Communication method and communication apparatus

Abstract

Provided in the present application are a communication method and a communication apparatus. In the communication method, when receiving a TA of a terminal device that is sent from a second network device or when sending a TA to the terminal device, a first network device may start a first timer; and when the first timer expires, the first network device may send first indication information to the second network device, wherein the first indication information is used for instructing the stopping of dynamic scheduling for the terminal device, and / or the first indication information is used for instructing the stopping of reception of an uplink message from the terminal device on a pre-configured resource. Therefore, the problem of resource waste caused by frequent transmission of dynamic scheduling and / or frequent reception of an uplink message by a network device is avoided, thereby saving resources.

Description

Communication methods and communication devices

[0001] This application claims priority to Chinese Patent Application No. 202411759917.X, filed with the State Intellectual Property Office of China on November 30, 2024, entitled "Communication Method and Communication Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and specifically to communication methods and devices within the field of communications. Background Technology

[0003] In existing communication systems, before transmitting data with network devices, terminal devices must first connect to the network. Typically, this connection is made via random access, which takes time and results in significant latency. This is especially true during handover scenarios, where a terminal device moves from the coverage area of ​​one network device to another. The random access method leads to further latency, impacting transmission performance. To reduce latency, terminal devices can use non-random access methods. However, in some handover techniques triggered by the terminal device, the network device is unaware of when the terminal will connect. Therefore, the network device needs to provide more transmission resources to ensure timely connection, resulting in substantial resource overhead. Summary of the Invention

[0004] This application provides a communication method and a communication device that can save resources.

[0005] Firstly, a communication method is provided. This method can be executed by a first network device with computing capabilities or a component (such as a chip or module) of the first network device with computing capabilities. For example, the first network device can be an access network device, or an access computing node. Alternatively, the method can also be executed by a computing device with communication capabilities or a component (such as a chip or module) of the computing device with communication capabilities. The following explanation uses the first network device as the executing entity of this method as an example. In actual implementation, the executing entity of this method can be other names.

[0006] The communication method includes: when receiving a timed advance TA from a terminal device of a second network device or when sending a TA to a terminal device, starting a first timer, wherein the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device; if the first timer times out, sending a first indication information to the second network device, the first indication information being used to indicate stopping the dynamic scheduling of the terminal device, and / or, the first indication information being used to indicate stopping the reception of uplink messages from the terminal device on pre-configured resources.

[0007] In the above scheme, when the first network device receives a TA from the second network device or sends a TA to the terminal device, it can start a first timer. When the first timer expires, the first network device can send a first indication message to the second network device. The first indication message is used to indicate that the dynamic scheduling of the terminal device should be stopped, and / or the first indication message is used to indicate that the uplink message of the terminal device should be stopped on the pre-configured resources. This avoids the problem of resource waste caused by the network device frequently sending dynamic scheduling and / or frequently trying to receive uplink messages, and can save resources.

[0008] Optionally, the second network device can determine the TA of the terminal device and send the TA of the terminal device to the first network device. When the first network device receives the TA of the terminal device from the second network device, it can start a first timer. When the first timer expires, the first network device considers the TA of the terminal device to be invalid and can send a first indication message to the second network device to instruct the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0009] Optionally, the second network device can determine the TA of the terminal device and send the TA of the terminal device to the first network device. After the first network device receives the TA of the terminal device from the second network device, it can send the TA of the terminal device to the terminal device. After the first network device sends the TA of the terminal device to the terminal device, it can start a first timer. When the first timer expires, the first network device considers the TA of the terminal device to be invalid and can send a first indication message to the second network device to instruct the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0010] Optionally, the second network device can determine the TA of the terminal device and send the TA of the terminal device to the first network device. After the first network device receives the TA of the terminal device from the second network device, it can send the TA of the terminal device to the terminal device. Between the time the first network device receives the TA of the terminal device from the second network device and the time the first network device sends the TA of the terminal device to the terminal device, the first network device can start a first timer. When the first timer expires, the first network device considers the TA of the terminal device to be invalid and can send a first indication message to the second network device to instruct the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0011] Optionally, the TA of the terminal device can be the TA value of the terminal device.

[0012] Optionally, when receiving a timed advance TA from the terminal device of the second network device or sending a TA to the terminal device, a first timer is started, wherein the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device; if the first timer expires, a first indication message is sent to the second network device. Alternatively, the first network device may send a first indication message to the second network device after the first time period ends following receiving the timed advance TA from the terminal device of the second network device or sending a TA to the terminal device, wherein the length of the first time period is used to determine whether the TA of the terminal device is valid.

[0013] In some possible implementations, the communication method also includes obtaining the duration of the first timer from a second network device.

[0014] In the above scheme, the second network device can indicate the duration of the first timer to the first network device, and the first network device can obtain the duration of the first timer from the second network device. For example, the second network device can determine the duration of the first timer based on the coverage area of ​​the second network device. If the coverage area of ​​the second network device is large, the duration of the first timer can be smaller; if the coverage area of ​​the second network device is small, the duration of the first timer can be larger.

[0015] Optionally, the duration of the first timer can be determined by the first network device or specified by the protocol; this application embodiment does not impose any restrictions on this.

[0016] Optionally, the duration of the first timer is used to determine whether the TA of the terminal device is valid.

[0017] In some possible implementations, the first indication information is also used to indicate that the TA of the terminal device is invalid.

[0018] In the above scheme, when the first timer expires, it indicates that the TA of the terminal device is invalid. Therefore, the terminal device may not be able to access the second network device. The first network device can send a first indication information to the second network device so that the second network device can stop the dynamic scheduling of the terminal device according to the first indication information, and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0019] Secondly, a communication method is provided, comprising: the method can be executed by a first network device with computing capabilities or a component (such as a chip or module) of the first network device with computing capabilities, for example, the first network device can be an access network device, or an access computing node; or, the method can also be executed by a computing device with communication capabilities or a component (such as a chip or module) of the computing device with communication capabilities. The following description uses the first network device as the executing entity of this method as an example; in actual implementation, the executing entity of this method can be other names.

[0020] The communication method includes: receiving a first message from a terminal device; and sending a first indication message to a second network device according to the first message, wherein the first indication message is used to indicate stopping dynamic scheduling of the terminal device, and / or, the first indication message is used to indicate stopping receiving uplink messages from the terminal device on pre-configured resources, wherein the first network device is a serving network device of the terminal device, and the second network device is a candidate network device of the terminal device.

[0021] In the above scheme, the first network device can send a first indication message to the second network device based on the first message sent by the terminal device. The second network device can then stop dynamically scheduling the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources based on the first indication message. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization.

[0022] The first message is used by the first network device to determine whether to send a first indication message to the second network device. Optionally, the first message is used by the first network device to determine whether the second network device stops dynamically scheduling the terminal device; or, the first message is used by the first network device to determine whether the second network device stops receiving uplink messages from the terminal device on pre-configured resources; or, the first message is used by the first network device to determine whether the second network device stops receiving uplink messages from the terminal device on pre-configured resources and whether to stop dynamically scheduling the terminal device.

[0023] In some possible implementations, the first message includes at least one of the following: a measurement report of at least one candidate cell managed by the second network device, a measurement report of at least one beam of at least one candidate cell, a measurement report of at least one reference signal of at least one candidate cell, an indication message for indicating that the timing advance TA of the terminal device has failed, an indication message for indicating that the target beam of at least one candidate cell has failed, an indication message for indicating that the change in the cell-level reference signal received power (RSRP) of at least one candidate cell exceeds a threshold value, an indication message for indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value, an indication message for indicating that the cell-level RSRP of at least one candidate cell is less than a threshold value, or an indication message for indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value, wherein the target beam is the beam that the terminal device will use when accessing the second network device.

[0024] In some possible implementations, based on the first message, a first instruction message is sent to the second network device, including:

[0025] After determining that the TA has failed based on the first message, a first instruction message is sent to the second network device.

[0026] In the above scheme, after the first network device determines that the TA of the terminal device has failed, the terminal device may not connect to the second network device. Therefore, the first network device can send a first indication message so that the second network device can stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources, which can save resources.

[0027] Optionally, the first network device may determine that the TA of the terminal device has failed based on at least one of the following in the first message: an indication that the timing advance TA of the terminal device has failed; an indication that the change in the cell-level reference signal received power (RSRP) of at least one candidate cell exceeds a threshold value; an indication that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value; an indication that the cell-level RSRP of at least one candidate cell is less than a threshold value; or an indication that the RSRP of the reference signal of at least one candidate cell is less than a threshold value.

[0028] In some possible implementations, the first indication information is also used to indicate that the TA of the terminal device has failed.

[0029] In the above scheme, the first indication information sent by the first network device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources because the TA of the terminal device has failed, so that the second network device can know the reason.

[0030] In some possible implementations, based on the first message, a first instruction message is sent to the second network device, including:

[0031] After determining that the target beam has failed based on the first message, a first instruction message is sent to the second network device. The target beam is the beam that the terminal device will use when accessing the second network device.

[0032] In the above scheme, after the first network device determines that the target beam has failed, the terminal device may not connect to the second network device. Therefore, a first indication message can be sent so that the second network device can stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources, which can save resources.

[0033] Optionally, the first network device may determine that the target beam of the terminal device is faulty based on at least one of the following in the first message: indication information for indicating that the target beam of at least one candidate cell is faulty, indication information for indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value, or indication information for indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value.

[0034] In some possible implementations, the first indication information is also used to indicate that the target beam has failed.

[0035] In the above scheme, the first indication information sent by the first network device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources because the target beam has failed, so that the second network device can know the reason.

[0036] In some possible implementations, the first indication information is used to indicate stopping the dynamic scheduling of the terminal device using the target beam and using the updated target beam for dynamic scheduling of the terminal device, and / or, the first indication information is used to indicate stopping the reception of the terminal device's uplink messages on the pre-configured resources using the target beam and using the updated target beam to receive the terminal device's uplink messages on the pre-configured resources, wherein the updated target beam is the updated beam that the terminal device will use when accessing the second network device.

[0037] In the above scheme, when the first network device determines that the target beam has failed, the first indication information sent by the first network device is used to indicate to stop using the target beam to dynamically schedule the terminal device, and to use the updated target beam to dynamically schedule the terminal device. And / or, the first indication information sent by the first network device is used to indicate to stop receiving uplink messages on the pre-configured resources, and to use the updated target beam to receive uplink messages from the terminal device on the pre-configured resources. This can avoid the situation of terminal device handover interruption and help improve the success rate of terminal device handover.

[0038] In some possible implementations, the communication method also includes: determining the updated target beam based on the first message.

[0039] Optionally, the first network device may determine the updated target beam based on the measurement report of at least one beam of at least one candidate cell in the first message.

[0040] In some possible implementations, sending a first indication message to a second network device according to a first message includes: after determining that the probability of the terminal device switching to a first candidate cell managed by the second network device is less than a threshold according to the first message, sending the first indication message to the second network device.

[0041] In the above scheme, the first message may include a measurement report of the first candidate cell. The first network device can determine the first probability of the terminal device switching to the first candidate cell based on the measurement report of the first candidate cell. If the first probability of the terminal device switching to the first candidate cell is less than a threshold, it means that the possibility of the terminal device switching to the second network device is low. Therefore, a first indication message can be sent to the second network device to instruct the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages of the terminal device on the pre-configured resources. This avoids the problem of resource waste caused by the second network device frequently sending dynamic scheduling and / or frequently receiving uplink messages when the terminal device is unlikely to switch to the second network device, and is conducive to improving resource utilization.

[0042] In some possible implementations, the first indication information is also used to indicate that the first probability of the terminal device switching to the first candidate cell managed by the second network device is less than a threshold.

[0043] In the above scheme, the first indication information sent by the first network device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources because the first probability of the terminal device switching to the first candidate cell managed by the second network device is less than a threshold, so that the second network device can know the reason.

[0044] Thirdly, a communication method is provided, comprising: the method can be executed by a second network device with computing capabilities or a component (such as a chip or module) of a second network device with computing capabilities, for example, the second network device can be an access network device, or an access computing node; or, the method can also be executed by a computing device with communication capabilities or a component (such as a chip or module) of a computing device with communication capabilities. The following description uses a second network device as the executing entity of this method as an example; in actual implementation, the executing entity of this method can be other names.

[0045] The communication method includes: receiving first indication information from a first network device, the first indication information being used to indicate stopping dynamic scheduling of the terminal device, and / or, the first indication information being used to indicate stopping receiving uplink messages from the terminal device on pre-configured resources, the first network device being a serving network device of the terminal device, and a second network device being a candidate network device of the terminal device; stopping dynamic scheduling of the terminal device according to the first indication information, and / or stopping receiving uplink messages from the terminal device on pre-configured resources.

[0046] In the above scheme, the second network device can stop dynamically scheduling the terminal device according to the first instruction information, and / or stop receiving uplink messages from the terminal device on the pre-configured resources. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization.

[0047] In some possible implementations, the communication method further includes: instructing the first network device on the duration of a first timer, and triggering the first network device to send a first indication message after the first timer expires.

[0048] In some possible implementations, the first indication information is also used to indicate that the TA of the terminal device has failed. The TA of the terminal device is determined by a second network device.

[0049] In some possible implementations, the first indication information is also used to indicate that the target beam is invalid, the target beam being the beam that the terminal device will use when accessing the second network device.

[0050] In some possible implementations, the first indication information is used to indicate stopping the dynamic scheduling of the terminal device using the target beam and using the updated target beam for dynamic scheduling of the terminal device, and / or, the first indication information is used to indicate stopping the reception of the terminal device's uplink messages on the pre-configured resources using the target beam and using the updated target beam to receive the terminal device's uplink messages on the pre-configured resources, wherein the updated target beam is the updated beam that the terminal device will use when accessing the second network device;

[0051] The step of stopping dynamic scheduling of the terminal device according to the first instruction information, and / or stopping receiving uplink messages from the terminal device on pre-configured resources, includes:

[0052] Based on the first instruction, stop dynamically scheduling the terminal device using the target beam, and then dynamically schedule the terminal device using the updated target beam; and / or,

[0053] According to the first instruction information, stop using the target beam to receive uplink messages from the terminal device on the pre-configured resources, and use the updated target beam to receive uplink messages from the terminal device on the pre-configured resources.

[0054] Specifically, the description of the third aspect can be found in the description of the second aspect.

[0055] Fourthly, a communication method is provided, which can be executed by a terminal device or by a component of the terminal device (such as a chip or module), and this application does not limit the method. For ease of description, the following explanation uses execution by a terminal device as an example.

[0056] The communication method includes: receiving second indication information from a first network device for indicating the TA and / or target beam of a terminal device;

[0057] Based on the instruction information, a first message is sent to the first network device;

[0058] The first message includes at least one of the following:

[0059] The second network device manages measurement reports for at least one candidate cell, measurement reports for at least one beam of at least one candidate cell, indication information for indicating early timing (TA) failure of the terminal device, indication information for indicating target beam failure of at least one candidate cell, indication information for indicating that the change in the cell-level reference signal received power (RSRP) of at least one candidate cell exceeds a threshold value, indication information for indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value, indication information for indicating that the cell-level RSRP of at least one candidate cell is less than a threshold value, or indication information for indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value, wherein the target beam is the beam that the terminal device will use when accessing the second network device; wherein the first network device is the serving network device of the terminal device, and the second network device is a candidate network device of the terminal device.

[0060] In the above scheme, the terminal device can send a first message to the first network device. This first message is used by the first network device to determine whether to send a first instruction to the second network device. The second network device can then stop dynamically scheduling the terminal device based on the first instruction, and / or stop receiving uplink messages from the terminal device on pre-configured resources. This avoids resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization.

[0061] Optionally, the second indication information can indicate the target beam by means of the identifier of the reference signal or the transmission configuration indicator state ID (TCI State ID).

[0062] In some possible implementations, sending a first message to the first network device based on the second indication information includes: the terminal device starts a second timer when it receives the second indication information, and sends a first message to the first network device after the second timer expires. The first message includes indication information for indicating that the terminal device's timer early TA has expired.

[0063] In the above scheme, the terminal device can start a second timer when it receives a TA (Telematics Request) from the terminal device. When the second timer expires, the TA becomes invalid. Therefore, the first message sent by the terminal device to the first network device may include indication information indicating that the TA of at least one candidate cell has become invalid. For example, the duration of the second timer may be the validity duration of the TA. The duration of the second timer may be sent by the first network device to the terminal device, or it may be sent by the second network device to the terminal device through the first network device. This application embodiment does not limit this.

