Beam failure recovery equipment, method and device

Abstract

Exemplary embodiments of the present disclosure relate to a device, method and apparatus for beam failure recovery of a cell. In one aspect, a first network device determines a radio resource control (RRC) reconfiguration prepared by the first network device for one or more cells. The RRC reconfiguration includes a beam failure recovery configuration to be used by the terminal device to perform beam failure recovery for the one or more cells. And the first network equipment sends the RRC reconfiguration to the second network equipment. Through this procedure, the UE may restore to the non-serving cell if a beam failure is detected.

Description

Technical Field

[0001] Various example embodiments relate to the field of communications, and in particular to a terminal device, a network device, a method, an apparatus and a computer-readable storage medium for beam failure recovery, especially beam failure recovery of a non-serving cell. Background Art

[0002] According to the latest 3GPP protocol, Layer 1 (L1) / Layer 2 (L2) triggered mobility (LTM) is divided into four phases: a preparation phase, during which the serving central unit (CU) identifies the target cell based on the layer 3 (L3) measurement report, prepares the target cell and shares the target cell configuration with the user equipment (UE); an early synchronization phase, during which the serving distribution unit (DU) requires the UE to perform timing advance (TA) acquisition for a specific target cell by considering L1 measurements; an execution phase, during which the serving DU decides the target cell and requires the UE to switch to the target cell, and the UE switches to the target cell and starts receiving data from the target cell; and a completion phase, during which the UE context is released from the prepared cell.

[0003] Inter-cell beam management was introduced in Rel.17 and enables a UE to be served by a beam of a neighboring cell without changing the serving cell. This means that the UE will continue to have its context in the serving cell and the UE will listen to the broadcast (e.g., cell-specific common) channels of the serving cell, but data (e.g., UE-specific channels / signals) will be provided to the UE from a borrowed beam from a non-serving cell. However, both LTM and inter-cell beam management (ICBM) still involve the following challenges: in the event of a beam failure, the UE is only allowed to recover in the serving cell even if there is another better beam in the non-serving cell, and beam failure resources are configured separately for the serving cell and the secondary cell, which results in a waste of resources. Summary of the invention

[0004] In general, exemplary embodiments of the present disclosure provide a solution for performing beam failure recovery, for example, performing beam failure recovery on a non-serving cell.

[0005] In a first aspect, a first network device is provided. The first network device may include: at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, cause the first network device to at least: determine a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and send the RRC reconfiguration to a second network device.

[0006] In a second aspect, a second network device is provided. The second network device may include: at least one processor and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the second network device to at least: receive from the first network device a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and send the RRC reconfiguration to the terminal device.

[0007] In a third aspect, a terminal device is provided. The terminal device may include: at least one processor and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the terminal device to at least: receive a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device from a second network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and perform beam failure recovery on the one or more cells based on the beam failure recovery configuration.

[0008] In a fourth aspect, a method is provided. The method may include: determining, at a first network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and sending the RRC reconfiguration to a second network device.

[0009] In a fifth aspect, a method is provided. The method may include: receiving, at a second network device, from a first network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and sending the RRC reconfiguration to the terminal device.

[0010] In a sixth aspect, a method is provided. The method may include: receiving, at a terminal device, from a second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and performing beam failure recovery on the one or more cells based on the beam failure recovery configuration.

[0011] In a seventh aspect, an apparatus is provided. The apparatus may include: a component for determining, at a first network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and a component for sending the RRC reconfiguration to a second network device.

[0012] In an eighth aspect, an apparatus is provided. The apparatus may include: a component for receiving, at a second network device, from a first network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and a component for sending the RRC reconfiguration to the terminal device.

[0013] In a ninth aspect, an apparatus is provided. The apparatus may include: a component for receiving, at a terminal device, from a second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and a component for performing beam failure recovery on the one or more cells based on the beam failure recovery configuration.

[0014] In a tenth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium comprising program instructions for causing an apparatus to at least execute a method according to any one of the fourth aspect or the sixth aspect.

[0015] In an eleventh aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to at least: determine a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration comprises a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and send the RRC reconfiguration to a second network device.

[0016] In a twelfth aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to at least: receive from a first network device a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration comprises a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery on the one or more cells; and send the RRC reconfiguration to the terminal device.

[0017] In a thirteenth aspect, a computer program comprising instructions is provided, which, when executed by an apparatus, causes the apparatus to at least: receive, from a second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and perform beam failure recovery on the one or more cells based on the beam failure recovery configuration.

[0018] In a fourteenth aspect, a first network device is provided. The first network device may include: a determining circuit system for determining a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and a sending circuit system for sending the RRC reconfiguration to a second network device.

[0019] In a fifteenth aspect, a second network device is provided. The second network device may include: a receiving circuit system for receiving, from a first network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery for the one or more cells; and a transmitting circuit system for sending the RRC reconfiguration to the terminal device.

[0020] In a sixteenth aspect, a terminal device is provided. The terminal device may include: a receiving circuit system for receiving a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device from a second network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and an execution circuit system for performing beam failure recovery on the one or more cells based on the beam failure recovery configuration.

[0021] It should be understood that the invention summary is not intended to determine the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which:

[0023] Figure 1 illustrates a communication environment in which some embodiments of the present disclosure may be implemented;

[0024] Figure 2 illustrates a signaling diagram showing a communication process according to some embodiments of the present disclosure;

[0025] Figure 3illustrates an exemplary signaling diagram for performing beam failure recovery on a non-serving cell according to some embodiments of the present disclosure;

[0026] Figure 4 illustrates an exemplary signaling diagram for performing beam failure recovery on a non-serving cell according to some embodiments of the present disclosure;

[0027] Figure 5 illustrates a flow chart of a method implemented at a first network device according to some embodiments of the present disclosure;

[0028] Figure 6 A flowchart of a method implemented at a second network device according to some embodiments of the present disclosure is illustrated;

[0029] Figure 7 A flowchart of a method implemented at a terminal device according to some embodiments of the present disclosure is illustrated;

[0030] Figure 8 illustrates a simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure; and

[0031] Fig. 9 A block diagram of an example computer-readable medium is illustrated in accordance with some embodiments of the present disclosure.

[0032] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0033] The principle of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only to illustrate and help those skilled in the art to understand and implement the present disclosure, and do not represent any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various other ways except the way described below.

