signaling, MAC CE, or DCI. In addition, when a SCell is deactivated, the UE may assume OD-SSB is deactivated on the SCell jointly with the deactivation of the SCell. The UE may assume a SCell is deactivated upon reception of the SCell activation / deactivation MAC CE or upon expiry of a SCell deactivation timer.

[0100] In some implementations, as described above, the UE may be configured with a specific timer (e.g., the OD-SSB-activeTimer parameter, denoted as TOD-SSB) for OD-SSB deactivation. When OD-SSB is activated, the UE may start / restart the timer. When the timer expires, the UE may assume OD-SSB is deactivated. The initial value of the timer may also be configured by the serving RAN via RRC signaling as part of OD-SSB configuration.

[0101] In some implementations, different OD-SSB patterns / numerologies may be associated with different values of the timer TOD-SSB.

[0102] In some implementations, all the configured OD-SSB patterns may be associated with a common value of the timer TOD-SSB.

[0103] In some implementations, the timer TOD-SSBmay be re-started if the associated OD-SSB patterns are re-configured.

[0104] In some implementations, the timer TOD-SSBmay be stopped / released with the deactivation / release of the associated operating cell / OD-SSB pattern.

[0105] Configuration for BFD / BFR

[0106] For a BFD procedure, the gNB may configure the UE with a BFD reference signal (BFD-RS) (e.g., an SSB or a CSI-RS). The UE may declare a beam failure when the number of beam failure instance indications from the physical layer reaches a configured threshold before a configured timer expires.

[0107] In some implementations, for the BFD in a multi-Transmission Reception Point (multi-TRP) operation, the gNB may configure the UE with two sets of the BFD-RSs. The UE may declare the beam failure for a TRP or a BFD-RS set when the number of the beam failure instance indications associated with the corresponding set of the BFD-RSs from the physical layer reaches the configured threshold before the configured timer expires.

[0108] More specifically, the UE may be configured with a set of BFD-related parameters per BWP so that the UE may perform a BFD / BFR procedure based on the BFD-RS set. The BFD-related parameters may include at least one of the following parameters (a) to (e).

[0109] (a) A list or a set of reference signals (the SSB and / or the CSI-RS) for the beam failure detection, which may be referred to as a BFD-RS set. For example, a set of periodic CSI-RS (or SSB) resource configuration indexes may be configured by the failureDetectionResourcesToAddModList IE or the bfdResourcesToAddModList IE. Unless stated otherwise, when the BFD-RS set includes SSB indexes, the BFD-RS set may refer to the AO-SSB. The UE may assume the BFD-RS set is associated with a list of the reference signals (the CSI-RS and / or the SSB) identifying the candidate beams for recovery.

[0110] (b) A BFD timer (e.g., the beamFailureDetectionTimer IE) for the beam failure detection. The timer may be configured per BFR-RD set (e.g., per BFD-RS set). The value may be configured in a number of the reporting periods of a Beam Failure Instance (BFI) in the PHY layer in the UE. The BFD timer defines a time window during which the beam failure instances are counted.

[0111] (c) A BFI maximum count (e.g., the beamFailureInstanceMaxCount IE) that determines after how many beam failure instances are received the UE triggers the beam failure recovery. This parameter may be configured per BFR-RD set.

[0112] (d) A list of reference signals (the CSI-RS and / or the SSB) identifying the candidate beams for recovery. For example, a set of periodic CSI-RS resource configuration indexes and / or SSB indexes may be configured by the candidateBeamRSList IE or the candidateBeamRSListExt IE for radio link quality measurements on the BWP of the serving cell. Unless stated otherwise, when the list of candidate beams includes the SSB indexes, the list may refer to the AO-SSB. The UE may assume the list of the reference signals (the CSI-RS and / or the SSB) identifying the candidate beams for recovery is associated with the BFD-RS set.

[0113] (e) An RSRP threshold for the BFR of the serving cell. In some implementations, the RSRP threshold may be configured per BFD-RS set.

[0114] In some implementations, when the UE is configured with a single BFD-RS set for the serving cell, the MAC entity of the UE may perform the BFR procedure for the cell (or for the BFD-RS set). For the cell that is configured with the single BFD-RS set, the UE may expect the set to include up to two RS indexes.

[0115] In some implementations, when the UE is configured with multiple BFD-RS sets for the serving cell, the MAC entity of the UE may perform the BFR procedure for the BFD-RS set. For the cell that is configured with multiple BFD-RS sets, the UE may expect the set to include up to a number of RS indexes, where the number may be indicated by the NW via the maxBFD-RS-resourcesPerSetPerBWP IE.

[0116] In some implementations, the proposed mechanisms and an On-Demand SSB (OD-SSB) activation / de-activation / implementation may be associated with a specific BWP (e.g., a Downlink BWP). Therefore, the proposed mechanisms / configurations may be applied / configured to each BWP (e.g., the DL BWP) independently. In some implementations, common parameters / configurations may be applied / shared by the BFD / OD-SSB operation among different DL-BWP(s) configured to one cell. In addition, one cell (e.g., the serving cell or a secondary cell) may be associated with one or more DL / UL BWP configurations. Accordingly, the proposed mechanism may be configured, activated, enabled, disabled, implemented, interrupted, or reset by BWP switching triggered by the serving RAN or the UE itself.

[0117] In some implementations, the proposed mechanisms and the OD-SSB activation / de-activation / implementation may be associated with a specific cell. Therefore, the proposed mechanisms / configurations may be applied / configured to each cell independently. In some implementations, the common parameters / configurations may be applied / shared by the BFD / OD-SSB operation among different cell(s) configured to one cell group. In addition, one cell group (e.g., the serving cell group or the secondary cell group) may be associated with one or more DL / UL BWP configurations. Accordingly, the proposed mechanism may be configured, activated, enabled, disabled, implemented, interrupted, or reset by the (secondary) cell activation / de-activation triggered by the serving RAN or the UE itself.

[0118] In some implementations, the proposed mechanisms and the OD-SSB activation / de-activation / implementation may be associated with a specific cell group (e.g., a master cell group or a secondary cell group) managed by one MAC entity. Therefore, the proposed mechanisms / configurations may be applied / configured to each cell group / MAC entity independently. In some implementations, the common parameters / configurations may be applied / shared by the BFD / OD-SSB operation among different cell group(s) configured to one UE. In addition, one UE may be associated with one or more cell group configurations. Accordingly, the proposed mechanism may be configured, activated, enabled, disabled, implemented, interrupted, or reset by a cell group configuration / release / reset triggered by the serving RAN or the UE itself.

[0119] Configuration for OD-SSB enabled BFD / BFR

[0120] For an SCell supporting the OD-SSB operation, the UE may use the OD-SSB for the BFD / BFR. To enable the OD-SSB based BFD / BFR for such the SCell, the UE may be configured with the BFD-RS set that contains or refers to the OD-SSB, which means the reference signals (e.g., the SSBs) configured by the BFD-RS set may refer to the OD-SSB. It should be noted that, unless stated otherwise, a configured BFD-RS set may contain or refer to the AO-SSB, which means the reference signals (e.g., the SSBs) configured by the BFD-RS set may refer to the AO-SSB.

[0121] FIG. 1 is a schematic diagram illustrating BFD-RS set configuration(s) that refers to an OD-SSB, according to an example implementation of the present disclosure. Various alternatives may be utilized to configure the BFD-RS set for the OD-SSB, as shown in FIG. 1 and Table 2 below.

[0122] Referring to FIG. 1, in a first alternative implementation (e.g., denoted as Alt. 1), the BFD-RS set for / containing the OD-SSB may be configured via the existing failureDetectionResourcesToAddModList IE 102 for the serving cell, where the IE may be configured within a radio link monitoring configuration (e.g., the RadioLinkMonitoringConfig IE 101) for the serving cell. This approach utilizes legacy configuration structures to support the OD-SSB.

[0123] In some implementations, when the BFD-RS set is configured via the existing failureDetectionResourcesToAddModList IE 102 for the cell, if the cell is configured as a Case 1 SCell (e.g., a cell where only the OD-SSB is configured without the AO-SSB), the UE may assume or determine that the reference signals configured by the BFD-RS set refer to the OD-SSB.