[0064] In some possible implementations, sending a first message to the first network device based on the second indication information includes: upon receiving the second indication information, measuring the change in the cell-level RSRP of the at least one candidate cell compared to the current cell-level RSRP of the at least one candidate cell; if the change in the cell-level RSRP exceeds a threshold, then sending a first message to the first network device. The first message may include indication information indicating that the change in the cell-level RSRP of the at least one candidate cell exceeds a threshold, and / or indication information indicating that the TA of the terminal device has failed.

[0065] Optionally, upon receiving the second indication information, measuring the change in the cell-level RSRP of the at least one candidate cell compared to the current cell-level RSRP of the at least one candidate cell includes: measuring the change in the cell-level RSRP of the at least one candidate cell compared to the current cell-level RSRP of the at least one candidate cell upon receiving the second indication information.

[0066] In the above scheme, the terminal device can measure the change in RSRP at the cell level of at least one candidate cell. If the change in RSRP at the cell level of at least one candidate cell exceeds a threshold value, it indicates that the location of the terminal device has changed significantly, and the TA (Transmission Terminal) of the terminal device has failed. Therefore, the first message sent by the terminal device to the first network device may include indication information indicating TA failure. Optionally, the first message may also include indication information indicating that the change in RSRP at the cell level of at least one candidate cell exceeds a threshold value.

[0067] In some possible implementations, sending a first message to the first network device based on the second indication information includes: upon receiving the second indication information, measuring the cell-level RSRP of the at least one candidate cell; if the cell-level RSRP is less than a threshold value, sending a first message to the first network device; the first message may include indication information indicating that the cell-level RSRP of the at least one candidate cell is less than a threshold value, and / or indication information indicating that the TA of the terminal device is invalid.

[0068] Optionally, upon receiving the second indication information, measuring the cell-level RSRP of the at least one candidate cell includes: periodically measuring the cell-level RSRP of the at least one candidate cell after receiving the second indication information.

[0069] In the above scheme, after receiving the second indication information, the terminal device can measure the cell-level RSRP of at least one candidate cell. If the cell-level RSRP of at least one candidate cell is less than a threshold value, it indicates that the location of the terminal device has changed significantly and the TA of the terminal device has failed. Therefore, the terminal device can include indication information indicating TA failure in the first message sent to the first network device. Optionally, the first message can also include indication information indicating that the cell-level RSRP of at least one candidate cell is less than a threshold value.

[0070] In some possible implementations, sending a first message to the first network device based on the second indication information includes: upon receiving the second indication information, measuring the change in the RSRP of the reference signal of the at least one candidate cell compared to the RSRP of the reference signal of the at least one candidate cell at the current time; if the change in the RSRP of the reference signal exceeds a threshold value, then sending a first message to the first network device. The first message may include indication information indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds a threshold value, and / or indication information indicating that the TA of the terminal device has failed.

[0071] Optionally, upon receiving the second indication information, measuring the change in the RSRP of the reference signal of the at least one candidate cell compared to the RSRP of the reference signal of the at least one candidate cell at the current time includes: upon receiving the second indication information, measuring the change in the RSRP of the reference signal of the at least one candidate cell compared to the RSRP of the reference signal of the at least one candidate cell at the current time.

[0072] In the above scheme, the terminal device can measure the RSRP change of the reference signal of at least one candidate cell. If the RSRP change of the reference signal of at least one candidate cell exceeds a threshold value, it indicates that the location of the terminal device has changed significantly, and the TA of the terminal device has failed. Therefore, the first message sent by the terminal device to the first network device may include indication information indicating TA failure. Optionally, the first message may also include indication information indicating that the RSRP change of the reference signal of at least one candidate cell exceeds a threshold value.

[0073] In some possible implementations, sending a first message to the first network device based on the second indication information includes: upon receiving the second indication information, measuring the RSRP of the reference signal of the at least one candidate cell; if the RSRP of the reference signal is less than a threshold value, then sending a first message to the first network device. The first message may include indication information indicating that the RSRP of the reference signal of the at least one candidate cell is less than a threshold value, and / or indication information indicating that the TA of the terminal device is invalid.

[0074] Optionally, upon receiving the second indication information, measuring the RSRP of the reference signal of the at least one candidate cell includes: periodically measuring the RSRP of the reference signal of the at least one candidate cell after receiving the second indication information.

[0075] In the above scheme, the terminal device can measure the RSRP of the reference signal of at least one candidate cell. If the RSRP of the reference signal of at least one candidate cell is less than a threshold value, it indicates that the location of the terminal device has changed significantly and the TA of the terminal device has failed. Therefore, the terminal device can include indication information indicating TA failure in the first message sent to the first network device. Optionally, the first message may also include indication information indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value.

[0076] In some possible implementations, sending a first message to the first network device based on the second indication information includes: upon receiving the second indication information, measuring the change in RSRP of the reference signal corresponding to the target beam compared to the RSRP of the reference signal corresponding to the target beam at the current time; if the change in RSRP exceeds a threshold value, then sending a first message to the first network device, wherein the first message includes indication information for indicating that the target beam of the at least one candidate cell has failed.

[0077] Optionally, upon receiving the second indication information, measuring the change in RSRP of the reference signal corresponding to the target beam compared to the RSRP of the reference signal corresponding to the target beam at the current time includes: upon receiving the second indication information, measuring the change in RSRP of the reference signal corresponding to the target beam compared to the RSRP of the reference signal corresponding to the target beam at the current time.

[0078] In the above scheme, the terminal device can measure the change in the reference signal RSRP corresponding to the target beam. If the change in the RSRP of the reference signal corresponding to the target beam exceeds a threshold value, it indicates that the target beam has failed. Therefore, the terminal device can include indication information indicating target beam failure in the first message sent to the first network device. Optionally, the first message can also include indication information indicating that the change in the RSRP of the target beam exceeds a threshold value.

[0079] In some possible implementations, sending a first message to a first network device based on the first indication information includes: upon receiving the second indication information, measuring the RSRP of the reference signal corresponding to the target beam; if the RSRP of the reference signal corresponding to the target beam is less than a threshold value, then sending a first message to the first network device, wherein the first message includes indication information for indicating that the target beam of the at least one candidate cell has failed.

[0080] Optionally, upon receiving the second indication information, measuring the RSRP of the reference signal corresponding to the target beam includes: periodically measuring the RSRP of the reference signal corresponding to the target beam after receiving the second indication information.

[0081] In the above scheme, the terminal device can measure the RSRP of the reference signal corresponding to the target beam. If the RSRP of the reference signal corresponding to the target beam exceeds a threshold value, it indicates that the target beam is faulty. Therefore, the terminal device can include indication information indicating target beam failure in the first message sent to the first network device. Optionally, the first message can also include indication information indicating that the RSRP of the reference signal corresponding to the target beam is less than a threshold value.

[0082] In some possible implementations, the terminal device may measure at least one candidate cell managed by the second network device, and may include a measurement report of at least one candidate cell in a first message sent to the first network device.

[0083] In some possible implementations, the terminal device may measure at least one reference signal of at least one candidate cell and may include a measurement report of at least one reference signal of at least one candidate cell in a first message sent to the first network device, or the measurement report of at least one reference signal of at least one candidate cell may be referred to as a measurement report of at least one beam, wherein at least one beam corresponds one-to-one with at least one reference signal.

[0084] Fifthly, this method can be executed by a second network device with computing capabilities or a component (such as a chip or module) of such a device. For example, the second network device can be an access network device, or an access computing node; alternatively, the method can also be executed by a computing device with communication capabilities or a component (such as a chip or module) of such a device. The following explanation uses a second network device as the executing entity of this method; however, in actual implementation, the executing entity can be any other name.

[0085] The communication method includes: when receiving the remaining valid duration information of the time advance TA of the terminal device from the first network device, starting the first timer; when the first timer times out, stopping the dynamic scheduling of the terminal device and / or stopping the reception of uplink messages from the terminal device on the pre-configured resources; wherein the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device.

[0086] In the above scheme, when the second network device receives the remaining valid duration information of the TA of the terminal device from the first network device, it can start the first timer. After the first timer expires, the second network device stops the dynamic scheduling of the terminal device and / or stops receiving uplink messages from the terminal device on the pre-configured resources. In this way, the resource waste caused by the second network device frequently sending dynamic scheduling or frequently trying to receive uplink messages from the terminal device is avoided, thereby improving the utilization rate of resources.

[0087] In some possible implementations, the communication method further includes sending the total effective duration information of the TA to the first network device, the total effective duration information being used to determine the remaining effective duration information.

[0088] Optionally, if the first timer times out, it indicates that the TA of the terminal device has failed. Therefore, the second network device may stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0089] In the above scheme, the second network device can send the total effective duration information of TA to the first network device so that the second network device can determine the remaining effective duration information based on the total effective duration information.

[0090] Optionally, the total effective duration indicated by the total effective duration information can be related to the coverage of the second network device and / or the speed of the terminal device.

[0091] Optionally, the first network device may also determine the total effective duration information; for example, the first network device determines the total effective duration indicated by the total effective duration information based on the coverage of the second network device and / or the speed of the terminal device.

[0092] In some possible implementations, the duration of the first timer is the remaining valid duration.

[0093] Sixthly, a communication method is provided, comprising: the method can be executed by a first network device with computing capabilities or a component (such as a chip or module) of the first network device with computing capabilities, for example, the first network device can be an access network device, or an access computing node; or, the method can also be executed by a computing device with communication capabilities or a component (such as a chip or module) of the computing device with communication capabilities. The following description uses the first network device as the executing entity of this method as an example; in actual implementation, the executing entity of this method can be other names.

[0094] The communication method includes: receiving from a second network device the total effective duration information of the timing advance TA of the terminal device; and sending to the second network device the remaining effective duration information of the TA, wherein the remaining effective duration information is determined based on the total effective duration information, as well as the time of receiving the TA and / or the time of sending the TA to the terminal device.

[0095] Among them, the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device.

[0096] In the above scheme, the first network device can send the remaining valid duration information, determined based on the total valid duration information, the time of receiving the TA, and / or the time of sending the TA to the terminal device, to the second network device. When the second network device receives the remaining valid duration information, it starts a first timer. After the first timer expires, the second network device stops dynamically scheduling the terminal device and / or stops receiving uplink messages from the terminal device on the pre-configured resources. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization.

[0097] Optionally, the first network device can determine the remaining valid duration information based on the total valid duration information, and the time of receiving the TA and / or the time of sending the TA to the terminal device. Optionally, the first network device can receive the TA from the terminal device at a first moment, and the first network device can subtract a first time interval (from the first moment to the second moment) from the total valid duration, with the second moment being the moment the first network device determines the remaining valid duration information. Optionally, the first network device can send the TA to the terminal device at a third moment, and the first network device can subtract a second time interval (from the third moment to the second moment) from the total valid duration, with the second moment being the moment the first network device determines the remaining valid duration information.

[0098] Optionally, the first network device can determine the total valid duration information. In this case, the first network device does not need to receive the total valid duration information from the second network device.

[0099] In a seventh aspect, a communication device is provided, which has the function of implementing any of the above aspects. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. For example, a transceiver module or unit, a processing module or unit, an acquisition module or unit, etc.

[0100] Eighthly, embodiments of this application provide a communication device, including: a memory and a processor, wherein the memory is used to store a computer program; and the processor is used to cause the communication device to execute any of the communication methods described above when the computer program is invoked.

[0101] Ninthly, embodiments of this application provide a chip system including a processor coupled to a memory, the processor executing a computer program stored in the memory to implement the communication method of any of the above aspects.

[0102] The chip system can be a single chip or a chip module composed of multiple chips.

[0103] In a tenth aspect, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the communication method of any of the above aspects.

[0104] Eleventhly, embodiments of this application provide a computer program product that, when run on a communication device, causes the communication device to execute any of the communication methods described above.

[0105] It is understood that the beneficial effects of aspects seven through eleven above can be found in the relevant descriptions of the above aspects, and will not be repeated here. Attached Figure Description

[0106] Figure 1 is a schematic diagram of the communication system provided in an embodiment of this application.

[0107] Figure 2 is a schematic diagram of the structure of the network device provided in an embodiment of this application.

[0108] Figure 3 is a schematic diagram of the communication method provided in an embodiment of this application.

[0109] Figure 4 is a schematic diagram of another communication method provided in an embodiment of this application.

[0110] Figure 5 is a schematic diagram of another communication method provided in an embodiment of this application.

[0111] Figure 6 is a schematic diagram of another communication method provided in an embodiment of this application.

[0112] Figure 7 is a schematic diagram of another communication method provided in an embodiment of this application.

[0113] Figure 8 is a schematic diagram of another communication method provided in an embodiment of this application.

[0114] Figure 9 is a schematic diagram of another communication method provided in an embodiment of this application.

[0115] Figure 10 is a schematic diagram of another communication method provided in an embodiment of this application.

[0116] Figure 11 is a schematic diagram of another communication method provided in an embodiment of this application.

[0117] Figure 12 is a schematic block diagram of a communication device provided in an embodiment of this application.

[0118] Figure 13 is a schematic block diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0119] It should be understood that the methods, situations, categories, and classifications of embodiments in this application are for the convenience of description only and should not constitute a special limitation. Various methods, categories, situations, and features in embodiments can be combined without contradiction.

[0120] It should also be understood that the terms "first," "second," and "third" in the embodiments of this application are for distinction only and should not constitute any limitation on this application. It should also be understood that in the various embodiments of this application, the sequence number of each process does not imply 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 this application.

[0121] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0122] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0123] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0124] The methods and apparatus provided in this application are based on the same or similar technical concepts. Since the methods and apparatus solve problems in similar ways, the implementation of the apparatus and methods can refer to each other, and repeated parts will not be described again.

[0125] Figure 1 is a schematic diagram of a communication system applicable to an embodiment of this application. As shown in Figure 1, the wireless communication system may include a network device 110 and one or more terminal devices (such as terminal devices 121 and 122 shown in Figure 1) communicating with each other. When the network device 110 sends a signal, the network device 110 is the transmitter, and the terminal device 121 or terminal device 122 is the receiver. Conversely, when the terminal device 121 or terminal device 122 sends a signal, the terminal device 121 or terminal device 122 is the transmitter, and the network device 110 is the receiver. Optionally, terminal devices 121 and 122 can also communicate. When terminal device 121 sends a signal to terminal device 122, terminal device 121 is the transmitter, and terminal device 122 is the receiver. Conversely, when terminal device 122 sends a signal to terminal device 121, terminal device 122 is the transmitter, and terminal device 121 is the receiver.

[0126] Terminal equipment 121 or terminal equipment 122 can also be referred to as terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), roadside unit (RSU), etc. The terminal devices in this application can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, speakers, etc. They can also be wireless terminals used in scenarios such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grids, transportation safety, smart cities, smart wearables, intelligent transportation, and smart homes. In this application, the aforementioned terminal devices and chips applicable to them are collectively referred to as terminal devices. It should be understood that this application does not limit the specific technology or form of the terminal device.

[0127] Network device 110 can be a device in a wireless network, and can also be referred to as a network apparatus. For example, network device 110 can be a radio access network (RAN) node through which terminal devices access the wireless network, and can also be referred to as an access network device. Network device 110 includes, but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved Node B, or home Node B, HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), reception point (RP), or transmission and reception point (TRP) in a wireless fidelity (WIFI) system, and can also be network device in a 5G mobile communication system or other network device in future network systems. For example, a next-generation NodeB (gNB), transmission reception point (TRP), or TP in an NR system; or, one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G mobile communication system; or, network equipment 110 can also be a network node constituting a gNB or transmission point. For example, a BBU, or a distributed unit (DU), etc.

[0128] In some deployments, network device 110 may include a centralized unit (CU) and one or more distributed units (DUs). Network device 110 may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB, as shown in Figure 3. Each DU can connect to the CU via an F1 interface. Information exchange between different DUs can be completed based on forwarding by the CU. The CU and DU can be physically set together or separately; this embodiment does not impose such limitations. For example, the CU is responsible for handling non-real-time protocols and services, implementing the functions of the radio resource control (RRC) layer. The CU can also implement the service data adaptation protocol (SDAP) layer and the packet data convergence protocol (PDCP) layer. The DU is responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (RLC) layer, media access control (MAC) layer, and physical (PHY) layer. In some deployments, the CU can be further divided into a centralized unit control plane (CU-CP) node and a centralized unit user plane (CU-UP) node. The CU-CP is responsible for control plane functions, while the CU-UP is responsible for user plane functions. For example, the CU-CP and CU-UP can be implemented by different functional entities and connected via an E1 interface. The CU-CP and CU-UP can be coupled with the DU to jointly complete the base station's functions. The CU control plane CU-CP also includes a further segmented architecture, dividing the existing CU-CP into CU-CP1 and CU-CP2. CU-CP1 includes various radio resource management functions, while CU-CP2 only includes radio resource control (RRC) functions and PDCP-C functions (i.e., the basic functions of control plane signaling at the packet data convergence protocol (PDCP) layer).