[0034] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0035] In this disclosure, references to "one embodiment," "an embodiment," and "an example embodiment" indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, those skilled in the art believe that it is within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0036] It should be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0037] The terms used herein are only used to describe specific embodiments, and are not intended to limit exemplary embodiments. As used herein, unless the context clearly states otherwise, the singular forms "a", "an" and "the" also include plural forms. It is further understood that the terms "comprises", "comprising", "has", "having", "includes" and / or "including" specify the presence of the features, elements and / or components when used herein, but do not exclude the presence or addition of one or more other features, elements, components and / or their combinations. As used herein, "at least one of the following: <list of two or more elements>" and "at least one of the lists of <two or more elements>" and similar wording (wherein the list of two or more elements is connected by "and" or "or") refer to at least any one of these elements, or at least any two or more of these elements, or at least all of these elements.

[0038] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0039] (a) a pure hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and

[0040] (b) a combination of hardware circuitry and software such as (where applicable):

[0041] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0042] (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions, and

[0043] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), which requires software (e.g., firmware)

[0044] The software can be non-existent when no operation is needed.

[0045] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0046] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation of communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocol and / or any other protocol currently known or to be developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there will certainly be future types of communication technologies and systems that can embody the present disclosure. The scope of the present disclosure should not be limited to the above-mentioned systems.

[0047] As used herein, the term "network device" refers to a node in a communication network, via which a terminal device accesses the network and receives services from the network. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), such as a NodeB (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a repeater, a low-power node (such as a femto, a pico), etc.

[0048] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not limitation, a terminal device may also be referred to as a communication device, a user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), consumer electronic devices, commercially operated equipment, and / or industrial wireless networks, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0049] As mentioned above, according to the latest 3GPP protocol, Layer 1 (L1) / Layer 2 (L2) Triggered Mobility (LTM) is divided into four phases: a preparation phase, during which the serving central unit (CU) identifies the target cell based on the layer 3 (L3) measurement report, prepares the target cell and shares the target cell configuration with the user equipment (UE); an early synchronization phase, during which the serving distribution unit (DU) requires the UE to perform timing advance (TA) acquisition on a specific target cell by considering L1 measurements; an execution phase, during which the serving DU decides the target cell and requires the UE to switch to the target cell, and the UE switches to the target cell and starts receiving data from the target cell; a completion phase, during which the UE context is released from the prepared cell (this is optional, and in the case of dynamic switching, the UE context can be retained, depending on how long the CU will keep the UE context).

[0050] In case of beam failure, the UE is expected to revert to the serving cell even if the UE has a configuration of multiple cells (i.e., target cell configuration) provided earlier (in the preparation phase).

[0051] In Rel.17, Inter-Cell Beam Management (ICBM) is introduced and enables a UE to be served by a beam of a neighboring cell without changing the serving cell. This means that the UE will continue to have its context in the serving cell and the UE will listen to the broadcast (e.g., cell-specific common) channels of the serving cell, but data (e.g., UE-specific channels / signals) will be provided to the UE from a borrowed beam from a non-serving cell.

[0052] In ICBM, the UE is configured with a beam from a secondary cell based on L3 measurement reports. The ICBM configuration is provided to the UE in RRC. The serving cell can then select the beam of the secondary cell and the secondary cell based on L1 measurements, and initiate service to the UE through the secondary (non-serving, neighboring) cell. It should be noted that prior to Rel. 18, ICBM was strictly an intra-DU concept. It should also be noted that in the context of this disclosure, the terms "non-serving" and "secondary" can be used interchangeably.

[0053] Furthermore, in the current 3GPP NR specification, i.e. Rel 15, beam failure is identified by counting beam failure instance (BFI) indications from the lower layers to the MAC entity. If a BFI is not identified within a certain amount of time (i.e., beam failure detection timer), the BFI counter will be reset. If the BFI counter reaches the maximum number configured in the RRC, the UE will declare a beam failure and start the beam failure recovery procedure (see [TS 38.321 Section 5.17]); in this case, it will perform a new beam search and will identify the best beam from the serving cell to be recovered.

[0054] If the BFR process fails, the UE will declare a radio link failure (RLF) and start searching for candidate beams for connection reestablishment. These beams can be from serving cells or non-serving cells. However, declaring RLF and initiating connection reestablishment will increase the interruption time.

[0055] Resources for performing BFR are configured to the UE in RRC. The beam for performing BFR is configured in BFR SSB resources or BFR CSIRS resources, where specific RACH resources are allocated to enable the UE to access the configured beam. If no specific RACH resources are allocated, the UE will perform contention-based access using the recovery beam.

[0056] Therefore, in the LTM framework and ICBM framework, the following challenges still exist: in the case of beam failure, even if there is another better beam in the non-serving cell, the UE is only allowed to recover in the serving cell, and the beam failure resources are configured separately for the serving cell and the secondary cell, which leads to resource waste.

[0057] In view of the above situation, some embodiments of the present disclosure propose a solution for performing beam failure recovery on a cell (e.g., a non-serving cell). In the solution, a first network device determines a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by a terminal device to perform beam failure recovery on the one or more cells. Then, the first network device sends the RRC reconfiguration to a second network device.

[0058] According to this embodiment, a UE configured with ICBM and BFR to a non-serving cell will monitor the dedicated channel from the secondary cell and the broadcast channel from the serving cell if a beam failure is detected, and a UE configured with LTM and BFR to a non-serving cell will change to a target cell if a beam failure is detected so that the UE only monitors the channels from the target cell.

[0059] The principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Figure 1 , Figure 1 An example communication system 100 is illustrated in which embodiments of the present disclosure may be implemented.

[0060] like Figure 1 As shown, the system 100 includes a CU 110 (which is a network device and is also referred to as a first network device), a source DU 120 (which is a network device and is also referred to as a second network device), and a plurality of candidate cells 130 prepared by the CU 110. Among the plurality of prepared candidate cells 130, a corresponding cell 131 serves as a secondary cell or a target cell 131 for beam failure recovery. Figure 1 As shown, the system 100 also includes a terminal device 140 (also referred to as UE). Figure 1 As shown, the terminal device 140 is moving from the serving cell of the source DU 120 to another non-serving cell, and a serving cell change needs to be performed at this time.