[0124] In some implementations, when the BFD-RS set is configured via the existing failureDetectionResourcesToAddModList IE 102 for the cell, if the cell is configured as a Case 2c SCell (e.g., a cell where the AO-SSB and the OD-SSB are configured with the same frequency and the same SSB indices), the UE may assume or determine that the reference signals configured by the BFD-RS set refer to both the AO-SSB and the OD-SSB jointly when the OD-SSB is activated on the cell (by the serving RAN).

[0125] In some implementations, when the BFD-RS set is configured via the existing failureDetectionResourcesToAddModList IE 102 for the cell, if the cell is configured as the Case 2c SCell, the UE may assume or determine that the reference signals configured by the BFD-RS set refer to the AO-SSB only if the OD-SSB is deactivated on the cell.

[0126] In some implementations, the UE may assume the beam failure detection timer and / or the beam failure instance indication maximum count configured within the same radio link monitoring configuration are associated with the BFD-RS set for / containing the OD-SSB.

[0127] For example, the RadioLinkMonitoringConfig IE 101 described in Alt. 1 may include: RadioLinkMonitoringConfig ::= SEQUENCE { failureDetectionResourcesToAddModList　　　　SEQUENCE (SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS 　　　　OPTIONAL, -- Need N failureDetectionResourcesToReleaseList　　　　SEQUENCE (SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS-Id 　　　　OPTIONAL, -- Need N beamFailureInstanceMaxCount　　　　ENUMERATED {n1, n2, n3, n4, n5, n6, n8, n10} 　　　　OPTIONAL, -- Need R beamFailureDetectionTimer　　　　　　　　ENUMERATED {pbfd1, pbfd2, pbfd3, pbfd4, pbfd5, pbfd6, pbfd8, pbfd10} 　　　　OPTIONAL, -- Need R }

[0128] Referring to FIG. 1, in a second alternative implementation (e.g., denoted as Alt. 2), the BFD-RS set for / containing the OD-SSB may be configured within a new introduced IE container (e.g., the failureDetectionSet3 IE 103), which indicates the reference signals configured by the BFD-RS set (e.g., the bfdResourcesToAddModList IE 104 within the new container) refer to the OD-SSB. The new introduced container IE may further include a beam failure detection timer and / or a beam failure instance indication maximum count that are assumed to be associated with the BFD-RS set containing the OD-SSB.

[0129] In some implementations, when the BFD-RS set is configured via the new introduced container IE, the UE may assume the reference signals configured by the BFD-RS set refer to the OD-SSB only. In other words, the NW may not configure a BFD-RS set (containing the AO-SSB only) within the introduced IE.

[0130] For example, the RadioLinkMonitoringConfig IE 101 described in Alt. 2 may include: RadioLinkMonitoringConfig ::= SEQUENCE { failureDetectionSet3-r19　　　　BeamFailureDetectionSet-r17　　　　OPTIONAL, -- Need R } BeamFailureDetectionSet-r17 ::= SEQUENCE { bfdResourcesToAddModList-r17　　　　SEQUENCE (SIZE(1..maxNrofBFDResourcePerSet-r17)) OF BeamLinkMonitoringRS-r17　　　　OPTIONAL, -- Need N bfdResourcesToReleaseList-r17　　　　SEQUENCE (SIZE(1..maxNrofBFDResourcePerSet-r17)) OF BeamLinkMonitoringRS-Id-r17　　　　OPTIONAL, -- Need N beamFailureInstanceMaxCount-r17　　　　ENUMERATED {n1, n2, n3, n4, n5, n6, n8, n10} 　　　　OPTIONAL, -- Need R beamFailureDetectionTimer-r17　　　　ENUMERATED {pbfd1, pbfd2, pbfd3, pbfd4, pbfd5, pbfd6, pbfd8, pbfd10}　　　　OPTIONAL, -- Need R ... }

[0131] Referring to FIG. 1, in a third alternative implementation (e.g., denoted as Alt. 3), the BFD-RS set for / containing the OD-SSB may be configured by a new introduced IE (e.g., the failureDetectionResourcesToAddModList-r19 IE 105) within the radio link monitoring configuration (e.g., the RadioLinkMonitoringConfig IE 101) for a cell, which indicates the BFD-RS set refers to the OD-SSB.

[0132] In some implementations, a beam failure detection timer may be configured by a new IE (e.g., the beamFailureDetectionTimer-r19 IE 106) within the radio link monitoring configuration 101, which indicates the timer is associated with the BFD-RS set for / containing the OD-SSB.

[0133] In some implementations, a beam failure instance indication maximum count may be configured by a new IE (e.g., the beamFailureInstanceMaxCount-r19 IE 107) within the radio link monitoring configuration 101, which indicates the count is associated with the BFD-RS set for / containing the OD-SSB.

[0134] For example, the RadioLinkMonitoringConfig IE 101 described in Alt. 3 may include: RadioLinkMonitoringConfig ::= SEQUENCE { failureDetectionResourcesToAddModList-r19　　　　SEQUENCE (SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS 　　　　OPTIONAL, -- Need N failureDetectionResourcesToReleaseList-r19　　　　SEQUENCE (SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS-Id 　　　　OPTIONAL, -- Need N beamFailureInstanceMaxCount-r19　　　　ENUMERATED {n1, n2, n3, n4, n5, n6, n8, n10} 　　　　OPTIONAL, -- Need R beamFailureDetectionTimer-r19　　　　ENUMERATED {pbfd1, pbfd2, pbfd3, pbfd4, pbfd5, pbfd6, pbfd8, pbfd10}　　　　OPTIONAL, -- Need R }

[0135] FIG. 2 is a schematic diagram illustrating configuration(s) for OD-SSB enabled BFR, according to an example implementation of the present disclosure.

[0136] To enable the OD-SSB based BFR, as shown in FIG. 2, the UE may be configured with an RSRP threshold for the BFR and / or a list of candidate beams to be associated with the BFD-RS set for / containing the OD-SSB. The RSRP threshold for the BFR that is associated with the BFD-RS set containing the OD-SSB may be configured by the existing IE (e.g., the rsrp-ThresholdBFR IE 201) or a new IE (e.g., the rsrp-ThresholdBFR2 IE 202). The list of candidate beams that is associated with the BFD-RS set containing the OD-SSB may be configured by the existing IE (e.g., the candidateBeamRS-List IE 203 or the candidateBeamRS-List2 IE 204) or a new IE (e.g., the candidateBeamRS-List3 IE 205). When the list of candidate beams is associated with the BFD-RS set containing the OD-SSB, the SSB index(es) configured by the list may refer to the OD-SSB.

[0137] In some implementations, if the UE is configured with only the BFD-RS set containing the OD-SSB for a Case 1 SCell, the UE may determine the RSRP threshold for the BFR that is associated with the BFD-RS set for / containing the OD-SSB.

[0138] In some implementations, when the UE is configured with only the BFD-RS set containing the OD-SSB for the Case 1 SCell, if the new IE (e.g., the rsrp-ThresholdBFR2 IE 202) is absent, the UE may apply the value of the existing IE (e.g., the rsrp-ThresholdBFR IE 201). If the new IE (e.g., the rsrp-ThresholdBFR2 IE 202) is present, the UE may apply the value of the new IE (e.g., the rsrp-ThresholdBFR2 IE 202).

[0139] In some implementations, the RSRP threshold configured by the new IE (e.g., the rsrp-ThresholdBFR2 IE 202) is optionally present for a cell when the BFD-RS set for / containing the AO-SSB is not configured for the cell.

[0140] In some implementations, if the UE is configured with only the BFD-RS set containing the OD-SSB for the Case 1 SCell, the UE may determine the list of candidate beams that is associated with the BFD-RS set for / containing the OD-SSB.

[0141] In some implementations, when the UE is configured with only the BFD-RS set containing the OD-SSB for the Case 1 SCell, if the new IE (e.g., the candidateBeamRS-List3 IE 205) is absent, the UE may apply the list configured by the existing IE (e.g., the candidateBeamRS-List IE 203 or the candidateBeamRS-List2 IE 204). If the new IE (e.g., the candidateBeamRS-List3 IE 205) is present, the UE may apply the list configured by the new IE (e.g., the candidateBeamRS-List3 IE 205).

