Communication method and related device

Abstract

The invention provides a communication method and a related device, which are beneficial for a source base station to accurately adjust configuration required by terminal equipment for cell switching. The method comprises: a second access network device obtaining LBT failure information, the LBT failure information being used for indicating at least one consistent LBT failure event of the second access network device; and the second access network equipment sends the LBT failure information to the first access network equipment. And the first access network equipment adjusts switching configuration based on the LBT failure information.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a communication method and related devices. Background Art

[0002] With the increasing number of access network devices, limited wireless spectrum resources cannot meet the huge demand for data services. To solve this problem, long term evolution (LTE) and new radio (NR) have respectively launched license assisted access (LAA) and NR unlicensed (NR-U) systems for use in unlicensed frequency bands.

[0003] Unlicensed spectrum is distributed in 2.4 GHz, 5 GHz, and 6 GHz. 5 GHz is already used by wireless fidelity (Wi-Fi) and LAA, and the NR-U system can operate in the 6 GHz band.

[0004] Taking the NR-U system as an example, in order to meet the regulatory requirements for the use of unlicensed spectrum, when the terminal device performs cell switching on the unlicensed spectrum, or switches from the idle state / inactive state to the active state, it is necessary to initiate a listen before talk (LBT) detection on the unlicensed frequency band. Specifically, before data transmission, the terminal device performs an LBT detection to determine whether the channel is idle. If the channel is idle, data transmission is performed during the subsequent channel occupation time; if the channel is occupied, it is considered that LBT has failed and data cannot be transmitted.

[0005] Currently, in a cell handover scenario, the target base station also performs LBT detection before data transmission, and there may be LBT failures, which will cause the random access message 2 (message 2) or message 4 (message 4) to fail to send. The terminal device cannot determine whether the target base station has LBT failures during the handover execution, which will cause the source base station to incorrectly analyze the cause of the terminal device handover failure, and then make incorrect adjustments to the configuration required for the terminal device to perform cell handover. Summary of the invention

[0006] The present application provides a communication method and related apparatus, which are conducive to a source base station accurately adjusting the configuration required for a terminal device to perform a cell switching.

[0007] In a first aspect, a communication method is provided, which can be performed by a communication device, and the communication device can be a first access network device, or a component configured in the first access network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software implementation that can realize all or part of the functions of the communication device, which is not limited in this application. The method includes: receiving LBT failure information from a second access network device, the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device; based on the LBT failure information, adjusting the switching configuration, and the switching configuration is used for the terminal device to perform cell switching.

[0008] In one possible scenario, consider a scenario in which a terminal device performs a cell switching, the first access network device is the source base station of the terminal device, and the second access network device is the target base station of the terminal device. The first access network device receives the LBT failure information in a switching failure scenario, and the reason for the switching failure is that a consistent LBT failure event occurs in the second access network device, resulting in the failure to successfully send the random access message 2 / message 4. In this case, the at least one consistent LBT failure event indicated by the LBT failure information may include only the consistent LBT failure event that caused this switching failure, or may include the consistent LBT failure event that caused this switching failure and at least one LBT failure event that caused the switching failure in historical time.

[0009] In another possible case, the first access network device and the second access network device exchange their respective LBT failure information based on the trigger condition. That is, the second access network device can send its own recorded LBT failure information to the first access network device based on the trigger condition, and the first access network device can also send its own recorded LBT failure information to the second access network device based on the trigger condition.

[0010] Optionally, the first access network device and the second access network device may periodically record consistent LBT failure events occurring within a period of time.

[0011] In the prior art, if a terminal device fails to switch from a first access network device to a second access network device, the first access network device cannot learn whether a consistent LBT failure event occurs in the second access network device, and therefore cannot accurately analyze the reason for the switching failure of the terminal device. The first access network device may think that the switching failure is caused by the terminal device or its own problems, thereby incorrectly optimizing the switching configuration of the station. In the present application, the first access network device can receive the LBT failure information of the second access network device, and according to the LBT failure information, it can be determined that the reason for the switching failure is that a consistent LBT failure event occurs in the second access network device. Then, the first access network device can more accurately adjust the configuration required for the terminal device to perform cell switching.

[0012] In combination with the first aspect, in some implementations of the first aspect, adjusting the switching configuration based on the LBT failure information includes: updating the random access channel (RACH) configuration based on the LBT failure information. The method also includes: sending the updated RACH configuration to the terminal device.

[0013] In the present application, the RACH configuration is used for the terminal device to access the second access network device. The first access network device can update the RACH configuration based on the LBT failure information, and such an update is more reliable, or in other words, the RACH configuration updated based on the LBT failure information is more suitable for the terminal device to access the second access network device, so the success rate of the terminal device accessing the second access network device based on the updated RACH configuration is improved.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the RACH configuration is updated based on the LBT failure information, including: determining the first beam based on the LBT failure information, the signal quality of the cell covered by the first beam is higher than the first preset threshold, and / or the number of consistent LBT failure events occurring on the channel corresponding to the first beam is lower than the second preset threshold; obtaining the RACH configuration corresponding to the first beam; and updating the RACH configuration (the RACH configuration used for the terminal device to access the second access network device) to the RACH configuration corresponding to the first beam.

[0015] Different beams correspond to different RACH configurations. Updating the RACH configuration here can be understood as updating the RACH configuration used for the terminal device to access the second access network device to the RACH configuration corresponding to a certain beam. The RACH configuration corresponding to the beam indicates the time-frequency position for sending message 1. At the LBT detection time for sending message 2 / message 4 corresponding to the time-frequency position for sending message 1, the probability of idleness of the downlink channel is relatively high, and the probability of LBT failure of the second access network device is relatively low.

[0016] In combination with the first aspect, in some implementations of the first aspect, obtaining the RACH configuration corresponding to the first beam includes: sending an identifier of the first beam to a second access network device; and receiving the RACH configuration corresponding to the first beam from the second access network device.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the identifier of the first beam is carried in a switching request message, and the switching request message is used to request switching of the terminal device from the first access network device to the second access network device.

[0018] Optionally, the identifier of the first beam and the switching request message may be carried in one message.

[0019] In combination with the first aspect, in some implementations of the first aspect, before adjusting the switching configuration based on the LBT failure information, the method further includes: obtaining a radio link failure (RLF) report, the RLF report being used to indicate that the terminal device has failed to switch from the first access network device to the second access network device. Adjusting the switching configuration based on the LBT failure information includes: adjusting the switching configuration based on the LBT failure information and the RLF report.

[0020] The above RLF report also indicates the possible reasons for the current switching failure analyzed by the terminal device. Because the terminal device does not know whether a consistent LBT failure event occurs in the second access network device, the possible reasons for the current switching failure obtained by the terminal device are inaccurate. In the present application, the first access network device analyzes the reasons for the switching failure in combination with the RLF report and the LBT failure information, and the possible reasons for the current switching failure obtained are more accurate, thereby avoiding the problem of incorrectly adjusting the switching configuration due to incorrect analysis of the reasons for the switching failure, which is beneficial to improving the success rate of terminal device switching.

[0021] In combination with the first aspect, in certain implementations of the first aspect, adjusting the switching configuration based on the LBT failure information and the RLF report includes: determining, based on the LBT failure information and the RLF report, that the reason for the switching failure of the terminal device is that a consistent LBT failure event occurs in the second access network device; and reducing the number of times the terminal device is switched to the second access network device based on the reason for the switching failure of the terminal device. This helps to avoid the switching failure of the terminal device, thereby avoiding the problem of data transmission interruption caused by the switching failure.

[0022] In combination with the first aspect, in certain implementations of the first aspect, each consistent LBT failure event indicates one or more of the following parameters: an identifier of the terminal device, a time when the LBT detection fails, an identifier of a beam corresponding to a channel where the LBT failure occurs, the number of LBT failures, an indication of a failure to send message 2 of a random access process, an indication of a failure to send message 4 of a random access process, or an identifier of a target cell. The identifier of the terminal device is the identifier of the terminal device where the handover failure occurs.

[0023] In a second aspect, a communication method is provided, which can be performed by a communication device, which can be a second access network device, or a component configured in the second access network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software implementation that can realize all or part of the functions of the communication device, which is not limited in this application. The method includes: obtaining LBT failure information, the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device; sending the LBT failure information to the first access network device.

[0024] In the present application, the second access network device may periodically record consistent LBT failure events occurring within a period of time, and the number of LBT failure events occurring within the period of time is at least once.

[0025] The second access network device can exchange respective LBT failure information with other access network devices (such as the first access network device) based on the trigger condition. In addition, in the scenario where the terminal device fails to switch cells, the second access network device, as the target base station of the terminal device, can send the consistent LBT failure event of this switching failure to the first access network device (as the source base station of the terminal device), and can also send the consistent LBT failure event that caused this switching failure and at least one LBT failure event that caused the switching failure within the recorded historical time to the first access network device.

[0026] Based on the technical solution of the present application, the exchange of LBT failure information between the first access network device and the second access network device is conducive to considering the LBT failure information of the target base station when the first access network device or the second access network device acts as a source base station, thereby correctly adjusting the switching configuration, which in turn is conducive to improving the success rate of terminal equipment accessing the target base station and reducing access delay.

[0027] In combination with the second aspect, in certain implementations of the second aspect, sending the LBT failure information to the first access network device includes: when the number of consistent LBT failure events occurring on the channel corresponding to the second beam exceeds a third preset threshold, sending the LBT failure information to the first access network device.

[0028] In combination with the second aspect, in certain implementations of the second aspect, sending the LBT failure information to the first access network device includes: periodically sending the LBT failure information to the first access network device.

[0029] In combination with the second aspect, in some implementations of the second aspect, before sending the LBT failure information to the first access network device, the method further includes: receiving a request message from the first access network device, the request message being used to request the LBT failure information. Sending the LBT failure information to the first access network device includes: sending the LBT failure information to the first access network device based on the request message.

[0030] In combination with the second aspect, in certain implementations of the second aspect, after obtaining the LBT failure information, the method also includes: adjusting the RACH configuration of the second access network device based on the LBT failure information, the RACH configuration of the second access network device being used to access the second access network device; and sending the adjusted RACH configuration to the first access network device.