[0061] It should be understood that Figure 1 The specific number of various communication devices, the specific number of various communication links, the specific number of other elements, and the specific shape of the cell shown are for illustration purposes only and do not represent any limitation. The communication system 100 may include any suitable number of communication devices, any suitable number of communication links, any suitable number of other elements, and any suitable shape of cells suitable for implementing the embodiments of the present disclosure. In addition, it should be understood that various wireless and wired communications (if necessary) may exist between all communication devices.

[0062] The communication in the communication system 100 can be implemented according to any appropriate communication protocol, including but not limited to cellular communication protocols of the first generation (1G), second generation (2G), third generation (3G), fourth generation (4G) and fifth generation (5G), wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 1002.11, and / or any other protocol currently known or to be developed in the future. In addition, the communication can utilize any appropriate wireless communication technology, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread spectrum OFDM (DFT-s-OFDM) and / or any other technology currently known or to be developed in the future.

[0063] In the following, reference will be made to Figures 2 to 4 An example method for performing beam failure recovery for a non-serving cell is described. Figure 2 , Figure 2 An exemplary signaling diagram illustrating a communication process according to some embodiments of the present disclosure is illustrated.

[0064] like Figure 2 As shown, the first network device 110 determines (205) a radio resource control (RRC) reconfiguration 215 for one or more cells prepared by the first network device 110. The RRC reconfiguration 215 includes a beam failure recovery configuration to be used by the terminal device (UE) 140 to perform beam failure recovery for the one or more cells. The first network device 110 sends (210) the RRC reconfiguration 215 to the second network device 120. Accordingly, the second network device 120 receives (220) the RRC reconfiguration 215 from the first network device 110.

[0065] After receiving the RRC reconfiguration 215, the second network device 120 sends (225) the RRC reconfiguration 215 to the terminal device 140. Accordingly, the terminal device 140 receives (230) the RRC reconfiguration from the second network device 120. Then, in the event that a beam failure is detected, the terminal device 140 performs (235) beam failure recovery for one or more cells based on the RRC reconfiguration.

[0066] In some embodiments, the beam failure recovery configuration may instruct the terminal device 140 to initiate a beam failure recovery process for one or more cells other than the serving cell when a beam failure is detected. For example, the serving cell refers to a cell serving the terminal device 140 and belongs to the second network device (source DU) 120.

[0067] In some embodiments, the beam failure recovery configuration may instruct the second network device 120 to perform inter-cell beam management (ICBM) through a cell other than the serving cell in the event of beam failure recovery. Thus, the terminal device 140 is served using ICBM through a cell other than the serving cell. ICBM enables the terminal device to be served by a beam of a cell other than the serving cell without changing the serving cell.

[0068] In some embodiments, the first network device 110 may determine to establish ICBM and beam failure recovery for a cell other than the serving cell. The first network device 110 may send a terminal device context modification request to the second network device 120, and accordingly, the second network device 120 may receive the terminal device context modification. Then, the second network device 120 may send a terminal device context modification response to the first network device 110, and the terminal device context modification response may include a beam failure recovery configuration for performing beam failure recovery for a cell other than the serving cell. Then, the first network device 110 may configure the RRC configuration based on the received terminal device context modification response.

[0069] In some embodiments, a cell other than the serving cell may also be referred to as a secondary cell, and the secondary cell and the serving cell may belong to the same network device, such as the second network device or the source DU 120 .

[0070] In some embodiments, in the event of a beam failure being detected, the terminal device 140 may initiate beam failure recovery to the secondary cell based on the beam failure recovery configuration. For example, in response to detecting a beam failure, the terminal device 140 may perform beam selection from one or more prepared cells, identify that the selected beam to be served belongs to the secondary cell, and access the secondary cell.

[0071] In some embodiments, the terminal device 140 may send a beam failure recovery media access control (MAC) control element (CE) to the second network device 120. After receiving the beam failure recovery MAC CE, the second network device 140 decides that the terminal device 140 is served using ICBM through a cell other than the serving cell.

[0072] In some embodiments, the beam failure recovery configuration may include a contention-free random access configuration for cells other than the serving cell. Based on the contention-free random access configuration, the terminal device 140 may access cells other than the serving cell.

[0073] In some examples, based on the contention-free random access configuration, the terminal device 140 may send a contention-free random access preamble to the second network device 120 , and then the terminal device 140 may send a beam failure recovery MAC CE to the second network device 120 .

[0074] In some embodiments, the beam failure recovery configuration may include a contention-based random access configuration for cells other than the serving cell. Based on the contention-based random access configuration, the terminal device 140 may access cells other than the serving cell.

[0075] In some examples, based on the contention-based random access configuration, the terminal device 140 may send a contention-based random access preamble to the second network device 120 , and then the terminal device 140 may send a beam failure recovery MAC CE to the second network device 120 .

[0076] In some embodiments, the beam failure recovery MAC CE may include an indication of beam failure recovery, an identifier of the terminal device, and an identifier of the serving cell. For example, the identifier of the terminal device may include a beam failure recovery cell radio network temporary identifier (BFR-C-RNTI), a C-RNTI of the terminal device, or other identifiers, and the BFR-C-RNTI is allocated specifically for the terminal device.

[0077] In some embodiments, the beam failure recovery configuration may instruct the terminal device to perform beam failure recovery on a cell other than the serving cell using a layer 1 / layer 2 triggered mobility (TM) configuration when a beam failure is detected. The LTM configuration is determined by the first network device 110. The LTM enables the terminal device to switch to a cell other than the serving cell.

[0078] In some embodiments, a cell other than a serving cell may also be referred to as a target cell, and the target cell and the serving cell may belong to the same node, for example, a second network device or a source DU 120; or the target cell and the serving cell may belong to different nodes, for example, the target cell may belong to a target DU, and the serving cell may belong to a source DU 131.

[0079] In some embodiments, in the case of detecting a beam failure, the terminal device 140 may initiate beam failure recovery for the target cell based on the beam failure recovery configuration. For example, in response to detecting a beam failure, the terminal device 140 may perform beam selection from one or more prepared cells, identify that the selected beam to be served belongs to the target cell, and access the target cell.

