CN114586466A

CN114586466A - Communication method and device

Info

Publication number: CN114586466A
Application number: CN202080070902.6A
Authority: CN
Inventors: 李娇娇; 张向东
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2022-06-03
Also published as: WO2021147003A1

Abstract

The application provides a communication method and device, relates to the technical field of communication, and can reduce time delay of terminal equipment accessing to network equipment. The method comprises the following steps: the terminal device determines a first cell. The terminal device determines the second cell. And if the first cell is consistent with the second cell, the terminal equipment ignores the switching command and continues to execute the process of establishing connection with the first network equipment. Wherein the first cell is a cell satisfying the execution condition of the conditional handover, and the second cell is a cell indicated by the handover command. The first network device is a network device corresponding to the first cell.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

In a wireless communication system, when the quality of a wireless link between a terminal device and a source cell is increasingly poor and/or the quality of a wireless link between the terminal device and other cells except the source cell is increasingly good, the terminal device is switched from the source cell to a target cell to ensure the link quality during message transmission between the terminal device and a network device.

For a terminal device configured with a Conditional Handover (CHO) mechanism and a Dual Active Protocol Stack (DAPS) mechanism, if the terminal device first initiates a Random Access Channel (RACH) procedure to a network device corresponding to a cell satisfying an execution condition of the conditional handover, and then receives a Handover (HO) command (command) from a network device corresponding to a source cell, the terminal device stops the RACH procedure between network devices corresponding to cells satisfying the execution condition of the conditional handover, and initiates the RACH procedure between network devices corresponding to cells indicated by the handover command. In the above process, when the cell indicated by the handover command and the cell satisfying the condition for performing the conditional handover are the same cell, unnecessary delay may be introduced.

Disclosure of Invention

The embodiment of the application provides a communication method and device, which can shorten the time for terminal equipment to access a cell and reduce unnecessary time delay.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, an embodiment of the present application provides a communication method, where the method includes: the terminal device determines a first cell. The terminal device determines the second cell. And if the first cell is consistent with the second cell, the terminal equipment continues to execute the process of establishing connection with the first network equipment. That is, if the first cell and the second cell coincide, the terminal device ignores the handover command. The first cell is a cell satisfying the execution condition of the conditional handover, the second cell is a cell indicated by the handover command, and the first network device is a network device corresponding to the first cell.

Therefore, after the terminal equipment receives the switching command, the terminal equipment determines the cell meeting the execution condition of the conditional switching and the cell indicated by the switching command, and under the condition that the cell meeting the execution condition of the conditional switching and the cell indicated by the switching command are consistent, the terminal equipment ignores the switching command and continues to execute the process of establishing connection with the first network equipment, so that the terminal equipment is accessed to the cell indicated by the switching command without re-executing the process of establishing connection with the first network equipment, the time of accessing the cell indicated by the switching command by the terminal equipment is shortened, and unnecessary time delay is reduced.

In one possible design, if the first cell is consistent with the second cell, the terminal device continues to perform a process of establishing a connection with the first network device, where the process includes: and if the first cell is consistent with the second cell and the connection establishment process of the terminal equipment and the first network equipment reaches a first condition, the terminal equipment continues to execute the process of establishing connection with the first network equipment. That is, if the first cell is consistent with the second cell and the connection establishment procedure between the terminal device and the first network device reaches the first condition, the terminal device ignores the handover command. Here, even if the cell indicated by the handover command has the latest configuration information, the terminal device continues to perform the procedure of establishing connection with the first network device to shorten the connection establishment time between the terminal device and the network device. After the connection establishment process is completed, the terminal device can modify the established connection through the connection reconfiguration process, thereby ensuring the quality of the wireless link between the terminal device and the network device.

In one possible design, the communication method according to the embodiment of the present application further includes: and if the first cell is consistent with the second cell and the connection establishment process of the terminal equipment and the first network equipment does not reach the first condition, the terminal equipment re-executes the connection establishment process with the first network equipment according to the switching command. That is, in the case that the connection establishment procedure between the terminal device and the first network device does not reach the first condition, since the cell indicated by the handover command has the latest configuration information, the terminal device re-executes the RACH procedure with the first network device according to the handover command to access the cell indicated by the handover command, thereby securing the quality of the radio link between the terminal device and the network device.

In one possible design, the communication method according to the embodiment of the present application further includes: and if the first cell is inconsistent with the second cell, the terminal equipment executes the process of establishing connection with second network equipment according to the switching command, wherein the second network equipment is the network equipment corresponding to the second cell. Here, since the priority of the handover command is high, in the case where the first cell does not coincide with the second cell, the terminal device preferentially accesses the second cell. And the cell indicated by the switching command is the latest determined cell, and the cell indicated by the switching command has the latest configuration information, so that the reliability of connection between the terminal equipment and the network equipment is guaranteed.

In one possible design, the first cell is a cell to which the connection being established between the terminal device and the first network device corresponds.

In a second aspect, an embodiment of the present application provides a communication method, where the method includes: and the terminal equipment determines a third cell, and if the terminal equipment determines that the connection establishment between the network equipment corresponding to the fourth cell fails, the terminal equipment executes the process of establishing connection with the network equipment corresponding to the third cell. Wherein the third cell is a cell satisfying the execution condition of the conditional handover, and the fourth cell is a cell indicated by the handover command.

That is, the terminal device determines the third cell before determining that the connection setup with the fourth network device has failed. Even if the terminal device determines the third cell, the connection between the network devices corresponding to the third cell is not established immediately, but the terminal device establishes the connection between the network devices corresponding to the third cell (i.e., the third network device) only when the terminal device determines that the connection establishment between the network devices corresponding to the fourth cell (i.e., the fourth network device) fails. After determining that the connection with the fourth network device is failed to be established, the terminal device does not need to determine a cell meeting the execution condition of the conditional handover, but executes a process of establishing connection with the network device corresponding to the third cell (namely, the third network device) based on the determined third cell, so that the time for accessing the cell by the terminal device is shortened, and unnecessary time delay is reduced.

In one possible design, the third cell is one of the cells satisfying the execution condition of the conditional handover except for the fourth cell. Therefore, the terminal equipment removes the fourth cell from the cells meeting the execution condition of the condition switching so as to avoid the process that the terminal equipment executes the connection establishment with the network equipment corresponding to the fourth cell, and correspondingly improve the probability of successful connection establishment, thereby being beneficial to shortening the time for successfully establishing the connection between the terminal equipment and the network equipment and reducing the time delay.

In a possible design, before the terminal device determines that the connection establishment between the network devices corresponding to the fourth cell fails, the communication method in the embodiment of the present application further includes: the terminal device postpones the execution of the process of establishing a connection with the network device corresponding to the third cell. In this way, in the process of establishing the connection between the network device corresponding to the fourth cell, even if the terminal device determines the third cell, the terminal device does not access the third cell, so that the terminal device is ensured to access the cell indicated by the handover command with higher priority, and the link quality between the terminal device and the network device is ensured.

In a possible design, the communication method according to the embodiment of the present application further includes: and the terminal equipment records the time length of the third cell meeting the execution condition of the condition switching. And the duration of the third cell meeting the execution condition of the condition switching is less than or equal to the preset time length. Since the terminal device may be in a moving state, here, the terminal device measures whether the cell satisfies the execution condition of the conditional handover by recording the duration of the third cell satisfying the execution condition of the conditional handover.