[0129] The communication system shown in Figure 1 can be 4G, 5G, 6G or future communication systems, and this application embodiment does not limit it.

[0130] For ease of description, the device numbers are omitted in the following embodiments. For example, "terminal device" means "terminal device 121 or terminal device 122", and "network device" means "network device 110".

[0131] In this application embodiment, terminal devices and network devices are used as examples for description. In practical applications, this application embodiment can also be applied to other scenarios, such as satellite communication scenarios.

[0132] In existing communication systems, during handover scenarios, before transmitting data with a target network device, the terminal device must first access the target network device. Typically, this involves a random access process, which takes time, resulting in significant latency. In some embodiments, the terminal device can access the target network device without random access, thereby reducing latency. During this process, the terminal device can use dynamic scheduling sent by the target network device or send uplink messages on pre-configured resources to access the target network device. However, the target network device may frequently send dynamic scheduling messages, or it may reserve pre-configured resources for an extended period, wasting resources if no terminal device accesses the target network device.

[0133] In this embodiment of the application, the first network device can be the source network device, and the second network device can be called the candidate network device before the handover. After the terminal device determines to hand over to the candidate network device, the second network device can be the target network device. The cell managed by the second network device can be called the candidate cell before the terminal device handover. After the terminal device determines to hand over to a candidate cell managed by the second network device, the cell managed by the second network device can be called the target cell.

[0134] To reduce the latency of terminal devices accessing network devices, terminal devices can use a non-random access method to access network devices. However, in some handover technologies triggered by terminal devices, since the candidate network device does not know when the terminal device will access, the candidate network device needs to provide more transmission resources to the terminal device so that the terminal device can access in time, which will result in a large resource overhead.

[0135] The following describes the terminology used in the embodiments of this application.

[0136] In random access (RA) or random access channel (RACH) methods, when a terminal device accesses a network device, it can send multiple preambles to the network device and select one. The network device can blindly detect the preamble. After detecting the preamble, the network device can send an uplink grant to the terminal device. The uplink grant may include timing advance (TA). The terminal device sends uplink messages based on the uplink grant. Therefore, the latency of a terminal device accessing a network device via random access is relatively long. However, through random access, the terminal device and the network device can achieve uplink synchronization based on the TA, and the network device can also determine the beam direction based on the resources received from the preamble. In this way, the terminal device and the network device can communicate using aligned beam directions.

[0137] Without random access, the terminal device can send uplink messages based on the uplink grant (DG) dynamically scheduled by the network device. For example, the network device can send a physical downlink control channel (PDCCH), which may include the dynamically scheduled uplink grant. Alternatively, the terminal device can send uplink messages based on a pre-configured uplink grant (CG), without needing to send a preamble. Therefore, without random access, the latency of the terminal device accessing the network device is reduced. The pre-configured uplink grant is also called a semi-static uplink grant. The pre-configured uplink grant is equivalent to the network device pre-configuring resources for sending uplink messages for the terminal device.

[0138] In a handover, a terminal device can move from the coverage area of ​​a first network device to the coverage area of ​​a second network device. The first network device can be the network device to which the serving cell (or source cell) of the terminal device belongs. The terminal device can switch from the first network device to the second network device. The handover can be either a handover triggered by the terminal device or a handover triggered by the first network device. A handover triggered by the terminal device can be triggered by the terminal device after determining that the handover conditions are met. A handover triggered by the first network device can be triggered by the first network device sending a handover command to the terminal device after determining that the handover conditions are met. In scenarios where handover is triggered by a terminal device, to reduce the time it takes for the terminal device to access the first network device, the terminal device can switch to the second network device using a dynamically scheduled uplink grant or a pre-configured uplink grant (CG) sent by the second network device. However, in these scenarios, the second network device doesn't know when the terminal device will switch, leading to frequent dynamic scheduling and wasted resources. Alternatively, in handover scenarios, the second network device can grant the terminal device a pre-configured uplink grant, but if the terminal device doesn't access the second network device for an extended period, the pre-configured uplink grant cannot be allocated to other terminal devices, also resulting in wasted resources.

[0139] In this embodiment, after the first timer expires, the first network device can send a first indication message to the second network device. The second network device can then stop dynamically scheduling the terminal device based on the first indication message. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages. Before the first network device sends the first indication message, the second network device can send dynamic scheduling messages. If the terminal device determines that the handover conditions are met, it can use dynamic scheduling to access the second network device. This non-random access method saves latency for the terminal device accessing the second network device. After receiving the first indication message, the second network device can stop sending dynamic scheduling messages, which not only saves resources but also meets the terminal device's need to access the second network device.

[0140] In this embodiment, after the first timer expires, the first network device can send a first indication message to the second network device. The second network device can then stop receiving uplink messages on pre-configured resources based on the first indication message. Before receiving the first indication message, the second network device can attempt to receive uplink messages sent by the terminal device; for example, the terminal device can send uplink messages on pre-configured resources. Once the second network device receives the first indication message, it can stop receiving uplink messages from the terminal device on the pre-configured resources. This avoids the second network device frequently waiting for uplink messages from the terminal device. Before receiving the first indication message, the second network device can allocate the pre-configured resources to the terminal device. After receiving the first indication message, the second network device can determine that the terminal device may not use the pre-configured resources to access the second network device. Therefore, the second network device can allocate the pre-configured resources allocated to the terminal device to other terminal devices, thus improving resource utilization, especially in situations of insufficient resources, and preventing resources from being occupied by a single terminal device for an extended period. Before the second network device receives the first indication information, if the terminal device determines that the handover conditions are met, the terminal device can send an uplink message to the second network device using the pre-configured resources. The second network device can receive the uplink message from the terminal device on the pre-configured resources. If the terminal device determines that the handover conditions are not met, it will not send an uplink message. After the second network device receives the first indication information, it can allocate the pre-configured resources allocated to the terminal device to other terminal devices. This not only saves resources but also meets the needs of the terminal device to access the second network device. This non-random access method can also save the latency of the terminal device accessing the second network device.

[0141] The communication method in the embodiments of this application is described below with reference to the accompanying drawings. As shown in Figure 3, the communication method 300 includes:

[0142] S310, the second network device sends the timing advance (TA) of the terminal device to the first network device, and the first network device receives the TA of the terminal device from the second network device.

[0143] Optionally, after S310, the communication method further includes: the first network device sending the terminal device's TA to the terminal device, the terminal device receiving the terminal device's TA, and the terminal device performing uplink synchronization with the second network device based on the TA.

[0144] Optionally, S310 can be replaced by: the second network device instructing the terminal device's TA to the first network device, and the first network device obtaining the terminal device's TA according to the instruction of the second network device.

[0145] Optionally, prior to S310, the first network device may instruct the terminal device to send a preamble to the second network device. The terminal device may send the preamble to the second network device, and the second network device determines the TA of the terminal device based on the preamble sent by the terminal device. After the second network device determines the TA of the terminal device, it may execute S310.

[0146] S320: When the first network device receives a TA from the terminal device sent by the second network device, it starts the first timer.

[0147] Optionally, if the first network device receives the TA (Translation Target) of the terminal device from the second network device and then sends the TA to the terminal device, then S320 can be replaced by starting the first timer when the first network device sends the TA to the terminal device. Alternatively, starting the first timer when the first network device sends the TA to the terminal device can be replaced by starting the first timer after the first network device sends the TA to the terminal device.

[0148] Optionally, the first timer can be started when the first network device receives a TA from the terminal device sent by the second network device. Alternatively, the first timer can be started after the first network device receives a TA from the terminal device sent by the second network device.

[0149] Optionally, the timing at which the first network device starts the first timer may not be limited to receiving a TA from the terminal device sent by the second network device or sending a TA to the terminal device. For example, the first timer may be started at any time between the moment the second network device receives the TA from the terminal device and the moment it sends the TA to the terminal device.

[0150] Optionally, the second network device can indicate the duration of the first timer to the first network device, and the first network device can obtain the duration of the first timer from the second network device. For example, before S320, the second network device can indicate the duration of the first timer to the first network device, or before S320, the first network device can request the duration of the first timer from the second network device, and the second network device can indicate the duration of the first timer to the first network device based on the request. Optionally, the duration of the first timer can be related to the coverage area of ​​the second network device. For example, if the coverage area of ​​the second network device is large, the duration of the first timer can be smaller; if the coverage area of ​​the second network device is small, the duration of the timer can be larger. Optionally, the duration of the first timer can also be specified by the protocol, or determined by the first network device. For example, the first network device can determine it based on the coverage area of ​​the second network device. This application embodiment does not limit the method of determining the duration of the first timer. Optionally, the duration of the first timer can be related to the moving speed of the terminal device. If the first network device or the second network device determines that the moving speed of the terminal device is relatively fast, the duration of the first timer can be shorter. If the moving speed of the terminal device is relatively slow, the duration of the first timer can be longer.

[0151] Optionally, the duration of the first timer can also be called the effective duration of the TA, that is, the TA of the terminal device is valid during the operation of the first timer, and the TA of the terminal device is invalid after the first timer expires.

[0152] S330, if the first timer expires, the first network device sends a first indication message to the second network device, and the second network device receives the first indication message from the first network device. The first indication message is used to indicate the cessation of dynamic scheduling of the terminal device, or the first indication message is used to indicate the cessation of receiving uplink messages from the terminal device on the pre-configured resources, or the first indication message is used to indicate the cessation of dynamic scheduling of the terminal device and the cessation of receiving uplink messages from the terminal device on the pre-configured resources.

[0153] Optionally, if the first timer times out, it indicates that the TA of the terminal device has failed, and the terminal device may not be able to access the second network device. Therefore, the first network device can send a first indication message to the second network device. At this time, the first indication message can also indicate that the TA of the terminal device has failed. That is, the reason why the first terminal device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving the uplink messages of the terminal device on the pre-configured resources is that the TA of the terminal device has failed.

[0154] Optionally, the first indication information used to indicate the cessation of dynamic scheduling of the terminal device, or the first indication information used to indicate the cessation of receiving uplink messages from the terminal device on pre-configured resources, or the first indication information used to indicate the cessation of both dynamic scheduling of the terminal device and receiving uplink messages from the terminal device on pre-configured resources, can be replaced with: the first indication information used to indicate that the terminal device is not expected to access the second network device, or replaced with: the first indication information used to indicate that the possibility of the terminal device accessing the second network device is low; or replaced with: the first indication information used to indicate that the terminal device has no need to access the second network device; or replaced with: The first instruction information is used to instruct the second network device not to perform preparation work for the handover of the terminal device, etc. The specific content of the first instruction information may vary, but after receiving the first instruction information, the second network device can determine that the terminal device will not switch to the second network device. Therefore, the second network device stops the related operations for the handover of the terminal device, such as stopping the dynamic scheduling of the terminal device and / or stopping receiving the uplink message of the terminal device on the pre-configured resources. Therefore, determining to stop the dynamic scheduling of the terminal device and / or stop receiving the uplink message of the terminal device on the pre-configured resources according to the first instruction information is within the protection scope of the embodiments of this application.

[0155] Optionally, the first network device sending the first indication information to the second network device includes: the first network device sending the first indication information to the second network device through a third network device. For example, the first network device is DU1, the second network device is DU2, and the third network device is CU. The CU manages DU1 and DU2, and DU1 can send the first indication information to DU2 through the CU. Alternatively, the first network device sending the first indication information to the second network device includes: the first network device sending the first indication information to the second network device through a third and a fourth network device. For example, the first network device is DU1, the third network device is CU1, the second network device is DU2, and the fourth network device is CU2. DU1 sends the first indication information to CU1, CU1 sends the first indication information to CU2, and CU2 sends the first indication information to DU2. In other words, the first network device can send the first indication information to the second network device through at least one intermediate device.

[0156] S340, the second network device stops dynamically scheduling the terminal device according to the first instruction information, or stops receiving uplink messages from the terminal device on the pre-configured resources, or stops both dynamically scheduling the terminal device and receiving uplink messages from the terminal device on the pre-configured resources.

[0157] If the first indication information in S330 is used to indicate stopping dynamic scheduling of the terminal device, then in S340, the second network device stops dynamic scheduling of the terminal device, that is, the second network device no longer allocates dynamic resources to the terminal device; if the first indication information in S340 is used to indicate stopping receiving uplink messages from the terminal device on the pre-configured resources, then in S340, the second network device stops receiving uplink messages from the terminal device on the pre-configured resources; if the first indication information in S340 is used to indicate stopping both dynamic scheduling of the terminal device and stopping receiving uplink messages from the terminal device on the pre-configured resources, then in S340, the second network device stops receiving uplink messages from the terminal device on the pre-configured resources and stops dynamic scheduling of the terminal device.

[0158] Optionally, prior to S330, the second network device may send dynamic scheduling to the terminal device. Upon receiving the first indication information, which instructs the second network device to stop dynamic scheduling of the terminal device, the second network device may cease dynamic scheduling of the terminal device.

[0159] Optionally, prior to S330, the second network device may attempt to receive uplink messages from the terminal device on pre-configured resources. After receiving the first indication information, which instructs the second network device to stop receiving uplink messages from the terminal device on the pre-configured resources, the second network device may stop receiving uplink messages from the terminal device on the pre-configured resources. Optionally, prior to S310, the second network device may pre-configure resources for the terminal device. These pre-configured resources are used by the terminal device to send uplink messages. For example, the second network device may use pre-configured uplink authorization to instruct the pre-configured resources.

[0160] In communication method 300, after the first timer expires, the first network device can send a first indication message to the second network device. The second network device can then stop dynamically scheduling the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources based on the first indication message. This avoids resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization. Furthermore, before receiving the first indication message, the second network device can send dynamic scheduling messages and / or receive uplink messages from the terminal device on pre-configured resources. If the terminal device determines that the handover conditions are met, it can access the second network device using dynamic scheduling or by using uplink messages. This non-random access method saves latency when the terminal device accesses the second network device.

[0161] In some cases, the first network device can send a first instruction message to the second network device based on a first message from the terminal device. The following describes the communication method 400 in conjunction with Figure 4. As shown in Figure 4, the communication method 400 includes:

[0162] S410, the terminal device sends a first message to the first network device, and the first network device receives the first message from the terminal device.

[0163] Optionally, the first message is used by the first network device to determine whether to send first indication information to the second network device. Optionally, the first message is used by the first network device to determine whether the second network device should stop dynamic scheduling of the terminal device; or, the first message is used by the first network device to determine whether the second network device should stop receiving uplink messages from the terminal device on pre-configured resources; or, the first message is used by the first network device to determine whether the second network device should stop receiving uplink messages from the terminal device on pre-configured resources and whether to stop dynamic scheduling of the terminal device. In other words, the first network device can send the first indication information to the second network device in S420 based on the first message. The specific name and content of the first message are not limited in this embodiment.

[0164] Optionally, prior to S410, the terminal device may receive second indication information from the first network device. The second indication information is used to indicate the TA of the terminal device, or the second indication information is used to indicate the target beam, or the second indication information is used to indicate the TA and the target beam of the terminal device. The target beam is the beam that the terminal device will use when accessing the second network device, or the target beam is the beam that the terminal device is aligned with the second network device, or the target beam is the beam that the terminal device will use when accessing at least one candidate cell of the second network device.

[0165] Optionally, the first message includes one or more of the following: a measurement report of at least one candidate cell managed by the second network device; a measurement report of at least one beam of at least one candidate cell; a measurement report of the reference signal of at least one candidate cell; an indication message for indicating that the timing advance TA of the terminal device has failed; an indication message for indicating that the target beam of at least one candidate cell has failed; an indication message for indicating that the change in the cell-level reference signal receiving power (RSRP) of at least one candidate cell exceeds a threshold value; an indication message for indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value; an indication message for indicating that the cell-level RSRP of at least one candidate cell is less than a threshold value; or an indication message for indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value. Optionally, the RSRP of the reference signal of at least one candidate cell can be the RSRP of the reference signal corresponding to the target beam, or it can be the RSRP of the reference signal used to calculate path loss. Optionally, the identifier of the reference signal can indicate the target beam, or the TCI State ID can indicate the target beam.

[0166] The first message is described below in different scenarios.