[0080] In some embodiments, the terminal device 140 may send an RRC reconfiguration completion message to the node 131 providing a cell other than the serving cell, the RRC reconfiguration completion message including an indication of beam failure recovery. Then, the node 131 providing a cell other than the serving cell may send an RRC reconfiguration completion message to the first terminal device. After receiving the RRC reconfiguration completion message, the first terminal device 110 may perform a cell handover so that the terminal device 140 may be switched to a cell other than the serving cell.

[0081] In some embodiments, the LTM configuration for cells other than the serving cell may be a contention-free random access configuration for cells other than the serving cell.Based on the contention-free random access configuration, the terminal device 140 may access cells other than the serving cell.

[0082] In some examples, based on the contention-free random access configuration, the terminal device 140 may use the LTM configuration of the cell other than the serving cell to send a contention-free random access preamble to the node 131 providing the cell other than the serving cell, and then the terminal device 140 may send an RRC reconfiguration completion message to the node 131 providing the cell other than the serving cell.

[0083] In some embodiments, the LTM configuration of cells other than the serving cell may include a contention-based random access configuration for cells other than the serving cell. Based on the contention-based random access configuration, the terminal device 140 may access the cell other than the serving cell.

[0084] In some examples, based on the contention-based random access configuration, the terminal device 140 may use the LTM configuration of the cell other than the serving cell to send a contention-based random access preamble to the node 131 providing the cell other than the serving cell, and then the terminal device 140 may send an RRC reconfiguration completion message to the node 131 providing the cell other than the serving cell.

[0085] In some embodiments, the RRC reconfiguration complete message may include an indication of beam failure recovery and an identifier of the terminal device, and may also include an identifier of the serving cell. For example, the identifier of the terminal device may include a beam failure recovery cell radio network temporary identifier (BFR-C-RNTI) allocated specifically for the terminal device, a C-RNTI of the terminal device, or other identifier.

[0086] In some embodiments, when acquiring the timing advance of the terminal device, the terminal device 140 may send an RRC reconfiguration complete message to the node 131 providing a cell other than the serving cell. For example, the timing advance of the terminal device may be acquired via an early timing advance acquisition process or UE-based timing advance measurement.

[0087] In the following, reference will be made to Figure 3 An exemplary signaling diagram 300 for performing beam failure recovery for a non-serving cell according to some embodiments of the present disclosure is described. In this exemplary solution, it is proposed that the serving cell and the secondary cell belong to the same DU, the UE 140 is configured with BFR resources of the secondary cell, and the BFR resources are configured as a set of CSI-RS resources of the secondary cell. In case of detecting beam failure in the serving cell, the UE 140 sends an indication about BFR to the secondary cell, and the UE 140 identifies its arrival at the secondary cell so that the UE 140 can access there. Then, the UE 140 ends with ICBM with the secondary cell. The steps of BFR and ICBM operation to the non-serving cell are as follows: Figure 3 , and the steps are described below.

[0088] At steps 1 to 2, UE 140 provides a measurement report, such as an L3 measurement report, to CU 110. At step 3, CU 110 decides to establish ICBM and BFR using resources from secondary cells (eg, secondary cell 1, secondary cell 2, secondary cell 3).

[0089] At steps 4 to 5, the CU 110 with the UE context modification request requests the DU 120 to establish ICBM and BFR using resources from the secondary cells 1, 2, 3; the DU 120 responds with a UE context modification response containing the BFR configuration (e.g., SSB / CSI-RS, preamble, etc.) of the secondary cells 1, 2, 3. It should be noted that for the ICBM configuration of cells 1, 2, 3, the UE 140 is configured to measure and / or report beams from these cells.

[0090] At steps 6 to 8, CU 110 prepares the RRC reconfiguration using the BFR resources from the secondary cell and provides the RRC reconfiguration to UE 140. At steps 11-14, UE 140 confirms the correct reception of the RRC reconfiguration.

[0091] At steps 11-14, UE 140 provides L1 measurement report to serving DU 120, and serving DU 120 decides to start ICBM operation using borrowed beam from non-serving cell (e.g., cell 1) at a certain point in time. UE 140 starts to be served by neighboring cell (e.g., cell 1) through ICBM (using borrowed beam from non-serving cell). It will be appreciated by those skilled in the art that steps 11-14 are not mandatory.

[0092] At step 15, at some point in time, UE 140 experiences beam failure. At step 16, upon detecting beam failure, UE 140 performs beam selection and identifies that the best beam to serve belongs to a secondary cell (eg, secondary cell 2).

[0093] In option 1, which can be applied to the CFRA case, at step 17, UE 140 sends a CFRA preamble to secondary cell 2. Considering the CFRA preamble, secondary cell 2 understands that the UE accessing the secondary cell performs BFR on secondary cell 2. At step 18, UE 140 sends a BFR MAC CE to secondary cell 2.

[0094] In option 2, which may be applicable to the CBRA case (e.g., when the same BFR RACH resources are allocated to multiple UEs of multiple different cells or / and the same cell), at step 19, UE 140 issues a CBRA preamble to the secondary cell. At step 20, UE 140 issues a BFR MAC CE to the secondary cell 2. To be identified by the secondary cell 2, UE 140 includes in the MAC CE an indication that this is a BFR to the secondary cell, as well as a unique identifier of the UE (e.g., a BFR-C-RNTI specifically allocated for this purpose, its C-RNTI, or another identifier) ​​and an identifier of the serving cell. Using these identifiers, DU 120 can associate the UE context with the source cell.

[0095] At step 21, ICBM is provided through the secondary cell to the UE 140. In this case, the original serving cell does not change, which indicates no mobility.

[0096] In the following, Figure 4 An exemplary signaling diagram for performing beam failure recovery to a non-serving cell according to some embodiments of the present disclosure is illustrated. In this solution, it is proposed that upon beam failure detection in the serving cell, after identifying the beam to be recovered in the target cell, the UE applies a new configuration, specifically, the UE performs an autonomous LTM switch to BFR. In the case of CFRA, the UE uses RACH resources for LTM. This gives an implicit indication to the target node: it is an LTM switch for beam failure recovery as well as beam specific recovery. In the case of CBRA, the UE uses CBRA resources but indicates to the target cell (in RRC reconfiguration complete or MAC CE) that this is a BFR to a non-serving cell. If the TA for the target cell has been acquired, the UE will indicate in the RRC reconfiguration complete that it is a BFR. The steps of BFR and LTM operations to non-serving cells are as follows: Figure 4 shown, and Figure 4 The steps are described below.