In one possible design, the communication method according to the embodiment of the present application further includes: and if the terminal equipment determines that the connection establishment between the network equipment corresponding to the fourth cell fails and the third cell does not exist, the terminal equipment executes the connection reestablishment process of the network equipment corresponding to the target cell. The target cell is a cell determined by the terminal device and is also called a candidate cell.

In this way, when the terminal device determines that the connection establishment between the terminal device and the fourth network device (i.e., the network device corresponding to the fourth cell) fails and the third cell does not exist, the terminal device can also determine the target cell and then perform the connection reestablishment process of the network device corresponding to the target cell, so that the terminal device accesses the network.

In a third aspect, an embodiment of the present application provides a communication apparatus, including: means for performing the steps of any of the above aspects. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the terminal device in the second aspect, or a device including the terminal device.

In a fourth aspect, an embodiment of the present application provides a communication device, which includes a processor and an interface circuit, where the processor is configured to communicate with other devices through the interface circuit and perform the communication method provided in any one of the above aspects. The processor includes one or more. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the terminal device in the second aspect, or a device including the terminal device.

In a fifth aspect, an embodiment of the present application provides a communication apparatus, including a processor, configured to connect to a memory, and configured to call a program stored in the memory to execute the communication method provided in any aspect. The memory may be located within the communication device or external to the communication device. And the processor includes one or more. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the terminal device in the second aspect, or a device including the terminal device.

In a sixth aspect, an embodiment of the present application provides a communication apparatus, including at least one processor and at least one memory, where the at least one processor is configured to execute the communication method provided in any one of the above aspects. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the terminal device in the second aspect, or a device including the terminal device.

In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed on a computer, the computer may execute the communication method of any one of the foregoing aspects.

In an eighth aspect, embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, enable the computer to perform the communication method of any one of the above aspects.

In a ninth aspect, embodiments of the present application provide circuitry comprising processing circuitry configured to perform the communication method of any one of the above aspects.

In a tenth aspect, an embodiment of the present application provides a chip, where the chip includes a processor, a coupling of the processor and a memory, and the memory stores program instructions, and when the program instructions stored in the memory are executed by the processor, the communication method in any one of the above aspects is implemented.

In an eleventh aspect, an embodiment of the present application provides a communication system, which includes a terminal device and a first network device. The terminal device is used for determining the first cell. The first cell is a cell satisfying an execution condition of the conditional handover, and the first network device is a network device corresponding to the first cell. The terminal device is further configured to determine a second cell. Wherein the second cell is the cell indicated by the handover command. The terminal device is further configured to continue to perform a process of establishing a connection with the first network device if the first cell is consistent with the second cell. That is, the terminal device is further configured to ignore the handover command if the first cell is consistent with the second cell.

In one possible design, the terminal device is specifically configured to: and if the first cell is consistent with the second cell and the connection establishment process with the first network equipment reaches the first condition, continuing to execute the process of establishing connection with the first network equipment. That is, the terminal device is specifically configured to: if the first cell is consistent with the second cell and the connection establishment process with the first network equipment reaches the first condition, the switching command is ignored.

In a possible design, the terminal device is further configured to, if the first cell is consistent with the second cell and the connection establishment procedure with the first network device does not reach the first condition, re-execute the procedure of establishing connection with the first network device according to the handover command.

In one possible design, the communication system according to this embodiment further includes a second network device. The second network device is a network device corresponding to the second cell. The terminal device is further configured to execute a process of establishing a connection with the second network device according to the handover command if the first cell is inconsistent with the second cell.

In a twelfth aspect, an embodiment of the present application provides a communication system, where the communication system includes a terminal device, a third network device, and a fourth network device. The terminal device is configured to determine a third cell. The third cell is a cell satisfying the execution condition of the conditional handover, and the third network device is a network device corresponding to the third cell. The terminal device is further configured to perform a procedure of establishing a connection with a fourth network device. The fourth network device is a network device corresponding to the fourth cell. The fourth cell is the cell indicated by the handover command. The terminal device is further configured to execute a process of establishing a connection with the third network device when the connection with the fourth network device fails to be established.

In one possible design, the third network device is a network device corresponding to one of the cells other than the fourth cell in the third cell.

In one possible design, the terminal device is further configured to postpone performing the process of establishing the connection with the third network device before determining that the connection with the fourth network device has failed to be established.

In one possible design, the terminal device is further configured to record a duration for which the third cell satisfies the execution condition of the conditional handover. And the duration of the third cell meeting the execution condition of the condition switching is less than or equal to the preset time length.

In one possible design, the communication system according to this embodiment further includes a fifth network device. The fifth network device is a network device corresponding to the target cell. The terminal device is further configured to execute a connection reestablishment process with the fifth network device if it is determined that the connection establishment with the fourth network device fails and the third cell does not exist. The target cell is the cell determined by the terminal equipment.

For technical effects brought by any one of the design manners in the second aspect to the twelfth aspect, reference may be made to technical effects brought by different design manners in the first aspect, and details are not described herein.

Drawings

Fig. 1 is a schematic flow chart of a cell handover method provided in the related art;

fig. 2 is a schematic flow chart of another cell handover method provided in the related art;

fig. 3 is a schematic flow chart of another cell handover method provided in the related art;

fig. 4 is a schematic diagram of a wireless communication network architecture according to an embodiment of the present application;

fig. 5 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 6 is a flowchart illustrating a random access procedure according to an embodiment of the present application;

fig. 7 is a flowchart illustrating another communication method according to an embodiment of the present application;

fig. 8 is a flowchart illustrating a further communication method according to an embodiment of the present application;

fig. 9 is a flowchart illustrating a further communication method according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 11 is a schematic hardware structure diagram of a communication device according to an embodiment of the present disclosure;

fig. 12 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

The terms "first" and "second" and the like in the description and drawings of the present application are used for distinguishing different objects or for distinguishing different processes for the same object, and are not used for describing a specific order of the objects. Furthermore, the terms "including" and "having," and any variations thereof, as referred to in the description of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

First, technical terms involved in the related art are introduced:

switching:

in a wireless communication system, when a terminal device moves from one cell to another cell, or due to network reasons, adjustment of traffic load, device failure, etc., the terminal device may be handed over from a source cell to a target cell to ensure continuity of communication between the terminal device and the network. The above process is called "handover". The cell accessed by the terminal device before the handover occurs is called a source cell due to the reasons of mobility, network, adjustment of service load, device failure and the like. The cell accessed after the terminal equipment is switched is called a target cell due to the reasons of mobility, network, service load adjustment, equipment failure and the like. In the related art, there are three handover processing methods as follows:

first, conventional Handover (HO)

Referring to fig. 1, the process of the conventional handover includes the following steps:

s100, the terminal device 10 determines a trigger event.

For example, the trigger event may be that the signal quality of the source cell is below a preset value.

S101, the terminal device 10 sends a measurement report to the network device 11. Accordingly, the network device 11 receives the measurement report from the terminal device 10.

The network device 11 is a network device corresponding to the source cell. The measurement report includes information such as the reference signal reception quality of the source cell and the reference signal reception quality of the neighboring cell.