[0142] In some implementations, the list configured by the new IE (e.g., the candidateBeamRS-List3 IE 205) is optionally present for a cell when the BFD-RS set for / containing the AO-SSB is not configured for the cell.

[0143] In some implementations, when both the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB are configured for a Case 2a / 2b SCell, the UE may determine the RSRP threshold for the BFR that is associated with the BFD-RS set containing the OD-SSB.

[0144] In some implementations, if the UE is configured with a first RSRP threshold (e.g., via the rsrp-ThresholdBFR IE 201) and a second threshold (e.g., via the rsrp-ThresholdBFR2 IE 202) for a cell, the UE may determine the first RSRP threshold is associated with the BFD-RS set for / containing the AO-SSB and the second RSRP threshold is associated with the BFD-RS set for the OD-SSB.

[0145] In some implementations, if the UE is configured with a single RSRP threshold (e.g., via the rsrp-ThresholdBFR IE 201) for a cell, the UE may determine the configured RSRP threshold is associated with both the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB.

[0146] In some implementations, if the UE is not configured with the RSRP threshold via the new IE rsrp-ThresholdBFR2 202 for a cell, the UE may determine the RSRP threshold via the existing IE rsrp-ThresholdBFR 201 is associated with both the BFD-RS set containing the AO-SSB and the BFD-RS set containing the OD-SSB.

[0147] In some implementations, when both the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB are configured for a Case 2a / 2b SCell, the UE may determine the list of candidate beams that is associated with the BFD-RS set containing the OD-SSB.

[0148] In some implementations, if the UE is configured with a first candidate beam list (e.g., via the candidateBeamRS-List IE 203 or the candidateBeamRS-List2 IE 204) and a second candidate beam list (e.g., via the candidateBeamRS-List3 IE 205) for a cell, the UE may determine the first candidate beam list is associated with the BFD-RS set for / containing the AO-SSB and the second candidate beam list is associated with the BFD-RS set for / containing the OD-SSB.

[0149] In some implementations, if the UE is configured with a single candidate beam list (e.g., via the candidateBeamRS-List IE 203) for a cell, the UE may determine the configured candidate beam list is associated with both the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB.

[0150] In some implementations, if the UE is not configured with the candidate beam list via the new IE candidateBeamRS-List3 205 for a cell, the UE may determine the candidate beam list via the existing IE candidateBeamRS-List 203 or candidateBeamRS-List2 204 is associated with both the BFD-RS set containing the AO-SSB and the BFD-RS set containing the OD-SSB.

[0151] In should be noted that, the implementations above applied when the UE is configured with only the BFD-RS set containing the OD-SSB for the Case 1 SCell may be applied when the UE is configured with the BFD-RS set that refers to both the AO-SSB and the OD-SSB for a Case 2c SCell.

[0152] For example, the BeamFailureRecoveryRSConfig IE 206 may include: BeamFailureRecoveryRSConfig-r16 ::= SEQUENCE { rsrp-ThresholdBFR-r16　　　　RSRP-Range　　　　OPTIONAL, -- Need M rsrp-ThresholdBFR2-r19　　　　RSRP-Range　　　　OPTIONAL, -- Need M candidateBeamRS-List-r16　　　　SEQUENCE (SIZE(1..maxNrofCandidateBeams-r16)) OF CandidateBeamRS-r16　　　　OPTIONAL, -- Need M candidateBeamRS-List2-r17　　　　SEQUENCE (SIZE(1..maxNrofCandidateBeams-r16)) OF CandidateBeamRS-r16　　　　OPTIONAL, -- Need M candidateBeamRS-List3-r19　　　　SEQUENCE (SIZE(1..maxNrofCandidateBeams-r16)) OF CandidateBeamRS-r16　　　　OPTIONAL -- Need R }

[0153] Beam Failure Detection (BFD)

[0154] In some implementations, the physical layer in the UE may assess a radio link quality according to the configured BFD-RS set(s) against the configured threshold for the BFD that is associated with the BFD-RS set, where the threshold may be indicated by the network via the rlmInSyncOutOfSyncThreshold IE. Moreover, the physical layer in the UE may provide an indication to the higher layers (e.g., the MAC layer) when the radio link quality for all corresponding resource configurations in the BFD-RS set is worse than the threshold with a periodicity. In a non-DRX mode operation, the periodicity may be determined by the maximum between the shortest periodicity among the SSBs on the PCell or the PSCell and / or the periodic CSI-RS configurations in the BFD-RS set and 2 msec. In a DRX mode operation, the periodicity may be determined by the SSB periodicity (i.e., the ssb-periodicityServingCell IE), the DRX cycle length, and / or the configured periodicity for the (CSI) reporting.

[0155] OD-SSB enabled BFD

[0156] When the UE is configured with a BFD-RS set for / containing the OD-SSB for a cell, the RRC layer or the MAC layer in the UE may determine whether the reference signals configured by the BFD-RS set for / containing the OD-SSB is activated based on whether the OD-SSB is activated on the cell. The RRC layer or the MAC layer in the UE may indicate the activation / deactivation information to the PHY layer in the UE.

[0157] In some implementations, if the OD-SSB on the cell is activated, the RRC layer or the MAC layer in the UE may assume or determine the reference signals configured by the BFD-RS set are activated. If the OD-SSB on the cell is deactivated, the RRC layer or the MAC layer in the UE may assume or determine the reference signals configured by the BFD-RS set are deactivated.

[0158] In some implementations, when the BFD-RS set is configured for a Case 2c SCell, which means the reference signals configured by the BFD-RS set refer to both the AO-SSB and the OD-SSB, the RRC layer or the MAC layer in the UE may assume or determine the reference signals configured by the BFD-RS set are activated regardless of whether the OD-SSB is activated on the cell.

[0159] When the BFD-RS set (e.g., containing the OD-SSB) is activated, the physical layer in the UE may assess the radio link quality according to the BFD-RS set against the configured RSRP threshold that is associated with the BFD-RS set. More specifically, the UE may apply the configured RSRP threshold to the L1-RSRP measurement obtained from the SSB indicated by the BFD-RS set. When the L1-RSRP measurement results for all corresponding resource configurations in the BFD-RS set are worse than the threshold, the physical layer in the UE may provide the higher layers with the indication of the Beam Failure Instance (BFI).

[0160] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB (e.g., for a Case 2a / 2b SCell), if the BFD-RS set for / containing the OD-SSB is activated, the UE may stop or skip assessing the radio link quality according to the BFD-RS set for the AO-SSB.

[0161] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB (e.g., for the Case 2a / 2b SCell), if the BFD-RS set for / containing the OD-SSB is activated, the UE may keep assessing the radio link quality according to the BFD-RS set for the AO-SSB.

[0162] When the BFD-RS set for / containing the OD-SSB is deactivated, the physical layer in the UE may stop or skip assessing the radio link quality according to the BFD-RS set (e.g., containing the OD-SSB) against the configured threshold for the BFD.

[0163] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB (e.g., for the Case 2a / 2b SCell), if the BFD-RS set for / containing the OD-SSB is deactivated, the UE may start to assess the radio link quality according to the BFD-RS set for the AO-SSB.

[0164] It should be noted that, the UE may be configured with a list of SSB transmission periodicities for the OD-SSB on a cell. When the OD-SSB is activated, the UE may determine one of the OD-SSB transmission periodicities to be applied, used, or activated on the cell.

[0165] In some implementations, for the BFD-RS set for / containing the OD-SSB, if the OD-SSB transmission periodicity is changed, the PHY layer in the UE may apply the changed OD-SSB transmission periodicity to determine the periodicity that is used to provide the BFI from the PHY layer to the higher layers, where the changed OD-SSB transmission periodicity may be determined by the UE or indicated by the network. In some implementations, the RRC layer or the MAC layer in the UE may indicate the information of the changed OD-SSB periodicity to the PHY layer in the UE.

[0166] For the Case 2c SCell, the UE may assume the reference signals configured by the BFD-RS set refer to the AO-SSB and the OD-SSB, where the periodicity of the AO-SSB and the periodicity of the OD-SSB may be configured to be different.