[0097] At step 1-2, UE 140 provides measurement report to CU 110. At step 3, CU 110 decides to use BFR from target cell to establish LTM. At step 4-5, CU 110 with UE settings configures BFR to non-serving cell of LTM. At step 6-7, CU 110 provides target cell configuration to serving DU 120.

[0098] At steps 8-10, CU 110 prepares an RRC configuration with a BFR to non-serving cell configuration and provides it to UE 140. At steps 11-12, UE 140 confirms correct reception of the RRC reconfiguration. At steps 13-17, UE 140 performs early DL / UL synchronization. UL synchronization can be triggered by the network using a PDCCH order, triggering UE 140 to issue a RACH to the target cell 131. The target cell 131 obtains the timing advance of the UE and sends it to the source DU 120. At step 18, UE 140 provides L1 measurements to DU 120 for beam management and mobility.

[0099] At a certain point in time, UE 140 experiences beam failure at step 19. At step 20, after beam failure detection, UE 140 performs beam selection and identifies that the best beam to serve belongs to the prepared LTM candidate target cell.

[0100] In option 1, which can be applied to the CFRA case, at step 21, UE 140 issues a CFRA preamble to target cell 131. In view of the CFRA preamble, target cell 131 understands that UE 140 accessing it performs mobility, and it provides timing advance to the UE in a random access response. At step 22, UE 140 issues an RRC reconfiguration including an indication that it is a BFR.

[0101] In option 2, which may be applied to the CBRA case, at step 23, UE 140 issues a CBRA preamble to target cell 131. Target cell 131 considers this to be a regular cell access to the target cell, which is related to mobility. It then provides a timing advance to UE 140 in a random access response. At step 24, UE 140 issues an RRC reconfiguration including an indication that it is a BFR. UE 140 may also include its unique identifier (e.g., a BFR-C-RNTI specifically allocated for this purpose, its C-RNTI, or another identifier) ​​and an identifier of the serving cell. Using these identifiers, the DU may associate the UE context with the source cell.

[0102] In option 3, which may be applicable where the UE is aware of the timing advance (eg, via an early TA acquisition procedure or based on UE's TA measurements), at step 25, the UE 140 issues an RRC Reconfiguration Complete including an indication that it is a BFR.

[0103] At step 26, the target DU 131 issues an RRC reconfiguration including an indication that it is a BFR to the CU 110 using UL RRC messaging; the CU 110 performs a cell change. At step 27, the DU 131 issues an access success message, as it interprets the access to the target as a mobility procedure.

[0104] In this case, if each serving cell has been configured with BFR RACH resources for recovery, the UE will decide to trigger LTM recovery instead of CFRA if the LTM target beam is better than the BFR SSB of the source cell. The DU can configure radio condition differences to prioritize LTM recovery over BFR via the serving cell beam.

[0105] Figure 5 FIG. 5 is a flow chart of a method 500 implemented at a first network device (eg, CU 110) according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figure 1 The method 500 is described from the perspective of the CU 110 .

[0106] At block 510, the first network device 110 determines a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by the terminal device to perform beam failure recovery for the one or more cells. At block 520, the first network device 110 sends the RRC reconfiguration to the second network device 120.

[0107] In some embodiments, the beam failure recovery configuration instructs the terminal device to initiate a beam failure recovery process to a cell other than the serving cell in one or more cells when a beam failure is detected.

[0108] In some embodiments, the beam failure recovery configuration instructs the second network device to perform inter-cell beam management through a cell other than a serving cell in the event of beam failure recovery based on reception of a beam failure recovery media access control (MAC) control element (CE).

[0109] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration for a cell other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access a cell other than the serving cell based on the contention-free random access configuration. In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-free random access preamble to the second network device; and send a beam failure recovery MAC CE to the second network device.

[0110] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration for cells other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the serving cell based on the contention-based random access configuration.

[0111] In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-based random access preamble to the second network device; and send a beam failure recovery MAC CE to the second network device. In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device, and an identifier of the serving cell.

[0112] In some embodiments, the first network device 110 sends a terminal device context modification request to the second network device 120; receives a terminal device context modification response from the second network device 120, the terminal device context modification response including a beam failure recovery configuration for performing beam failure recovery on a cell other than a serving cell; and configures RRC reconfiguration based on the received terminal device context modification response.

[0113] In some embodiments, the first network device 110 receives an RRC reconfiguration complete message including an indication of beam failure recovery from a node 131 providing a cell other than the serving cell; and performs cell switching based on the reception of the indication of beam failure recovery.

[0114] In some embodiments, the first network device 110 determines a layer 1 / layer 2 triggered mobility (LTM) configuration for one or more cells; and the beam recovery configuration instructs the terminal device to perform beam failure recovery on cells other than the serving cell using the LTM configuration for cells other than the serving cell when a beam failure is detected.

[0115] In some embodiments, the LTM configuration for cells other than the serving cell includes a contention-free random access configuration for cells other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the serving cell based on the contention-free random access configuration when a beam failure is detected.

[0116] In some embodiments, the beam failure recovery configuration instructs the terminal device to: use the LTM configuration of the cell other than the serving cell, send a contention-free random access preamble code to the node providing the cell other than the serving cell; and send an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0117] In some embodiments, the LTM configuration of cells other than the service cell includes a contention-based random access configuration of cells other than the service cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the service cell based on the contention-based random access configuration when a beam failure is detected.

[0118] In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-based random access preamble to a node providing a cell other than the serving cell using an LTM configuration for the cell other than the serving cell; and send an RRC reconfiguration complete message including an indication of beam failure recovery to the node providing the cell other than the serving cell. In some embodiments, the RRC reconfiguration complete message also includes an identifier of the terminal device.

[0119] In some embodiments, the beam failure recovery configuration instructs the terminal device to send an RRC reconfiguration complete message including an indication of beam failure recovery to a node providing a cell other than the serving cell based on obtaining a timing advance of the terminal device.

[0120] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0121] Figure 6 FIG. 6 is a flowchart of a method 600 implemented at a second network device according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figure 1 The method 600 is described from the perspective of the source DU 120 .

[0122] At block 610, the second network device 120 receives from the first network device 110 a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by the terminal device to perform beam failure recovery for the one or more cells. At block 620, the second network device 120 sends the RRC reconfiguration to the terminal device 140.