S102, the network device 11 makes a handover decision based on the measurement report and Radio Resource Management (RRM) information, and determines a cell to be accessed.

Wherein, the cell to be accessed is a cell.

S103, the network device 11 sends a request to the network device 12. Accordingly, network device 12 receives a handover request from network device 11.

The network device 12 is a network device corresponding to a cell to be accessed. The handover request is for requesting a handover of a connection between the terminal device 10 and a network device from the network device 11 to one of the network devices 12. The network device 12 determines whether to establish a connection with the terminal device 10 according to the current state of the network device 12, and if so, the corresponding network device 12 executes S104:

s104, the network device 12 sends a handover request Acknowledgement (ACK) to the network device 11. Accordingly, network device 11 receives a handover request acknowledgement from network device 12.

S105, the network device 11 sends a handover command (command) to the terminal device 10. Accordingly, the terminal device 10 receives the handover command from the network device 11.

The handover command includes the configuration information of the cell to be accessed, which is determined in the above S102.

S106, the terminal device 10 releases the connection with the network device 11 according to the handover command. Accordingly, the network device 11 also releases the connection with the terminal device 10.

S107, the terminal device 10 initiates a Random Access Channel (RACH) procedure to the network device corresponding to the target cell according to the handover command. Accordingly, the network device corresponding to the target cell performs the RACH procedure with the terminal device 10.

However, in the above process, two phenomena often occur due to the wireless network: firstly, a measurement report cannot reach network equipment corresponding to a source cell; second, the handover command cannot reach the terminal device 10. Therefore, the connection between the terminal device and the network device is interrupted, and the user experience is affected.

Second, conditional switching (CHO)

In order to avoid the two phenomena, the mobile reliability and robustness of the terminal equipment are improved, and a conditional switching mechanism is introduced. Referring to fig. 2, the process of the conditional switching mechanism includes the following steps:

s201, the terminal device 20 sends a measurement report to the network device 21. Accordingly, the network device 21 receives the measurement report from the terminal device 20.

The network device 21 is a network device corresponding to the source cell.

S202, the network device 21 makes a handover decision of the conditional handover based on the measurement report and the RRM information, and determines a cell to be accessed.

The cell to be accessed may be one cell or a plurality of cells.

S203, the network device 21 sends a handover request to the network device 22. Accordingly, network device 22 receives the handover request from network device 21.

The network device 22 is a network device corresponding to a cell to be accessed. In the case where the cell to be accessed is one cell, the number of network devices 22 is one. In the case where the cell to be accessed is a plurality of cells, the number of the network devices 22 may be one or more. Illustratively, two network devices, network device 22a and network device 22b, are shown in FIG. 2. Each of the plurality of network devices 22 determines whether to establish a connection with the terminal device 20 according to the current state of the network device, and if so, the corresponding network device 22 executes S204:

s204, the network device 22 sends a handover request acknowledgement to the network device 21. Accordingly, network device 21 receives a handover request acknowledgement from network device 22.

Illustratively, referring to fig. 2, network device 22a sends a handover request acknowledgement to network device 21. Accordingly, network device 21 receives a handover request acknowledgement from network device 22 a. Network device 22b sends a handover request acknowledgement to network device 21. Accordingly, network device 21 receives a handover request acknowledgement from network device 22 b.

S205, the network device 21 sends a conditional switch command to the terminal device 20. Accordingly, the terminal device 20 receives the conditional switch command from the network device 21.

Wherein the conditional handover command includes configuration information of the candidate cell and an execution condition of the conditional handover. In the embodiment of the present application, the network device corresponding to the candidate cell has already confirmed to establish connection with the terminal device 20. The execution condition of the conditional switch may be, for example, but not limited to, the following example:

first, the signal quality of the candidate cell is higher than the signal quality of the source cell, and the difference is greater than the threshold.

Second, the signal quality of the source cell is below threshold 1 and the signal quality of the candidate cell is above threshold 2.

In both examples, the signal may be a Synchronization Signal Block (SSB) or a channel state information-reference signal (CSI-RS). In the case of the SSB signal, the signal quality may be a Reference Signal Receiving Power (RSRP), a Reference Signal Receiving Quality (RSRQ), or a reference signal-to-interference plus noise ratio (RS-SINR) of the SSB. In the case where the signal is a CSI-RS, the signal quality may also be RSRP, RSRQ, or RS-SINR of the CSI-RS. The SSB includes Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and a Physical Broadcast Channel (PBCH).

S206, the terminal device 20 evaluates the candidate cells in the conditional handover command according to the execution condition of the conditional handover, and determines the cells that satisfy the execution condition of the conditional handover.

S207, the terminal device 20 initiates a RACH procedure to the network device 22 a. Accordingly, the network device 22a performs a RACH procedure with the terminal device 20.

The network device 22a is a network device corresponding to a cell that satisfies the execution condition of the conditional handover. After the terminal device 20 establishes a connection with one of the network devices 22 (e.g., the network device 22a), Uplink (UL) information and/or Downlink (DL) information may be transmitted through the established connection.

In the above process, the network device pre-configures one or more candidate cells for the terminal device. And the network equipment pre-configures the execution condition of the condition switching for the terminal equipment. After the terminal device determines the cell satisfying the execution condition of the conditional handover, it can initiate the RACH procedure without waiting for receiving a handover command from the network device. Since the above process can be executed before the network condition becomes worse, the possibility of connection interruption between the terminal device and the network device can be reduced, and the successful transmission of the message between the terminal device and the network device can be ensured.

3. Dual active protocol stack handover (DAPS HO)

During a DAPS handover, the terminal device uses two protocol stacks. One protocol stack is used for communicating with the network device corresponding to the source cell, and the other protocol stack is used for communicating with the network device corresponding to the target cell. And the network equipment corresponding to the source cell sends a switching command to the terminal equipment. Correspondingly, the terminal device receives a handover command from the network device corresponding to the source cell. And the cell indicated by the switching command is a target cell to be accessed by the terminal equipment. The terminal device still maintains the connection between the network devices corresponding to the source cell. And simultaneously, the terminal equipment initiates the RACH process to the network equipment corresponding to the target cell indicated by the switching command according to the switching command. After the connection establishment process of the terminal device and the network device corresponding to the target cell is finished, the terminal device releases the connection of the network device corresponding to the source cell. If the switching fails and the connection between the terminal equipment and the network equipment corresponding to the source cell is still available, zero millisecond interruption can be realized.

4. Configuring a conditional handover mechanism and a handover of a DAPS mechanism

In order to reduce the interruption time between the terminal equipment and the network equipment and meet the service requirements of low time delay and high reliability, a wireless communication system introduces a conditional switching mechanism and a DAPS mechanism. Referring to fig. 3, the handover process configured with the conditional handover mechanism and the DAPS mechanism includes the following steps:

s301, the terminal device 30 sends a measurement report to the network device 31. Accordingly, the network device 31 receives the measurement report from the terminal device 30.

The network device 31 is a network device corresponding to the source cell.

S302, the network device 31 makes a handover decision of the conditional handover based on the measurement report and the RRM information, and determines a cell to be accessed.

The cell to be accessed may be one cell or a plurality of cells.