[0031] In combination with the second aspect, in certain implementations of the second aspect, the RACH configuration of the second access network device includes one or more of the following: the maximum number of attempts for a terminal device to access the second access network device, the size of the random access response window, or the duration of the contention resolution timer.

[0032] The RACH configuration of the second access network device may be the same or different for different terminal devices.

[0033] In combination with the second aspect, in certain implementations of the second aspect, after sending LBT failure information to the first access network device, the method also includes: receiving an identifier of a first beam from the first access network device, the signal quality of a cell covered by the first beam is higher than a first preset threshold, and / or the number of consistent LBT failure events occurring on a channel corresponding to the first beam is lower than a second preset threshold; and sending a RACH configuration corresponding to the first beam to the first access network device.

[0034] In combination with the second aspect, in certain implementations of the second aspect, each consistent LBT failure event indicates one or more of the following parameters: the identification of the terminal device where the switching failure occurred, the time of the LBT detection failure, the identification of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures, an indication of the failure to send message 2 of the random access process, an indication of the failure to send message 4 of the random access process, or the identification of the target cell.

[0035] In a third aspect, a communication device is provided, including: a module for executing a method in any possible implementation of any of the above aspects. Specifically, the device includes a module for executing a method in any possible implementation of the above first aspect.

[0036] In one design, the device may include a module corresponding to each of the methods / operations / steps / actions described in any of the above aspects. The module may be a hardware circuit, software, or a combination of hardware circuit and software.

[0037] In another design, the device is a communication chip, which may include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0038] In another design, the apparatus is a terminal device, and the first access network device or the second access network device may include a transmitter for sending information or data and a receiver for receiving information or data.

[0039] In another design, the apparatus is used to execute the method in any possible implementation of any of the above aspects, and the apparatus can be configured in the first access network device or the second access network device.

[0040] In a fourth aspect, a communication device is provided, comprising: a processor, wherein the processor is used to call and run a computer program from a memory, so that the device executes a method in any possible implementation manner of any of the above aspects.

[0041] Optionally, the device further comprises a memory, which can be used to store instructions and data. The memory is coupled to the processor, and when the processor executes the instructions stored in the memory, the methods described in the above aspects can be implemented.

[0042] Optionally, the device further includes: a transmitter (transmitter) and a receiver (receiver), and the transmitter and the receiver can be separately arranged or integrated together, which is called a transceiver (transceiver).

[0043] In a fifth aspect, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute a method in any possible implementation of any of the above aspects.

[0044] In a sixth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instruction) which, when executed on a computer, enables the computer to execute a method in any possible implementation of any of the above aspects.

[0045] In a seventh aspect, the present application provides a chip system comprising at least one processor for supporting the implementation of the functions involved in any of the above aspects, such as receiving or processing the data involved in the above method.

[0046] In one possible design, the chip system also includes a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0047] Optionally, the chip system may consist of a chip, or may include a chip and other discrete devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flow chart of a random access method based on contention;

[0049] Figure 2 It is a flowchart of a random access method based on non-contention;

[0050] Figure 3 is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application;

[0051] Figures 4 to 8 is a schematic flow chart of a communication method provided in an embodiment of the present application;

[0052] Figures 9 to 11 It is a schematic block diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0054] Before introducing the parameter determination method and related devices provided in the embodiments of the present application, the following points are explained.

[0055] First, in the embodiments shown below, various terms and English abbreviations, such as LBT failure information, consistent LBT failure event, RACH configuration, etc., are illustrative examples given for the convenience of description and should not constitute any limitation to this application. This application does not exclude the possibility of defining other terms that can achieve the same or similar functions in existing or future protocols.

[0056] Second, the first, second and various digital numbers in the embodiments shown below are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application. For example, to distinguish different configuration information.

[0057] Third, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c, where a, b, c can be single or multiple.

[0058] Fourth, the "sending" and "receiving" in this application indicate the direction of signal transmission. For example, "sending an updated RACH configuration to a terminal device" can be understood as the destination of the updated RACH configuration being the terminal device, which can include direct sending through the air interface, and also includes indirect sending through the air interface by other units or modules. "Receiving LBT failure information from a second access network device" can be understood as the source of the LBT failure information being the second access network device, which can include directly receiving it from the second access network device through the air interface, and also includes indirectly receiving it from the second access network device through the air interface from other units or modules. "Sending" can also be understood as the "output" of the chip interface, and "receiving" can also be understood as the "input" of the chip interface.

[0059] In other words, sending and receiving can be performed between devices, for example, between terminal equipment and access network equipment; it can also be performed within a device, for example, sending or receiving between components, modules, chips, software modules or hardware modules within the device through a bus, wiring or interface.

[0060] The following is an introduction to the relevant technologies and concepts involved in this application.

[0061] Usually, when a terminal device needs to establish communication with a network device, it needs to send information to the network device through RACH to obtain uplink synchronization and obtain the identification of the terminal device to prepare for subsequent network-side scheduling of the terminal device.

[0062] The random access (RA) process refers to the process from when the terminal device sends a random access preamble to try to access the network to when a basic signaling connection is established with the network. The purpose of random access design is to enable the terminal device to achieve uplink synchronization with the network device, and the network device to allocate uplink resources to the terminal device. During the random access process, the terminal device needs to initiate access on a specific physical random access channel (PRACH) time-frequency resource. The signal when the terminal device initiates access is a random access preamble, which is used to indicate that the network device has a random access request, so that the network device can estimate the transmission delay between it and the terminal device.

[0063] Currently, there are two different mechanisms for random access, including contention-based random access and non-contention-based random access.

[0064] For contention-based random access, the terminal device randomly selects a random access preamble within the range of the system information block 1 (SIB1) broadcast, so there may be a situation where multiple terminal devices select the same random access preamble, resulting in a random access preamble collision problem. Since the network device cannot distinguish the random access preambles sent by different terminal devices, the terminal device needs to send a message related to itself to the network device so that the network device can distinguish the random access preambles sent by different terminal devices.

[0065] The following takes the network device as an access network device as an example to introduce the above two different random access processes.

[0066] Figure 1 FIG. 1 is a flow chart of a contention-based random access method 100. Figure 1 As shown, the method 100 includes S101 to S104, and the specific steps are as follows:

[0067] S101, a terminal device sends a random access preamble to an access network device. Correspondingly, the access network device receives the random access preamble.

[0068] This step can also be called the transmission of message 1. The initial random access is initiated by the media access control (MAC) sublayer of the terminal device. Before S101, the access network device can notify all terminal devices on which PRACH resources are allowed to transmit random access preambles. RACH is used as an uplink random access channel to transmit random access preambles. PRACH is responsible for carrying RACH and is a physical channel mapped by RACH. It has fixed time-frequency resources, which can be obtained through SIB1 messages.

[0069] S102: The access network device sends a random access response (RAR) to the terminal device. Correspondingly, the terminal device receives the random access response.

[0070] This step may also be referred to as the transmission access network device of message 2, after receiving the random access preamble, scheduling resources for the temporary cell-radio network temporary identity (TC-RNTI), uplink and downlink.

[0071] The access network device sends a random access response through the physical downlink shared channel (PDSCH). The random access response includes the random access preamble identifier, timing advance (TA), initial uplink scheduling and cell-radio network temporary identity (C-RNTI). One PDSCH can carry the random access response and send it to multiple terminal devices.

[0072] After sending the random access preamble, the terminal device monitors the physical downlink control channel (PDCCH) and waits for the arrival of the random access response in the random access response window. Specifically, if the terminal device receives a response with an identifier of the random access preamble in the random access response window, and the identifier is the same as the identifier of the random access preamble sent by the terminal device in message 1, the response is successful, and the terminal device can then send uplink scheduling information to the access network device. If the terminal device does not receive a response within the random access response window or fails to verify the response, the response fails. In this case, if the number of RA attempts is less than the upper limit, the terminal device continues to send random access preambles to retry RA. If the number of RA attempts reaches the upper limit, RA fails.

[0073] S103, the terminal device sends uplink scheduling information to the access network device. Correspondingly, the access network device receives the uplink scheduling information.

[0074] This step may also be referred to as the transmission of message 3. The terminal device sends the uplink scheduling information via the physical uplink shared channel (PUSCH). The uplink scheduling information may include TC-RNTI and contention resolution identifier. After the terminal device sends the uplink scheduling information, the contention resolution timer (4ms) starts timing.

[0075] The messages sent by the terminal device vary in different RA scenarios. Examples are as follows:

[0076] Initial radio resource control connection setup (RRC connection setup) scenario: The terminal device transmits an RRC connection setup request message via the common control channel (CCCH) in the transparent mode (TM) of the radio link control (RLC) layer.

[0077] RRC connection reestablishment scenario: The terminal device transmits the RRC connection reestablishment request message via the CCCH in the TM of the RLC layer.

[0078] Handover (HO) scenario: When a terminal device accesses a target cell and there is no dedicated random access preamble during the handover process, a contention-based RA is triggered. The terminal device transmits an RRC handover confirmation message and C-RNTI via a dedicated control channel. Optionally, the terminal device also sends a buffer status report (BSR).

[0079] Other scenarios: at least send the C-RNTI of the terminal device.

[0080] S104, the access network device sends contention resolution information to the terminal device. Correspondingly, the terminal device receives the contention resolution message.

[0081] This step may also be referred to as transmission of message 4. The access network device uses the C-RNTI on the PDCCH or the contention resolution identifier on the PDCSH to help the terminal device perform contention resolution.

[0082] The terminal device continues to monitor the PDCCH before the contention resolution timer expires. When any of the following conditions is met, the contention resolution is considered successful and the timer stops:

[0083] 1. The terminal device receives C-RNTI via PDCCH.

[0084] 2. The terminal device receives the TC-RNTI via the PDCCH, and the MAC-PDU is successfully decoded. Specifically, the contention resolution identifier received by the terminal device via the PSCDH is the same as the contention resolution identifier carried in the message 3 sent by the terminal device.

[0085] If any of the above conditions are not met before the contention resolution timer expires, the terminal device considers contention resolution to have failed. In this case, if the number of RA attempts has not reached the upper limit, the terminal device attempts RA again, and if the number of RA attempts reaches the upper limit, RA fails.