[0123] In some embodiments, the beam failure recovery configuration instructs the terminal device to initiate a beam failure recovery process to a cell other than the serving cell in one or more cells when a beam failure is detected.

[0124] In some embodiments, the second network device 120 performs inter-cell beam management through cells other than the serving cell based on reception of a beam failure recovery media access control (MAC) control element (CE) in the case of beam failure recovery.

[0125] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration for cells other than the serving cell, and the beam failure recovery configuration instructs the terminal device to access the cell other than the serving cell based on the contention-free random access configuration.

[0126] In some embodiments, the second network device 120 receives a contention-free random access preamble from the terminal device 140 , and receives a beam failure recovery MAC CE from the terminal device 140 .

[0127] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration for cells other than the serving cell, and the beam failure recovery configuration instructs the terminal device to access the cell other than the serving cell based on the contention-based random access configuration.

[0128] In some embodiments, the second network device 120 receives a contention-based random access preamble from the terminal device; and receives a beam failure recovery MAC CE from the terminal device.

[0129] In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device and an identifier of the serving cell.

[0130] In some embodiments, the second network device 120 receives a terminal device context modification request from the first network device; and sends a terminal device context modification response to the first network device, the terminal device context modification response including a beam failure recovery configuration for performing beam failure recovery on a cell other than a serving cell.

[0131] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0132] Figure 7 FIG. 1 is a flowchart of a method implemented at a terminal device according to some other embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 The method 700 is described from the perspective of the terminal device 140 .

[0133] At block 710, the terminal device 140 receives a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device from the second network device 120, wherein the RRC reconfiguration includes a beam failure recovery configuration. At block 720, the terminal device 140 performs beam failure recovery for the one or more cells based on the beam failure recovery configuration.

[0134] In some embodiments, the terminal device 140 detects a beam failure; and based on a beam failure recovery configuration, initiates a beam failure recovery process to a cell other than a serving cell in one or more cells.

[0135] In some embodiments, the terminal device 140 sends a beam failure recovery media access control (MAC) control element (CE) to the second network device. The beam failure recovery configuration instructs the second network device to perform inter-cell beam management through a cell other than the serving cell in the case of beam failure recovery based on the second network device's reception of the beam failure recovery MAC CE.

[0136] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration for cells other than the serving cell, and the terminal device is further caused to access the cell other than the serving cell based on the contention-free random access configuration.

[0137] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 sends a contention-free random access preamble to the second network device; and sends a beam failure recovery MAC CE to the second network device.

[0138] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration of cells other than the serving cell, and the terminal device is further caused to access the cells other than the serving cell based on the contention-based random access configuration.

[0139] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 sends a contention-based random access preamble to the second network device; and sends a beam failure recovery MAC CE to the second network device.

[0140] In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device and an identifier of the serving cell.

[0141] In some embodiments, the terminal device 140 sends an RRC reconfiguration complete message including an indication of beam failure recovery to a cell other than the serving cell.

[0142] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 uses the LTM configuration of cells other than the serving cell to perform beam failure recovery on cells other than the serving cell when beam failure is detected.

[0143] In some embodiments, the LTM configuration for cells other than the serving cell includes a contention-free random access configuration for cells other than the serving cell, and the terminal device is further enabled to access cells other than the serving cell based on the contention-free random access configuration when beam failure is detected.

[0144] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 uses the LTM configuration of the cell other than the serving cell, sends a contention-free random access preamble code to the node providing the cell other than the serving cell; and sends an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0145] In some embodiments, the LTM configuration for cells other than the serving cell includes a contention-based random access configuration for cells other than the serving cell, and the terminal device is further enabled to access cells other than the serving cell based on the contention-based random access configuration when a beam failure is detected.

[0146] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 uses the LTM configuration of the cell other than the serving cell, sends a contention-based random access preamble code to the node providing the cell other than the serving cell; and sends an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0147] In some embodiments, the RRC reconfiguration complete message also includes an identifier of the terminal device.

[0148] In some embodiments, based on the beam failure recovery configuration, the terminal device 140 obtains a timing advance of the terminal device; and sends an RRC reconfiguration complete message including an indication of beam failure recovery to a network device providing a cell other than the serving cell.

[0149] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0150] In some embodiments, a device capable of executing method 500 (eg, CU 110) may include a component for executing the corresponding steps of method 500. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit system or a software module.

[0151] In some embodiments, the apparatus comprises means for determining a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration comprises a beam failure recovery configuration to be used by the terminal device to perform beam failure recovery for the one or more cells. The apparatus comprises means for sending the RRC reconfiguration to the second network device 120.

[0152] In some embodiments, the beam failure recovery configuration instructs the terminal device to initiate a beam failure recovery process to a cell other than the serving cell in one or more cells when a beam failure is detected.

[0153] In some embodiments, the beam failure recovery configuration instructs the second network device to perform inter-cell beam management through a cell other than a serving cell in the event of beam failure recovery based on reception of a beam failure recovery media access control (MAC) control element (CE).

[0154] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration for a cell other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access a cell other than the serving cell based on the contention-free random access configuration. In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-free random access preamble to the second network device; and send a beam failure recovery MAC CE to the second network device.

[0155] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration for cells other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the serving cell based on the contention-based random access configuration.

[0156] In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-based random access preamble to the second network device; and send a beam failure recovery MAC CE to the second network device. In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device, and an identifier of the serving cell.

[0157] In some embodiments, the apparatus further comprises a component for sending a terminal device context modification request to a second network device; a component for receiving a terminal device context modification response from the second network device, the terminal device context modification response comprising a beam failure recovery configuration for performing beam failure recovery on a cell other than a serving cell; and a component for configuring RRC reconfiguration based on the received terminal device context modification response.

[0158] In some embodiments, the apparatus further comprises means for receiving an RRC reconfiguration complete message including an indication of beam failure recovery from a node 131 providing a cell other than a serving cell; and means for performing a cell switching based on the receipt of the indication of beam failure recovery.

[0159] In some embodiments, the apparatus further comprises a component for determining a layer 1 / layer 2 triggered mobility (LTM) configuration of one or more cells; and the beam recovery configuration instructs the terminal device to perform beam failure recovery on cells other than the serving cell using the LTM configuration of cells other than the serving cell when a beam failure is detected.