[0167] In some implementations, for the BFD-RS set that refers to both the AO-SSB and the OD-SSB, to determine the periodicity that is used to provide the BFI from the PHY layer to the higher layers, the UE may apply the maximum between the periodicity of the AO-SSB and the periodicity of the OD-SSB.

[0168] In some implementations, the UE may determine the periodicity that is used to provide the BFI from the PHY layer to the higher layers based on the periodicity of the AO-SSB and / or the periodicity of the OD-SSB. For example, the periodicity of the BFI report may be determined based on minimum values between the periodicity of the AO-SSB and the periodicity of the OD-SSB (e.g., the periodicity of the BFI = alpha * minimum{periodicity of the AO-SSB, periodicity of the OD-SSB}, where alpha may be a positive value).

[0169] In some implementations, the UE may determine a new SSB periodicity based on the periodicity of the AO-SSB and the periodicity of the OD-SSB. Afterwards, the UE may determine the periodicity that is used to provide the BFI to the higher layers based on the new SSB periodicity. In some implementations, the proposed BFI report periodicity adaptation mechanism may be applied in the PHY layer of the UE side (e.g., based on the configurations and inputs from the RRC entity / MAC entity of the UE side). In some implementations, the proposed BFI report periodicity adaptation mechanism may be applied in the MAC layer of the UE side (e.g., based on the configurations and inputs from the RRC entity / PHY layer of the UE side).

[0170] BFR procedure

[0171] For each serving cell, when the UE is configured with one or more BFD-RS sets for the cell, the UE may perform the BFR procedure for each BFD-RS set based on the BFD-related parameters associated with the BFD-RS set. When the UE is configured with a single BFD-RS set for a cell, the UE may perform the BFR procedure for this cell based on the BFD-related parameters associated with the BFD-RS set.

[0172] The UE may perform the BFR procedure for the BFD-RS set of the serving cell, where the BFR procedure may include one or more of the following actions: 　　　　- The beam failure may be detected by counting the BFI indication from the lower layers (e.g., the PHY layer) to the MAC entity. 　　　　- After the beam failure is detected for the BFD-RS set of the serving cell, the UE may trigger the BFR for the BFD-RS set. 　　　　- Afterward, the UE may try to select a suitable beam for this BFD-RS set and indicate whether the suitable beam (e.g., which may be a new beam) is found or not along with the information about the beam failure for this BFD-RS set in the BFR MAC CE. 　　　　- Upon reception of the PDCCH indicating an uplink grant for a new transmission for the HARQ process used for the transmission of the BFR MAC CE, the beam failure recovery for this BFD-RS set may be considered complete.

[0173] In some implementations, if the BFI indication for the BFD-RS set has been received from the lower layers, the UE may increase the BFI counter (e.g., the BFI_COUNTER IE) of the BFD-RS set by 1. If the counter is greater than or equal to the beam failure instance maximum count associated with this BFD-RS set, the UE may determine the beam failure is detected and trigger the BFR for the BFD-RS set of the serving cell.

[0174] In addition, if the BFI indication for the BFD-RS set has been received from the lower layers, the UE may start or restart the BFD timer (e.g., the beamFailureDetectionTimer IE) of the BFD-RS set. Once the timer expires, the UE may set the counter of the BFD-RS set to 0. Moreover, the UE may set the counter of the BFD-RS set to 0 if one or more BFD-related parameters for this cell are reconfigured by the upper layers, where the parameters may include the BFD-RS set, the BFD timer, or the BFI maximum count.

[0175] OD-SSB enabled BFR

[0176] When the serving cell is the 2a / 2b SCell, the UE may be configured with both the BFD-RS set for / containing the OD-SSB and the BFD-RS set for / containing the AO-SSB simultaneously. In some implementations, the UE may be allowed to perform the BFR procedure for each BFD-RS set simultaneously. In some implementations, the UE may not be allowed to perform the BFR procedure for each BFD-RS set simultaneously.

[0177] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB for the serving cell, if the BFD-RS set for / containing the OD-SSB is activated, the UE may perform the BFR procedure for the BFD-RS set for / containing the OD-SSB and stop performing the BFR procedure(s) for the BFD-RS set for / containing the AO-SSB. Once the BFD-RS set for / containing the OD-SSB is activated, the UE may cancel or terminate the (e.g., ongoing) BFR procedure(s) for the BFD-RS set for / containing the AO-SSB and reset the corresponding parameters (e.g., the BFI counter) that are associated with the BFD-RS set containing the AO-SSB. Once the BFD-RS set for / containing the OD-SSB is activated, the UE may cancel the BFRs triggered for the BFD-RS set for / containing the AO-SSB.

[0178] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB for the serving cell, if the BFD-RS set for / containing the OD-SSB is deactivated, the UE may perform the BFR procedure for the BFD-RS set for / containing the AO-SSB and stop performing the BFR procedure(s) for the BFD-RS set for the OD-SSB. Once the BFD-RS set for / containing the OD-SSB is deactivated, the UE may cancel or terminate the (e.g., ongoing) BFR procedure(s) for the BFD-RS set for / containing the OD-SSB and reset the corresponding parameters (e.g., the BFI counter) that are associated with the BFD-RS set containing the OD-SSB. Once the BFD-RS set for / containing the OD-SSB is deactivated, the UE may cancel the BFRs triggered for the BFD-RS set for / containing the OD-SSB.

[0179] In some implementations, when the UE is configured with the BFD-RS set for / containing the AO-SSB and the BFD-RS set for the OD-SSB, the UE may perform the BFR procedure(s) for each of the BFD-RS set for / containing the AO-SSB and the BFD-RS set for / containing the OD-SSB.

[0180] During the BFR procedure for the BFD-RS set for / containing the OD-SSB of the serving cell, the UE may set the counter of the BFD-RS set to 0 if at least one of the following conditions is satisfied: 　　　　- One or more BFD-related parameters for the cell configured with the OD-SSB are reconfigured by the upper layers, where the BFD-related parameter may be the BFD-RS set containing the OD-SSB, the BFD timer, and / or the BFI maximum count; 　　　　- One or more SSB related parameters for the OD-SSB on the cell are reconfigured by the upper layers, where the parameters may be at least one of those parameters described above. 　　　　- The OD-SSB on the cell is deactivated.

[0181] When the BFD-RS set is configured for the Case 2c SCell, which means the reference signals configured by the BFD-RS set refer to both the AO-SSB and the OD-SSB, the UE may assume the reference signals configured by the BFD-RS set are always activated regardless of whether the OD-SSB is activated on the cell. Thus, during the BFR procedure for the BFD-RS set of the Case 2c SCell, the UE may not set the BFI counter of the BFD-RS set to 0 if the OD-SSB on this cell is deactivated.

[0182] When the UE is configured with the BFD-RS set for / containing the OD-SSB for the serving cell, if the OD-SSB transmission periodicity is changed, the UE may apply the changed OD-SSB transmission periodicity to determine the periodicity that is used to provide the BFI to the higher layers for this BFD-RS set.

[0183] In some implementations, for the BFD-RS set containing the OD-SSB, when the BFD timer associated with this BFD-RS set is not running, once the periodicity that is used to provide the BFI indication to the higher layers is changed to a new value, the UE may apply the new value to determine the value of the BFD timer.

[0184] In some implementations, for the BFD-RS set containing the OD-SSB, when the BFD timer associated with this BFD-RS set is running (e.g., or has been started), once the periodicity that is used to provide the BFI indication to the higher layers is changed to a new value, the UE may stop the BFD timer, apply the new value to determine the (e.g., remaining) value of the BFD timer, and restart the BFD timer with the new value. In some implementations, for the BFD-RS set containing the OD-SSB, the MAC layer in the UE may restart the BFD timer with the new value when receiving the BFI indication from the PHY layer in the UE.

[0185] In some implementations, the beamFailureDetectionTimer IE that may serve as a timer for the beam failure detection. The value of the timer may be configured in a number of “Qout,LRreporting periods of Beam Failure Detection Reference Signal”. For example, a value pbfd1 may correspond to 1 Qout,LRreporting period of the Beam Failure Detection Reference Signal, a value pbfd2 may correspond to 2 Qout,LRreporting periods of the Beam Failure Detection Reference Signal, and so on.