[0086] Combine the following Figure 2 Introduce non-contention based random access.

[0087] For non-contention-based random access, the access network device will allocate dedicated random access preambles to different terminal devices. In this case, the terminal devices will not collide with random access preambles. However, when the dedicated random access preambles are insufficient, the access network device will instruct the terminal device to initiate contention-based random access.

[0088] Figure 2 FIG. 2 is a schematic flow chart of a non-contention-based random access method 200. Figure 2 As shown, the method 200 includes S201 to S204, and the specific steps are as follows:

[0089] S201, the access network device sends random access preamble allocation information to the terminal device, where the random access preamble allocation information is used to indicate a random access preamble dedicated to the terminal device. Correspondingly, the terminal device receives the random access preamble allocation information.

[0090] The access network device allocates dedicated random access preambles to different terminal devices. The access network device carries the random access preamble allocation information through RRC messages or downlink control information (DCI). The following are some examples of scenarios for sending the random access preamble allocation information:

[0091] Handover scenario: The source base station carries the random access preamble allocation information through mobility control information.

[0092] Downlink data arrival scenario: When downlink data arrives at the access network device, the access network device instructs the terminal device to start RA through the DCI on the PDCCH, and the PDCCH carries the random access preamble allocation information.

[0093] Non-standalone (NSA) networking scenario: When joining an NR cell in NSA, the access network device commands the terminal device to initiate RA through the PDCCH, and the PDCCH carries the dedicated random access preamble code allocated to the terminal device.

[0094] S202: The terminal device sends a random access preamble to the access network device. Correspondingly, the access network device receives the random access preamble.

[0095] This step may also be referred to as transmission of message 1.

[0096] S203, the access network device sends a random access response to the terminal device. Correspondingly, the terminal device receives the random access response.

[0097] This step may also be referred to as transmission of message 2.

[0098] For the above handover scenario, the random access response includes a timing advance and an initial uplink scheduling.

[0099] For the above-mentioned downlink data arrival scenario, when the downlink data arrives at the access network device, the random access response includes timing alignment information and a random access preamble identifier (RAPID).

[0100] For the above NSA networking scenario, when joining an NR cell in NSA, the random access response includes timing alignment information and RAPID.

[0101] S204, the terminal device sends uplink scheduling information to the access network device. Correspondingly, the access network device receives the uplink scheduling information.

[0102] This step may also be referred to as transmission of message 3. The terminal device sends uplink scheduling information to the access network device at a determined sending time according to the time advance or timing alignment information.

[0103] Common RA triggering scenarios include but are not limited to: initial RRC connection establishment, RRC connection reestablishment, switching, downlink data arrival, uplink data transmission, migration from RRC inactive state (RRC_inactive) to RRC connected state (RRC_connected), requesting other system information (OSI) based on message 1 or requesting OSI based on message 3.

[0104] For the above handover scenario, during the cell handover process of the terminal device, the terminal device will initiate RA in the target cell. Non-contention-based random access is preferred, but when the dedicated random access preamble is used up, the access network device will instruct the terminal device to use contention-based random access.

[0105] With the increasing number of access network devices, limited wireless spectrum resources are unable to meet the huge demand for data services. In order to solve this problem, unlicensed frequency bands have attracted attention from organizations including the 3rd Generation Partnership Project (3GPP) and the Institute of Electrical and Electronics Engineers (IEEE) due to their convenience (no authorization required) and large bandwidth, and have played an important role in alleviating the high load of licensed frequency bands.

[0106] Unlicensed frequency bands are distributed in 2.4GHz, 5GHz, and 6GHz. Common wireless communication systems that work in unlicensed frequency bands include Wi-Fi, Bluetooth, etc. Although the use of unlicensed frequency bands does not require authorization, in order to ensure fair use of resources and avoid interference, devices that usually use unlicensed frequency bands will detect the current occupancy of the channel before occupying the channel to transmit data. At the same time, the maximum transmission time on the channel is also limited.

[0107] Unlicensed spectrum technology based on 3GPP was first introduced in the form of LAA in R13. NR-U research and work items will introduce unlicensed bands in the 5GHz and 6GHz frequency ranges in frequency band 1 (FR1) into NR. The 5GHz band has been used by Wi-Fi and LTE-based LAA. 6GHz is a newly built band, but there is a lack of regulatory requirements. The extended range of the 6GHz band can be 5925~7125MHz or 5925~6425MHz. In the 6GHz band, NR-U's channel access mechanism will coexist with other systems in the same band where permitted.

[0108] NR-U uses NR technology and needs to adopt channel occupancy detection and access mechanism, channel occupancy strategy and channel occupy time (COT) structure, initialization access strategy, hybrid automatic repeat request (HARQ) and MAC scheduling strategy, uplink signal spectrum change and other technologies to meet the regulatory requirements for unlicensed spectrum use.

[0109] When Wi-Fi or other networks exist in the unlicensed spectrum, NR-U needs to perform channel detection based on 20MHz LBT. At the same time, NR-U supports different types and levels of LBT according to different situations.

[0110] LBT detection is a widely used technology in radio communications. Before starting data transmission, the radio transmitter will listen to its radio environment and perform clear channel assessment (CCA) to detect whether the channel is idle. If the channel is idle, the radio transmitter will transmit data during the subsequent channel occupancy time; if the channel is busy, the radio transmitter will wait until the channel is idle before transmitting, which can avoid channel access conflicts and achieve channel spectrum sharing. Usually, radio transmitters use energy detection (ED) to determine whether the channel is idle.

[0111] LBT detection is performed based on the bandwidth part (BWP). For each BWP, if the LBT detection fails, the bottom layer will report an LBT failure indication to the MAC layer, indicating that an LBT failure has occurred. If the number of LBT failures does not reach the configured maximum number of failures, or the duration of the LBT detection has not reached the configured maximum time length, the radio transmitter will re-perform the LBT detection. If the data is finally sent successfully, the number of LBT failures that occurred before is the number of LBT failures that occurred in the BWP. If the data is not successfully sent when the number of LBT failures reaches the configured maximum number of failures, or the duration of the LBT detection reaches the configured maximum time length, the MAC layer triggers a consistent LBT failure event and clears / resets the number of LBT failure indications (LBT failure recovery). If there are other BWPs to try, the radio transmitter can change a BWP and perform LBT detection again.

[0112] It should be understood that for a BWP, when performing an LBT detection, if the channel is detected to be busy (occupied), it is considered that the LBT has failed. The number of LBT failure indications reported by the MAC layer is the number of LBT failures. When the number of LBT failures reaches the configured maximum time length or the maximum number of failures, it is considered that a consistent LBT failure event has occurred. That is, a consistent LBT failure event contains at least one LBT failure.

[0113] The consistent LBT failure in this application may also be referred to as LBT consistent failure, continuous LBT failure or LBT continuous failure, which is not limited in this application.

[0114] In the existing NR-U system, when the terminal device performs cell switching on the unlicensed frequency band, or changes from the idle state / inactive state to the active state, it is necessary to initiate LBT detection on the unlicensed frequency band. If the LBT detection fails, the unlicensed frequency band cannot be used. Currently, 3GPP has agreed to add the following RACH report and RLF report to the SON report.

[0115] The content of the RACH report indication includes, but is not limited to: indication information for triggering the reporting of the RACH report, the number of LBT failures, other BWP information (i.e., the location, bandwidth, subcarrier spacing, absolute frequency, etc. of the previously attempted BWP), and LBT failure indication (indicating whether an LBT failure has occurred during the RA process). The indication information for triggering the reporting of the RACH report may include consistent LBT failure.

[0116] The contents of the RLF report indication include but are not limited to: the cause of the radio link failure, RACH report, and the received signal strength indication (RSSI) of the available NR-U channel. The cause of the radio link failure may include LBT failure.

[0117] The information in the above SON report is for uplink LBT, and downlink LBT is not considered. However, the target base station may have a downlink LBT failure in the switching scenario. The downlink LBT failure of the target base station may cause the failure to send message 2 during the random access process, or the failure to send message 4 during the random access process. At present, the source base station and the terminal device are unable to obtain the information about the downlink LBT failure of the target base station. The source base station and the terminal device do not know whether the downlink LBT failure of the target base station has occurred. Therefore, the terminal device cannot determine the real reason for not receiving message 2 or message 4, which will cause the source base station to incorrectly analyze the reason for the terminal device switching failure, and then make incorrect adjustments to the configuration required for the terminal device to perform cell switching, resulting in the terminal device being unable to access the target base station for a long time.

[0118] In this application, uplink LBT refers to the LBT detection performed by the terminal device before data transmission, and downlink LBT refers to the LBT detection performed by the access network device before data transmission.

[0119] In view of the above-mentioned problem that the terminal device and the source base station are unaware of whether a downlink LBT failure occurs in the target base station, resulting in the terminal device being unable to access the target base station for a long time, an embodiment of the present application provides a communication method and related apparatus, in which the first access network device and the second access network device can exchange LBT failure information, so that after the first access network device (as the source base station of the terminal device) receives the LBT failure information from the second access network device (as the target base station), it can accurately adjust the switching configuration for the terminal device to access the second access network device based on the LBT failure information.

[0120] Figure 3 Schematic diagram of the architecture of a communication system applicable to the embodiment of the present application. The method of the embodiment of the present application can be applied to a wireless communication system with artificial intelligence (AI) training / inference function. Figure 3 As shown, the radio access network (RAN) is connected to the core network (CN), and the core network can be, for example, the core network of LTE or the core network of the fifth generation mobile communication technology (5G). Figure 3 The access network devices deployed in the wireless access network shown in the figure include a first access network device and a second access network device. In addition, more other access network devices may be deployed in the wireless access network, which is not limited here.

[0121] Access network equipment deployed in the wireless access network (such as Figure 3 The first access network device or the second access network device in the example may have a centralized unit (CU) and a distributed unit (DU) separation architecture. CU and DU can be understood as the division of access network devices from a logical function perspective. CU and DU can be physically separated or deployed together. Multiple DUs can share one CU. One DU can also be connected to multiple CUs ( Figure 3 The CU and the DU may be connected via an interface, such as an F1 interface.