S303, the network device 31 sends a handover request to the network device 32. Accordingly, network device 32 receives a handoff request from network device 31.

The network device 32 is a network device corresponding to a cell to be accessed. In the case where the cell to be accessed is one cell, the number of network devices 32 is one. In the case where the cell to be accessed is a plurality of cells, the number of the network devices 32 may be one or more. Illustratively, fig. 3 shows two network devices 32, namely network device 32a and network device 32 b. Each of the plurality of network devices 32 determines whether to establish a connection with the terminal device 30 according to the current state, and if so, the corresponding network device 32 performs S304:

s304, the network device 32 sends a handover request acknowledgement to the network device 31. Accordingly, network device 31 receives a handover request acknowledgement from network device 32.

Illustratively, referring to fig. 3, network device 32a sends a handover request acknowledgement to network device 31. Accordingly, network device 31 receives a handover request acknowledgement from network device 32 a. Network device 32b sends a handover request acknowledgement to network device 31. Accordingly, network device 31 receives a handover request acknowledgement from network device 32 b.

S305, the network device 31 sends a conditional switch command to the terminal device 30. Accordingly, the terminal device 30 receives the conditional switch command from the network device 31.

Wherein the conditional handover command includes configuration information of the candidate cell and an execution condition of the conditional handover. For the related description of the conditional switch command, reference may be made to the related description of S205, which is not described herein again.

S306, the terminal device 30 evaluates the candidate cells in the conditional handover command according to the execution condition of the conditional handover, and determines the cells meeting the execution condition of the conditional handover.

S307, the terminal device 30 initiates a RACH procedure to the network device 32 a. Accordingly, the RACH procedure is performed between the network device 32a and the terminal device 30.

The network device 32a is a network device corresponding to a cell that satisfies the execution condition of the conditional handover, and is one of the network devices 32 corresponding to the candidate cells. After the connection establishment between the terminal device 30 and the network device 32a is finished, the terminal device 30 executes S308:

and S308, the terminal equipment 30 releases the connection with the network equipment 31. Accordingly, the network device 31 also releases the connection with the terminal device 30.

It should be noted that before the RACH procedure is finished, information transmission is still performed between the terminal device 30 and the network device 31, for example, the terminal device 30 sends uplink information to the network device 31, and the network device 31 sends downlink information to the terminal device 30. After the RACH procedure is ended, information transmission is performed between the terminal device 30 and the network device 32a, such as the terminal device 30 transmitting uplink information to the network device 32a and the network device 32a transmitting downlink information to the terminal device 30. After the RACH procedure is ended, the network device 31 still transmits downlink information to the terminal device 30 before the connection of the terminal device 30 with the network device 32a is released. Accordingly, the terminal device 30 still receives the downlink information from the network device 31. After the connection between the terminal device 30 and the network device 32a is released, no information is transmitted between the network device 31 and the terminal device 30.

In performing the RACH procedure between the terminal device 30 and the network device 32a, since the terminal device 30 remains connected to the network device 31, the network device 31 can still transmit information to the terminal device 30, such as the network device 31 transmitting a handover command to the terminal device 30. Accordingly, the terminal device 30 receives the handover command from the network device 31. Since the priority of the handover command is high, the terminal device 30 stops the RACH procedure between the network devices 32a and initiates the RACH procedure between the network devices corresponding to the cell indicated by the handover command. In the above procedure, when the cell indicated by the handover command is the same cell as the cell in which the terminal device 30 is establishing connection, the terminal device 30 also re-initiates the RACH procedure to the network device 32 a. As such, unnecessary time delays are introduced.

In view of this, an embodiment of the present application provides a communication method, which is applicable to various communication systems. The communication method provided by the embodiment of the application can be applied to a Long Term Evolution (LTE) system, or a fifth-generation (5G) communication network, or other similar networks, or other networks in the future. Fig. 4 is a schematic architecture diagram of a communication system applicable to the communication method according to the embodiment of the present application, and the communication system may include a terminal device 40 and a network device 41. Wherein, the terminal device 40 is wirelessly connected with the network device 41. The number of the terminal devices 40 may be one or more, and the number of the network devices 41 may also be one or more. Only one network device and two terminal devices are shown in fig. 4. In fig. 4, one ellipse represents one cell. Fig. 4 is a schematic diagram only, and does not constitute a limitation to an applicable scenario of the communication method according to the embodiment of the present application.

The terminal device 40, also called User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), etc., is a device for providing voice/data connectivity to a user, for example, a handheld device or a vehicle-mounted device with a wireless connection function. The terminal device may specifically be: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm top computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (smart security), a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), a terminal in a future 5G communication network or a communication network after 5G, and the like, which are not limited by the embodiments of the present invention.

The network device 41 is a device in a wireless communication network, for example, a Radio Access Network (RAN) node that accesses the terminal device 40 to the wireless communication network. Currently, some examples of RAN nodes are: a gbb, a Transmission Reception Point (TRP), an evolved Node B (eNB), a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (e.g., home evolved Node B, or home Node B, HNB), a Base Band Unit (BBU), or a wireless fidelity (Wifi) Access Point (AP), or a network side device in a future 5G communication network or a communication network after 5G, and the like.

The communication system and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation on the technical solution provided in the embodiment of the present application. As can be known to those skilled in the art, with the evolution of network architecture and the emergence of new service scenarios, the technical solution provided in the embodiments of the present application is also applicable to similar technical problems.

The following specifically explains the communication method provided in the embodiment of the present application.

It should be noted that, in the following embodiments of the present application, the names of messages between network elements or the names of parameters in messages, etc. are only examples, and other names may also be used in specific implementations, which are described in a unified manner herein and will not be described again below.

The embodiment of the application provides a communication method, which is applied to a cell switching process. Referring to fig. 5, the communication method includes the steps of:

s501, the terminal device determines a first cell.

Wherein the first cell is a cell satisfying an execution condition of the conditional handover. The first cell may be one cell or a plurality of cells.

For example, the specific implementation process of S501 may refer to the relevant descriptions of S301 to S306, and is not described herein again.

S502, the terminal device executes the process of establishing connection with the first network device.

The first network device is a network device corresponding to the first cell.

Here, if there is one cell that satisfies the execution condition of the conditional handover, the terminal device executes a procedure of establishing a connection with a network device (i.e., a first network device) corresponding to the first cell. If there are multiple cells meeting the execution condition of the conditional switch, the terminal device selects one cell meeting the execution condition of the conditional switch from the multiple cells meeting the execution condition of the conditional switch according to a preset condition or rule, and then executes a process of establishing connection with a network device (i.e., a first network device) corresponding to the cell. That is, in the conditional handover mechanism, after the terminal device determines a cell satisfying the execution condition of the conditional handover, the terminal device always performs a process of establishing a connection with a network device corresponding to one cell to access one cell satisfying the execution condition of the conditional handover.

For example, a contention-based random access procedure is taken as an example to describe a specific implementation procedure of S502. Referring to fig. 6, S502 may be embodied as the following steps:

s5021, the terminal device sends a Random Access Preamble (RAP) to the first network device. Accordingly, the first network device receives the RAP from the terminal device.