[0186] In some implementations, when the “Qout,LRreporting periods of Beam Failure Detection Reference Signal” is changed to a new value X by the RRC layer, the MAC layer, or the PHY layer, the RRC layer or the MAC layer in the UE may apply the new value X to determine the (e.g., remaining) value of the beamFailureDetectionTimer IE. In other words, the beamFailureDetectionTimer IE may be restarted with a new initial value decided by the new reporting period of the Beam Failure Detection Reference Signal.

[0187] BFR MAC CE

[0188] When at least one BFR has been triggered and not cancelled for an SCell, the UE may determine the format of the BFR MAC CE and generate / transmit the corresponding BFR MAC CE once UL-SCH resources are available for a new transmission and if the UL-SCH resources can accommodate the BFR MAC CE plus its subheader as a result of a Logical Channel Prioritization (LCP).

[0189] In some implementations, for a serving cell, the UE may be configured with one or more BFD-RS sets. To convey beam failure information for each BFD-RS set to the network, different BFR MAC CE formats may be applied depending on whether there is at least one serving cell with two BFD-RS sets. More specifically, there are two types of BFR MAC CE format, and each type has a truncated format additionally.

[0190] In some implementations, the (e.g., Truncated) BFR MAC CE may indicate, for each serving cell (e.g., while a single BFD-RS set is configured), whether the beam failure is detected and whether there is a suitable beam for the beam failure recovery.

[0191] In some implementations, the (e.g., Truncated) Enhanced BFR MAC CE may indicate the beam failure recovery information for each serving cell as follows: 　　　　- For the serving cell (e.g., while the single BFD-RS set is configured), it indicates whether the beam failure is detected and whether there is a suitable beam for the beam failure recovery. 　　　　- For the serving cell configured with two BFD-RS sets, it indicates, for each BFD-RS set of the serving cell, whether the beam failure is detected and whether there is a suitable beam for the beam failure recovery.

[0192] Thus, when at least one BFR has been triggered and not cancelled for the SCell, if none of the serving cell(s) of the MAC entity of the UE are configured with two BFD-RS sets, the UE may generate and transmit the BFR MAC CE or the Truncated BFR MAC CE. If at least one serving cell of the MAC entity of the UE is configured with two BFD-RS sets, the UE may generate and transmit the Enhanced BFR MAC CE or the Truncated Enhanced BFR MAC CE.

[0193] When the UE is generating the MAC CE for the BFR, the MAC layer in the UE may request the PHY layer to determine whether there is a suitable beam per BFD-RS set for recovery. Upon request from the MAC layer, the PHY layer in the UE indicates whether there is at least one SSB index from the list (e.g., the candidateBeamRSList IE) of candidate beams that is associated with the BFD-RS set with corresponding L1-RSRP beam measurements larger than or equal to the configured RSRP threshold (e.g., the rsrp-ThresholdBFR IE). Moreover, the PHY layer may also provide the SSB indexes from the list (e.g., the candidateBeamRSList IE) of candidate beams that is associated with the BFD-RS set and the corresponding L1-RSRP measurements larger than or equal to the configured RSRP thresholds (e.g., the rsrp-ThresholdBFR IE).

[0194] In some implementations, for the serving cell that is configured with the OD-SSB, the UE may be configured with one or more than one BFD-RS sets as described below.

[0195] For a Case 1 SCell, the UE may be configured with one BFD-RS set containing the OD-SSB. The UE may generate and transmit the (e.g., Truncated) BFR MAC CE to convey the beam failure information for this type of cell.

[0196] For a Case 2a / 2b SCell, the UE may be configured with one BFD-RS set for / containing the AO-SSB and one BFD-RS set for the OD-SSB. In some implementations, the (e.g., Truncated) New-Type-1 BFR MAC CE may be introduced. The UE may generate and transmit the (e.g., Truncated) New-Type-1 BFR MAC CE to convey the beam failure information for this type of cell.

[0197] For a Case 2c SCell, the UE may be configured with one BFD-RS set referring to both the AO-SSB and the OD-SSB. The UE may generate and transmit the (e.g., Truncated) BFR MAC CE to convey the beam failure information for this type of cell.

[0198] For the beam failure detection in the multi-TRP operation, the UE may be configured with two BFD-RS sets for / containing the AO-SSB and one BFD-RS set for / containing the OD-SSB. In some implementations, the (e.g., Truncated) New-Type-2 BFR MAC CE may be introduced. The UE may generate and transmit the (e.g., Truncated) New-Type-2 BFR MAC CE to convey the beam failure information for this type of cell.

[0199] When at least one BFR is triggered and not cancelled for the SCell, the UE may determine the format of the BFR MAC CE to be applied depending on whether there is at least one cell configured with two or three BFD-RS sets.

[0200] In some implementations, if at least one cell of the MAC entity is configured with three BFD-RS sets, the UE may generate and transmit the (e.g., Truncated) New-Type-2 BFR MAC CE.

[0201] In some implementations, if none of the serving cells of the MAC entity is configured with three BFD-RS sets and at least one cell is configured with two BFD-RS sets, the UE may generate and transmit the (e.g., Truncated) New-Type-1 BFR MAC CE.

[0202] In some implementations, if all the serving cells are configured with a single BFD-RS set, the UE may generate and transmit the (e.g., Truncated) BFR MAC CE.

[0203] FIG. 3 is a schematic diagram illustrating a (e.g., Truncated) New-Type-1 BFR MAC CE, according to an example implementation of the present disclosure.

[0204] Referring to FIG. 3, the (e.g., Truncated) New-Type-1 BFR MAC CE 300 may include at least one of the following fields: 　　　　- An SP field 301: the SP field 301 may indicate a beam failure detection for the SpCell of the MAC entity and a presence of octet(s) containing the AC field 304 if the SpCell is configured with multiple BFD-RS sets. For the SpCell configured with two BFD-RS sets, the SP field 301 set to 1 may indicate that the beam failure is detected for at least one BFD-RS set and the octet(s) containing the AC field 304 is present for the SpCell; otherwise, the SP field 301 may be set to 0. The octet(s) containing the AC field 304 for the SpCell may be included before those of the SCell(s). For the SpCell not configured with multiple BFD-RS sets, the SP field 301 may be set to 1 to indicate that the beam failure is detected for the SpCell; otherwise, the SP field 301 may be set to 0. 　　　　- A Cifield 302: the Cifield may indicate the beam failure detection and the presence of octet(s) containing the AC field 304 for the SCell with a ServCellIndex i. The Cifield 302 set to 1 may indicate that the beam failure is detected for the SCell or at least one BFD-RS set of the SCell, and the octet(s) containing the AC field 304 is present for the SCell with the ServCellIndex i. The Cifield 302 set to 0 may indicate either that the beam failure is not detected for the SCell or any BFD-RS set of the SCell, and the octet(s) containing the AC field 304 is not present for the SCell with the ServCellIndex i; or that the beam failure is detected for the SCell or at least one BFD-RS set of the SCell but an evaluation of the candidate beams according to requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octets containing the AC field 304 is not present for the SCell with the ServCellIndex i. The octets containing the AC field 304 may be present in an ascending order based on the ServCellIndex and may be included after the octet(s) containing the AC field 304 for the SpCell. 　　　　- A Skfield 303: the Skfield 303 may correspond to the kth Serving Cell for which the SP field 301 or the Cifield 302 is set to 1 and is configured with two BFD-RS sets, where either the two BFD-RS sets may both refer to the AO-SSB or one BFD-RS set refers to the AO-SSB and another BFD-RS set refers to the OD-SSB. The Serving Cells for which the SP field 301 or the Cifield 302 is set to 1 and are configured with two BFD-RS sets, may be indexed sequentially starting with the SpCell and followed by the SCells in the ascending order of the ServCellIndex i. The Skfield 303 not mapped to any Serving Cell may be set to 0. The Skfield 303 may indicate whether the beam failure is detected for one or both BFD-RS sets and the presence of one or two octets containing the AC field 304 of the Serving Cell. The Skfield 303 set to 1 may indicate that the beam failure is detected for both the BFD-RS sets, and the octets containing the AC field 304 are present for both the BFD-RS sets, of the Serving Cell. The Skfield 303 set to 0 may indicate that the beam failure is either detected for one of the BFD-RS sets or the beam failure is detected for both the BFD-RS sets but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed for both the BFD-RS sets, and the octet containing the AC field 304 is present for only one BFD-RS set of the Serving Cell. 　　　　- An AC field 304: the AC field 304 may indicate the presence of the Candidate RS ID field 305 in this octet. If at least one of the SSBs with an SS-RSRP above the configured RSRP threshold (e.g., the rsrp-ThresholdBFR IE, or the rsrp-ThresholdBFR2-r19 IE) amongst the SSBs in the list of candidate beams (e.g., the candidateBeamRS-List IE, the candidateBeamRS-List2 IE, or the candidateBeamRS-List3 IE), the AC field 304 may be set to 1; otherwise, the AC field 304 may be set to 0. If the AC field 304 is set to 1, the Candidate RS ID field 305 may be present. If the AC field 304 is set to 0, R bits 305 may be present instead. 　　　　- A Candidate RS ID field 305: the Candidate RS ID field 305 may be set to an index of an SSB with the SS-RSRP above the configured RSRP threshold (e.g., the rsrp-ThresholdBFR IE, or the rsrp-ThresholdBFR2 IE) amongst the SSBs in the list of candidate beams (e.g., the candidateBeamRS-List IE, the candidateBeamRS-List2 IE, or the candidateBeamRS-List3 IE). The Candidate RS ID field 305 set to 0 may correspond to a first entry in the list of candidate beams, the Candidate RS ID field 305 set to 1 may correspond to a second entry in the list and so on. The length of the Candidate RS ID field 305 may be 6 bits.