[0122] CU and DU can be divided according to the protocol layer of the wireless network. For example, one possible division method is: CU is used to perform the functions of the radio resource control (RRC) layer, the service data adaptation protocol (SDAP) layer and the packet data convergence protocol (PDCP) layer, while DU is used to perform the functions of the RLC layer, the MAC layer, the physical layer, etc.

[0123] It can be understood that the above division of the processing functions of the CU and DU according to the protocol layer is only an example, and can also be divided in other ways. For example, the CU or DU can be divided into functions with more protocol layers. For example, the CU or DU can also be divided into partial processing functions with protocol layers.

[0124] In one design, part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are set in the DU.

[0125] In another design, the functions of CU or DU may be divided according to service type or other system requirements, such as by latency, where functions whose processing time needs to meet latency requirements are set in DU, and functions that do not need to meet the latency requirements are set in CU.

[0126] In another design, the CU may also have one or more functions of the core network. One or more CUs may be centrally set or separately set. For example, the CU may be set on the network side for centralized management. The DU may have multiple RF functions or the RF functions may be remotely set.

[0127] The functions of CU can be implemented by one entity or by different entities. For example, the functions of CU can be further divided, for example, the control plane (CP) and the user plane (UP) are separated, that is, the control plane of CU (CU-CP) and the user plane of CU (CU-UP). For example, CU-CP and CU-UP can be implemented by different functional entities and connected through an E1 interface. The CU-CP and CU-UP can be coupled with DU to jointly complete the functions of the access network device.

[0128] The access network device provided in the embodiment of the present application may be a base station, a Node B, an evolved Node B (eNodeB or eNB), a transmission reception point (TRP), a next generation Node B (gNB) in 5G / NR, an access network device in an open radio access network (O-RAN or open RAN), and a next generation base station in 6G. Alternatively, the access network device may also be a satellite base station in a non-terrestrial network (NTN) communication network, or a base station in a future mobile communication system, or an access node in a Wi-Fi system. Alternatively, the access network device may also be a module or unit that performs some functions of a base station, for example, a CU, DU, CU-CP module, or CU-UP module. The access network device may be a satellite base station or a macro base station. The access network device may also be a micro base station or an indoor station, or a relay node or a host node. The specific technology and specific device form adopted by the access network device are not limited in this application.

[0129] The terminal device provided in the embodiment of the present application may also be referred to as a terminal, user equipment (UE), mobile station, or mobile terminal. The terminal device can be widely used in various scenarios for communication. The scenario includes, for example, but is not limited to at least one of the following scenarios: enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), massive machine-type communications (mMTC), device-to-device (D2D), vehicle to everything (V2X), machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, or smart city. The terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a helicopter, an airplane, a drone, a ship, a robot, a robotic arm, or a smart home device. The present application does not limit the specific technology and specific device form adopted by the terminal device.

[0130] The access network equipment and / or terminal equipment can be fixed or movable. The access network equipment and / or terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or can be deployed on the water surface; or can be deployed on aircraft, balloons and artificial satellites in the air. The present application does not limit the environment / scenario in which the access network equipment and terminal equipment are located. The access network equipment and terminal equipment can be deployed in the same or different environments / scenarios, for example, the access network equipment and the terminal equipment are deployed on land at the same time; or, the access network equipment is deployed on land and the terminal equipment is deployed on the water surface, etc., which will not be listed one by one here. The present application does not limit the communication method between the access network equipment and the terminal equipment.

[0131] In the embodiments of the present application, the terminal device and the access network device may be hardware devices, or software functions running on dedicated hardware, or software functions running on general-purpose hardware, such as virtualization functions instantiated on a platform (e.g., a cloud platform), or entities including dedicated or general-purpose hardware devices and software functions. The present application does not limit the specific forms of the terminal device and the access network device.

[0132] This application takes the communication between the terminal device and the access network device in the NR-U system as an example. The terminal device and the access network device need to perform LBT detection on the channel in the NR-U system before data transmission. In addition, the communication method of this application can also be extended to other systems operating in unlicensed frequency bands, such as Wi-Fi, LTE-based LAA, etc., which are not limited here.

[0133] The communication method provided below involves interaction between a first access network device, a second access network device, and a terminal device. The first access network device and the second access network device may be, for example, a base station, and the terminal device may be, for example, a mobile phone. This application does not limit the specific forms of the first access network device and the second access network device.

[0134] Figure 4 400 is a schematic flow chart of a communication method 400 provided in an embodiment of the present application. The method 400 includes S401 to S403, and the specific steps are as follows:

[0135] S401, the second access network device obtains LBT failure information, where the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device.

[0136] Combined with the introduction of the related technologies of random access and LBT detection in the above text, it can be known that in the scenario of cell switching, when the terminal device and the access network device communicate on the unlicensed frequency band, both need to perform LBT detection on the channel before data transmission. For example, when the terminal device sends message 1, it needs to perform LBT detection on the uplink channel; for example, after the access network device receives message 1, it needs to perform LBT detection on the downlink channel when sending message 2 to the terminal device.

[0137] There may be a switching failure during the switching process. The reasons for the switching failure include but are not limited to: switching too early, switching too late, incorrect neighboring cell parameter configuration, unreasonable switching timer setting, access network equipment failing to detect the random access preamble in PRACH, terminal equipment failing to decode message 2, downlink LBT detection failure resulting in message 1 / message 3 failing to be sent successfully, downlink LBT detection failure resulting in message 2 / message 4 failing to be sent successfully.

[0138] The embodiment of the present application considers that in the scenario of historical switching failure, the reason for the switching failure is the failure of the downlink LBT detection of the second access network device, which results in the inability to send the random access message 2 / message 4. The second access network device can record the consistent LBT failure event of each switching failure, which can also be understood as recording the reason for each switching failure because the consistent LBT failure event occurs when the second access network device performs downlink LBT detection, resulting in the inability to send message 2 / message 4.

[0139] It should be understood that, in the embodiment of the present application, the second access network device configures a BWP to perform LBT detection as an example, and the consistent LBT failure event includes at least one LBT failure that occurs in the BWP. In other words, when the number of LBT failures that occur in the BWP reaches the maximum number of failures, or when the duration of the LBT detection in the BWP reaches the maximum time length, a consistent LBT failure event is triggered. Within the duration of the maximum time length limit, the second access network device performs at least one LBT detection in the BWP, and the at least one LBT detection fails.

[0140] The second access network device in this step obtains LBT failure information, which can be understood as the second access network device periodically recording consistent LBT failure events that lead to switching failures within a period of time, and at least one consistent LBT failure event occurs during this period of time.

[0141] It should be noted that in the switching failure scenario, the second access network device records the consistent LBT failure event within the period as a target base station. During the period, there may be at least one terminal device expecting to access the second access network device, including at least one situation in which the terminal device is unable to access the second access network device due to the occurrence of a consistent LBT failure event.

[0142] Optionally, each of the at least one consistent LBT failure event indicates one or more of the following parameters: the time of LBT detection failure, the identifier of the beam corresponding to the channel where the LBT failure occurs, the number of LBT failures, an indication of the failure to send message 2 of the random access process, an indication of the failure to send message 4 of the random access process, or an identifier of the target cell.

[0143] The time of LBT detection failure includes one or more of the following: the time of each LBT failure, the time of the consistent LBT failure event, or the time of LBT failure every T times. It should be understood that the time of LBT detection failure can be the actual time point of occurrence, or the time difference between the time when the second access network device receives other messages (for example, a switching request message) and the actual time point of occurrence, etc., and the embodiments of the present application do not limit this.

[0144] For ease of description, message 2 of the random access process is referred to as message 2, and message 4 of the random access process is referred to as message 4.

[0145] Table 1 is an example of parameters indicated by a consistent LBT failure event indicated in the LBT failure information:

[0146] Table 1

[0147]

[0148] Table 1 shows that in a switching scenario, at time t, the consistent LBT failure event occurs on the channel corresponding to the beam marked as 0. The consistent LBT failure event includes 5 LBT failures, resulting in the failure to send message 2. The target cell of the terminal device in this switching scenario is marked as X.

[0149] Optionally, a flag bit "0" may be used to indicate that message 2 fails to be sent, and a flag bit "1" may be used to indicate that message 4 fails to be sent. The specific manner of indicating a message that fails to be sent is not limited in the embodiment of the present application.

[0150] It should be noted that different beams correspond to different RACH configurations, and the RACH configuration indicates the location of the time-frequency resources for sending message 1. Therefore, the terminal device uses different beams to send message 1 at different times, so the access network device receives message 1 at different times, and then the access network device sends message 2 at different times. Because the time when the access network device sends message 2 is related to the LBT detection time of the channel, the beam can be associated with the channel, that is, different beams will correspond to channels at different LBT detection times, and the service busyness of the channels at different LBT detection times is different, and the probability of the occurrence of the consistent LBT failure event may also be different.

[0151] S402: The second access network device sends LBT failure information to the first access network device. Correspondingly, the first access network device receives the LBT failure information.

[0152] Optionally, the first access network device and the second access network device are neighboring stations to each other.

[0153] The first access network device sending LBT failure information to the second access network device may involve two situations:

[0154] Case 1: The first access network device and the second access network device exchange the LBT failure information based on the trigger condition.

[0155] Case 2: In a switching scenario where the first access network device serves as the source base station for a terminal device and the second access network device serves as the target base station for the terminal device, and a consistent LBT failure event occurs in the second access network device, resulting in a switching failure, the first access network device can send the LBT failure information to the second access network device.

[0156] The above two situations will be described in detail below and will not be described in detail here.

[0157] S403: The first access network device adjusts the switching configuration based on the LBT failure information. The switching configuration is used for the terminal device to perform cell switching.

[0158] In this step, the first access network device can be the source base station of a certain terminal device, and the second access network device can be the target base station of the terminal device. In the prior art, if the terminal device fails to switch, the source base station cannot know whether a consistent LBT failure event occurs in the target base station, and therefore cannot accurately analyze the reason for the switching failure of the terminal device. The source base station may think that the switching failure is caused by a problem with the terminal device or the source base station, thereby incorrectly optimizing the switching configuration of this station, for example, incorrectly adjusting the cell signal quality threshold that must be met when the terminal device switches to other base stations, and incorrectly adjusting the time for the terminal device to report the measurement report. Based on the technical solution of the embodiment of the present application, the source base station can obtain the LBT failure information of the target base station, and according to the LBT failure information, it can be determined that the cause of the switching failure is a consistent LBT failure event in the target base station, and then the source base station can more accurately adjust the configuration required for the terminal device to perform cell switching.