Wherein, the RAP is used for requesting to access the first network device. And the first network equipment estimates the transmission delay between the first network equipment and the terminal equipment according to the RAP and allocates transmission resources for the terminal equipment. After that, the first network device performs S5022:

s5022, the first network device sends a Random Access Response (RAR) to the terminal device. Accordingly, the terminal device receives the RAR from the first network device.

Wherein, the RAR at least comprises the following information: the number of RAP, timing adjustment information, uplink resource location indication information allocated for the terminal device, and a cell radio network temporary identifier (C-RNTI) temporarily allocated.

S5023, the terminal device transmits a message 3 to the first network device through the uplink resource indicated by the RAR. Correspondingly, the first network device receives the message 3 from the terminal device through the uplink resource indicated by the RAR.

Wherein the message 3 comprises an identification of the terminal device.

For example, the message 3 may be a Radio Resource Control (RRC) connection request (connection request) or an RRC connection-reestablishment request (connection-update request).

S5024, the first network equipment sends a message 4 to the terminal equipment. Accordingly, the terminal device receives the message 4 from the first network device.

Wherein the message 4 comprises an identification of the terminal device. In the case where the identity of the terminal device in message 4 is identical to the identity of the terminal device in message 3, the terminal device determines that the connection establishment with the first network device is complete.

S503, the terminal device determines a second cell.

Wherein the second cell is the cell indicated by the handover command.

Illustratively, the terminal device receives a handover command from a network device corresponding to the source cell. Wherein the handover command includes a cell identity. The cell identified by the cell identifier is the cell to which the switching command indicates the terminal device to access.

S504, the terminal device determines whether the first cell is consistent with the second cell: if so, the terminal device continues to execute S502, and if not, the terminal device executes S505. If the terminal device continues to execute S502, that is, the terminal device ignores the handover command.

Illustratively, the first cell and the second cell each have a corresponding cell identity. The terminal equipment determines whether the first cell is consistent with the second cell by comparing the cell identification of the first cell with the cell identification of the second cell. And if the cell identifier of the first cell is the same as the cell identifier of the second cell, the terminal equipment determines that the first cell is consistent with the second cell. And if the cell identifier of the first cell is different from the cell identifier of the second cell, the terminal equipment determines that the first cell is inconsistent with the second cell.

Since the priority of the handover command is higher, in the case that the first cell is consistent with the second cell, the cell to which the connection being executed by the terminal device is accessed is the cell to which the handover command received by the terminal device is executed. The terminal device does not need to initiate an RACH procedure to the network device (i.e., the first network device) corresponding to the second cell according to the handover command, and the terminal device continues to execute S502.

In the case where the first cell does not coincide with the second cell, the terminal device executes S505. S505 is specifically explained as follows:

and S505, the terminal equipment executes the process of establishing connection with the second network equipment according to the switching command.

And the second network equipment is the network equipment corresponding to the second cell.

Here, since the priority of the handover command is higher, in the case where the first cell is inconsistent with the second cell, the terminal device preferentially accesses the second cell, and even if the terminal device is accessing the first cell, the terminal device initiates the RACH procedure to the second network device according to the handover command, and S502 is not executed any more. In this way, the terminal device can always access the cell indicated by the handover command with higher priority. And the cell indicated by the switching command is the latest determined cell, and the cell indicated by the switching command has the latest configuration information, so that the reliability of connection between the terminal equipment and the network equipment is guaranteed.

It should be noted that the terminal device may execute S503 in the process of executing S502. Alternatively, the terminal device may perform S503 first and then perform S502.

In the communication method provided by the embodiment of the application, for the terminal device configured with the conditional handover mechanism and the DAPS mechanism, after the terminal device receives the handover command, the terminal device determines the cell meeting the execution condition of the conditional handover and the cell indicated by the handover command, and when the cell meeting the execution condition of the conditional handover and the cell indicated by the handover command are consistent, the terminal device ignores the handover command and continues to execute the process of establishing connection with the first network device, so that the terminal device is accessed to the cell indicated by the handover command without re-executing the process of establishing connection with the first network device, thereby shortening the time for accessing the cell indicated by the handover command by the terminal device and reducing unnecessary time delay.

In some embodiments, in addition to determining whether the "first cell and the second cell are consistent", the terminal device further determines whether a connection establishment procedure of the terminal device and the first network device reaches a first condition to determine whether to continue to perform the procedure of establishing the connection with the first network device. Referring to fig. 7, in the case where the terminal device determines that the first cell coincides with the second cell, the terminal device performs S506:

s506, the terminal device determines whether the connection establishment process with the first network device reaches a first condition: if yes, the terminal device continues to execute S502; if not, the terminal device re-executes S502 according to the handover command.

Exemplarily, in a case where the connection establishment procedure of the terminal device with the first network device is implemented as a RACH procedure, the first condition may be implemented as two examples as follows:

example one, the first condition may be that the terminal device has completed S5022, i.e., the terminal device receives the RAR from the first network device. At this time, the terminal device determines whether the connection establishment procedure with the first network device meets the first condition, which may be implemented as: in a RACH procedure of the terminal device with the first network device, the terminal device determines whether a RAR from the first network device is received. If the terminal device determines that the RAR from the first network device is not received, the terminal device determines that the connection establishment process with the first network device does not reach a first condition; if the terminal device determines that the RAR from the first network device has been received, the terminal device determines that a connection establishment procedure with the first network device has reached a first condition.

Example two, the first condition may also be that the terminal device performs S5023 termination, that is, the terminal device sends message 3 to the first network device. At this time, the determining, by the terminal device, whether the connection establishment procedure with the first network device meets the first condition may be implemented as: in the RACH procedure of the terminal device with the first network device, the terminal device determines whether message 3 is transmitted to the first network device. If the terminal device does not send the message 3 to the first network device or is sending the message 3 to the first network device, the terminal device determines that the connection establishment process with the first network device does not meet a first condition; if the terminal device has sent message 3 to the first network device, the terminal device determines that the connection establishment procedure with the first network device has reached the first condition.

It should be noted that the terminal device may also execute S504 and S506 at the same time. In the case where S504 and S506 are performed simultaneously, there may be four cases as follows:

first, the first cell is consistent with the second cell, and the connection establishment process of the terminal device and the first network device reaches a first condition. In this case, the terminal device continues to execute S502.

Secondly, the first cell is consistent with the second cell, and the connection establishment process of the terminal device and the first network device does not reach the first condition. In this case, the terminal device re-executes S502 according to the handover command.

Thirdly, the first cell is inconsistent with the second cell, and the connection establishment process of the terminal device and the first network device reaches the first condition. In this case, the terminal device executes S505.

Fourthly, the first cell is inconsistent with the second cell, and the connection establishment process of the terminal equipment and the first network equipment does not reach the first condition. In this case, the terminal device executes S505. That is, in the case where the first cell does not coincide with the second cell, the terminal apparatus performs S505.

In this way, in the case where the connection establishment procedure between the terminal device and the first network device has reached the first condition, even if the cell indicated by the handover command has the latest configuration information, the terminal device continues to perform the procedure of establishing a connection with the first network device, so as to shorten the connection establishment time between the terminal device and the network device. After the connection establishment process is completed, the terminal device can modify the established connection through the connection reconfiguration process, thereby ensuring the quality of the wireless link between the terminal device and the network device. Under the condition that the connection establishment process between the terminal equipment and the first network equipment does not reach the first condition, the terminal equipment executes RACH with the first network equipment again according to the switching command because the cell indicated by the switching command has the latest configuration information so as to access the cell indicated by the switching command, and therefore the quality of a wireless link between the terminal equipment and the network equipment is guaranteed.