[0205] In some implementations, the number of octets containing the AC field 304 in the Truncated New-Type-1 BFR MAC CE may be zero.

[0206] To identify the BFD-RS set for the octet containing the AC field 304, a 1-bit field may be included in the (e.g., Truncated) New-Type-1 BFR MAC CE.

[0207] In some implementations, as shown in FIG. 3, the ID / AO field 306 may be included. The ID / AO field 306 may indicate an identity of the BFD-RS set.

[0208] For the serving cell configured with two BFD-RS sets for a multi-TRP operation, the ID / AO field 306 may be interpreted as the ID field 306. The ID field 306 may be set to 0 if the octet corresponds to the BFD-RS set one (e.g., failureDetectionSet1). The ID field 306 may be set to 1 if the octet corresponds to the BFD-RS set two (e.g., failureDetectionSet2).

[0209] For the serving cell configured with two BFD-RS sets where one set is for the AO-SSB and another one set is for the OD-SSB, the ID / AO field 306 may be interpreted as the AO field 306. The AO field 306 may be set to 0 if the octet corresponds to the BFD-RS set containing the AO-SSB. The AO field 306 may be set to 1 if the octet corresponds to the BFD-RS set containing the OD-SSB. In some implementations, the AO field 306 may be set to 0 if the octet corresponds to the BFD-RS set containing the OD-SSB. The AO field 306 may be set to 1 if the octet corresponds to the BFD-RS set containing the AO-SSB.

[0210] For the Serving cell not configured with two BFD-RS sets, the ID / AO field 306 may be set to 0.

[0211] In some implementations, the (e.g., Truncated) New-Type-2 BFR MAC CE may include at least one of the SP field, the Cifield, the AC field, and the Candidate RS ID field, which are the same as that in the (e.g., Truncated) New-Type-1 BFR MAC CE 300. In some implementations, the number of the octets containing the AC field in the Truncated New-Type-2 BFR MAC CE may be zero.

[0212] In some implementations, the (e.g., Truncated) New-Type-2 BFR MAC CE may include an ID field. The ID field may indicate the identity of the BFD-RS set. For the octet corresponding to the BFD-RS set containing the AO-SSB, the ID field may be set to 0 if the octet corresponds to the BFD-RS set one (e.g., failureDetectionSet1). The ID field may be set to 1 if the octet corresponds to the BFD-RS set two (e.g., failureDetectionSet2). For the octet corresponding to the BFD-RS set containing the OD-SSB, the ID field may be set to 0, indicating the R bit is present instead. For the Serving cell not configured with multiple BFD-RS sets, the ID field may be set to 0.

[0213] In some implementations, the UE may arrange the octet(s) corresponding to the BFD-RS set for / containing the AO-SSB and the octet corresponding to the BFD-RS set for / containing the OD-SSB in a specific order so that the network can interpret correctly. In some implementations, for the serving cell, all the octet(s) corresponding to the BFD-RS set for / containing the AO-SSB may be included before the octet corresponding to the BFD-RS set for the OD-SSB. In some implementations, for the serving cell, all the octet(s) corresponding to the BFD-RS set for / containing the AO-SSB may be included after the octet corresponding to the BFD-RS set for the OD-SSB.

[0214] To indicate whether the beam failure is detected for one or more BFD-RS sets in the (e.g., Truncated) New-Type-2 BFR MAC CE, at least one of the following alternatives may be adopted.

[0215] FIG. 4 is a schematic diagram illustrating a (e.g., Truncated) New-Type-2 BFR MAC CE, according to an example implementation of the present disclosure.

[0216] Referring to FIG. 4, in a first alternative (e.g., denoted as Alt. I), the Skfield 403 which is the same as that for the (e.g., Truncated) New-Type-1 BFR MAC CE may be included in the (e.g., Truncated) New-Type-2 BFR MAC CE 400. Moreover, the Okfield 407 may be introduced to be included.

[0217] In some implementations, the Skfield 403 may correspond to the kth Serving Cell for which the SP field 401 or the Cifield 402 is set to 1 and is configured with at least two BFD-RS sets, where either the two BFD-RS sets may both refer to the AO-SSB or one BFD-RS set refers to the AO-SSB and another BFD-RS set refers to the OD-SSB.

[0218] In some implementations, the Okfield 407 may correspond to the kth Serving Cell for which the SP field 401 or the Cifield 402 is set to 1 and is configured with the BFD-RS set containing the OD-SSB. The Serving Cells for which the Cifield 402 is set to 1 and are configured with three BFD-RS sets and one of three BFD-RS sets contains the OD-SSB, may be indexed sequentially in the ascending order of the ServCellIndex i. The Okfield 407 not mapped to any Serving Cell may be set to 0.

[0219] In some implementations, the Okfield 407 may indicate whether the beam failure is detected for the BFD-RS set for / containing the OD-SSB and the presence of one octet containing the AC field 404 of the Serving Cell.

[0220] In some implementations, the Okfield 407 set to 1 may indicate that the beam failure is detected for the BFD-RS set containing the OD-SSB, and the octet containing the AC field 404 is present for the BFD-RS set containing the OD-SSB, of the Serving Cell. The Okfield 407 set to 0 may indicate that the beam failure is detected for the BFD-RS set for / containing the OD-SSB, but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octet containing the AC field 404 is not present. The Okfield 407 may be interpreted as the R-bit if the cell is configured with less than or equal to two BFD-RS sets.

[0221] For Alt. I, the UE may set the Skfield 403 and the Okfield 407 to different values respectively depending on how the cell is configured one or more BFD-RS sets, as summarized in Table 3 below.

[0222] FIG. 5 is a schematic diagram illustrating a (e.g., Truncated) New-Type-2 BFR MAC CE, according to an example implementation of the present disclosure.

[0223] Referring to FIG. 5, in a second alternative (e.g., denoted as Alt. II), the 2-bit Xkfield 507 may be introduced to be included in the (e.g., Truncated) New-Type-2 BFR MAC CE 500.

[0224] In some implementations, the Xkfield 507 may correspond to the kth Serving Cell for which the SP field 501 or the Cifield 502 is set to 1 and is configured with two or three BFD-RS sets. The Serving Cells for which the Cifield 502 is set to 1 and are configured with the multiple (e.g., two or three) BFD-RS sets, may be indexed sequentially in the ascending order of the ServCellIndex i. The Xkfield 507 not mapped to any Serving Cell may be set to 0.

[0225] In some implementations, the Xkfield 507 may indicate whether the beam failure is detected for the BFD-RS set for / containing the AO-SSB and / or the BFD-RS set for / containing the OD-SSB and the presence of octet(s) containing the AC field 504 of the Serving Cell.