[0167] In scenario one, the first message includes indication information indicating that the TA (Transmission Ability) of the terminal device has failed. That is, before S410, the terminal device determines that its TA has failed. Optionally, the terminal device can start a second timer upon receiving the second indication information. When the second timer expires, the TA fails. For example, the duration of the second timer can be the valid duration of the TA. The duration of the second timer can be sent from the first network device to the first terminal device, or it can be sent from the second network device to the terminal device through the first network device. This embodiment does not limit this. Optionally, before S410, the terminal device receives the second indication information from the first network device. The second indication information is used to indicate the TA of the terminal device. The terminal device can measure the change in RSRP (Reference Signal Reduction Ratio) of the reference signal of at least one candidate cell at the time of receiving the second indication information compared to the RSRP of the reference signal of at least one candidate cell at the current time. If the change exceeds a threshold value, the RSRP change of the reference signal is relatively large. Therefore, the position change of the terminal device may be relatively large, and thus the TA is invalid. The reference signal can be a reference signal used to calculate path loss, or it can be a reference signal corresponding to the target beam. Optionally, prior to S410, the terminal device receives second indication information from the first network device. This second indication information is used to indicate the terminal device's TA (Target Aspect Ratio). The terminal device can measure the change in the cell-level RSRP of at least one candidate cell at the time of receiving the second indication information compared to the current time. If the change exceeds a threshold, the RSRP of at least one candidate cell is significantly altered. The RSRP of at least one candidate cell can be the combined RSRP of multiple reference signals from at least one candidate cell. Therefore, the location of the terminal device may change significantly, and the TA is invalid. For example, the RSRP of at least one candidate cell can be the RSRP of the downlink path loss reference signal of at least one candidate cell. Optionally, if the RSRP of at least one candidate cell is less than the threshold, it indicates that the signal quality of at least one candidate cell is poor, and the location of the terminal device may change significantly, thus the TA is invalid. Optionally, if the RSRP of the reference signal of at least one candidate cell is less than the threshold, it indicates that the quality of the reference signal received by the terminal device is poor, and the location of the terminal device may change significantly, thus the TA is invalid.

[0168] Taking the RSRP exceeding the threshold at the cell level as an example, for instance, if the RSRP of cell1 is x when the terminal device receives the second indication information, and the RSRP of cell1 at the current time is y, and the absolute value of the difference between x and y is greater than (or greater than or equal to) the threshold value, the TA can be determined to be invalid. Taking the RSRP of the reference signal exceeding the threshold as an example, for instance, if the RSRP of the reference signal of cell1 is w when the terminal device receives the second indication information, and the RSRP of the reference signal of cell1 at the current time is q, and the absolute value of the difference between w and q is greater than (or greater than or equal to) the threshold value, the TA can be determined to be invalid. This reference signal can be a reference signal used to calculate path loss, or it can be a reference signal corresponding to the target beam.

[0169] Scenario 2: The first message includes indication information indicating that the target beam of at least one candidate cell is invalid. The target beam of the at least one candidate cell can be understood as the beam that the terminal device will use when accessing the at least one candidate cell. That is, before S410, the terminal device determines that the target beam is invalid. Optionally, before S410, the terminal device receives second indication information from the first network device. The second indication information is used to indicate the terminal device's TA (Target Aspect Ratio). The terminal device can measure the change in the RSRP (Reference Signal Reduction Ratio) of the reference signal of the first candidate cell corresponding to the target beam at the time of receiving the second indication information compared to the current RSRP of the reference signal of the first candidate cell corresponding to the target beam. If the change exceeds a threshold, the RSRP of the reference signal is relatively large, therefore, the position of the terminal device may have changed significantly, and thus the target beam for receiving the reference signal is invalid. Optionally, if the RSRP of the reference signal of the first candidate cell is less than a threshold, it indicates that the quality of the reference signal received by the terminal device on the target beam is poor, and the position of the terminal device may have changed significantly, therefore the target beam is invalid.

[0170] Taking the RSRP of the reference signal exceeding the threshold as an example, for instance, when the terminal device receives the second indication information, the RSRP of the reference signal of cell1 is w, and the RSRP of the reference signal of cell1 at the current moment is q. When the absolute value of the difference between w and q is greater than (or greater than or equal to) the threshold value, it can be determined that the target beam receiving the reference signal is invalid.

[0171] Scenario 3: The first message includes indication information indicating that the change in the cell-level RSRP of the at least one candidate cell exceeds a threshold value. Optionally, before S410, the terminal device receives second indication information from the first network device. The second indication information is used to indicate the TA of the terminal device. The terminal device can measure the change in the RSRP of the at least one candidate cell at the time of receiving the second indication information compared to the current time. If the change exceeds a threshold value, the first message may include indication information indicating that the change in the cell-level RSRP of the at least one candidate cell exceeds a threshold value.

[0172] Taking the cell-level RSRP exceeding the threshold as an example, for instance, when the terminal device measures and receives the second indication information, the RSRP of cell1 is x, and the RSRP of cell1 at the current time is y. When the absolute value of the difference between x and y is greater than (or greater than or equal to) the threshold value, the first message may include indication information for indicating that the change in the cell-level RSRP of the at least one candidate cell exceeds the threshold value.

[0173] Scenario 4: The first message includes indication information indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds a threshold value. This reference signal can be a reference signal corresponding to the target beam or a reference signal used to calculate path loss. Optionally, before S410, the terminal device receives second indication information from the first network device. The second indication information is used to indicate the TA of the terminal device. The terminal device can measure the change in the RSRP of the reference signal of the at least one candidate cell at the time of receiving the second indication information compared to the current time. If the change exceeds a threshold value, the first message can include indication information indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds a threshold value.

[0174] Taking the RSRP of the reference signal exceeding the threshold as an example, for instance, when the terminal device receives the second indication information, the RSRP of the reference signal of cell1 is w, and the RSRP of the reference signal of cell1 at the current time is q. When the absolute value of the difference between w and q is greater than (or greater than or equal to) the threshold value, the first message may include indication information for indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds the threshold value.

[0175] Scenario 5: The first message includes indication information indicating that the cell-level RSRP of the at least one candidate cell is less than a threshold value. Optionally, the terminal device can measure the RSRP of at least one candidate cell at the current time. If the RSRP of at least one candidate cell is less than a threshold value, the first message may include indication information indicating that the cell-level RSRP of the at least one candidate cell is less than the threshold value.

[0176] Case 6: The first message includes indication information indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value. This reference signal can be a reference signal corresponding to the target beam or a reference signal used to calculate path loss. Optionally, the terminal device can measure the RSRP of the reference signal of at least one candidate cell at the current time. If the RSRP of the reference signal of at least one candidate cell is less than a threshold value, the first message can include indication information indicating that the RSRP of the reference signal of at least one candidate cell is less than the threshold value.

[0177] Optionally, if any one of the above conditions one through six is ​​met, the first message can be sent. That is, the terminal device can determine whether the TA is valid. If the TA is invalid, the first message can be sent. Alternatively, the terminal device can determine whether the target beam is valid. If the target beam is invalid, the first message can be sent. Alternatively, the terminal device can determine that the change in the RSRP of at least one candidate cell exceeds a threshold value, and the first message can be sent. Alternatively, the terminal device can determine that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value, and the first message can be sent. Alternatively, the terminal device can determine that the RSRP of at least one candidate cell is less than (or less than or equal to) a threshold value, and the first message can be sent. Alternatively, the terminal device can determine that the RSRP of the reference signal of at least one candidate cell is less than (or less than or equal to) a threshold value, and the first message can be sent.

[0178] Scenario 7: The first message includes a measurement report of at least one beam of at least one candidate cell. The terminal device can measure the reference signal transmitted by each of the at least one candidate cell through at least one beam, thereby obtaining a measurement report of at least one beam of each of the at least one cell. In this case, the first message may include indication information for the measurement report of at least one beam of the at least one candidate cell. Alternatively, the first message may include a measurement report of at least one reference signal of at least one candidate cell. The terminal device can measure at least one reference signal transmitted by the at least one candidate cell, thereby obtaining a measurement report of at least one reference signal of the at least one cell. In this case, the first message may include indication information for indicating the measurement report of at least one reference signal of the at least one candidate cell.

[0179] Case 8: The first message includes a measurement report of at least one candidate cell managed by the second network device. The terminal device can measure at least one candidate cell and generate a measurement report, which is then reported to the first network device via the first message.

[0180] Optionally, the threshold values ​​mentioned in the embodiments of this application may be configured by the first network device to the terminal device, or determined by the second network device and sent to the terminal device through the first network device, or the threshold values ​​may be specified by the protocol. For ease of description, the threshold values ​​are uniformly represented by the threshold values. In different embodiments, the threshold values ​​are different. For example, the first message includes indication information for indicating that the change in the RSRP of at least one candidate cell exceeds the first threshold value; the first message includes indication information for indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds the second threshold value; the first message includes indication information for indicating that the RSRP of at least one candidate cell is less than the third threshold value; the first message includes indication information for indicating that the RSRP of the reference signal of at least one candidate cell is less than the fourth threshold value. The first threshold value, the second threshold value, the third threshold value, and the fourth threshold value may be different threshold values, or if there are two or more threshold values, they may be the same threshold value. The embodiments of this application do not limit this.

[0181] S420, the first network device sends a first instruction message to the second network device according to the first message. The second network device receives the first instruction message. The first instruction message is used to instruct the cessation of dynamic scheduling of the terminal device, or the first instruction message is used to instruct the cessation of receiving uplink messages from the terminal device on pre-configured resources, or the first instruction message is used to instruct the cessation of both dynamic scheduling of the terminal device and receiving uplink messages from the terminal device on pre-configured resources.

[0182] Optionally, the first network device can be a source network device, and the second network device can be a target network device. Alternatively, the first network device can be a serving network device of the terminal device, and the second network device can be a candidate network device of the terminal device. For example, the first network device can be the network device to which the serving cell of the terminal device belongs, and the second network device can be the network device to which at least one candidate cell of the terminal device belongs.

[0183] Optionally, S420 includes: the first network device determines, based on a first message from the terminal device, that the terminal device may not access the second network device, or will not switch to the second network device, or the possibility of accessing the second network device is low, or the probability of switching to the second network device is low; therefore, the first network device may send a first indication message to the second network device.

[0184] Optionally, the first indication information used to indicate the cessation of dynamic scheduling of the terminal device, or the first indication information used to indicate the cessation of receiving uplink messages from the terminal device on pre-configured resources, or the first indication information used to indicate the cessation of both dynamic scheduling of the terminal device and receiving uplink messages from the terminal device on pre-configured resources, can be replaced with: the first indication information used to indicate that the terminal device is not expected to access the second network device, or replaced with: the first indication information used to indicate that the possibility of the terminal device accessing the second network device is low; or replaced with: the first indication information used to indicate that the terminal device has no need to access the second network device; or replaced with: The first instruction information is used to instruct the second network device not to perform preparation work for the handover of the terminal device, etc. The specific content of the first instruction information may vary, but after receiving the first instruction information, the second network device can determine that the terminal device will not switch to the second network device. Therefore, the second network device stops the related operations for the handover of the terminal device, such as stopping the dynamic scheduling of the terminal device and / or stopping receiving the uplink message of the terminal device on the pre-configured resources. Therefore, determining to stop the dynamic scheduling of the terminal device and / or stop receiving the uplink message of the terminal device on the pre-configured resources according to the first instruction information is within the protection scope of the embodiments of this application.

[0185] S420 is described below in different cases.

[0186] Scenario 1, S420, includes: After determining that the TA of the terminal device is invalid based on the first message, the first network device sends a first indication message to the second network device. For example, the first message may include indication information for indicating that the TA of the terminal device is invalid. The first network device determines that the TA of the terminal device is invalid based on the indication information, and the terminal device may not connect to the second network device; therefore, it can send the first indication message. In this case, the first message corresponds to Scenario 1 above. Another example is that the first message may include indication information for indicating whether the TA of the terminal device is valid. If the first network device determines that the TA of the terminal device is invalid based on this indication information, it can send the first indication message to the second network device; if the first network device determines that the TA of the terminal device is valid based on this indication information, it may not send the first indication message to the second network device. Yet another example is that the first message may include indication information that the change in the RSRP of at least one candidate cell exceeds a threshold value. The first network device determines based on this indication information that the change in the RSRP of at least one candidate cell measured by the terminal device is relatively large, indicating that the location of the terminal device may have changed significantly. Therefore, the TA of the terminal device may have been invalid, and thus, it can send the first indication message. In this case, the first message corresponds to Scenario 3 above. For example, the first message may include an indication that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value. The first network device can determine from this indication that the RSRP change of the reference signal of at least one candidate cell measured by the terminal device is relatively large. This reference signal can be the reference signal corresponding to the target beam or a reference signal used to calculate path loss. Therefore, the location of the terminal device may have changed significantly, and the TA of the terminal device may have failed. Thus, the first indication information can be sent. In this case, the first message corresponds to situation four above. Alternatively, the first message may include an indication that the RSRP of the reference signal of at least one candidate cell is less than a threshold value. The first network device can determine from this indication that the RSRP of the reference signal of at least one candidate cell is relatively small. This reference signal can be the reference signal corresponding to the target beam or a reference signal used to calculate path loss. Therefore, the signal quality of the reference signal is relatively poor, and the TA of the terminal device may have failed. In this case, the first message corresponds to situation six above. For example, the first message may include an indication that the RSRP of at least one candidate cell is less than a threshold value. The first network device can determine from this indication that the signal quality of at least one candidate cell is relatively poor and the TA of the terminal device may have failed. Therefore, the first indication information can be sent. In this case, the first message corresponds to the above situation five.For example, the first message may include measurement reports of at least one candidate cell. The first network device can determine from the measurement reports of at least one candidate cell that the signal quality of at least one candidate cell is relatively poor, therefore the TA of the terminal device may have failed. Thus, it can send a first indication message, in which case the first message corresponds to situation eight above. That is to say, the first network device can determine that the TA of the terminal device has failed based on the indication information in the first message that directly indicates that the TA of the terminal device has failed, or it can determine that the TA of the terminal device has failed based on other indication information included in the first message, such as indication information related to RSRP.

[0187] Optionally, if the first network device determines that the TA of the terminal device has failed based on the first message, the first indication information can also indicate that the TA of the terminal device has failed. That is, the reason why the first indication information sent by the first terminal device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving the uplink messages of the terminal device on the pre-configured resources is that the TA of the terminal device has failed.

[0188] Scenario 2, S420, includes: After determining that the target beam is invalid based on the first message, the first network device sends a first indication message to the second network device. The target beam is a beam aligned between the terminal device and the second network device, for example, a beam aligned between the terminal device and the first candidate cell of the second network device. For example, the first message may include indication information for indicating that the target beam is invalid. If the first network device determines that the target beam is invalid based on the indication information, the terminal device may not access the second network device; therefore, it can send the first indication message. In this case, the first message corresponds to Scenario 2 above. Alternatively, the first message may include indication information for indicating whether the target beam is valid. If the first network device determines that the target beam is invalid based on the indication information, it can send the first indication message to the second network device; if the first network device determines that the target beam is valid based on the indication information, it may not send the first indication message to the second network device. For example, the first message may include an indication that the RSRP change of the reference signal of at least one candidate cell exceeds a threshold value. The first network device can determine from this indication that the RSRP change of the target beam of the reference signal of at least one candidate cell received by the terminal device is relatively large. This reference signal may be the reference signal corresponding to the target beam. Therefore, the location of the terminal device may have changed significantly, and the target beam of the paired terminal device may have become invalid. Therefore, the first indication information can be sent, and the first message corresponds to situation four above. Alternatively, the first message may include an indication that the RSRP of the reference signal of at least one candidate cell is less than a threshold value. The first network device can determine from this indication that the RSRP of the target beam receiving the reference signal of at least one candidate cell is relatively small. For example, the reference signal may be the reference signal corresponding to the target beam. Therefore, the signal quality of the reference signal is relatively poor, and the target beam of the paired terminal device may have become invalid. Therefore, the first indication information can be sent, and the first message corresponds to situation six above. For example, the first message may include a measurement report of at least one beam or at least one reference signal. The first network device can determine that the target beam in at least one beam has failed based on the measurement report of at least one beam or at least one reference signal. Therefore, it can send a first indication message. In this case, the first message corresponds to situation seven above. That is, the first network device can determine the target beam based on the indication information in the first message that directly indicates the target beam of the terminal device is failed, or it can determine the target beam failure based on other information included in the first message, such as indication information or measurement reports related to RSRP.