In addition, in the related art, for the wireless communication system configured with the conditional handover mechanism, after the terminal device receives the conditional handover command from the network device corresponding to the source cell, the terminal device determines the cell satisfying the execution condition of the conditional handover according to the execution condition of the conditional handover in the conditional handover command. If the terminal device receives a handover command from the network device corresponding to the source cell before determining the cell satisfying the execution condition of the conditional handover, the terminal device initiates an RACH procedure to the network device corresponding to the cell indicated by the handover command. In the case that the RACH procedure between the terminal device and the network device corresponding to the cell indicated by the handover command fails, the terminal device still needs to access a new cell, and the manner in which the terminal device accesses the new cell may be, for example, but not limited to, the following three manners:

in the first mode, the terminal device performs a connection reestablishment process. In the connection reestablishment process, unnecessary time delay is introduced in the process of determining a new cell by the terminal equipment. Wherein, the connection reestablishment process is as follows: when the terminal device is in the RRC connection state, the RRC connection reestablishment procedure triggered by the reason of handover failure, radio link failure, and the like includes recovery of a Signaling Radio Bearer (SRB) 1 and secure reactivation of an Access Stratum (AS).

And secondly, the terminal equipment determines a new cell according to the S criterion. The terminal device determines whether the new cell coincides with the candidate cell in the conditional handover command: if so, the terminal equipment executes the switching process of the condition switching; if not, the terminal equipment executes the connection reestablishment process. Since the terminal device determines that the RACH procedure between network devices corresponding to the cell indicated by the handover command has failed (i.e., the terminal device determines that the handover command has failed), the terminal device starts determining a new cell. Thus, the procedure of "terminal device determines new cell" introduces unnecessary delay.

And thirdly, the terminal equipment detects the cells meeting the execution conditions of the condition switching. If the cell meeting the execution condition of the conditional switch exists, the terminal equipment initiates an RACH process to the network equipment corresponding to the cell meeting the execution condition of the conditional switch so that the terminal equipment is accessed to the cell meeting the execution condition of the conditional switch; and if the cell meeting the execution condition of the condition switching does not exist, the terminal equipment executes the connection reestablishment process. Since the terminal device determines that the RACH procedure between network devices corresponding to the cell indicated by the handover command fails (i.e., the terminal device determines that the execution of the handover command fails), the terminal device starts to detect a cell satisfying the execution condition of the conditional handover. Thus, the procedure of "the terminal device determines the cell satisfying the execution condition of the conditional handover", introduces unnecessary time delay.

In the technical solution of the third mode, further, if the cell satisfying the execution condition of the conditional handover and the cell indicated in the handover command are the same cell, the terminal device re-executes the RACH procedure between the network devices corresponding to the cell. In this case, the probability of RACH procedure failure between the terminal device and the network device corresponding to the cell satisfying the condition for executing the condition handover is high, and unnecessary time delay is further introduced, which may easily cause a connection interruption between the terminal device and the network device, thereby affecting user experience.

In view of this, the embodiment of the present application further provides another communication method, referring to fig. 8, the communication method includes the following steps:

s801, the terminal device determines a third cell.

Wherein the third cell is a cell satisfying an execution condition of the conditional handover.

For example, the specific implementation process of S801 may refer to the relevant descriptions of S301 to S306, and is not described herein again.

S802, the terminal device determines that the connection establishment between the terminal device and the fourth network device fails.

The fourth network device is a network device corresponding to a fourth cell, and the fourth cell is a cell indicated by the handover command.

Illustratively, the terminal device receives a handover command from a network device corresponding to the source cell. The handover command includes a cell identity. The cell identified by the cell identifier is the cell to which the switching command indicates the terminal device to access.

And S803, the terminal equipment executes the process of establishing connection with the third network equipment.

And the third network equipment is the network equipment corresponding to the third cell.

Illustratively, the terminal device initiates a RACH procedure to the third network device, and the terminal device establishes a connection with the third network device through the RACH procedure.

It should be noted that, because the priority of the handover command is higher, before the terminal device determines that the connection between the network devices corresponding to the fourth cell is failed to be established and after the cell meeting the execution condition of the conditional handover is determined, the terminal device does not immediately execute the process of establishing the connection with the network device corresponding to the third cell, and the process of establishing the connection with the network device corresponding to the third cell is postponed until the terminal device executes S802, and the terminal device executes S803 based on the third cell. Therefore, the time for the terminal equipment to access a new cell is shortened, and unnecessary time delay is reduced.

In the communication method provided by the embodiment of the present application, the terminal device determines the third cell before determining that the connection with the fourth network device is failed to be established. Even if the terminal device determines the third cell, the process of establishing connection with the network device corresponding to the third cell is not immediately performed, but the terminal device performs the process of establishing connection with the network device corresponding to the third cell (i.e., the third network device) only when the terminal device determines that the connection establishment between the network devices corresponding to the fourth cell (i.e., the fourth network device) fails. That is, the terminal device determines the cell satisfying the execution condition of the conditional handover before the start of the execution of the connection establishment procedure with the fourth network device or in the connection establishment procedure with the fourth network device. After determining that the connection with the fourth network device is failed to be established, the terminal device does not need to determine the cell meeting the execution condition of the conditional handover, but executes the process of establishing the connection with the network device corresponding to the third cell (namely, the third network device) based on the determined third cell, so that the time for accessing the cell by the terminal device is shortened, and unnecessary time delay is reduced.

In some embodiments, the third cell is one of the cells satisfying the execution condition of the conditional handover except for the fourth cell. The specific implementation process of S803 is as follows:

step one, the terminal equipment determines whether the cell meeting the execution condition of the condition switching is consistent with a fourth cell: if yes, the terminal device executes the step two, and if not, the terminal device executes the step three. Wherein, the specific description of the second step and the third step is as follows:

step two: and the terminal equipment executes the process of establishing connection with the network equipment corresponding to one of the cells except the fourth cell in the cells meeting the execution condition of the condition switching.

Illustratively, the number of cells satisfying the condition for executing the conditional handover is three, and the three cells are respectively denoted as cell 1, cell 2, and cell 3. The fourth cell is cell 1. In this case, the terminal device selects one cell from the cells 2 and 3 based on a preset condition or criterion, and then performs a process of establishing a connection with the network device corresponding to the cell. And under the condition that the selected cell is the cell 2, the terminal equipment executes the process of establishing connection with the network equipment corresponding to the cell 2. In the case where the selected cell is the cell 3, the terminal device performs a process of establishing a connection with a network device corresponding to the cell 3.

Step three: the terminal equipment executes the process of establishing connection with the network equipment corresponding to one of the cells meeting the execution condition of the condition switching.

Illustratively, the number of cells satisfying the condition for executing the conditional handover is three, and the three cells are respectively denoted as cell 1, cell 2, and cell 3. The fourth cell is cell 4. In this case, the terminal device selects one cell from the cell 1, the cell 2, and the cell 3, and establishes a connection with the network device corresponding to the cell.