[0226] For the cell configured with two BFD-RS sets containing the AO-SSB, when the Xkfield 507 is set to a first value, the Xkfield 507 may indicate that the beam failure is detected for one of the BFD-RS sets containing the AO-SSB, and the octet containing the AC field 504 is present for the BFD-RS set containing the AO-SSB, of the Serving Cell.

[0227] In some implementations, the Xkfield 507 may indicate the beam failure is detected for both the BFD-RS sets containing the AO-SSB but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octet containing the AC field 504 is present for only one of the BFD-RS set for the AO-SSB, of the Serving Cell. For the cell additionally configured with a BFD-RS set containing the OD-SSB, the Xkfield 507 may further indicate that the beam failure is detected for the BFD-RS set for / containing the OD-SSB but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octet containing the AC field 504 is not present for the BFD-RS set containing the OD-SSB.

[0228] For the cell configured with two BFD-RS sets containing the AO-SSB, when the Xkfield 507 is set to a second value, the Xkfield 507 may indicate that the beam failure is detected for both the BFD-RS sets for the AO-SSB, and the octets containing the AC field 504 are present for each of the BFD-RS sets for the AO-SSB, of the Serving Cell. For the cell additionally configured with a BFD-RS set containing the OD-SSB, the Xkfield 507 may further indicate that the beam failure is detected for the BFD-RS set for / containing the OD-SSB but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octet containing the AC field 504 is not present for the BFD-RS set for the OD-SSB.

[0229] For the cell configured with three BFD-RS sets, when the Xkfield 507 is set to a third value, the Xkfield 507 may indicate that the beam failure is detected for one of the BFD-RS sets containing the AO-SSB, and the octet containing the AC field 504 is present for the BFD-RS set containing the AO-SSB, of the Serving Cell.

[0230] In some implementations, the Xkfield 507 may indicate the beam failure is detected for both the BFD-RS sets containing the AO-SSB but the evaluation of the candidate beams according to the requirements (e.g., as specified in TS 38.133 V18.7.0) has not been completed, and the octet containing the AC field 504 is present for only one of the BFD-RS set for the AO-SSB, of the Serving Cell. Furthermore, the Xkfield 507 may also indicate that the beam failure is detected for the BFD-RS sets for the OD-SSB, and the octet containing the AC field 504 is present for the BFD-RS set for the OD-SSB, of the Serving Cell.

[0231] For the cell configured with three BFD-RS sets, when the Xkfield 507 is set to a fourth value, the Xkfield 507 may indicate that the beam failure is detected for both the BFD-RS sets for the AO-SSB, and the octets containing the AC field 504 are present for each of the BFD-RS sets for the AO-SSB, of the Serving Cell. Furthermore, the Xkfield 507 may also indicate that the beam failure is detected for the BFD-RS sets for the OD-SSB, and the octet containing the AC field 504 is present for the BFD-RS set for the OD-SSB, of the Serving Cell.

[0232] In some implementations, the Xkfield 507 may be interpreted as the R-bit if the cell is configured with the single BFD-RS set.

[0233] For Alt. II, the UE may set the Xkfield 507 to one of the four different values depending on how the cell is configured one or more BFD-RS sets, as summarized in Table 4 below.

[0234] FIG. 6 is a flowchart illustrating a method / process 600 performed by a UE for performing a BFR procedure, according to an example implementation of the present disclosure.

[0235] In action 601, the process 600 may start by receiving, from a BS, a first BFD-RS set and a second BFD-RS set for a serving cell. The first BFD-RS set may be associated with a first SSB, and the second BFD-RS set may be associated with a second SSB.

[0236] In some implementations, the first SSB may be an Always-On SSB (AO-SSB), and the second SSB may be an On-Demand SSB (OD-SSB). For example, the first BFD-RS set may contain or refer to the AO-SSB, and the second BFD-RS set may contain or refer to the OD-SSB. In some implementations, the BS may transmit the first BFD-RS set and the second BFD-RS set to the UE.

[0237] In action 602, the process 600 may receive, from the BS, a BFR configuration for the serving cell. The BFR configuration may include a first BFR-related parameter associated with the first SSB. For example, the BFR configuration may be the BeamFailureRecoveryRSConfig IE, as described above, received via an RRC signaling.

[0238] In some implementations, the first BFR-related parameter may include a first RSRP threshold. For example, the first RSRP threshold may be configured by the rsrp-ThresholdBFR IE, as described above.

[0239] In some implementations, the first BFR-related parameter may include a first candidate beam list. For example, the first candidate beam list may be configured by a candidateBeamRS-List IE or a candidateBeamRS-List2 IE, as described above.

[0240] In action 603, the process 600 may determine whether a second BFR-related parameter associated with the second SSB is configured in the BFR configuration.

[0241] In some implementations, the second BFR-related parameter may include a second RSRP threshold. For example, the second RSRP threshold may be configured by the rsrp-ThresholdBFR2 IE, as described above.

[0242] In some implementations, the second BFR-related parameter may include a second candidate beam list. For example, the second candidate beam list may be configured by the candidateBeamRS-List3 IE, as described above.

[0243] In action 604, in response to the second BFR-related parameter associated with the second SSB being configured in the BFR configuration, the process 600 may determine that the second BFR-related parameter is associated with the second SSB. The process 600 may then end.

[0244] In some implementations, if the UE is configured with the first RSRP threshold (e.g., the rsrp-ThresholdBFR IE) and the second RSRP threshold (e.g., the rsrp-ThresholdBFR2 IE) for the serving cell, the UE may determine the first RSRP threshold is associated with the first SSB (e.g., BFD-RS set for / containing the AO-SSB) and the second RSRP threshold is associated with the second SSB (e.g., the BFD-RS set for the OD-SSB).

[0245] In some implementations, if the UE is configured with the first candidate beam list (e.g., the candidateBeamRS-List IE or the candidateBeamRS-List2 IE) and the second candidate beam list (e.g., the candidateBeamRS-List3 IE), the UE may determine the first candidate beam list is associated with the first SSB (e.g., BFD-RS set for / containing the AO-SSB) and the second candidate beam list is associated with the second SSB (e.g., the BFD-RS set for the OD-SSB).

[0246] In action 605, in response to the second BFR-related parameter associated with the second SSB not being configured in the BFR configuration, the process 600 may determine that the first BFR-related parameter is associated with both the first SSB and the second SSB. The process 600 may then end.

[0247] In some implementations, if the UE is configured with a single RSRP threshold (e.g., rsrp-ThresholdBFR) for the serving cell, the UE may determine the configured RSRP threshold is associated with both the SSB (e.g., BFD-RS set for / containing the AO-SSB) and the second candidate beam list is associated with the second SSB (e.g., the BFD-RS set for the OD-SSB).

[0248] In some implementations, regarding the candidate beam lists, a third candidate beam list associated with the first SSB may be further configured in the BFR configuration. For example, the third candidate beam list may correspond to the candidateBeamRS-List IE or the candidateBeamRS-List2 IE (e.g., that is different from the first candidate beam list). In response to the second candidate beam list (e.g., the candidateBeamRS-List3 IE) associated with the second SSB not being configured in the BFR configuration, the UE may determine that the third candidate beam list is associated with both the first SSB and the second SSB.

[0249] In some implementations, after action 605, the UE may further determine whether the second SSB is activated or deactivated. For example, the UE may receive a MAC CE indicating whether the second SSB (e.g., OD-SSB) is activated or deactivated. In response to determining that the second SSB is activated, the UE may determine that the second SSB is transmitted on the serving cell. In response to determining that the second SSB is deactivated, the UE may determine that the second SSB is not transmitted on the serving cell.

[0250] Based on the implementations of the present disclosure, by determining whether the second BFR-related parameter associated with the second SSB (e.g., the OD-SSB) is configured, the UE may flexibly determine the association of the BFR parameters. When the specific parameter for the second SSB is not configured, the UE automatically applies the first BFR-related parameter (e.g., the RSRP threshold or the candidate beam list) associated with the first SSB (e.g., the AO-SSB) to the second SSB. This mechanism not only provides configuration flexibility for the network but also significantly reduces signaling overhead in the wireless communication system while ensuring that the BFR procedure is performed correctly and efficiently in scenarios supporting the On-Demand SSB.