[0189] Optionally, if the first network device determines that the target beam is invalid based on the first message, the first indication information can also indicate that the target beam is invalid. That is, the first indication information sent by the first terminal device instructs the second network device to stop dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources because the target beam is invalid. Optionally, before S420, the first network device can determine the target beam based on the measurement report sent by the terminal device and indicate the target beam to the terminal device, or it can indicate the target beam to the second network device. In this way, when the terminal device has a need to access the second network device and the handover conditions are met, the terminal device can use the target beam to access the second network device. Optionally, the target beam determined by the first network device based on the measurement report sent by the terminal device can be a pair of beams, including the transmit / receive beam of the terminal device and the transmit / receive beam of the second network device. The first network device can indicate the transmit / receive beam of the terminal device to the terminal device and the transmit / receive beam of the second network device to the second network device. Alternatively, the target beam determined by the first network device based on the measurement report of the terminal device can be the transmit / receive beam of the terminal device. The first network device can indicate the transmit / receive beam of the terminal device to the terminal device and to the second network device. The second network device can determine the transmit / receive beam of the second network device based on the transmit / receive beam of the terminal device. In other words, the second network device can determine the transmit / receive beam of the second network device that is paired with the transmit / receive beam of the terminal device.

[0190] Optionally, after determining that the target beam has failed, the first network device can determine an updated target beam based on the measurement report sent by the terminal device. In this case, the first indication information is used to instruct the cessation of dynamic scheduling of the terminal device using the target beam and to use the updated target beam for dynamic scheduling. That is, before S420, the second network device could use the target beam for dynamic scheduling of the terminal device. When the first network device determines that the target beam has failed, the first indication information sent by the first network device is used to instruct the cessation of dynamic scheduling of the terminal device using the target beam and to use the updated target beam for dynamic scheduling. For example, the first indication information can indicate the updated target beam. Optionally, the first network device can determine the updated target beam based on a first message. The updated target beam is the updated beam that the terminal device will use when accessing the first candidate cell of the second network device. For example, the first message may include a measurement report of the first candidate cell managed by the second network device, and the second network device determines the updated target beam based on the measurement report of the first candidate cell. Optionally, the first network device can determine the updated target beam based on the measurement report of the first candidate cell in the second message. The second message can be a different message from the first message. That is, if the target beam previously determined by the first network device between the second network device and the terminal device fails, the first network device can determine the updated target beam and indicate to the second network device that the target beam is unusable and needs to be used for dynamic scheduling. The second network device can then continue to send dynamic scheduling using the updated target beam, avoiding the situation where the second network device's dynamic scheduling is interrupted, thus affecting the random access of the terminal device.

[0191] Optionally, after determining that the target beam has failed, the first network device can determine an updated target beam based on the measurement report sent by the terminal device. In this case, the first indication information is used to instruct the device to stop using the target beam to receive uplink messages from the terminal device on the pre-configured resources, and to use the updated target beam to receive uplink messages from the terminal device on the pre-configured resources. That is, before S420, the second network device can attempt to receive uplink messages from the terminal device using the target beam on the pre-configured resources. When the first network device determines that the target beam has failed, the first indication information sent by the first network device is used to instruct the device to stop using the target beam to receive uplink messages from the terminal device on the pre-configured resources, and to use the updated target beam to receive uplink messages from the terminal device on the pre-configured resources. For example, the first indication information can indicate the updated target beam. Optionally, the first network device can determine the updated target beam based on the first message. The updated target beam is the updated beam that the terminal device will use when accessing the first candidate cell of the second network device. For example, the first message may include a measurement report of a first candidate cell managed by the second network device, and the second network device determines the updated target beam based on the measurement report of the first candidate cell. Optionally, the first network device may determine the updated target beam based on the measurement report of the first candidate cell in the second message, and the second message may be a different message from the first message. That is, when the target beam previously determined by the first network device to be aligned between the second network device and the terminal device fails, the first network device may determine an updated target beam and indicate to the second network device that the target beam is unusable and needs to be used to receive uplink messages from the terminal device on pre-configured resources. The second network device can then continue to receive uplink messages from the terminal device on pre-configured resources using the updated target beam, avoiding the situation where the second network device interrupts the reception of uplink messages from the terminal device, thereby affecting the random access of the terminal device.

[0192] Scenario 3, S420, includes: After determining, based on the first message, that the probability of the terminal device switching to the first candidate cell managed by the second network device is less than a threshold, the first network device sends a first indication message to the second network device. For example, the first message may include a measurement report of the first candidate cell (as in Scenario 8 above). The first network device can determine the probability of the terminal device switching to the first candidate cell based on the measurement report of the first candidate cell. If the probability of the terminal device switching to the first candidate cell is less than the threshold, it indicates that the possibility of the terminal device switching to the second network device is low. Therefore, the first indication message can be sent to the second network device to instruct the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages and / or frequently receiving uplink messages when the terminal device is unlikely to switch to the second network device, and helps to improve resource utilization. Optionally, if the measurement report of the first candidate cell indicates that the quality of the first candidate cell is good, the probability of the terminal device switching to the first candidate cell is high; if the measurement report of the first candidate cell indicates that the quality of the first candidate cell is poor, the probability of the terminal device switching to the first candidate cell is low. Optionally, if the first network device determines, based on the first message, that the first probability of the terminal device switching to the first candidate cell is less than a threshold, the first indication information can also indicate that the first probability of the terminal device switching to the first candidate cell is less than the threshold. That is, the reason why the first indication information sent by the first terminal device instructs the second network device to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources is that the first probability of the terminal device switching to the first candidate cell is low.

[0193] Optionally, the second network device may configure a threshold for the first network device, or the protocol may specify a threshold; this embodiment of the application does not impose such limitations.

[0194] Case 4, S420, includes: The first network device determines to send a first indication message to the second network device based on the indication information in the first message indicating that the change in the cell-level RSRP of at least one candidate cell exceeds a threshold value. In this case, the first message corresponds to Case 3 above. That is, the first network device can determine from the indication information that the change in the cell-level RSRP of at least one candidate cell measured by the terminal device is relatively large, indicating that the location of the terminal device may have changed significantly. Therefore, it needs to send the first indication message to the second network device to instruct the cessation of dynamic scheduling of the terminal device and / or the cessation of receiving uplink messages on pre-configured resources.

[0195] Case 5, S420, includes: The first network device, based on the indication information in the first message indicating that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold, determines to send a first indication message to the second network device. In this case, the first message corresponds to Case 4 above. The reference signal can be the reference signal corresponding to the target beam or a reference signal used to calculate path loss. That is, the first network device can determine from the indication information that the RSRP change of the reference signal of at least one candidate cell measured by the terminal device is relatively large, indicating that the location of the terminal device may have changed significantly. Therefore, it needs to send the first indication message to the second network device to instruct the cessation of dynamic scheduling of the terminal device and / or the cessation of receiving uplink messages on pre-configured resources.

[0196] Case 6, S420, includes: The first network device determines to send a first indication message to the second network device based on the indication information in the first message that at least one candidate cell's cell-level RSRP is less than a threshold value. In this case, the first message corresponds to Case 5 above. That is, the first network device can determine from the indication information that at least one candidate cell has a relatively small cell-level RSRP, therefore the signal quality of the candidate cell is relatively poor. Therefore, it needs to send the first indication message to the second network device to instruct the cessation of dynamic scheduling of the terminal device and / or the cessation of receiving uplink messages on pre-configured resources.

[0197] Case 7, S420, includes: The first network device determines to send a first indication message to the second network device based on the indication information in the first message that the RSRP of the reference signal of at least one candidate cell is less than a threshold value. In this case, the first message corresponds to Case 6 above. The reference signal can be the reference signal corresponding to the target beam or a reference signal used to calculate path loss. That is, the first network device can determine from the indication information that the RSRP of the reference signal of at least one candidate cell is relatively small, therefore the signal quality of the reference signal is relatively poor. Therefore, it needs to send the first indication message to the second network device to instruct the cessation of dynamic scheduling of the terminal device and / or the cessation of receiving uplink messages on pre-configured resources.

[0198] Optionally, in S420, the first network device sending first indication information to the second network device includes: the first network device sending the first indication information to the second network device through a third network device. For example, the first network device is DU1, the second network device is DU2, and the third network device is CU. CU manages DU1 and DU2, and DU1 can send the first indication information to DU2 through CU. Alternatively, the first network device sending the first indication information to the second network device includes: the first network device sending the first indication information to the second network device through a third and a fourth network device. For example, the first network device is DU1, the third network device is CU1, the second network device is DU2, and the fourth network device is CU2. DU1 sends the first indication information to CU1, CU1 sends the first indication information to CU2, and CU2 sends the first indication information to DU2. In other words, the first network device can send the first indication information to the second network device through at least one intermediate device.

[0199] S430, the second network device stops dynamically scheduling the terminal device according to the first instruction information, or stops receiving uplink messages from the terminal device on the pre-configured resources, or stops both dynamically scheduling the terminal device and receiving uplink messages from the terminal device on the pre-configured resources.

[0200] If the first indication information in S420 is used to indicate stopping dynamic scheduling of the terminal device, then in S430, the second network device stops dynamic scheduling of the terminal device, that is, the second network device no longer allocates dynamic resources to the terminal device; if the first indication information in S420 is used to indicate stopping receiving uplink messages from the terminal device on the pre-configured resources, then in S430, the second network device stops receiving uplink messages from the terminal device on the pre-configured resources; if the first indication information in S420 is used to indicate stopping both dynamic scheduling of the terminal device and stopping receiving uplink messages from the terminal device on the pre-configured resources, then in S430, the second network device stops receiving uplink messages from the terminal device on the pre-configured resources and stops dynamic scheduling of the terminal device.

[0201] Optionally, prior to S420, the second network device can send dynamic scheduling to the terminal device. After receiving the first indication information, which instructs the second network device to stop dynamic scheduling of the terminal device, the second network device can stop dynamic scheduling of the terminal device.

[0202] Optionally, prior to S420, the second network device may attempt to receive uplink messages from the terminal device on pre-configured resources. After receiving the first indication information, which instructs the second network device to stop receiving uplink messages from the terminal device on the pre-configured resources, the second network device may stop receiving uplink messages from the terminal device on the pre-configured resources. Optionally, prior to S410, the second network device may pre-configure resources for the terminal device. These pre-configured resources are used by the terminal device to send uplink messages. For example, the second network device may use pre-configured uplink authorization to instruct the pre-configured resources.

[0203] In the aforementioned communication method 400, the first network device can send a first indication message to the second network device based on a first message sent by the terminal device. The second network device can then stop dynamically scheduling the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources based on the first indication message. This avoids resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization. Furthermore, before receiving the first indication message, the second network device can send dynamic scheduling messages and / or receive uplink messages from the terminal device on pre-configured resources. If the terminal device determines that the handover conditions are met, it can access the second network device using dynamic scheduling or by using uplink messages. This non-random access method can save latency for the terminal device accessing the second network device.

[0204] In the above-described communication methods 300 and 400, the first network device sends a first indication information to the second network device. The second network device can stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources based on the first indication information. In some cases, the second network device can determine to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on pre-configured resources without relying on the first indication information from the first network device. The second network device can determine to stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device based on a first timer. The following description is in conjunction with communication method 500, as shown in Figure 5. Communication method 500 includes:

[0205] S510, the first network device sends the remaining valid duration information of the TA to the second network device, and the second network device receives the remaining valid duration information of the TA from the first network device.

[0206] Optionally, the remaining valid duration information can indicate the remaining valid duration of TA.

[0207] Optionally, prior to S510, the communication method 500 may further include: the second network device sending the total valid duration information of the terminal device's TA to the first network device; the first network device receiving the total valid duration information of the terminal device's TA from the second network device; the total valid duration information indicating the total valid duration of the TA; and the first network device determining the remaining valid duration information based on the total valid duration information. Optionally, the first network device sends a request message to the second network device, and the second network device may send the total valid duration information of the TA to the first network device based on the request message.

[0208] Optionally, the first network device can determine the remaining valid duration information based on the time it receives the TA from the second network device and / or the time it sends the TA to the terminal device, as well as the total valid duration information. Optionally, the first network device can receive the TA from the terminal device at a first moment. The first network device can subtract a first time interval (from the first moment to the second moment) from the total valid duration. The second moment is the moment when the first network device determines the remaining valid duration information. That is, after the first network device receives the TA, a period of time has elapsed between receiving it and determining the remaining valid duration information, so the first network device subtracts the elapsed time when determining the remaining valid duration. For example, if the total valid duration information indicates a duration of 20 milliseconds, and the first network device receives the TA at time t1 and determines the remaining valid duration information at time t2, with t1 to t2 being 3 milliseconds, then the remaining valid duration is 17(20-3) milliseconds. Optionally, the first network device may send a TA to the terminal device at time t3. The first network device can subtract the second time interval (from time t3 to time t2) from the total effective duration. Time t2 is the time when the first network device determines the remaining effective duration information. That is, after the first network device sends the TA to the terminal device, a period of time has passed between the time the remaining effective duration information is determined and the time already passed. Therefore, the first network device subtracts the time already passed when determining the remaining effective duration. For example, if the total effective duration information indicates a duration of 20 milliseconds, the first network device sends the TA to the terminal device at time t3, determines the remaining effective duration information at time t2, and the time interval from t2 to t3 is 5 milliseconds, then the remaining effective duration is 15(20-5) milliseconds. Optionally, the first network device receives the TA from the second network device at time t1, and sends the TA to the terminal device at time t3. Time t2 is the time when the first network device determines the remaining effective duration information. The first network device can determine the remaining valid duration based on the first time point, the second time point, the third time point, and the total valid duration. For example, if the fourth time point is the midpoint between the first and third time points, the first network device can subtract the third time period (from the fourth time point to the second time point) from the total valid duration. In other words, after the first network device receives the total valid duration information, a period of time has elapsed between receiving it and determining the remaining valid duration information. Therefore, the first network device subtracts the elapsed time when determining the remaining valid duration. For example, if the total valid duration information indicates a duration of 20 milliseconds, the first network device receives the TA at time t1, sends the TA to the terminal device at time t3, and determines the remaining valid duration information at time t2. The time from t1 to t3 is 4 milliseconds, and the time from t3 to t2 is 2 milliseconds. Therefore, the time from the midpoint between t1 and t3 to t2 is 4 milliseconds. Thus, the remaining valid duration is 16(20-2-4 / 2) milliseconds.

[0209] Optionally, the total valid duration information is used to indicate the total valid duration of the TA. The total valid duration of the TA means that the TA of the terminal device is valid within the valid duration, and the TA of the terminal device is invalid after the valid duration.

[0210] Optionally, the total effective duration of the TA (Total Timer) indicated by the total effective duration information can be determined by the second network device. For example, the total effective duration of the TA can be related to the coverage area of ​​the second network device. For instance, if the coverage area of ​​the second network device is large, the total effective duration of the TA can be smaller; if the coverage area of ​​the second network device is small, the total effective duration of the TA can be larger. Optionally, the total effective duration of the TA can also be specified by the protocol or determined by the first network device. For example, the first network device can determine it based on the coverage area of ​​the second network device. This application embodiment does not limit the method of determining the total effective duration of the TA. Optionally, the total effective duration of the TA can be related to the moving speed of the terminal device. If the first network device or the second network device determines that the moving speed of the terminal device is fast, the total effective duration of the TA can be smaller; if the moving speed of the terminal device is slow, the duration of the first timer can be larger.

[0211] S520, the second network device starts the first timer.

[0212] Optionally, S520 includes: when the second network device receives the remaining valid duration information of the TA from the first network device, it starts a first timer, the duration of which is the remaining valid duration of the TA indicated by the remaining valid duration information.

[0213] Optionally, the timing for the second network device to start the first timer is not limited to receiving the remaining valid duration information of the TA from the first network device. For example, the first timer can be started after receiving the remaining valid duration information of the TA from the first network device.

[0214] S530, the first timer times out, the second network device stops dynamically scheduling the terminal device, and / or stops receiving uplink messages from the terminal device on the pre-configured resources.

[0215] Optionally, in S530, after the first timer expires, it indicates that the TA of the terminal device has failed, and the terminal device may no longer be able to access the second network device. Therefore, the second network device can stop the dynamic scheduling of the terminal device and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

[0216] The first timer in communication method 300 and communication method 500 can be different timers.

[0217] In the aforementioned communication method 500, the second network device can start a first timer when it receives the remaining valid duration information of the TA (Transmission Time Acquisition) of the terminal device from the first network device. After the first timer expires, the second network device stops dynamically scheduling the terminal device and / or stops receiving uplink messages from the terminal device on pre-configured resources. This avoids the resource waste caused by the second network device frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the terminal device, thereby improving resource utilization. Furthermore, before the first timer expires, the second network device can send dynamic scheduling messages and / or receive uplink messages from the terminal device on pre-configured resources. If the terminal device determines that the handover conditions are met, the terminal device can access the second network device using dynamic scheduling or by using uplink messages. This non-random access method can save latency for the terminal device accessing the second network device.