Therefore, the terminal equipment removes the fourth cell from the cells meeting the execution condition of the condition switching so as to avoid the process that the terminal equipment executes the connection establishment with the network equipment corresponding to the fourth cell, and correspondingly improve the probability of successful connection establishment, thereby being beneficial to shortening the time for establishing the connection between the terminal equipment and the network equipment and reducing the time delay.

In some embodiments, the third cell is a cell that satisfies the execution condition of the conditional handover within a preset length of time. Referring to fig. 8, the communication method according to the embodiment of the present application further includes the following steps:

s804, the terminal device records the time length of the third cell meeting the execution condition of the condition switching.

And the time length of the third cell meeting the execution condition of the condition switching is less than or equal to the preset time length. The preset time length may be a time length that is configured for the terminal device in advance by the network device, or a time length that is set by the terminal device according to an actual service requirement.

As a possible implementation manner, after the terminal device executes S801, a timer is started. If the timer is not overtime, the terminal device determines that the cell still meets the execution condition of the conditional handover, that is, the third cell exists. If the timer is overtime, the terminal device determines that the cell no longer meets the execution condition of the conditional switch, that is, the third cell does not exist. Here, the timing duration of the timer is the preset time length.

As another possible implementation manner, after the terminal device executes S801, a timer is started. If the time length recorded by the timer is less than or equal to the preset time length, the terminal device determines that the cell still meets the execution condition of the conditional switch, that is, the third cell exists. If the time length recorded by the timer is longer than the preset time length, the terminal device determines that the cell no longer meets the execution condition of the conditional switch, that is, the third cell does not exist.

Since the terminal device may be in a mobile state, the terminal device records the duration of the third cell meeting the execution condition of the conditional handover to measure whether the cell meets the execution condition of the conditional handover. And under the condition that the duration recorded by the terminal equipment is less than or equal to the preset time length, the terminal equipment determines that the cell meets the execution condition of the conditional switch. And under the condition that the duration recorded by the terminal equipment is longer than the preset time length, the terminal equipment determines that the cell does not meet the execution condition of the condition switching any more.

In some embodiments, in a case that the terminal device determines that the connection establishment between the network devices corresponding to the fourth cell fails and the third cell does not exist, referring to fig. 9, the communication method in this embodiment further includes S805:

and S805, the terminal device executes a connection reestablishment process with the fifth network device.

The fifth network device is a network device corresponding to the target cell, and the target cell is a cell determined by the terminal device.

Here, the specific implementation steps of the connection reestablishment process may refer to the prior art, and are not described herein again.

It should be noted that "the third cell does not exist" includes the following three cases:

in case 1, the terminal device does not find a cell satisfying the execution condition of the conditional handover;

in case 2, the terminal device has found one cell that satisfies the execution condition of the conditional handover, and coincides with the fourth cell.

In case 3, the terminal device has found a cell satisfying the execution condition of the conditional handover, and the recorded duration that the cell satisfies the execution condition of the conditional handover exceeds the preset time length.

In this way, when the terminal device determines that the connection establishment between the terminal device and the fourth network device (i.e., the network device corresponding to the fourth cell) fails and the third cell does not exist, the terminal device can also determine the target cell and then perform the connection reestablishment process of the network device corresponding to the target cell (i.e., the fifth network device), so that the terminal device accesses the network.

The above-mentioned scheme provided by the embodiment of the present application is introduced mainly from the perspective of interaction between network elements. Correspondingly, the embodiment of the present application further provides a communication device, where the communication device may be a network element in the foregoing method embodiment, or a device including the foregoing network element, or a component that can be used for the network element. It is to be understood that the communication device comprises corresponding hardware structures and/or software modules for performing the respective functions in order to realize the above-mentioned functions. Those of skill in the art will readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Fig. 10 shows a schematic structural diagram of a communication apparatus 1000. The communication device 1000 includes a transceiver module 1001 and a processing module 1002.

For example, taking the communication apparatus 1000 as the terminal device in fig. 5 in the above method embodiment as an example,

the processing module 1002 is configured to determine a first cell. Wherein the first cell is a cell satisfying an execution condition of the conditional handover. The processing module 1002 is further configured to determine a second cell. Wherein the second cell is the cell indicated by the handover command. The processing module 1002 is further configured to continue to perform a process of establishing a connection with the first network device if the first cell is consistent with the second cell. That is, the processing module 1002 is further configured to ignore the handover command if the first cell is consistent with the second cell. The first network device is a network device corresponding to the first cell. Illustratively, in the process of establishing a connection with the first network device, the transceiver module 1001 is configured to send a RAP to the first network device, or the transceiver module 1001 is configured to receive a RAR from the first network device.

In one possible design, the processing module 1002 is specifically configured to: and if the first cell is consistent with the second cell and the connection establishment process with the first network equipment reaches a first condition, continuing to establish connection with the first network equipment. That is, the processing module 1002 is specifically configured to: and if the first cell is consistent with the second cell and the connection establishment process with the first network equipment reaches a first condition, ignoring the switching command.

In one possible design, processing module 1002 is further configured to: and if the first cell is consistent with the second cell and the connection establishment process with the first network equipment does not reach the first condition, re-executing the connection establishment process with the first network equipment according to the switching command.

In one possible design, processing module 1002 is further configured to: and if the first cell is inconsistent with the second cell, executing a process of establishing connection with a second network device according to the switching command, wherein the second network device is a network device corresponding to the second cell.

For example, taking the communication apparatus 1000 as the terminal device in fig. 8 in the above method embodiment as an example,

the processing module 1002 is configured to determine a third cell. Wherein the third cell is a cell satisfying an execution condition of the conditional handover. The processing module 1002 is further configured to, if it is determined that the connection between the network devices corresponding to the fourth cell fails to be established, execute a process of establishing a connection with the network device corresponding to the third cell. Wherein the fourth cell is the cell indicated by the handover command. For example, in the process of performing connection establishment with a network device corresponding to a third cell (i.e., a third network device), the transceiver module 1001 is configured to send a RAP to the network device corresponding to the third cell, or the transceiver module 1001 is configured to receive an RAR from the network device corresponding to the third cell.

In one possible design, the processing module 1002 is further configured to postpone performing a procedure of establishing a connection with a network device corresponding to the third cell before determining that the connection establishment between the network devices corresponding to the fourth cell fails.

In one possible design, the processing module 1002 is further configured to record a duration that the third cell satisfies the execution condition of the conditional handover. And the time length of the third cell meeting the execution condition of the condition switching is less than or equal to the preset time length.

In one possible design, the processing module 1002 is further configured to perform a connection reestablishment procedure of the network device corresponding to the target cell if it is determined that the connection establishment between the network devices corresponding to the fourth cell fails and the third cell does not exist. The target cell is the cell determined by the terminal equipment.

All relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

It should be understood that the processing module 1002 in the embodiments of the present application may be implemented by a processor or a processor-related circuit component, and the transceiver module 1001 may be implemented by a transceiver or a transceiver-related circuit component.