[0159] The specific implementation of adjusting the switching configuration will be described in detail below and will not be described in detail here.

[0160] Let's first combine Figure 5 and Figure 6 Situation 1 described in S402 above is introduced. In Situation 1, the first access network device and the second access network device can exchange their respective recorded LBT failure information. After receiving the LBT failure information of the second access network device, the first access network device updates the RACH configuration related to the second access network device based on the LBT failure information, and then the terminal device can access the second access network device according to the updated RACH configuration. Among them, updating the RACH configuration is a way to adjust the switching configuration. The RACH configuration related to the second access network device can be understood as the RACH configuration used for the terminal device to access the second access network device.

[0161] Figure 5 5 is a schematic flow chart of another communication method 500 provided in an embodiment of the present application. The method 500 includes S501 to S504, and the specific steps are as follows:

[0162] S501, the second access network device obtains LBT failure information, where the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device.

[0163] The second access network device in this step obtains LBT failure information, which can be understood as the second access network device periodically recording consistent LBT failure events that lead to switching failures within a period of time, and at least one consistent LBT failure event occurs during the period of time. The introduction of the second access network device obtaining LBT failure information can refer to the description of S401 above, which will not be repeated here.

[0164] S502: The second access network device sends LBT failure information to the first access network device. Correspondingly, the first access network device receives the LBT failure information.

[0165] Optionally, the first access network device and the second access network device are neighboring stations. This step is the interaction of information between the two access network devices and does not involve specific terminal devices. In other words, the first access network device can also perform similar actions as the second access network device, for example, obtaining LBT failure information and sending LBT failure information to other access network devices.

[0166] Optionally, the second access network device sends the LBT failure information to the first access network device based on the trigger condition, which may include the following implementation methods:

[0167] In a possible implementation, the second access network device sends the LBT failure information to the first access network device based on the implementation. For example, when the number of times the consistent LBT failure event is sent on the channel corresponding to the second beam exceeds a third preset threshold, the second access network device sends the LBT failure event to the first access network device.

[0168] In another possible implementation, the second access network device periodically / event-triggeredly sends the LBT failure information to the first access network device. The event used to trigger the second access network device to send the LBT failure information to the first access network device can be an information-based process, or an existing process can be reused, for example, the process of exchanging resource status between the second access network device and the first access network device, that is, carrying the LBT failure information in the resource status report in the resource status reporting initialization process, or sending the LBT failure information to the first access network device at the same time as the second access network device sends the resource status report to the first access network device, and the resource status report and the LBT failure information are carried by different messages.

[0169] In another possible implementation, the first access network device sends a request message to the second access network device, and the request message is used to request the LBT failure information. The second access network device sends the LBT failure information to the first access network device based on the request message. In this method, the conditions that trigger the first access network device to send the request message may include: the first access network device finds that the terminal device switching from the current station to the second access network device frequently fails to switch, and the first access network device is not sure whether the switching failure occurs specifically because of a problem with the terminal device, a problem with the first access network device, or a problem with the second access network device. In this case, the first access network device can request the LBT failure information from the second access network device to confirm the specific cause of the switching failure.

[0170] S503: The first access network device updates the RACH configuration based on the LBT failure information. The RACH configuration is used for the terminal device to access the second access network device.

[0171] In this step, since the LBT failure information indicates at least one LBT failure event of the second access network device, when the first access network device selects a target base station for a terminal device as the source base station of the terminal device, the first access network device can adjust the switching configuration related to the second access network device according to the LBT failure information.

[0172] In a possible implementation, the first access network device adjusts the handover configuration related to accessing the second access network device, which may include: updating the RACH configuration used for the terminal device to access the second access network device. The RACH configuration includes but is not limited to: RACH configuration index, root sequence index, random access preamble index, subframe number, random access occasion (RA occasion, RO) time-frequency position, maximum number of random access attempts, random access response window size, and contention resolution timer duration.

[0173] Different beams correspond to different RACH configurations. Updating the RACH configuration here can be understood as updating the RACH configuration used for the terminal device to access the second access network device to the RACH configuration corresponding to a certain beam. The RACH configuration corresponding to the beam indicates the time-frequency position for sending message 1. At the LBT detection time for sending message 2 / message 4 corresponding to the time-frequency position for sending message 1, the probability of the channel being idle is relatively high, and the probability of LBT failure in the second access network device is relatively low.

[0174] The beam can be determined based on the LBT failure information. The specific process of determining the beam is introduced below and will not be described in detail here.

[0175] In another possible implementation, the first access network device optimizes the switching configuration related to accessing the second access network device, which may include: the first access network device uses the LBT failure information as auxiliary information for selecting a target base station. Specifically, the first access network device weighs the signal quality of the current service cell of the terminal device and the LBT failure information, and decides whether to switch the terminal device to the second access network device.

[0176] Exemplarily, the first access network device determines based on the LBT failure information that the number of consistent LBT failure events that occur in a channel corresponding to a certain beam is small, but the signal quality of the cell covered by the beam is relatively poor, or the signal quality of the cell covered by the beam is lower than the signal quality of the current service cell. Therefore, the first access network device may not switch the terminal device to the second access network device, and reselect a target base station for the terminal device.

[0177] S504, the first access network device sends the updated RACH configuration to the terminal device. Correspondingly, the terminal device receives the updated RACH configuration.

[0178] After obtaining the updated RACH configuration, the first access network device sends the updated RACH configuration to the terminal device, so that the terminal device can send message 1 based on the time-frequency position indicated by the updated RACH configuration. The probability of the channel being idle at the LBT detection moment for sending message 2 / message 4 corresponding to the time-frequency position for sending message 1 is relatively high. Therefore, the probability of successful transmission of message 2 / message 4 is increased, which is beneficial to improving the access success rate of the terminal device and reducing the access delay.

[0179] As an optional embodiment, after obtaining the LBT failure information, the second access network device may adjust the RACH configuration of the station based on the LBT failure information, and send the adjusted RACH configuration to the first access network device. For example, the maximum number of attempts for the terminal device to access the second access network device, the size of the random access response window, or the duration of the contention resolution timer may be adjusted.

[0180] It should be understood that, for contention-based random access, the RACH configuration includes a contention resolution timer parameter. For non-contention-based random access, the RACH configuration may not include a contention resolution timer parameter.

[0181] Figure 66 is a schematic flow chart of another communication method 600 provided in an embodiment of the present application. Method 600 is a more specific implementation of method 500. In method 600, the first access network device updating the RACH configuration described above may be specifically: the first access network device requests the RACH configuration corresponding to a specific beam from the second access network device, and updates the RACH configuration related to the second access network device based on the RACH configuration corresponding to the specific beam.

[0182] The method 600 includes S601 to S606, and the specific steps are as follows:

[0183] S601, the second access network device obtains LBT failure information.

[0184] S602: The second access network device sends LBT failure information to the first access network device. Correspondingly, the first access network device receives the LBT failure information.

[0185] Among them, S601 and S602 are similar to the above description of S501 and S502, and are not repeated here.

[0186] S603: The first access network device determines a first beam based on the LBT failure information.

[0187] The process of the first access network device determining the first beam based on the LBT failure information may include: the first access network device determines the identifier of the beam corresponding to each consistent LBT failure event in the at least one consistent LBT failure event, if the signal quality of the cell covered by a certain beam is higher than the first preset threshold, and / or the number of consistent LBT failure events occurring on the channel corresponding to the beam is lower than the second preset threshold, then the first access network device may determine the beam as the first beam, and then obtain the RACH configuration corresponding to the first beam. The first access network device obtains the RACH configuration corresponding to the first beam, as described in S604 and S605 below.

[0188] In the embodiment of the present application, comparing the signal quality of the cell covered by the beam with the first preset threshold, and comparing the number of occurrences of the consistent LBT failure event with the second preset threshold are only examples. In another possible manner, the signal quality of the cell covered by the beam can also be compared with the preset threshold after corresponding data processing, and / or the number of occurrences of the consistent LBT failure event can be compared with the preset threshold after corresponding data processing. Among them, the data processing can be, for example, weighted processing, averaging processing, normalization processing, etc., which are not limited here.

[0189] S604: The first access network device sends the identifier of the first beam to the second access network device. Correspondingly, the second access network device receives the identifier of the first beam.

[0190] Optionally, in a handover scenario of a certain terminal device after the first access network device receives the LBT failure information, the first access network device (as a source base station) may carry the identifier of the first beam in a handover request message sent to the second access network device (as a target base station). The handover request message is used to request handover of the terminal device from the first access network device to the second access network device.

[0191] S605: The second access network device sends the RACH configuration corresponding to the first beam to the first access network device. Correspondingly, the first access network device receives the RACH configuration corresponding to the first beam.

[0192] Optionally, the second access network device (as the target base station) may carry the RACH configuration corresponding to the first beam in a handover request acknowledgement message sent to the first access network device (as the source base station).

[0193] S606: The first access network device sends the RACH configuration corresponding to the first beam to the terminal device.

[0194] Optionally, the first access network device (as the source base station) may carry the RACH configuration corresponding to the first beam in the RRC reconfiguration message sent to the terminal device. Afterwards, the terminal device may send message 1 to the second access network device based on the RACH configuration of the first beam for random access.

[0195] It should be understood that the above S602 is an information exchange between two access network devices and does not involve specific terminal devices. In other words, the first access network device can also perform actions similar to the second access network device to obtain LBT failure information and send LBT failure information to other access network devices. The subsequent S603 to S606 describe a switching scenario in which the first access network device serves as the source base station of a terminal device and the second access network device serves as the target base station of the terminal device. The first access network device can optimize the switching configuration related to the second access network device based on the LBT failure information.