[0218] In some embodiments, if the second network device can determine the identity of the terminal device based on the received preamble, the second network device can start a first timer after determining the TA of the terminal device based on the preamble. After the first timer expires, the second network device stops the dynamic scheduling of the terminal device and / or stops receiving uplink messages from the terminal device on the pre-configured resources. That is, the second network device can start the first timer according to its own implementation and does not need to receive the remaining valid duration information of the TA from the first network device. Therefore, S510 in the communication method 500 may not exist.

[0219] In this embodiment of the application, the second network device sending dynamic scheduling to the terminal device or performing dynamic scheduling on the terminal device can be called the DG mode, and the second network device stopping sending dynamic scheduling to the terminal device or stopping dynamic scheduling on the terminal device can be called the stop DG mode; the second network device receiving uplink messages from the terminal device on pre-configured resources is called the CG mode, and the second network device stopping receiving uplink messages from the terminal device on pre-configured resources is called the stop CG mode.

[0220] In the above communication methods 300-500, the first network device can be the source network device of the terminal device, and the second network device can be the target network device of the terminal device. In the CU-DU architecture, for example, if the terminal device is a UE, the UE may switch from a source DU of a CU to a target DU under the same CU. At this time, the first network device can be the source DU (S-DU), and the second network device can be the target DU or a candidate DU (C-DU). There can also be other DUs under a CU. Before the handover, the target DU can be called a candidate DU. When the UE determines that the target cell is a cell managed by a candidate DU, the candidate DU can be called the target DU. The following describes a specific embodiment of the communication method 300 in this scenario with reference to Figure 6. In Figure 6, the DUs managed by the CU include DU1 and DU2. DU1 is the source DU of the UE, and DU2 is the target DU of the UE. As shown in Figure 6, the communication method 600 includes:

[0221] S601, CU establishes a UE context with DU2 and obtains the configuration information of the candidate cells managed by DU2.

[0222] Optionally, if the CU manages other DUs besides DU2 and DU1, such as DU3, the CU can also request configuration information of the candidate cells managed by DU3 from DU3.

[0223] Optionally, DU2 is called a candidate DU before the UE handover. When the UE determines that it wants to hand over to the cell managed by DU2, DU2 can be called the target DU.

[0224] Optionally, the configuration information of the candidate cells managed by DU2 can be the configuration information used by the UE when accessing the candidate cells managed by DU2. Optionally, the configuration information of the candidate cells managed by DU2 may include at least one of the following: uplink physical channel configuration, downlink physical channel configuration, measurement configuration information, bearer configuration, etc.

[0225] Optionally, the configuration information of candidate cells managed by DU2 may also include handover condition indication information for the candidate cells, which indicates the handover conditions for the candidate cells. For example, the handover condition for a candidate cell may be that the reference signal quality of the candidate cell is higher than the reference signal quality of the UE's serving cell by a threshold.

[0226] Optionally, in S601, the CU can send a UE context setup request message to the DU2. The context setup request message can request the DU2 to provide the configuration information of the candidate cells managed by the DU2. The DU2 sends a context setup response message to the CU. The response message can include the configuration information of the candidate cells managed by the DU2.

[0227] Optionally, the response message to the context establishment request message may include indication information for indicating the duration of the first timer. For example, DU2 determines the duration of the first timer based on the coverage area of ​​DU2, or determines the duration of the first timer based on the moving speed of the terminal. For example, the duration of the first timer may be K milliseconds.

[0228] S602, the CU sends the configuration information of the candidate cells managed by DU2 to the UE through DU1, and the UE receives the configuration information of the candidate cells managed by DU2 sent by the CU through DU1.

[0229] Optionally, if DU2 sends indication information to CU for the duration of the first timer, CU can send indication information to DU1 for the duration of the first timer. For example, CU can send a context modification request message to DU1, which may include indication information for the duration of the first timer.

[0230] S603, the UE sends the L1 measurement result to DU1, and DU1 receives the L1 measurement result from the UE.

[0231] Among them, the L1 measurement results are the layer 1 measurement results.

[0232] Optionally, the L1 measurement results may include the measurement results of the source cell under DU1, and / or the measurement results of the candidate cells under DU2.

[0233] Optionally, prior to S603, the UE can measure the candidate cells managed by DU2 based on the measurement configuration information included in the configuration information in S602, and obtain the measurement results of the candidate cells managed by DU2.

[0234] Optionally, prior to S603, DU1 can send the measurement configuration information of the serving cell under DU1 to the UE. The UE measures the source cell according to the measurement configuration information of the serving cell and obtains the measurement result of the source cell.

[0235] S604, DU1 sends a physical downlink control channel (PDCCH) order to the UE. The PDCCH order is used to instruct the UE to send a preamble to the candidate cell managed by DU2.

[0236] Optionally, DU1 can determine whether the UE can send a preamble to the candidate cell managed by DU2 based on the L1 measurement report in S603. For example, DU2 manages candidate cell 1 and candidate cell 2. The L1 measurement report in S603 includes the measurement reports of candidate cell 1 and candidate cell 2. DU1 can determine whether the UE needs to send a preamble to candidate cell 1 based on the measurement reports of candidate cell 1 and candidate cell 2. Therefore, it can send the PDCCH order in S605, which instructs the UE to send a preamble to candidate cell 1.

[0237] S605, the UE sends a preamble to the candidate cell of DU2 according to the instructions of the PDCCH command.

[0238] S606, DU2 sends the UE's TA to DU1 through CU, and DU1 receives the UE's TA from DU2 through CU.

[0239] Among them, DU2 can determine the UE's TA based on the preamble sent by the UE in S606.

[0240] S607, DU1 sends a second indication information to the UE, and the UE receives the second indication information from DU1. The second indication information can indicate the UE's TA and / or target beam.

[0241] Optionally, the target beam can be the beam used by the UE when accessing a candidate cell managed by DU2. For example, DU1 can determine the target beam used by the UE when accessing a candidate cell managed by DU2 based on the measurement results of the candidate cells managed by DU2 transmitted in S604. For example, the second indication information can indicate the target beam by indicating the beam direction of the target beam, such as the identification information of the target beam, which can be a transmission configuration indicator state ID (TCI State ID) or a reference signal identifier.

[0242] S608, DU1 starts the first timer.

[0243] Optionally, DU1 can start the first timer when it receives the TA from the UE in S606.

[0244] Optionally, DU1 can start the first timer after sending the second indication information to the UE in S607.

[0245] Optionally, the duration of the first timer can be determined by DU1, or DU2 can send the duration of the first timer to DU1. For example, DU2 can send the duration of the first timer to DU1 through CU, or DU2 can send indication information for indicating the duration of the first timer to CU through a response message of a context setup request message. This application embodiment does not impose any restrictions on how DU1 obtains the duration of the first timer.

[0246] S609, DU1 sends a second message to DU2 through CU, and DU2 receives the second message from DU1 through CU.

[0247] Optionally, the second message is used to trigger DU2 to initiate dynamic scheduling of the UE, that is, the second message can trigger DU2 to initiate DG mode.

[0248] Optionally, the second message triggers DU2 to attempt to receive uplink messages from the UE on pre-configured resources; that is, the second message can trigger DU2 to initiate CG mode. Before receiving the second message, DU2 can allocate pre-configured resources to the UE. After receiving the second message, DU2 can determine that the UE will use the pre-configured resources, and therefore will not allocate the pre-configured resources allocated to the UE to other UEs, avoiding resource conflicts. Optionally, before receiving the second message, DU2 can allocate the pre-configured resources to other UEs to improve the utilization rate of uplink resources.

[0249] Optionally, the second message includes at least one of the following: an identifier of a candidate cell managed by DU2, the probability of the UE switching to a candidate cell managed by DU2, or the identifier of a target beam. The identifier of a candidate cell managed by DU2 indicates that the UE may switch to the candidate cell identified by that identifier; the probability of the UE switching to a candidate cell managed by DU2 can be replaced by the probability of the UE switching to a candidate cell managed by DU2; the identifier of the target beam can be indicated by a TCI State ID or a reference signal identifier, and DU2 can use the target beam identified by the TCI State ID or the reference signal identifier to send dynamic scheduling, and / or, DU2 can use the target beam identified by the TCI State ID or the reference signal identifier to receive uplink messages from the UE on pre-configured resources.

[0250] Optionally, in S609, the second message sent by DU1 to CU can be a DU-CU cell switch notification message. The DU-CU switch notification message may include a first field, the value of which indicates that the UE will switch to a candidate cell via conditional L1 / L2 triggered mobility (C-LTM) technology. C-LTM can also be understood as a handover triggered by the UE when the handover conditions are met. CU can identify the function of the DU-CU cell switch notification message based on the value of the first field, indicating that the UE will use C-LTM technology to switch to the candidate cell, and then forward the message to DU2. Optionally, in S610, the second message sent by CU to DU2 can be a CU-DU cell switch notification message. The CU-DU switch notification message may include a second field, the value of which indicates that the UE will switch to the candidate cell via C-LTM technology, so that DU2 can identify the function of the CU-DU cell switch notification message as triggering the DG and / or CG activation method, allowing the UE to use C-LTM technology for handover.

[0251] Optionally, in S609, for the sake of simplification, the message sent by DU1 to CU and the message sent by CU to DU2 are both referred to as the second message. In some cases, the message sent by DU1 to CU and the message sent by CU to DU2 can have different message names. For example, the message sent by DU1 to CU can be called message 1, and the message sent by CU to DU2 can be called message 2. Message 2 includes the information in message 1.

[0252] It is understandable that the order of S609 and S608 is not restricted, and S609 can be performed before, after, or simultaneously with S608; the order of S609 and S607 is not restricted, and S609 can be performed before, after, or simultaneously with S607.

[0253] S610, DU2 dynamically schedules the UE according to the second message, and / or attempts to receive the UE's uplink message on pre-configured resources.

[0254] S611, if the first timer expires, DU1 sends the first indication information to DU2 through CU, and DU2 receives the first indication information from DU1 through CU. The first indication information is used to indicate to stop sending dynamic scheduling to UE, and / or to stop receiving uplink messages on pre-configured resources.

[0255] Optionally, in S602, the UE may receive handover condition indication information. Between S609 and S611, if the UE meets the handover conditions indicated by the candidate small handover condition indication information, the UE may receive dynamic scheduling sent by DU2 and access DU2 through the dynamic scheduling sent by DU2. Alternatively, the UE may send an uplink message to DU2 on pre-configured resources to access DU2. Optionally, between S609 and S611, the UE may also not access DU2 if it does not meet the handover conditions.

[0256] Optionally, if the UE successfully accesses DU2, DU2 can send an access success message to CU. After receiving the access success message, CU can send an instruction to other candidate DUs, such as DU3, to instruct DU3 to stop sending dynamic scheduling instructions to the UE, or CU can send an instruction to DU3 to instruct DU3 to stop receiving uplink messages on the UE's pre-configured resources. The pre-configured resources allocated by DU3 to the UE can be allocated to other UEs. For example, DU2 and DU3 are candidate DUs. DU1 can send S610 to DU2 through CU, instructing DU2 to send dynamic scheduling to the UE and / or instructing DU2 to receive the UE's uplink messages on the pre-configured resources. At the same time, DU1 can also send a similar S610 message to DU3 through CU, instructing DU3 to send dynamic scheduling to the UE and / or instructing DU3 to receive the UE's uplink messages on the pre-configured resources. Subsequently, the UE successfully switches to DU2, and DU2 sends an access success message to CU. At this time, CU should send indication information to other candidate DUs (DU3), instructing the candidate DUs to stop sending dynamic scheduling to the UE and / or instructing DU3 to stop receiving the UE's uplink messages on the pre-configured resources. The pre-configured resources allocated by DU3 to this UE can be allocated to other UEs to improve resource utilization.

[0257] Optionally, in S611, for the sake of simplicity, the indication information sent by DU1 to CU and the indication information sent by CU to DU2 are both represented by the first indication information. In some cases, the indication information sent by DU1 to CU and the indication information sent by CU to DU2 can have different indication information names. For example, the indication information sent by DU1 to CU can be called indication information 1, and the indication information sent by CU to DU2 can be called indication information 2. The content indicated by indication information 2 includes the content indicated by indication information 1.

[0258] S612, DU2 stops dynamic scheduling of the UE according to the first indication information, and / or stops receiving uplink messages from the UE on pre-configured resources.

[0259] The communication method 600 described above describes a communication method provided in this application embodiment in a scenario where DU1 and DU2 belong to the same CU. After the first timer expires, DU1 can send a first indication message to DU2 through the CU. DU2 can stop dynamic scheduling of the UE and / or stop receiving uplink messages from the UE on pre-configured resources according to the first indication message. This avoids the problem of resource waste caused by DU2 frequently sending dynamic scheduling or frequently trying to receive uplink messages from the UE, thereby improving resource utilization. In addition, before DU2 receives the first indication message, DU2 can send dynamic scheduling to the UE and / or receive uplink messages sent by the UE on pre-configured resources according to the second message. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save the latency of the UE accessing DU2.

[0260] In the above communication method 300, the first network device can be the source network device of the terminal device, and the second network device can be the target network device of the terminal device. In a CU-DU architecture, for example, if the terminal device is a UE, the UE may switch from a source DU of a source CU to a target DU of another target CU. In this case, the first network device can be the source DU, and the second network device can be the target DU. Before the handover, the target DU can be called a candidate DU; when the UE determines that the target cell is a cell managed by a candidate DU, that candidate DU can be called the target DU. The following describes a specific embodiment of the communication method 300 in this scenario with reference to Figure 7. In Figure 7, CU1 is the source CU of the UE, the UE accesses DU1 managed by CU1, and the UE moves from DU1 managed by CU1 to DU2 managed by CU2. At this time, CU2 is the target CU, and DU2 is the target DU. As shown in Figure 7, the communication method 700 includes:

[0261] S701, CU1 establishes a UE context with DU2 through CU2 and obtains the configuration information of candidate cells managed by DU2.

[0262] Specifically, S701 refers to the description of S601. For example, CU1 and CU2 can request and obtain the configuration information of the candidate cell through a handover request and a handover request confirmation message, and CU2 and DU2 can request and obtain the configuration information of the candidate cell through a UE context establishment request and a UE context establishment request response message.

[0263] S702, CU1 sends the configuration information of the candidate cells managed by DU2 to the UE through DU1, and the UE receives the configuration information of the candidate cells managed by DU2 sent by CU1 through DU1.

[0264] Specifically, see the description of S602 for S702.

[0265] S702-S705 refer to S602-S605 respectively.

[0266] S706, DU2 sends the UE's TA to DU1 through CU2 and CU1, and DU1 receives the UE's TA from DU2 through CU1 and CU2.

[0267] Specifically, see the description of S606 for S706.

[0268] S707-S708 refer to S607-S608 respectively.

[0269] S709, DU1 sends a second message to DU2 through CU1 and CU2, and DU2 receives the second message from DU1 through CU2 and CU1.

[0270] Specifically, see the description of S609 for S709.

[0271] Optionally, in S709, for the sake of simplicity, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 are all referred to as the second message. In some cases, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 can have different message names. For example, the message sent by DU1 to CU1 can be called message 1, the message sent by CU1 to CU2 can be called message 2, and the message sent by CU2 to DU2 can be called message 3. Message 2 includes the information in message 1, and message 3 includes the information in message 2.

[0272] S710 refers to S610.

[0273] S711, if the first timer times out, DU1 sends the first indication information to DU2 through CU1 and CU2.

[0274] Specifically, S711 is described in conjunction with S611.

[0275] Optionally, for the sake of simplicity in S711, the indication information sent by DU1 to CU1, the indication information sent by CU1 to CU2, and the indication information sent by CU2 to DU2 are all represented by the first indication information. In some cases, the indication information sent by DU1 to CU1, the indication information sent by CU1 to CU2, and the indication information sent by CU2 to DU2 can have different indication information names. For example, the indication information sent by DU1 to CU1 can be called indication information 1, the indication information sent by CU1 to CU2 can be called indication information 2, and the indication information sent by CU2 to DU2 can be called indication information 3. The content indicated by indication information 2 includes the content indicated by indication information 1, and the content indicated by indication information 3 includes the content indicated by indication information 2.

[0276] S712 is a reference to S612.