[0160] In some embodiments, the LTM configuration for cells other than the serving cell includes a contention-free random access configuration for cells other than the serving cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the serving cell based on the contention-free random access configuration when a beam failure is detected.

[0161] In some embodiments, the beam failure recovery configuration instructs the terminal device to: use the LTM configuration of the cell other than the serving cell, send a contention-free random access preamble code to the node providing the cell other than the serving cell; and send an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0162] In some embodiments, the LTM configuration for cells other than the service cell includes a contention-based random access configuration for cells other than the service cell; and the beam failure recovery configuration instructs the terminal device to access cells other than the service cell based on the contention-based random access configuration when a beam failure is detected.

[0163] In some embodiments, the beam failure recovery configuration instructs the terminal device to: send a contention-based random access preamble to a node providing a cell other than the serving cell using an LTM configuration for a cell other than the serving cell; and send an RRC reconfiguration complete message including an indication of beam failure recovery to the node providing the cell other than the serving cell. In some embodiments, the RRC reconfiguration complete message also includes an identifier of the terminal device.

[0164] In some embodiments, the beam failure recovery configuration instructs the terminal device to send an RRC reconfiguration complete message including an indication of beam failure recovery to a node providing a cell other than the serving cell based on obtaining a timing advance of the terminal device.

[0165] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0166] In some embodiments, the apparatus further comprises means for performing other steps of some embodiments of method 500. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, enable execution of the apparatus.

[0167] In some embodiments, a device capable of executing method 600 (eg, source DU 120) may include components for executing corresponding steps of method 600. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0168] In some embodiments, the apparatus includes a component for receiving a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device from the first network device 110, wherein the RRC reconfiguration includes a beam failure recovery configuration to be used by the terminal device to perform beam failure recovery for the one or more cells. The apparatus also includes a component for sending the RRC reconfiguration to the terminal device 140.

[0169] In some embodiments, the beam failure recovery configuration instructs the terminal device to initiate a beam failure recovery process to a cell other than the serving cell in one or more cells when a beam failure is detected.

[0170] In some embodiments, the apparatus further comprises means for performing inter-cell beam management through a cell other than a serving cell based on reception of a beam failure recovery medium access control (MAC) control element (CE) in case of beam failure recovery.

[0171] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration of a cell other than the serving cell, and the beam failure recovery configuration instructs the terminal device to access the cell other than the serving cell based on the contention-free random access configuration.

[0172] In some embodiments, the apparatus further comprises a component for receiving a contention-free random access preamble from the terminal device 140 ; ​​and a component for receiving a beam failure recovery MAC CE from the terminal device 140 .

[0173] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration for cells other than the serving cell, and the beam failure recovery configuration instructs the terminal device to access the cell other than the serving cell based on the contention-based random access configuration.

[0174] In some embodiments, the apparatus further comprises means for receiving a contention-based random access preamble from a terminal device; and means for receiving a beam failure recovery MAC CE from the terminal device.

[0175] In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device and an identifier of the serving cell.

[0176] In some embodiments, the apparatus further comprises a component for receiving a terminal device context modification request from a first network device; and a component for sending a terminal device context modification response to the first network device, the terminal device context modification response comprising a beam failure recovery configuration for performing beam failure recovery on a cell other than a serving cell.

[0177] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0178] In some embodiments, the apparatus further comprises means for performing other steps of some embodiments of method 600. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, enable execution of the apparatus.

[0179] In some embodiments, an apparatus capable of executing method 700 (e.g., terminal device 140) may include a component for executing the corresponding steps of method 700. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit system or a software module.

[0180] In some embodiments, the apparatus further comprises means for receiving, from the second network device 120, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration comprises a beam failure recovery configuration. The apparatus further comprises means for performing beam failure recovery for the one or more cells based on the beam failure recovery configuration.

[0181] In some embodiments, the apparatus further comprises means for detecting beam failure; and means for initiating a beam failure recovery procedure to a cell other than the serving cell in the one or more cells based on the beam failure recovery configuration.

[0182] In some embodiments, the apparatus further comprises a component for sending a beam failure recovery media access control (MAC) control element (CE) to the second network device. The beam failure recovery configuration instructs the second network device to perform inter-cell beam management through a cell other than the serving cell in the event of beam failure recovery based on the second network device receiving the beam failure recovery MAC CE.

[0183] In some embodiments, the beam failure recovery configuration includes a contention-free random access configuration of a cell other than the serving cell, and the apparatus further comprises means for accessing the cell other than the serving cell based on the contention-free random access configuration.

[0184] In some embodiments, the apparatus further comprises means for sending a contention-free random access preamble to the second network device based on the beam failure recovery configuration; and means for sending a beam failure recovery MAC CE to the second network device.

[0185] In some embodiments, the beam failure recovery configuration includes a contention-based random access configuration for a cell other than the serving cell, and the apparatus further comprises means for accessing the cell other than the serving cell based on the contention-based random access configuration.

[0186] In some embodiments, the apparatus further comprises means for sending a contention-based random access preamble to the second network device based on the beam failure recovery configuration; and means for sending a beam failure recovery MAC CE to the second network device.

[0187] In some embodiments, the beam failure recovery MAC CE includes an indication of beam failure recovery, an identifier of the terminal device and an identifier of the serving cell.

[0188] In some embodiments, the apparatus further comprises means for sending an RRC reconfiguration complete message including an indication of beam failure recovery to a cell other than the serving cell.

[0189] In some embodiments, the apparatus further comprises means for performing beam failure recovery on cells other than the serving cell using the LTM configuration of the cells other than the serving cell based on the configuration information if beam failure is detected.

[0190] In some embodiments, the LTM configuration for cells other than the serving cell includes a contention-free random access configuration for cells other than the serving cell, and the apparatus further comprises a component for accessing cells other than the serving cell based on the contention-free random access configuration when beam failure is detected.

[0191] In some embodiments, the apparatus further comprises a component for sending a contention-free random access preamble to a node providing a cell other than the serving cell using an LTM configuration of the cell other than the serving cell based on a beam failure recovery configuration; and a component for sending an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0192] In some embodiments, the LTM configuration of cells other than the serving cell includes a contention-based random access configuration of cells other than the serving cell, and the apparatus further comprises a component for accessing cells other than the serving cell based on the contention-based random access configuration when beam failure is detected.