[0196] In an embodiment of the present application, when optimizing the switching configuration related to the second access network device, the first access network device can determine the first beam according to the LBT failure information of the second access network device, obtain the RACH configuration corresponding to the first beam from the second access network device, and then send the RACH configuration corresponding to the first beam to the terminal device. Since the signal quality of the cell covered by the first beam meets the first preset threshold, and / or the number of consistent LBT failure events occurring in the channel corresponding to the first beam is lower than the second preset threshold, the terminal device has a higher success rate in accessing the second access network device based on the RACH configuration corresponding to the first beam, which is beneficial to reducing access delay.

[0197] Let's first combine Figure 7 Situation 2 described in the above S402 is introduced. Situation 2 specifically considers that in a handover failure scenario, the first access network device analyzes the reason for the handover failure of the terminal device in combination with the LBT failure information and the RLF report, and adjusts the handover configuration of the terminal device.

[0198] Figure 7 It is a schematic flow chart of another communication method 700 provided in an embodiment of the present application. In the embodiment of the present application, the first access network device is the source base station of the terminal device, and the second access network device is the target base station of the terminal device. The terminal device fails to receive message 2 during the process of switching from the first access network device to the second access network device. The message 2 may be message 2 in a random access process based on contention, or message 2 in a random access process based on non-contention. In addition, the embodiment of the present application is also applicable to the scenario in which the terminal device successfully receives message 2 but fails to receive message 4 during a random access process based on contention, resulting in a switching failure.

[0199] The method 700 includes S701 to S713, and the specific steps are as follows:

[0200] S701, a first access network device sends a handover request message to a second access network device, the handover request message being used to request handover of the terminal device from the first access network device to the second access network device. Correspondingly, the second access network device receives the handover request message.

[0201] Optionally, before this step, when the terminal device is in the RRC connection state, the first access network device and the terminal device have an active Xn connection, the terminal device and the first access network device perform uplink and downlink data transmission, and the terminal device moves to the second access network device. The first access network device sends a measurement control message to the terminal device through an RRC reconfiguration message, and the content carried by the measurement control message includes but is not limited to: measurement identifier, neighboring cell list, measurement amount, measurement report amount, and reporting mode. The terminal device measures the signal quality of the neighboring cell and the signal quality of the serving cell based on the measurement control message, and sends a measurement report to the first access network device when the reporting standard is met. The measurement report carries the signal quality of the neighboring cell and the signal quality of the serving cell. Based on the measurement report and other information (for example, cell load), and taking into account the mobility restrictions and radio capabilities of the terminal device, the first access network device decides to perform cell switching and selects the second access network device as the target base station for switching. Afterwards, the first access network device can send the switching request message to the second access network device, requesting the second access network device to allocate resources for the terminal device in the target cell, and triggering the establishment of an X2 logical link between the first access network device and the second access network device. The X2 logical link is used to forward the data cached by the first access network device and related signaling.

[0202] Optionally, the first access network device sends the switching request message to the second access network device through the Xn interface. The switching request message may carry information such as an identifier of the target cell and a protocol data unit (PDU) session list.

[0203] S702: The second access network device performs admission control.

[0204] After receiving the handover request message, the second access network device performs access control to determine whether the terminal device is allowed to access. If it is determined that the terminal device is allowed to access, the second access network device allocates wireless resources including a temporary identifier to the terminal device in the target cell, and executes step S703. At the same time, the second access network device completes the establishment of the X2 logical link.

[0205] S703, the second access network device sends a handover request confirmation message to the first access network device, the handover request confirmation message is used to indicate that the terminal device is allowed to access the second access network device. Correspondingly, the first access network device receives the handover request confirmation message.

[0206] In this step, the handover request confirmation message carries resource information allocated to the terminal device in the target cell, and the resource information is used to instruct the terminal device to access the target cell.

[0207] S704, the first access network device sends an RRC reconfiguration message to the terminal device, where the RRC reconfiguration message is used to trigger Uu switching. Correspondingly, the terminal device receives the RRC reconfiguration message.

[0208] The RRC reconfiguration message in this step is not the same as the RRC reconfiguration message described in S701. The RRC reconfiguration message in this step includes the resource information allocated to the terminal device in the target cell, and the content carried by the RRC reconfiguration message includes but is not limited to: the target cell identifier, the new C-RNTI, the target base station security algorithm identifier of the selected security algorithm, the dedicated RACH configuration, the association between the RACH configuration and the SSB, the association between the RACH configuration and the terminal device-specific channel state information-reference signal (CSI-RS) configuration, the public RACH resources, and the system information of the target cell.

[0209] After receiving the RRC reconfiguration message, the terminal device disconnects from the first access network device.

[0210] S705: The first access network device sends a sequence number (SN) state transfer message to the second access network device, where the SN state transfer message is used to transfer cached data. Correspondingly, the second access network device receives the SN state transfer message.

[0211] Optionally, the cached data may include an uplink and downlink packet data convergence protocol sequence number (PDCP SN) and a hyper frame number (HFN) state. The first access network device starts buffering downlink data from a user plane function (UPF) network element and forwards it to the second access network device.

[0212] S706, the terminal device sends message 1 to the second access network device. Correspondingly, the second access network device receives message 1. Message 1 of the random access process is referred to as message 1 hereinafter. In other words, message 1 hereinafter refers to message 1 transmitted during the random access process.

[0213] After receiving the RRC reconfiguration message in S704, the terminal device initiates a contention / non-contention-based random access process in the second access network device based on the RRC reconfiguration message.

[0214] S707, a consistent LBT failure event occurs in the second access network device, resulting in failure to send message 2.

[0215] However, due to the failure of the downlink LBT detection, the consistent LBT failure event is triggered. The reason for the downlink LBT failure detection may be that the NR-U channel is occupied by other services.

[0216] The second access network device successfully receives message 1, but the downlink LBT detection of the second access network device during the random access response window fails, and the second access network device fails to successfully send message 2. The terminal device can re-initiate random access, that is, resend the random access preamble. When the terminal device continues to retransmit the random access preamble until the maximum number of attempts is reached, but the downlink LBT detection of the second access network device still fails, a consistent LBT failure event is triggered, and message 2 is ultimately not successfully sent, and this handover fails.

[0217] S708, the second access network device records this consistent LBT failure event.

[0218] The parameters of this consistent LBT failure event indication include one or more of the following: the time of LBT detection failure, the indication of message 2 sending failure, the number of LBT failures, the beam identifier, the cell identifier or the terminal device identifier.

[0219] S709: The second access network device adjusts RACH configuration.

[0220] The second access network device can analyze the relationship between the cause of the downlink LBT detection failure and the RACH configuration based on the parameters indicated by the consistent LBT failure event to adjust the RACH configuration of the station. The RACH configuration includes one or more of the following: the maximum number of attempts for the terminal device to access the second access network device, the size of the random access response window, or the duration of the contention resolution timer.

[0221] It should be understood that for contention-based random access, the RACH configuration includes a contention resolution timer parameter. For non-contention-based random access, the RACH configuration may not include a contention resolution timer parameter.

[0222] S710, the second access network device sends LBT failure information to the first access network device, where the LBT failure information is used to indicate at least one consistent LBT failure event. Correspondingly, the first access network device receives the LBT failure event.

[0223] Optionally, before S710, the first access network device sends a request message to the second access network device, the request message being used to request the LBT failure information. The request message may be implemented based on an existing mechanism, for example, the request message is a failure indication, or the request message carries a failure indication.

[0224] Optionally, the second access network device may send LBT failure information based on an existing mechanism, for example, by carrying the LBT failure information in a handover report.

[0225] In this step, the at least one consistent LBT failure event indicated by the LBT failure information includes a consistent LBT failure event that occurred in this switching scenario. In addition, the at least one consistent LBT failure event may also include a consistent LBT failure event that caused the switching failure of other terminal devices recorded by the second access network device before this switching failure scenario.

[0226] S711, the terminal device records an RLF report, where the RLF report is used to indicate that the terminal device fails to switch from the first access network device to the second access network device.

[0227] After the terminal device fails to switch to the second access network device, the terminal device records the information of the switching failure in the RLF report. The RLF report is a report that needs to be reported due to random access failure and switching failure.

[0228] On the terminal device side, in addition to the uplink LBT detection failure, possible reasons for the switching failure may also include: switching too late, switching too early, switching to the wrong cell, etc.

[0229] Switching too late means that the terminal device reports the measurement report too late. At this time, the signal quality of the serving cell has deteriorated, and the terminal device has a link failure at the source base station, resulting in a switching failure. The detection method for the switching too late scenario: After the terminal device has an RLF before or during the switching process, the terminal device re-establishes a wireless connection with other base stations (referred to as base station B) except the source base station (referred to as base station A). Base station B sends an RLF report about the terminal device to base station A, and the RLF report carries the identifier of the terminal device. Base station A can determine that a switching too late event has occurred based on the RLF report.

[0230] Switching too early means that the measurement report reported by the terminal device is too early. At this time, the signal quality of the service cell cannot meet the switching requirements, and the terminal device fails to access the target base station during switching. The detection method for premature switching is: RLF occurs shortly after the terminal device successfully switches from base station A to base station B, and then the terminal device reconnects to base station A. In order to prevent base station B from misjudging the premature switching of base station A as the late switching of base station B, base station B sets a timing parameter when the terminal device successfully switches to this station. If base station B receives an RLF report about the terminal device sent by base station A within the duration of the timing parameter, base station B determines that base station A switched too early based on the RLF report, and then sends a premature switching indication to base station A.

[0231] S712, the terminal device sends an RLF report to the first access network device. Correspondingly, the first access network device receives the RLF report.

[0232] After the terminal device fails to switch to the second access network device, it can establish a connection with the first access network device again. After the terminal device successfully establishes a connection with the first access network device, the first access network device requests the terminal device to report an RLF report, which carries the identifier of the terminal device.

[0233] In another possible implementation, after the terminal device fails to switch to the second access network device, it successfully establishes a connection with the third access network device, and the first access network device can receive the RLF report from the third access network device. The third access network device is an RLF report obtained from the terminal device. The third access network device is an access network device other than the first access network device and the second access network device.

[0234] S713, the first access network device adjusts the switching configuration based on the LBT failure information and the RLF report, and the switching configuration is used for the terminal device to perform cell switching.