[0277] The communication method 700 described above describes a communication method provided in this application embodiment in a scenario where DU1 and DU2 belong to different CUs. After the first timer expires, DU1 can send a first indication message to DU2 through CU1 and CU2. DU2 can stop dynamic scheduling of the UE and / or stop receiving uplink messages from the UE on pre-configured resources according to the first indication message. This avoids the problem of resource waste caused by DU2 frequently sending dynamic scheduling or frequently trying to receive uplink messages from the UE, thereby improving resource utilization. In addition, before DU2 receives the first indication message, DU2 can send dynamic scheduling to the UE and / or receive uplink messages sent by the UE on pre-configured resources according to the second message. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save the latency of the UE accessing DU2.

[0278] The following describes a specific embodiment of the communication method 400 in this scenario with reference to Figure 8. In Figure 8, the DU managed by the CU includes DU1 and DU2. Before handover, the target DU can be called a candidate DU. When the UE determines that the target cell is a cell managed by a candidate DU, the candidate DU can be called the target DU. DU1 is the source DU of the UE, and DU2 is the target DU of the UE. As shown in Figure 8, the communication method 800 includes:

[0279] S801-S807 refer to S601-S607 respectively.

[0280] S808-S809 refer to S609-S610 respectively.

[0281] S810, the UE sends the first message to DU1, and DU1 receives the first message from the UE.

[0282] The first message includes one or more of the following: a measurement report of at least one candidate cell managed by DU2, a measurement report of at least one beam of at least one candidate cell, a measurement report of at least one reference signal of at least one candidate cell, an indication message indicating TA failure of the UE, an indication message indicating target beam failure of at least one candidate cell, an indication message indicating that the change in RSRP of at least one candidate cell exceeds a threshold value, an indication message indicating that the change in RSRP of the reference signal of at least one candidate cell exceeds a threshold value, an indication message indicating that the RSRP of at least one candidate cell is less than a threshold value, or an indication message indicating that the RSRP of the reference signal of at least one candidate cell is less than a threshold value, wherein the target beam is the beam that the UE will use when accessing DU2, or the target beam is the beam that the UE is aligned with DU2, or the target beam is the beam that the UE will use when accessing at least one candidate cell of DU2.

[0283] Specifically, the change in the RSRP of at least one candidate cell exceeding a threshold can be defined as the change in the RSRP of at least one candidate cell from the time the UE receives the second indication information in S807 to the current time exceeding a threshold. Similarly, the change in the RSRP of the reference signal of at least one candidate cell exceeding a threshold can also be defined as the change in the RSRP of the reference signal of at least one candidate cell from the time the UE receives the second indication information in S807 to the current time exceeding a threshold. The RSRP of the reference signal of at least one candidate cell can be the RSRP of the reference signal corresponding to the target beam, or it can be the RSRP of the reference signal used to calculate path loss.

[0284] Optionally, prior to S808, the UE can determine whether to send the first message. For example, the UE can determine whether the TA is valid; if the TA is invalid, the UE can trigger the sending of the first message. Alternatively, the UE can determine whether the target beam is valid; if the target beam is invalid, the UE can trigger the sending of the first message. Alternatively, the UE can determine that the change in the RSRP of at least one candidate cell managed by DU2 exceeds a threshold value, and thus trigger the sending of the first message. Alternatively, the UE can determine that the change in the RSRP of the reference signal of at least one candidate cell exceeds a threshold value, and thus trigger the sending of the first message. Alternatively, the UE can determine that the RSRP of at least one candidate cell is less than (or less than or equal to) a threshold value, and thus trigger the sending of the first message. Alternatively, the terminal device can determine that the RSRP of the reference signal of at least one candidate cell is less than (or less than or equal to) a threshold value, and thus trigger the sending of the first message.

[0285] Understandably, there are no restrictions on the order of S809 and S810; S809 can be performed before, after, or simultaneously with S810.

[0286] S811, DU1 determines that the UE's TA is invalid, or the target beam is invalid, or the probability of the UE switching to at least one candidate cell is lower than the threshold based on the first message, then executes S810.

[0287] Specifically, how DU1 determines the probability of the UE, the target beam failing, or the UE switching to at least one candidate cell being lower than the threshold based on the first message can be found in the description of the aforementioned communication method 400, which will not be described in detail to avoid redundancy.

[0288] S812-S813 refer to S611-S612 respectively.

[0289] The communication method 800 described above describes a communication method provided in this application embodiment where DU1 and DU2 belong to the same CU. DU1 can send a first indication information to DU2 through the CU based on a first message sent by the UE. DU2 can stop dynamic scheduling of the UE and / or stop receiving uplink messages from the UE on pre-configured resources according to the first indication information. This avoids the resource waste caused by DU2 frequently sending dynamic scheduling or frequently attempting to receive uplink messages from the UE, thereby improving resource utilization. In addition, before DU2 receives the first indication information, DU2 can send dynamic scheduling and / or receive uplink messages sent by the UE on pre-configured resources. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save the latency of the UE accessing DU2.

[0290] In the above communication method 400, the first network device can be the source network device of the terminal device, and the second network device can be the target network device of the terminal device. In a CU-DU architecture, for example, if the terminal device is a UE, the UE may switch from a source DU of a source CU to a target DU of another target CU. In this case, the first network device can be the source DU, and the second network device can be the target DU. Before the handover, the target DU can be called a candidate DU; when the UE determines that the target cell is a cell managed by a candidate DU, that candidate DU can be called the target DU. The following describes a specific embodiment of the communication method 400 in this scenario with reference to Figure 9. In Figure 9, CU1 is the source CU of the UE, the UE accesses DU1 managed by CU1, and the UE moves from DU1 managed by CU1 to DU2 managed by CU2. At this time, CU2 is the target CU, and DU2 is the target DU. As shown in Figure 9, the communication method 900 includes:

[0291] S901, CU1 establishes a UE context with DU2 through CU2 and obtains the configuration information of the candidate cells managed by DU2.

[0292] Specifically, S901 refers to the description of S601. For example, CU1 and CU2 can request and obtain the configuration information of the candidate cell through a handover request and a handover request confirmation message, and CU2 and DU2 can request and obtain the configuration information of the candidate cell through a UE context establishment request and a UE context establishment request response message.

[0293] S902, CU1 sends the configuration information of the candidate cells managed by DU2 to the UE through DU1, and the UE receives the configuration information of the candidate cells managed by DU2 sent by CU1 through DU1.

[0294] Specifically, see the description of S602 for S902.

[0295] S902-S905 refer to S802-S805 respectively.

[0296] S906, DU2 sends the UE's TA to DU1 through CU2 and CU1.

[0297] Specifically, see the description of S606 for S906.

[0298] S907 refers to S607.

[0299] S908, DU1 sends a second message to DU2 through CU1 and CU2, and DU2 receives the second message from DU1 through CU2 and CU1.

[0300] Optionally, in S908, for the sake of simplicity, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 are all referred to as the second message. In some cases, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 can have different message names. For example, the message sent by DU1 to CU1 can be called message 1, the message sent by CU1 to CU2 can be called message 2, and the message sent by CU2 to DU2 can be called message 3. Message 2 includes the information in message 1, and message 3 includes the information in message 2.

[0301] Specifically, see the description in S609 for S908.

[0302] S909-S911 refer to S809-811 respectively.

[0303] S912, DU1 sends the first indication information to DU2 through CU1 and CU2, and DU2 receives the first indication information through CU2 and CU1.

[0304] Specifically, see the description in S611 for S912.

[0305] Optionally, in S912, for the sake of simplicity, the indication information sent by DU1 to CU1, the indication information sent by CU1 to CU2, and the indication information sent by CU2 to DU2 are all represented by the first indication information. In some cases, the indication information sent by DU1 to CU1, the indication information sent by CU1 to CU2, and the indication information sent by CU2 to DU2 can have different indication information names. For example, the indication information sent by DU1 to CU1 can be called indication information 1, the indication information sent by CU1 to CU2 can be called indication information 2, and the indication information sent by CU2 to DU2 can be called indication information 3. The content indicated by indication information 2 includes the content indicated by indication information 1, and the content indicated by indication information 3 includes the content indicated by indication information 2.

[0306] S913 refers to S813.

[0307] The communication method 900 described above describes a communication method provided in this application embodiment where DU1 and DU2 belong to different CUs. DU1 can send a first indication information to DU2 through CU1 and CU2 based on a first message sent by the UE. DU2 can stop dynamic scheduling of the UE and / or stop receiving uplink messages from the UE on pre-configured resources according to the first indication information. This avoids the resource waste caused by DU2 frequently sending dynamic scheduling or frequently attempting to receive uplink messages from the UE, thereby improving resource utilization. In addition, before DU2 receives the first indication information, DU2 can send dynamic scheduling and / or receive uplink messages sent by the UE on pre-configured resources. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save the latency of the UE accessing DU2.

[0308] The following describes a specific embodiment of the communication method 500 in this scenario with reference to Figure 10. In Figure 10, the DU managed by the CU includes DU1 and DU2. Before handover, the target DU can be called a candidate DU; when the UE determines that the target cell is a cell managed by a candidate DU, the candidate DU can be called the target DU. DU1 is the UE's source DU, and DU2 is the UE's target DU. As shown in Figure 10, the communication method 1000 includes:

[0309] S1001-1007 refer to S601-S607 respectively.

[0310] S1008, DU1 sends a second message to DU2 through CU, and DU2 receives the second message from DU1 through CU. The second message includes the remaining valid duration information of TA, which is used to indicate the remaining valid duration of TA.

[0311] Prior to S1008, DU1 can receive the total valid duration information of the TA from DU2 via the CU. This total valid duration information indicates the total valid duration of the TA. For example, in S1006, DU2 can send the TA and its total valid duration information to DU1 via the CU. As another example, in S1002, the configuration information of the candidate cell sent by DU2 to DU1 via the CU may include the total valid duration information of the TA.

[0312] Optionally, DU1 can determine the remaining valid duration information of TA based on the total valid duration information of TA. Optionally, DU1 can determine the remaining valid duration information of TA based on the total valid duration information of TA, including: DU1 determines the remaining valid duration information of TA based on the time of receiving TA in S1006 and the time in S1008. For example, DU1 subtracts the time period from the time DU1 receives TA in S1006 to the time of sending the second message to DU2 in S1008 from the total valid duration of TA indicated by the total valid duration information to obtain the remaining valid duration. Optionally, DU1 can determine the remaining valid duration information of TA based on the total valid duration information of TA, including: DU1 determines the remaining valid duration information of TA by sending the time of TA in S1007 to UE and the time of S1008 based on the total valid duration information of TA. For example, DU1 subtracts the time period from the time of sending TA to UE in S1007 to the time of sending the second message to DU2 in S1008 from the total valid duration of TA indicated by the total valid duration information to obtain the remaining valid duration.

[0313] Optionally, in S1008, for the sake of simplification, the message sent by DU1 to CU and the message sent by CU to DU2 are both referred to as the second message. In some cases, the message sent by DU1 to CU and the message sent by CU to DU2 can have different message names. For example, the message sent by DU1 to CU can be called message 1, and the message sent by CU to DU2 can be called message 2. Message 2 includes the information in message 1.

[0314] S1009, when DU2 receives the second message, it starts the first timer. The duration of the first timer is the remaining valid duration of TA indicated by the remaining valid duration information.

[0315] S1010, DU2 dynamically schedules the UE according to the second message, and / or attempts to receive the UE's uplink message on the pre-configured resources.

[0316] S1011, if the first timer expires, DU2 stops the dynamic scheduling of the UE, and / or stops receiving uplink messages from the UE on the pre-configured resources.

[0317] Optionally, in S1002, the UE may receive handover condition indication information. Between S1010 and S1011, if the UE meets the handover conditions indicated by the candidate small handover condition indication information, the UE may receive dynamic scheduling sent by DU2 and access DU2 through dynamic scheduling sent by DU2. Alternatively, the UE may send an uplink message to DU2 on pre-configured resources to access DU2. Optionally, between S1010 and S1011, the UE may not access DU2 if it does not meet the handover conditions.

[0318] Optionally, if the UE successfully accesses DU2, DU2 can send an access success message to CU. After receiving the access success message, CU can send an instruction to other candidate DUs, such as DU3, to instruct DU3 to stop sending dynamic scheduling instructions to the UE, or CU can send an instruction to DU3 to instruct DU3 to stop receiving uplink messages on the UE's pre-configured resources. The pre-configured resources allocated by DU3 to the UE can be allocated to other UEs. For example, DU2 and DU3 are candidate DUs. DU1 can send S610 to DU2 through CU, instructing DU2 to send dynamic scheduling to the UE, and / or instructing DU2 to receive the UE's uplink messages on the pre-configured resources. At the same time, DU1 can also send a message similar to S1008 to DU3 through CU, instructing DU3 to send dynamic scheduling to the UE, and / or instructing DU3 to receive the UE's uplink messages on the pre-configured resources. Subsequently, the UE successfully switches to DU2, and DU2 sends an access success message to CU. At this time, CU should send indication information to other candidate DUs (DU3), instructing the candidate DUs to stop sending dynamic scheduling to the UE, and / or instructing DU3 to stop receiving the UE's uplink messages on the pre-configured resources. The pre-configured resources allocated by DU3 to this UE can be allocated to other UEs to improve resource utilization.

[0319] It is understandable that there are no restrictions on the order of S1009 and S1010; S1009 can be performed before, after, or simultaneously with S1010.

[0320] The communication method described in the above-described communication method 1000, in a scenario where DU1 and DU2 belong to the same CU, provides a communication method in this application embodiment. When DU2 receives the remaining valid duration information of the UE's TA from DU1 via the CU, it starts a first timer. After the first timer expires, DU2 stops dynamically scheduling the UE and / or stops receiving uplink messages from the UE on pre-configured resources. This avoids the resource waste caused by DU2 frequently sending dynamic scheduling or frequently attempting to receive uplink messages from the UE, thereby improving resource utilization. Furthermore, before the first timer expires, DU2 can send dynamic scheduling and / or receive uplink messages sent by the UE on pre-configured resources. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save latency for the UE accessing DU2.

[0321] In the above communication method 500, the first network device can be the source network device of the terminal device, and the second network device can be the target network device of the terminal device. In a CU-DU architecture, for example, if the terminal device is a UE, the UE may switch from a source DU of a source CU to a target DU under another target CU. In this case, the first network device can be the source DU, and the second network device can be the target DU. Before the handover, the target DU can be called a candidate DU; when the UE determines that the target cell is a cell managed by a candidate DU, that candidate DU can be called the target DU. The following describes a specific embodiment of the communication method 500 in this scenario with reference to Figure 11. In Figure 11, CU1 is the source CU of the UE, the UE accesses DU1 managed by CU1, and the UE moves from DU1 managed by CU1 to DU2 managed by CU2. At this time, CU2 is the target CU, and DU2 is the target DU. As shown in Figure 11, the communication method 1100 includes:

[0322] S1101, CU1 establishes a UE context with DU2 through CU2 and obtains the configuration information of the candidate cells managed by DU2.

[0323] Specifically, S1101 is described in S601.

[0324] S1102, CU1 sends the configuration information of the candidate cells managed by DU2 to the UE through DU1, and the UE receives the configuration information of the candidate cells managed by DU2 sent by CU1 through DU1.

[0325] Specifically, S1102 is described in S602.

[0326] S1103-S1105 refer to S1003-S1005 respectively.

[0327] S1106, DU2 sends the UE's TA to DU1 through CU2 and CU1, and DU1 receives the UE's TA from DU2 through CU1 and CU2.

[0328] Specifically, see the description of S606 for S106.

[0329] S1107 refers to S1007.

[0330] S1108, DU1 sends a second message to DU2 through CU1 and CU2, and DU2 receives the second message from DU1 through CU2 and CU1.

[0331] Specifically, see the description of S1008 for S1108.

[0332] Optionally, in S1108, for the sake of simplicity, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 are all referred to as the second message. In some cases, the message sent by DU1 to CU1, the message sent by CU1 to CU2, and the message sent by CU2 to DU2 can have different message names. For example, the message sent by DU1 to CU1 can be called message 1, the message sent by CU1 to CU2 can be called message 2, and the message sent by CU2 to DU2 can be called message 3. Message 2 includes the information in message 1, and message 3 includes the information in message 2.

[0333] S1109-S1111 refer to S1009-S1011 respectively.

[0334] It is understandable that there are no restrictions on the order of S1109 and S1110; S1109 can be performed before, after, or simultaneously with S1110.