[0193] In some embodiments, the apparatus further comprises a component for sending a contention-based random access preamble to a node providing a cell other than the serving cell using an LTM configuration of the cell other than the serving cell based on a beam failure recovery configuration; and a component for sending an RRC reconfiguration completion message including an indication of beam failure recovery to the node providing the cell other than the serving cell.

[0194] In some embodiments, the RRC reconfiguration complete message also includes an identifier of the terminal device.

[0195] In some embodiments, the apparatus further comprises a component for obtaining a timing advance of a terminal device based on a beam failure recovery configuration; and a component for sending an RRC reconfiguration completion message including an indication of beam failure recovery to a network device providing a cell other than a serving cell.

[0196] In some embodiments, the first network device 110 comprises a central unit of a base station; and the second network device 120 comprises a distributed unit of a base station.

[0197] In some embodiments, the apparatus further comprises means for performing other steps of some embodiments of method 700. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, enable execution of the apparatus.

[0198] Figure 8 800 is a simplified block diagram of a device 800 suitable for implementing an embodiment of the present disclosure. The device 800 may be provided to implement a communication device, such as Figure 1 The terminal device 140 and the network devices 110, 120 and 130 are shown. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processors 810, and one or more communication modules 840 coupled to the processors 810.

[0199] The communication module 840 is used for two-way communication. The communication module 840 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communication with other network devices.

[0200] Processor 810 may be of any type suitable for the local technology network, and may include, as non-limiting examples, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 800 may have multiple processors, such as application specific integrated circuit chips that are time slaved to a clock synchronized with a main processor.

[0201] The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 824, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic storage devices and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 822 and other volatile memories that do not persist during power outages.

[0202] The computer program 830 includes computer executable instructions that are executed by the associated processor 810. The program 830 may be stored in the ROM 824. The processor 810 may perform any suitable actions and processes by loading the program 830 into the RAM 822.

[0203] The embodiments of the present disclosure can be implemented by means of program 830, so that the device 800 can execute the reference Figures 2 to 7 Any process of the present disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0204] In some embodiments, the program 830 may be tangibly contained in a computer-readable medium, which may be included in the device 800 (such as in the memory 820) or in other storage devices accessible to the device 800. The device 800 may load the program 830 from the computer-readable medium to the RAM 822 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0205] Fig. 9An example of a computer readable medium 900 in the form of a CD or DVD according to some embodiments of the present disclosure is illustrated. The computer readable medium has stored thereon a program 830. It should be noted that although the computer readable medium 900 is depicted in the form of a CD or DVD, the computer readable medium 900 may be in any other form suitable for carrying or storing the program 830.

[0206] Generally, various embodiments of the present disclosure may be implemented using hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented using hardware, while other aspects may be implemented using firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented using hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0207] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as instructions included in a program module, which are executed in a device on a target real or virtual processor to perform the above reference Figures 5 to 7 The described methods 500, 600 or 700. Typically, a program module includes a routine, program, library, object, class, component, data structure, etc. that performs a specific task or implements a specific abstract data type. In various embodiments, the functions of the program modules can be combined or split between program modules as needed. The machine executable instructions of the program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0208] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code is implemented when executed by the processor or controller in the flow chart and / or the block diagram. The program code can be executed completely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or completely on a remote machine or server.

[0209] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0210] Computer readable medium can be a computer readable signal medium or a computer readable storage medium. Computer readable medium can include but is not limited to electrical, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. More specific examples of computer readable storage medium will include electrical connections with one or more wires, portable computer floppy disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. The term "non-transient" used herein is a restriction on the medium itself (i.e., tangible, rather than signal), rather than a restriction on data storage persistence (e.g., RAM and ROM).

[0211] In addition, although the operations are described in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in order or performing all the operations shown to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the present disclosure, but rather descriptions of features that may be specific to a particular embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features that may be described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0212] Although the present disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or actions described above. Instead, the specific features or actions described above are disclosed as example forms of implementing the claims.

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the terminal device to at least: receiving, from the second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by the first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and Based on the beam failure recovery configuration, beam failure recovery is performed on the one or more cells.

2. The terminal device according to claim 1, wherein the terminal device is further configured to: Failure to detect beam; and Based on the beam failure recovery configuration, a beam failure recovery process is initiated to cells other than the serving cell among the one or more cells.

3. The terminal device according to claim 1 or 2, wherein the terminal device is further configured to send a beam failure recovery media access control (MAC) control element (CE) to the second network device, and The beam failure recovery configuration indicates that the second network device performs inter-cell beam management through the cell other than the serving cell in case of beam failure recovery based on the reception of the beam failure recovery MAC CE by the second network device.

4. The terminal device according to claim 3, wherein: The beam failure recovery configuration includes: a contention-free random access configuration for the cell other than the serving cell, and The terminal device is also configured to: access the cell other than the serving cell based on the contention-free random access configuration.

5. The terminal device according to claim 3, wherein: The beam failure recovery configuration includes: a contention-based random access configuration of the cell other than the serving cell, and The terminal device is also caused to: access the cell other than the serving cell based on the contention-based random access configuration.

6. The terminal device according to claim 1 or 2, wherein the terminal device is further configured to: send an RRC reconfiguration completion message including an indication of the beam failure recovery to a cell other than a serving cell.

7. A terminal device according to claim 6, wherein the terminal device is also configured to: based on the configuration information, when the beam failure is detected, use the LTM configuration for the cell other than the service cell to perform the beam failure recovery on the cell other than the service cell.

8. The terminal device according to claim 7, wherein: The LTM configuration for the cell other than the serving cell comprises: a contention-free random access configuration for the cell other than the serving cell, and The terminal device is also configured to: upon detecting that the beam failure has occurred, access the cell other than the serving cell based on the contention-free random access configuration.

9. A method for communication, comprising: receiving, at a terminal device, from a second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration includes a beam failure recovery configuration; and Based on the beam failure recovery configuration, beam failure recovery is performed on the one or more cells.

10. An apparatus for communication, comprising: means for receiving, at a terminal device, from a second network device, a radio resource control (RRC) reconfiguration for one or more cells prepared by a first network device, wherein the RRC reconfiguration comprises a beam failure recovery configuration; as well as Means for performing beam failure recovery for the one or more cells based on the beam failure recovery configuration.

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