[0235] The first access network device associates the LBT failure information and the RLF report based on the identifier of the terminal device, accurately analyzes the reason why the terminal device failed to switch from the first access network device to the second access network device, and determines that the reason for the switching failure is due to a downlink LBT detection failure in the second access network device. Based on the reason for the switching failure, the first access network device can adjust the switching configuration of this site.

[0236] In a possible implementation, the first access network device adjusts the handover configuration of the local station, which may include: the first access network device reduces the number of times the local terminal device is handed over to the second access network device; or, in other words, reduces the number of times the local terminal device is handed over to the beam / channel / target cell where the consistent LBT failure event is prone to occur. The local terminal device of the first access network device refers to a terminal device that uses the first access network device as a source base station for handover.

[0237] It should be understood that if the first access network device is not associated with the LBT failure information, it may incorrectly analyze the reason for the switching failure of the terminal device (for example, switching too early, switching too late, the second access network device did not receive message 1, and the downlink wireless link was interfered, resulting in the terminal device failing to successfully decode the random access response). As a result, the first access network device may incorrectly adjust the switching configuration, for example, incorrectly adjusting the cell signal quality threshold that needs to be met to trigger the switching, incorrectly adjusting the reporting time of the measurement report, etc.

[0238] In an embodiment of the present application, the first access network device associates LBT failure information and RLF report to analyze the cause of the failure of the terminal device. Compared with the prior art that only analyzes the cause of the switching failure based on the RLF report, the technical solution of the embodiment of the present application can avoid incorrect adjustment of the switching configuration of the site due to incorrect analysis of the cause of the switching failure, which is beneficial to improve the success rate of the terminal device switching.

[0239] The above application embodiment is a solution designed for a handover failure scenario. For a successful handover scenario, the first access network device may also associate a successful handover report (SHR) with the LBT failure information to analyze the handover process of the terminal device. In this scenario, the LBT failure information not only indicates at least one consistent LBT failure event, but also indicates the LBT detection success event that occurs in each successful handover scenario.

[0240] For example, when a terminal device switches from a first access network device to a second access network device, after the second access network device receives message 1, before sending message 2 to the terminal device, the first access network device detects the occupancy of the channel. During the LBT detection process, if the number of LBT failures has not reached the configured maximum number of failures, or the duration of the LBT detection has not reached the maximum time length, the LBT detection is successful, and the first access network device also records the LBT detection success event, which includes at least one LBT failure.

[0241] Optionally, the terminal device may record the SHR based on a triggering event.

[0242] Optionally, the triggering event may be that the waiting time of message 2 / message 4 exceeds a first proportion of the maximum time window.

[0243] Optionally, the first ratio is 80%.

[0244] Figure 8 It is a schematic flow chart of another communication method 800 provided in an embodiment of the present application. In the embodiment of the present application, the first access network device is a source base station of the terminal device, and the second access network device is a target base station of the terminal device.

[0245] In the above method 700, after the second access network device triggers the consistent LBT failure event resulting in a handover failure, the second access network device sends LBT failure information to the first access network device. In the method 800, the second access network device sends LBT failure information to the first access network device during the handover process (at this time, the handover has not failed).

[0246] It should be noted that the LBT failure information in method 800 is different from the content indicated by the LBT failure information in the above methods 400, 500, 600 and 700. For the convenience of description, the LBT failure information in the above methods 400, 500, 600 and 700 is referred to as the first LBT failure information, and the LBT failure information in method 800 is referred to as the second LBT failure information. The first LBT failure information is used to indicate at least one consistent LBT failure event, and the second LBT failure information is used to indicate at least one LBT failure.

[0247] It should be noted that for the switching scenario of non-dual active protocol stack (DAPS) switching, the terminal device is disconnected from the source base station after receiving the RRC reconfiguration message, and the terminal device cannot receive messages from the source base station after that. In the embodiment of the present application, the connection between the terminal device and the source base station is retained before the switching is completed. The solution of the embodiment of the present application can also be applied to the DAPS switching scenario.

[0248] Method 800 includes S701 to S706 in method 700, which will not be described in detail here. Method 800 also includes S801 to S803, S710 to S803 are executed after S706, and the specific steps are as follows:

[0249] S801, the second access network device sends second LBT failure information to the first access network device. Correspondingly, the first access network device receives the second LBT failure information.

[0250] The second LBT failure information indicates at least one LBT failure of the second access network device in this switching scenario. If the second access network device determines that an LBT failure has occurred during the downlink LBT detection, it can send the second LBT failure information to the first access network device in real time to assist the first access network device in adjusting the switching configuration of the terminal device.

[0251] In one possible implementation, the second access network device counts the number of LBT failures during downlink LBT detection. If the number of consecutive LBT failures reaches a fourth preset threshold, the second access network device sends a second LBT failure message to the first access network device. The second LBT failure message includes one or more of the following parameters: the identifier of the terminal device, the identifier of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures in this switching scenario, an indication of the failure to send message 2, or the identifier of the target cell. The second LBT failure message can reflect the busyness of the channel where the LBT failure occurred in the future.

[0252] S802: The first access network device adjusts the switching configuration based on the second LBT failure information.

[0253] Based on the second LBT failure information, the first access network device determines that the failure to receive message 2 for a long time during the random access corresponding window is because the second access network device has at least one LBT failure, rather than the failure to receive message 1. Based on this, the first access network device can adjust the switching configuration of the terminal device.

[0254] The first access network device may adjust the switching configuration of the terminal device, which may include: the first access network device adjusts the RACH configuration of the terminal device.

[0255] In one possible implementation, the first access network device may increase the maximum number of attempts for the terminal device to access the second access network device. For example, if the second LBT failure information indicates that N LBT failures have occurred, the first access network device may instruct the terminal device to increase the maximum number of attempts for accessing the second access network device by N times.

[0256] In another possible implementation, the first access network device may reduce the actual number of attempts of the terminal device to access the second access network device. For example, if the second LBT failure information indicates that N LBT failures have occurred, the first access network device may instruct the terminal device to subtract N times from the actual number of attempts to access the second access network device.

[0257] In this way, the chance of the terminal device accessing the second access network device can be increased, thereby improving the success rate of the terminal device accessing the second access network device and reducing the access delay.

[0258] In yet another possible implementation, the first access network device may adjust the size of the corresponding random access window.

[0259] In another possible implementation, the first access network device may instruct the terminal device to stop accessing the second access network device. In this way, the first access network device may analyze the second access network device's downlink channel busy based on the second LBT failure information, and may be temporarily unable to successfully send message 2, thereby causing the terminal device to temporarily be unable to successfully access the second access network device. Based on this, the first access network device may instruct the terminal device to stop accessing the second access network device, and reselect other access network devices as the target base station of the terminal device to perform the switching process.

[0260] S803, the first access network device sends a switching adjustment indication to the terminal device, where the switching adjustment indication is used to indicate one or more of the following: an identifier of the target cell, a RACH configuration adjustment indication, a target cell switching stop indication, and a switching stop reason (LBT failure occurs and the number of times).

[0261] Among them, the RACH configuration adjustment indication is as described in S802, including indicating to increase the maximum number of attempts for the terminal device to access the second access network device, or indicating to reduce the actual number of attempts for the terminal device to access the second access network device, or indicating to adjust the size of the corresponding random access window.

[0262] In an embodiment of the present application, after the first access network device sends an RRC reconfiguration message to the terminal device, the connection between the first access network device and the terminal device is still maintained, so that the first access network device can send a switching adjustment instruction to the terminal device in real time, so that the terminal device can access the second access network device based on the adjusted switching configuration, which is conducive to improving the success rate of the terminal device accessing the second access network device and reducing the access delay. Alternatively, the terminal device stops accessing the second access network device based on the adjusted switching configuration and switches to other access network devices again, which is conducive to reducing the signaling overhead of the terminal device and improving the probability of successful switching of the terminal device.

[0263] In the embodiment of the present application, non-contention-based random access is taken as an example. After the second access network device receives message 1, message 2 is not successfully sent due to at least one LBT failure. In addition, the embodiment of the present application is also applicable to contention-based random access. After the second access network device receives message 1, message 2 is not successfully sent due to at least one LBT failure. Alternatively, after receiving message 1, the second access network device successfully sends message 2, but after receiving message 3, message 4 is not successfully sent due to at least one LBT failure. When the method of the embodiment of the present application is used in a contention-based random access scenario, the RACH configuration adjustment indication in the above S802 may also indicate the adjustment of the duration of the contention resolution timer.

[0264] It should be understood that the sequence numbers of the above processes do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0265] Combined with the above Figures 4 to 8 , describes in detail the communication method according to the embodiment of the present application, and will be combined with Figures 9 to 11 , a communication device according to an embodiment of the present application is described in detail.

[0266] Fig. 9 It is a schematic block diagram of a communication device 900 provided in an embodiment of the present application. The device 900 includes: a transceiver module 910 and a processing module 920.

[0267] The transceiver module 910 is used to receive LBT failure information from a second access network device, where the second access network device is a target base station of the terminal device, and the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device. The processing module 920 is used to adjust a switching configuration based on the LBT failure information, where the switching configuration is used for the terminal device to perform a cell switching.

[0268] Optionally, the processing module 920 is used to: update the RACH configuration based on the LBT failure information; and send the updated RACH configuration to the terminal device.

[0269] Optionally, the processing module 920 is used to: determine, based on the LBT failure information, the first beam, the signal quality of the cell covered by the first beam is higher than a first preset threshold, and / or the number of consistent LBT failure events occurring on the channel corresponding to the first beam is lower than a second preset threshold; obtain the RACH configuration corresponding to the first beam; and update the RACH configuration to the RACH configuration corresponding to the first beam.

[0270] Optionally, the transceiver module 910 is used to: send an identifier of the first beam to the second access network device; and receive a RACH configuration corresponding to the first beam from the second access network device.

[0271] Optionally, the identifier of the first beam is carried in a switching request message, and the switching request message is used to request to switch the terminal device from the first access network device to the second access network device.

[0272] Optionally, the processing module 920 is used to: obtain an RLF report, where the RLF report is used to indicate that the terminal device fails to switch from the first access network device to the second access network device; and adjust the switching configuration based on the LBT failure information and the RLF report.