[0335] The communication method described in the above-described communication method 1100, which assumes DU1 and DU2 belong to different CUs, provides a communication method in this application embodiment. When DU2 receives the remaining valid duration information of the UE's TA from DU1 through CU2 and CU1, it starts a first timer. After the first timer expires, DU2 stops dynamically scheduling the UE and / or stops receiving uplink messages from the UE on pre-configured resources. This avoids the resource waste caused by DU2 frequently sending dynamic scheduling messages or frequently attempting to receive uplink messages from the UE, thereby improving resource utilization. Furthermore, before the first timer expires, DU2 can send dynamic scheduling messages and / or receive uplink messages sent by the UE on pre-configured resources. If the UE determines that the handover conditions are met, the UE can access DU2 using dynamic scheduling or by using uplink messages. This non-random access method can save the latency of the UE accessing DU2.

[0336] In this embodiment of the application, the interaction process between the first network device and the second network device can be direct interaction or forwarding through an intermediate device. For example, if the first network device is DU1 and the second network device is DU2, the interaction between DU1 and DU2 can be forwarded through CU, and CU manages DU1 and DU2. As another example, if the first network device is DU1 and the second network device is DU2, the interaction between DU1 and DU2 can be forwarded through CU1 and CU2, where DU1 is managed by CU1 and DU2 is managed by CU2.

[0337] It is understandable that in the above communication methods 600 to 1100, the UE switches from a cell under one DU to a cell under another DU. In some scenarios, the UE can switch from a cell under one DU to another cell under that DU. In such scenarios, the interaction between the CU and the DU can be implemented internally by the network device.

[0338] Optionally, RSRP in the embodiments of this application can be replaced with parameters such as reference signal received quality (RSRQ) or signal to interference plus noise ratio (SINR). RSRP can be a beam-level measurement result or a cell-level measurement result.

[0339] Optionally, in the embodiments of this application, "less than" can be replaced with "less than or equal to", and "more than" can be replaced with "greater than" or "greater than or equal to".

[0340] Figure 12 is a schematic block diagram of a communication device provided in an embodiment of this application. As shown in Figure 12, the communication device 1200 may include a processing unit 1210 and a communication unit 1220. The communication unit 1220 can implement corresponding communication functions, which can be internal communication within the communication device 1200 or communication between the communication device 1200 and other devices; the processing unit 1210 can implement corresponding processing functions. The communication unit 1220 may also be referred to as a communication interface or a transceiver unit. Optionally, the communication device 1200 may further include a storage unit, which can be used to store instructions and / or data. The processing unit 1210 can read the instructions and / or data in the storage unit to enable the device to implement the aforementioned method embodiment.

[0341] In one possible design, the communication device 1200 may be the first network device or DU1 in the above-described communication method embodiments, or it may be a module or chip applied to the first network device or DU1. The communication device 1200 may be used to execute the steps or processes performed by the first network device or DU1 in the above-described method embodiments.

[0342] In another possible design, the communication device 1200 may be the second network device or DU2 in the above communication method embodiments, or it may be a module or chip applied to the second network device or DU2. The communication device 1200 may be used to execute the steps or processes performed by the second network device or DU2 in the above method embodiments.

[0343] In another possible design, the communication device 1200 can be a terminal device or UE as described in the communication method embodiments above, or it can be a module or chip applied to the terminal device or UE. The communication device 1200 can be used to execute the steps or processes performed by the terminal device or UE in the above method embodiments.

[0344] For details regarding the steps or processes executed by each unit in the communication device 1200, please refer to the embodiments of the method described above; they will not be elaborated here.

[0345] It should be understood that the "unit" in the communication device 1200 can be implemented in hardware, software, or by hardware executing corresponding software. For example, the "unit" can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, combined logic circuitry, and / or other suitable components supporting the described functions. As another example, the communication unit 1220 can be replaced by a transceiver circuit (e.g., it may include receiving and transmitting circuitry), and the processing unit 1210 can be replaced by a processor or processing circuitry.

[0346] Figure 13 shows a schematic block diagram of another communication device 1300 provided in an embodiment of this application. The communication device 1300 may be a terminal device, a first network device, a second network device, a UE, DU1, or DU2, or it may be a chip, chip system, or processor that supports the first network device, the second network device, the UE, DU1, or DU2 in implementing the above methods. This device can be used to implement the methods described in the above method embodiments; for details, please refer to the descriptions in the above method embodiments.

[0347] The communication device 1300 may include one or more processors 1310, which may also be referred to as processing units, and can implement certain control functions. The processor 1310 may be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device (e.g., base station, baseband chip, user chip, DU or CU, etc.), execute software programs, and process data from the software programs.

[0348] In an alternative design, processor 1310 may also store instructions and / or data that can be executed by processor 1310 to cause communication device 1300 to perform the methods described in the above method embodiments. Optionally, processing unit 1210 in communication device 1200 may be processor 1310.

[0349] In another alternative design, the communication device 1300 may include a communication interface 1320 for implementing receiving and transmitting functions. For example, the communication interface 1320 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals. Optionally, the communication unit 1220 in the communication device 1200 may be the communication interface 1320.

[0350] Optionally, the communication device 1300 may include one or more memories 1330, which may store instructions that can be executed on the processor 1310, causing the communication device 1300 to perform the methods described in the above method embodiments. Optionally, the memories 1330 may also store data. Optionally, the processor 1310 may also store instructions and / or data. The processor 1310 and the memories 1330 may be provided separately or integrated together.

[0351] Those skilled in the art will understand that, for ease of explanation, Figure 13 only shows one memory and processor. In actual communication devices, multiple processors and memories may exist. Memory may also be referred to as storage medium or storage device, etc., and the embodiments of this application do not impose such limitations.

[0352] For example, a processor may include a baseband processor and a central processing unit (CPU). The baseband processor is mainly used for processing communication protocols and communication data, while the CPU is mainly used for controlling the entire terminal device, executing software programs, and processing the data in the software programs. The processor in Figure 13 integrates the functions of a baseband processor and a CPU. Those skilled in the art will understand that the baseband processor and CPU can also be independent processors interconnected via technologies such as buses. Those skilled in the art will understand that a terminal device may include multiple baseband processors to adapt to different network standards, and a terminal device may include multiple CPUs to enhance its processing capabilities. The various components of the terminal device can be connected via various buses. The baseband processor can also be described as a baseband processing circuit or a baseband processing chip. The CPU can also be described as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor or stored in a storage unit as a software program, which is then executed by the processor to implement the baseband processing function.

[0353] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the methods disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0354] It should be noted that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuitry in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0355] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0356] This application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the terminal device, the first network device, the second network device, the UE, the DU1, or the DU2 in any of the above method embodiments.

[0357] This application also provides a computer-readable storage medium storing program code that, when executed on a computer, causes the computer to perform the various steps or processes performed by the terminal device, the first network device, the second network device, the UE, the DU1, or the DU2 in any of the above method embodiments.

[0358] This application also provides a communication device, including a processor and an interface for sending and / or receiving signals, such that the processor executes the various steps or processes performed by the terminal device, the first network device, the second network device, the UE, the DU1, or the DU2 in any of the above method embodiments.

[0359] This application also provides a communication system, which includes at least two of the following: a terminal device, a first network device, or a second network device; or includes at least two of the following: a UE, DU1, or DU2.

[0360] The above-described device and method embodiments are completely corresponding, with corresponding modules or units performing corresponding steps. For example, a communication unit or communication interface performs the receiving or sending steps in the method embodiment, while other steps besides sending and receiving can be performed by a processing unit or processor.

[0361] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0362] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable storage media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0363] Those skilled in the art will recognize that the various illustrative logical blocks and steps 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0364] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be based on the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0365] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0366] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0367] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0368] In the above embodiments, the functions of each functional unit can be implemented entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions (programs). When the computer program instructions (programs) are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs), etc.

[0369] If the aforementioned functions are implemented as software functional units 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 this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0370] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to the first network device, including: When a timer is started when a terminal device receives a timed advance TA from a second network device or when the TA is sent to the terminal device, the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device. If the first timer times out, a first indication message is sent to the second network device. The first indication message is used to indicate that the dynamic scheduling of the terminal device should be stopped, and / or the first indication message is used to indicate that the uplink messages of the terminal device should be stopped on the pre-configured resources.

2. The communication method according to claim 1, characterized in that, The communication method further includes: Obtain the duration of the first timer from the second network device.

3. The communication method according to claim 1 or 2, characterized in that, The first indication information is also used to indicate that the TA of the terminal device is invalid.

4. A communication method, characterized in that, Applied to the first network device, including: Receive the first message from the terminal device; According to the first message, a first instruction message is sent to the second network device. The first instruction message is used to instruct the cessation of dynamic scheduling of the terminal device, and / or the first instruction message is used to instruct the cessation of receiving uplink messages from the terminal device on pre-configured resources. The first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device.

5. The communication method according to claim 4, characterized in that, The first message includes at least one of the following: The second network device manages measurement reports of at least one candidate cell, measurement reports of at least one beam of the at least one candidate cell, indication information for indicating that the terminal device's timing advance TA has failed, indication information for indicating that the target beam of the at least one candidate cell has failed, indication information for indicating that the change in the cell-level reference signal received power (RSRP) of the at least one candidate cell exceeds a threshold value, indication information for indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds a threshold value, indication information for indicating that the cell-level RSRP of the at least one candidate cell is less than a threshold value, or indication information for indicating that the RSRP of the reference signal of the at least one candidate cell is less than a threshold value, wherein the target beam is the beam that the terminal device will use when accessing the second network device.

6. The communication method according to claim 4 or 5, characterized in that, The step of sending a first indication message to the second network device according to the first message includes: After determining that the TA has failed based on the first message, the first indication information is sent to the second network device.

7. The communication method according to claim 6, characterized in that, The first indication information is also used to indicate that the TA of the terminal device has failed.

8. The communication method according to any one of claims 4 to 7, characterized in that, The step of sending a first indication message to the second network device according to the first message includes: After determining that the target beam has failed based on the first message, a first indication message is sent to the second network device, wherein the target beam is the beam that the terminal device will use when accessing the second network device.

9. The communication method according to claim 8, characterized in that, The first indication information is also used to indicate that the target beam is ineffective.

10. The communication method according to claim 8 or 9, characterized in that, The first indication information is used to indicate stopping the dynamic scheduling of the terminal device using the target beam and using the updated target beam for dynamic scheduling of the terminal device, and / or, the first indication information is used to indicate stopping the reception of the uplink message of the terminal device on the pre-configured resources using the target beam and using the updated target beam to receive the uplink message of the terminal device on the pre-configured resources, wherein the updated target beam is the updated beam that the terminal device will use when accessing the second network device.

11. The communication method according to claim 10, characterized in that, The communication method further includes: The updated target beam is determined based on the first message.

12. The communication method according to any one of claims 4 to 11, characterized in that, The step of sending a first instruction message to the second network device according to the first message includes: After determining that the probability of the terminal device switching to the first candidate cell managed by the second network device is less than a threshold based on the first message, the terminal device sends a first indication message to the second network device.

13. The communication method according to claim 12, characterized in that, The first indication information is also used to indicate that the probability of the terminal device switching to the first candidate cell managed by the second network device is less than a threshold.

14. A communication method, characterized in that, Applied to second network devices, including: Receive first indication information from a first network device, the first indication information being used to indicate stopping dynamic scheduling of the terminal device, and / or, the first indication information being used to indicate stopping receiving uplink messages from the terminal device on pre-configured resources, the first network device being the serving network device of the terminal device, and the second network device being the candidate network device of the terminal device; According to the first instruction information, stop the dynamic scheduling of the terminal device, and / or stop receiving uplink messages from the terminal device on the pre-configured resources.

15. The communication method according to claim 14, characterized in that, The communication method further includes: Indicate the duration of the first timer to the first network device.

16. The communication method according to claim 14 or 15, characterized in that, The first indication information is also used to indicate that the TA of the terminal device has failed.

17. The communication method according to any one of claims 14 to 16, characterized in that, The first indication information is also used to indicate that the target beam is invalid, and the target beam is the beam that the terminal device will use when it accesses the second network device.

18. The communication method according to claim 17, characterized in that, The first indication information is used to indicate to stop using the target beam to dynamically schedule the terminal device and to use the updated target beam to dynamically schedule the terminal device, and / or, the first indication information is used to indicate to stop using the target beam to receive the uplink message of the terminal device on the pre-configured resources and to use the updated target beam to receive the uplink message of the terminal device on the pre-configured resources, wherein the updated target beam is the updated beam that the terminal device will use when accessing the second network device; The step of stopping the dynamic scheduling of the terminal device according to the first indication information, and / or stopping the reception of uplink messages from the terminal device on the pre-configured resources, includes: According to the first indication information, stop dynamically scheduling the terminal device using the target beam, and dynamically schedule the terminal device using the updated target beam; and / or, According to the first instruction information, stop using the target beam to receive uplink messages from the terminal device on the pre-configured resources, and use the updated target beam to receive uplink messages from the terminal device on the pre-configured resources.

19. A communication method, characterized in that, Applied to terminal devices, including: Receive second indication information from the first network device to instruct the terminal device to advance the timing advance TA and / or the target beam; Based on the second instruction information, a first message is sent to the first network device; The first message includes at least one of the following: Measurement reports of at least one candidate cell managed by the second network device, measurement reports of at least one reference signal of the at least one candidate cell, indication information for indicating that the timing advance TA of the terminal device has failed, indication information for indicating that the target beam of the at least one candidate cell has failed, indication information for indicating that the change in the cell-level reference signal received power (RSRP) of the at least one candidate cell exceeds a threshold value, indication information for indicating that the change in the RSRP of the reference signal of the at least one candidate cell exceeds a threshold value, indication information for indicating that the cell-level RSRP of the at least one candidate cell is less than a threshold value, or indication information for indicating that the RSRP of the reference signal of the at least one candidate cell is less than a threshold value, wherein the target beam is the beam that the terminal device will use when accessing the second network device; Wherein, the first network device is the serving network device of the terminal device, and the second network device is the candidate network device of the terminal device.

20. The communication method according to claim 19, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: When the terminal device receives the second indication information, it starts a second timer. When the second timer expires, it sends a first message to the first network device. The first message includes indication information indicating that the TA of the terminal device has failed.

21. The communication method according to claim 19 or 20, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the change in the cell-level RSRP of the at least one candidate cell compared to the current cell-level RSRP of the at least one candidate cell is measured. If the change in the cell-level RSRP exceeds a threshold, a first message is sent to the first network device. The first message may include indication information indicating that the change in the cell-level RSRP of the at least one candidate cell exceeds a threshold, and / or indication information indicating that the TA of the terminal device has failed.

22. The communication method according to claim 19 or 20, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the cell-level RSRP of the at least one candidate cell is measured. If the cell-level RSRP is less than a threshold value, a first message is sent to the first network device. The first message may include indication information indicating that the cell-level RSRP of the at least one candidate cell is less than the threshold value, and / or indication information indicating that the TA of the terminal device is invalid.

23. The communication method according to claim 19 or 20, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the change in RSRP of the reference signal of the at least one candidate cell compared to the current RSRP of the reference signal of the at least one candidate cell is measured. If the change in RSRP of the reference signal exceeds a threshold value, a first message is sent to the first network device. The first message may include indication information indicating that the change in RSRP of the reference signal of the at least one candidate cell exceeds a threshold value, and / or indication information indicating that the TA of the terminal device is invalid.

24. The communication method according to claim 19 or 20, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the RSRP of the reference signal of the at least one candidate cell is measured. If the RSRP of the reference signal is less than a threshold value, a first message is sent to the first network device. The first message may include indication information indicating that the RSRP of the reference signal of the at least one candidate cell is less than the threshold value, and / or indication information indicating that the TA of the terminal device is invalid.

25. The communication method according to any one of claims 19 to 24, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the change in RSRP of the reference signal corresponding to the target beam and the RSRP of the reference signal corresponding to the target beam at the current time is measured. If the change in RSRP exceeds a threshold value, a first message is sent to the first network device. The first message includes indication information for indicating that the target beam of the at least one candidate cell has failed.

26. The communication method according to any one of claims 19 to 24, characterized in that, The step of sending a first message to the first network device based on the second indication information includes: Upon receiving the second indication information, the RSRP of the reference signal corresponding to the target beam is measured. If the RSRP of the reference signal corresponding to the target beam is less than a threshold value, a first message is sent to the first network device. The first message includes indication information for indicating that the target beam of the at least one candidate cell has failed.

27. A communication device, characterized in that, This includes performing the communication method as described in any one of claims 1 to 26.

28. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the communication method as described in any one of claims 1 to 26.

29. A chip, characterized in that, The chip includes a processor connected to a memory for storing computer programs, and the processor is configured to execute the computer programs stored in the memory to cause the chip to perform the communication method as described in any one of claims 1 to 26.

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