[0251] FIG. 7 is a block diagram illustrating a node 700 for wireless communication in accordance with various aspects of the present disclosure. As illustrated in FIG. 7, a node 700 may include a transceiver 720, a processor 728, a memory 734, one or more presentation components 738, and at least one antenna 736. The node 700 may also include a radio frequency (RF) spectrum band module, a BS communications module, a network communications module, and a system communications management module, Input / Output (I / O) ports, I / O components, and a power supply (not illustrated in FIG. 7).

[0252] Each of the components may directly or indirectly communicate with each other over one or more buses 740. The node 700 may be a UE or a BS that performs various functions disclosed with reference to FIGS. 1 to 6.

[0253] The transceiver 720 has a transmitter 722 (e.g., transmitting / transmission circuitry) and a receiver 724 (e.g., receiving / reception circuitry) and may be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 720 may be configured to transmit in different types of subframes and slots including, but not limited to, usable, non-usable, and flexibly usable subframes and slot formats. The transceiver 720 may be configured to receive data and control channels.

[0254] The node 700 may include a variety of computer-readable media. Computer-readable media may be any available media that may be accessed by the node 700 and include volatile (and / or non-volatile) media and removable (and / or non-removable) media.

[0255] The computer-readable media may include computer-storage media and communication media. Computer-storage media may include both volatile (and / or non-volatile media), and removable (and / or non-removable) media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or data.

[0256] Computer-storage media may include RAM, ROM, EPROM, EEPROM, flash memory (or other memory technology), CD-ROM, Digital Versatile Disks (DVD) (or other optical disk storage), magnetic cassettes, magnetic tape, magnetic disk storage (or other magnetic storage devices), etc. Computer-storage media may not include a propagated data signal. Communication media may typically embody computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transport mechanisms and include any information delivery media.

[0257] The term “modulated data signal” may mean a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media may include wired media, such as a wired network or direct-wired connection, and wireless media, such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above listed components should also be included within the scope of computer-readable media.

[0258] The memory 734 may include computer-storage media in the form of volatile and / or non-volatile memory. The memory 734 may be removable, non-removable, or a combination thereof. Example memory may include solid-state memory, hard drives, optical-disc drives, etc. As illustrated in FIG. 7, the memory 734 may store a computer-readable and / or computer-executable instructions 732 (e.g., software codes) that are configured to, when executed, cause the processor 728 to perform various functions disclosed herein, for example, with reference to FIGS. 1 to 6. Alternatively, the instructions 732 may not be directly executable by the processor 728 but may be configured to cause the node 700 (e.g., when compiled and executed) to perform various functions disclosed herein.

[0259] The processor 728 (e.g., having processing circuitry) may include an intelligent hardware device, e.g., a Central Processing Unit (CPU), a microcontroller, an ASIC, etc. The processor 728 may include memory. The processor 728 may process the data 730 and the instructions 732 received from the memory 734, and information transmitted and received via the transceiver 720, the baseband communications module, and / or the network communications module. The processor 728 may also process information to send to the transceiver 720 for transmission via the antenna 736 to the network communications module for transmission to a CN.

[0260] One or more presentation components 738 may present data indications to a person or another device. Examples of presentation components 738 may include a display device, a speaker, a printing component, a vibrating component, etc.

[0261] In view of the present disclosure, it is obvious that various techniques may be used for implementing the disclosed concepts without departing from the scope of those concepts. Moreover, while the concepts have been disclosed with specific reference to certain implementations, a person of ordinary skill in the art may recognize that changes may be made in form and detail without departing from the scope of those concepts. As such, the disclosed implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the particular implementations disclosed and many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.

Claims

1. A User Equipment (UE) for performing a Beam Failure Recovery (BFR) procedure in a wireless communication system, the UE comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the UE to: 　　　　　　　　receive, from a Base Station (BS), a first Beam Failure Detection Reference Signal (BFD-RS) set associated with a first Synchronization Signal Block (SSB) and a second BFD-RS set associated with a second SSB, for a serving cell; 　　　　　　　　receive, from the BS, a Beam Failure Recovery (BFR) configuration for the serving cell, the BFR configuration comprising a first BFR-related parameter associated with the first SSB; 　　　　　　　　in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determine that the second BFR-related parameter is associated with the second SSB; and 　　　　　　　　in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determine that the first BFR-related parameter is associated with both the first SSB and the second SSB.

2. The UE of claim 1, wherein the first BFR-related parameter comprises a first Reference Signal Received Power (RSRP) threshold, and the second BFR-related parameter comprises a second RSRP threshold.

3. The UE of claim 1, wherein the first BFR-related parameter comprises a first candidate beam list, and the second BFR-related parameter comprises a second candidate beam list.

4. The UE of claim 3, wherein a third candidate beam list associated with the first SSB is further configured in the BFR configuration, and the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: 　　　　in response to the second candidate beam list associated with the second SSB is not configured in the BFR configuration, determine that the third candidate beam list is associated with both the first SSB and the second SSB.

5. The UE of claim 1, wherein the one or more computer-executable instructions, when executed by the at least one processor, further cause the UE to: 　　　　determine whether the second SSB is activated or deactivated; 　　　　in response to determining that the second SSB is activated, determine that the second SSB is transmitted on the serving cell; and 　　　　in response to determining that the second SSB is deactivated, determine that the second SSB is not transmitted on the serving cell.

6. A Base Station (BS) comprising: 　　　　at least one processor; and 　　　　at least one non-transitory computer-readable medium coupled to the at least one processor and storing one or more computer-executable instructions that, when executed by the at least one processor, cause the BS to: 　　　　　　　　transmit, to a User Equipment (UE), a first Beam Failure Detection Reference Signal (BFD-RS) set associated with a first Synchronization Signal Block (SSB) and a second BFD-RS set associated with a second SSB, for a serving cell of the UE; and 　　　　　　　　transmit, to the UE, a Beam Failure Recovery (BFR) configuration for the serving cell, the BFR configuration comprising a first BFR-related parameter associated with the first SSB, wherein the BFR configuration causes the UE to: 　　　　　　　　　　　　in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determine that the second BFR-related parameter is associated with the second SSB; and 　　　　　　　　　　　　in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determine that the first BFR-related parameter is associated with both the first SSB and the second SSB.

7. The BS of claim 6, wherein the first BFR-related parameter comprises a first Reference Signal Received Power (RSRP) threshold, and the second BFR-related parameter comprises a second RSRP threshold.

8. The BS of claim 6, wherein the first BFR-related parameter comprises a first candidate beam list, and the second BFR-related parameter comprises a second candidate beam list.

9. The BS of claim 8, wherein a third candidate beam list associated with the first SSB is further configured in the BFR configuration, and the BFR configuration further causes the UE to: 　　　　in response to the second candidate beam list associated with the second SSB is not configured in the BFR configuration, determine that the third candidate beam list is associated with both the first SSB and the second SSB.

10. The BS of claim 6, wherein the BFR configuration further causes the UE to: 　　　　determine whether the second SSB is activated or deactivated; 　　　　in response to determining that the second SSB is activated, determine that the second SSB is transmitted on the serving cell; and 　　　　in response to determining that the second SSB is deactivated, determine that the second SSB is not transmitted on the serving cell.

11. A method performed by a User Equipment (UE) for performing a Beam Failure Recovery (BFR) procedure in a wireless communication system, the method comprising: 　　　　receiving, from a Base Station (BS), a first Beam Failure Detection Reference Signal (BFD-RS) set associated with a first Synchronization Signal Block (SSB) and a second BFD-RS set associated with a second SSB, for a serving cell; 　　　　receiving, from the BS, a BFR configuration for the serving cell, the BFR configuration comprising a first BFR-related parameter associated with the first SSB; 　　　　in response to a second BFR-related parameter associated with the second SSB is configured in the BFR configuration, determining that the second BFR-related parameter is associated with the second SSB; and 　　　　in response to the second BFR-related parameter associated with the second SSB is not configured in the BFR configuration, determining that the first BFR-related parameter is associated with both the first SSB and the second SSB.

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