[0273] Optionally, processing module 920 is used to: determine, based on LBT failure information and RLF report, that the cause of the terminal device switching failure is a consistent LBT failure event occurring in the second access network device; and, based on the cause of the terminal device switching failure, reduce the number of times the terminal device is switched to the second access network device.

[0274] Optionally, each consistent LBT failure event indicates one or more of the following parameters: the terminal device identifier, the time when the LBT detection failed, the identifier of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures, the indication of the failure to send message 2 of the random access process, the indication of the failure to send message 4 of the random access process, or the identifier of the target cell. Among them, the terminal device identifier is the identifier of the terminal device where the handover failure occurred.

[0275] In an optional example, those skilled in the art can understand that the device 900 can be specifically the first access network device in the above embodiment, or the function of the first access network device in the above embodiment can be integrated in the device 900. The above functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. For example, the above transceiver module 910 can be a communication interface, such as a transceiver interface. The device 900 can be used to execute each process and / or step corresponding to the first access network device in the above method embodiment.

[0276] Fig.10 It is a schematic block diagram of a communication device 1000 provided in an embodiment of the present application. The device 1000 includes: a processing module 1010 and a transceiver module 1020.

[0277] The processing module 1010 is used to obtain LBT failure information, where the LBT failure information indicates at least one consistent LBT failure event. The transceiver module 1020 is used to send the LBT failure information to the first access network device.

[0278] Optionally, the transceiver module 1020 is used to send the LBT failure information to the first access network device when the number of consistent LBT failure events occurring on the channel corresponding to the second beam exceeds a third preset threshold.

[0279] Optionally, the transceiver module 1020 is used to: periodically send the LBT failure information to the first access network device.

[0280] Optionally, the transceiver module 1020 is used to: receive a request message from the first access network device, the request message being used to request the LBT failure information; and, based on the request message, send the LBT failure information to the first access network device.

[0281] Optionally, the processing module 1010 is used to: adjust the RACH configuration of the second access network device based on the LBT failure information, and the RACH configuration is used to access the second access network device. The transceiver module 1020 is used to: send the adjusted RACH configuration to the first access network device.

[0282] Optionally, the RACH configuration of the second access network device includes one or more of the following: a maximum number of attempts for a terminal device to access the second access network device, a size of a random access response window, or a duration of a contention resolution timer.

[0283] Optionally, the transceiver module 1020 is used to: receive an identifier of a first beam from a first access network device, the signal quality of a cell covered by the first beam is higher than a first preset threshold, and / or the number of consistent LBT failure events occurring on a channel corresponding to the first beam is lower than a second preset threshold; and send a RACH configuration corresponding to the first beam to the first access network device.

[0284] Optionally, each consistent LBT failure event indicates one or more of the following parameters: the identification of the terminal device where the switching failure occurred, the time of the LBT detection failure, the identification of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures, an indication of the failure to send message 2 of the random access process, an indication of the failure to send message 4 of the random access process, or the identification of the target cell.

[0285] In an optional example, those skilled in the art can understand that the device 1000 can be specifically the second access network device in the above embodiment, or the function of the second access network device in the above embodiment can be integrated in the device 1000. The above functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. For example, the above transceiver module 1020 can be a communication interface, such as a transceiver interface. The device 1000 can be used to execute each process and / or step corresponding to the second access network device in the above method embodiment.

[0286] It should be understood that the apparatus 900 and the apparatus 1000 herein are embodied in the form of functional modules. The term "module" herein may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (e.g., a shared processor, a dedicated processor, or a group processor, etc.) and a memory for executing one or more software or firmware programs, a combined logic circuit, and / or other suitable components that support the described functions.

[0287] In the embodiment of the present application, the apparatus 900 and the apparatus 1000 may also be a chip or a chip system, such as a system on chip (SoC). Correspondingly, the transceiver module may be a transceiver circuit of the chip, which is not limited here.

[0288] Fig.111 is a schematic block diagram of another communication device 1100 provided in an embodiment of the present application. The device 1100 includes a processor 1110, a transceiver 1120, and a memory 1130. The processor 1110, the transceiver 1120, and the memory 1130 communicate with each other through an internal connection path, the memory 1130 is used to store instructions, and the processor 1110 is used to execute the instructions stored in the memory 1130 to control the transceiver 1120 to send signals and / or receive signals.

[0289] It should be understood that the device 1100 can be specifically the first access network device or the second access network device in the above embodiment, or the functions of the first access network device or the second access network device in the above embodiment can be integrated in the device 1100, and the device 1100 can be used to execute the various steps and / or processes corresponding to the first access network device or the second access network device in the above method embodiment. Optionally, the memory 1130 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A part of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type. The processor 1110 can be used to execute instructions stored in the memory, and when the processor executes the instruction, the processor 110 can execute the various steps and / or processes corresponding to the first access network device or the second access network device in the above method embodiment.

[0290] It should be understood that in the embodiments of the present application, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0291] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0292] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0293] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0294] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0295] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0296] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0297] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0298] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: Applied to a first access network device, where the first access network device is a source base station of a terminal device, the method includes: Receiving listen-before-speak LBT failure information from a second access network device, where the second access network device is a target base station of the terminal device, and the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device; Based on the LBT failure information, the switching configuration is adjusted, and the switching configuration is used for the terminal device to perform cell switching.

2. The method according to claim 1, characterized in that: The adjusting the switching configuration based on the LBT failure information includes: Based on the LBT failure information, updating a RACH configuration, where the RACH configuration is used for the terminal device to access the second access network device; The method further comprises: Sending an updated RACH configuration to the terminal device.

3. The method according to claim 2, characterized in that The updating of RACH configuration based on the LBT failure information includes: Determine a first beam based on the LBT failure information, wherein the signal quality of a cell covered by the first beam is higher than a first preset threshold, and / or the number of times the consistent LBT failure event occurs on a channel corresponding to the first beam is lower than a second preset threshold; Obtaining a RACH configuration corresponding to the first beam; The RACH configuration is updated to the RACH configuration corresponding to the first beam.

4. The method according to claim 3, characterized in that The acquiring the RACH configuration corresponding to the first beam includes: Sending an identifier of the first beam to the second access network device; Receive a RACH configuration corresponding to the first beam from the second access network device.

5. The method according to claim 4, characterized in that The identifier of the first beam is carried in a switching request message, and the switching request message is used to request to switch the terminal device from the first access network device to the second access network device.

6. The method according to claim 1, characterized in that Before adjusting the switching configuration based on the LBT failure information, the method further includes: Obtain a radio link failure RLF report, where the RLF report is used to indicate that a terminal device fails to switch from the first access network device to the second access network device; The adjusting the switching configuration based on the LBT failure information includes: Based on the LBT failure information and the RLF report, the switching configuration is adjusted.

7. The method according to claim 6, characterized in that The adjusting the switching configuration based on the LBT failure information and the RLF report includes: Based on the LBT failure information and the RLF report, determining that the reason for the handover failure of the terminal device is that the consistent LBT failure event occurs in the second access network device; Based on the reason for the failure of the terminal device switching, reduce the number of times the terminal device is switched to the second access network device.

8. The method according to any one of claims 1 to 7, characterized in that Each of the consistent LBT failure events indicates one or more of the following parameters: The identification of the terminal device, the time when the LBT detection failed, the identification of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures, the indication of the failure to send message 2 of the random access process, the indication of the failure to send message 4 of the random access process, or the identification of the target cell.

9. A communication method, characterized in that: Applied to a second access network device, the method comprises: Acquire listen-before-speak LBT failure information, where the LBT failure information is used to indicate at least one consistent LBT failure event of the second access network device; The LBT failure information is sent to the first access network device.

10. The method according to claim 9, characterized in that The sending the LBT failure information to the first access network device includes: When the number of times the consistent LBT failure event occurs on the channel corresponding to the second beam exceeds a third preset threshold, the LBT failure information is sent to the first access network device.

11. The method according to claim 9, characterized in that The sending the LBT failure information to the first access network device includes: Periodically send the LBT failure information to the first access network device.

12. The method according to claim 9, characterized in that Before sending the LBT failure information to the first access network device, the method further includes: receiving a request message from the first access network device, where the request message is used to request the LBT failure information; The sending the LBT failure information to the first access network device includes: Based on the request message, the LBT failure information is sent to the first access network device.

13. The method according to any one of claims 9 to 12, characterized in that After obtaining the LBT failure information, the method further includes: Based on the LBT failure information, adjust the random access channel RACH configuration of the second access network device, where the RACH configuration of the second access network device is used to access the second access network device; Send the adjusted RACH configuration to the first access network device.

14. The method according to claim 13, characterized in that The RACH configuration of the second access network device includes one or more of the following: The maximum number of attempts for a terminal device to access the second access network device, the size of the random access response window or the duration of the contention resolution timer.

15. The method according to any one of claims 9 to 12, characterized in that After sending the LBT failure information to the first access network device, the method further includes: Receiving an identifier of a first beam from the first access network device, the signal quality of a cell covered by the first beam is higher than a first preset threshold, and / or the number of times the consistent LBT failure event occurs on a channel corresponding to the first beam is lower than a second preset threshold; Send the RACH configuration corresponding to the first beam to the first access network device.

16. The method according to any one of claims 9 to 15, characterized in that Each of the consistent LBT failure events indicates one or more of the following parameters: The identification of the terminal device where the switching failure occurred, the time when the LBT detection failed, the identification of the beam corresponding to the channel where the LBT failure occurred, the number of LBT failures, the indication of the failure to send message 2 in the random access process, the indication of the failure to send message 4 in the random access process, or the identification of the target cell.

17. A communication device, characterized in that: The method comprises a module for implementing the method according to any one of claims 1 to 8, or comprises a module for implementing the method according to any one of claims 9 to 16.

18. A communication device, characterized in that: The method comprises a processor coupled to a memory, wherein the memory is used to store programs or instructions. When the programs or instructions are executed by the processor, the method according to any one of claims 1 to 8 is executed, or the method according to any one of claims 9 to 16 is executed.

19. A computer-readable storage medium, characterized in that: Used to store a computer program, which, when executed on a computer, causes the method according to any one of claims 1 to 8 to be executed, or causes the method according to any one of claims 9 to 16 to be executed.

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