As shown in fig. 11, an embodiment of the present application further provides a communication apparatus 1100, where the communication apparatus is implemented as a terminal device, the communication apparatus 1100 includes a processor 1110, a memory 1120 and a transceiver 1130. Wherein the memory 1120 stores instructions or programs, and the processor 1110 is configured to execute the instructions or programs stored in the memory 1120. When the instructions or programs stored in the memory 1120 are executed, the processor 1110 is configured to perform the operations performed by the processing module 1002 in the above embodiment, and the transceiver 1130 is configured to perform the operations performed by the transceiver module 1001 in the above embodiment.

It should be understood that the communication apparatus 1000 or 1100 of the embodiment of the present application may correspond to the terminal device in the communication method of fig. 5 of the embodiment of the present application, and the operation and/or function of each module in the communication apparatus 1000 or 1100 are respectively for realizing the corresponding flow of each method in fig. 5. Alternatively, the communication apparatus 1000 or 1100 according to this embodiment of the present application may correspond to the terminal device in the communication method in fig. 8 according to this embodiment of the present application, and the operation and/or the function of each module in the communication apparatus 1000 or 1100 are respectively to implement the corresponding flow of each method in fig. 8, and are not described herein again for brevity.

When the communication apparatus is a terminal device, fig. 12 shows a schematic structural diagram of a simplified terminal device. For easy understanding and convenience of illustration, in fig. 12, the terminal device is exemplified by a mobile phone. As shown in fig. 12, the terminal device includes a processor, a memory, a radio frequency circuit, an antenna, and an input-output device. The processor is mainly used for processing communication protocols and communication data, controlling the terminal equipment, executing software programs, processing data of the software programs and the like. The memory is used primarily for storing software programs and data. The radio frequency circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user. It should be noted that some kinds of terminal devices may not have input/output devices.

When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs baseband signals to the radio frequency circuit, and the radio frequency circuit performs radio frequency processing on the baseband signals and sends the radio frequency signals to the outside in the form of electromagnetic waves through the antenna. When data is transmitted to the terminal equipment, the radio frequency circuit receives radio frequency signals through the antenna, converts the radio frequency signals into baseband signals and outputs the baseband signals to the processor, and the processor converts the baseband signals into the data and processes the data. For ease of illustration, only one memory and processor are shown in FIG. 12. In an actual end device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be provided independently of the processor, or may be integrated with the processor, which is not limited in this embodiment.

In the embodiment of the present application, the antenna and the radio frequency circuit having the transceiving function may be regarded as a transceiving unit of the terminal device, and the processor having the processing function may be regarded as a processing unit of the terminal device. As shown in fig. 12, the terminal device includes a transceiving unit 1210 and a processing unit 1220. The transceiver unit 1210 may also be referred to as a transceiver, a transceiving device, etc. The processing unit 1220 may also be referred to as a processor, a processing board, a processing module, a processing device, etc. Optionally, a device in the transceiver unit 1210 for implementing a receiving function may be regarded as a receiving unit, and a device in the transceiver unit 1210 for implementing a transmitting function may be regarded as a transmitting unit, that is, the transceiver unit 1210 includes a receiving unit and a transmitting unit. Transceiver unit 1210 may also sometimes be referred to as a transceiver, transceiving circuitry, or the like. A receiving unit may also be referred to as a receiver, a receiving circuit, or the like. A transmitting unit may also sometimes be referred to as a transmitter, or a transmitting circuit, etc.

It should be understood that the transceiving unit 1210 is configured to perform the transmitting operation and the receiving operation on the terminal device side in the above method embodiments, and the processing unit 1220 is configured to perform other operations besides the transceiving operation on the terminal device in the above method embodiments.

For example, in one implementation manner, the transceiver 1210 is configured to perform transceiver operation on the terminal device side in S502 in fig. 5, the transceiver 1210 is further configured to perform transceiver operation on the terminal device side in S505 in fig. 5, and/or the transceiver 1210 is further configured to perform other transceiver steps on the terminal device side in this embodiment. The processing unit 1220 is configured to execute S501, S503, and S504 in fig. 5, and/or the processing unit 1220 is further configured to execute other processing steps on the terminal device side in the embodiment of the present application.

For another example, in another implementation manner, the transceiver 1210 is configured to perform a transmitting operation on the terminal device side in S5021 and S5023 in fig. 6, or a receiving operation on the terminal device side in S5022 and S5024, and/or the transceiver 1210 is further configured to perform other transceiving steps on the terminal device side in this embodiment. The processing unit 1220 is configured to execute other processing steps on the terminal device side in the embodiment of the present application.

For another example, in another implementation manner, the transceiver unit 1210 is configured to perform transceiver operation on the terminal device side in S502 in fig. 7, the transceiver unit 1210 is further configured to perform transceiver operation on the terminal device side in S505 in fig. 7, and/or the transceiver unit 1210 is further configured to perform other transceiver steps on the terminal device side in this embodiment. The processing unit 1220 is configured to execute steps S501, S503, S504, and S506 in fig. 7, and/or the processing unit 1220 is further configured to execute other processing steps on the terminal device side in this embodiment of the present application.

For another example, in another implementation manner, the transceiver unit 1210 is configured to perform transceiver operations on the terminal device side in S803 in fig. 8, and/or the transceiver unit 1210 is further configured to perform other transceiver steps on the terminal device side in the embodiment of the present application. The processing unit 1220 is configured to execute S801, S802, and S804 in fig. 8, and/or the processing unit 1220 is further configured to execute other processing steps on the terminal device side in the embodiment of the present application.

For another example, in another implementation manner, the transceiver unit 1210 is configured to perform transceiver operations on the terminal device side in S805 in fig. 9, and/or the transceiver unit 1210 is further configured to perform other transceiver steps on the terminal device side in the embodiment of the present application. The processing unit 1220 is configured to execute other processing steps on the terminal device side in the embodiment of the present application.

When the communication device is a chip-like device or circuit, the device may comprise a transceiver unit and a processing unit. The transceiver unit may be an input/output circuit and/or a communication interface; the processing unit is an integrated processor or microprocessor or integrated circuit.

When the communication apparatus in the embodiment of the present application is a terminal device, reference may be made to the device shown in fig. 13. As an example, the device may perform functions similar to processor 1110 of FIG. 11. In fig. 13, the apparatus includes a processor 1310, a transmit data processor 1320, and a receive data processor 1330. The processing module 1002 in the above embodiment may be the processor 1310 in fig. 13, and performs the corresponding functions. The transceiver module 1001 in the above embodiments may be the transmit data processor 1320 and/or the receive data processor 1330 in fig. 13. Although fig. 13 shows a channel encoder, a channel decoder, a symbol generation module, and a channel estimation module, it is to be understood that these modules are not intended to limit the embodiments of the present application, but are merely illustrative.

FIG. 14 shows another form of embodiment of the present application. The processing device 1400 includes modules such as a modulation subsystem, a central processing subsystem, and peripheral subsystems. The communication device in the embodiment of the present application may be used as a modulation subsystem therein. In particular, the modulation subsystem may include a processor 1403, an interface 1401. The processor 1403 completes the functions of the processing module 1002, and the interface 1401 completes the functions of the transceiver module 1001. As another variation, the modulation subsystem includes a memory 1402, a processor 1403, and a program stored on the memory 1402 and executable on the processor, and the processor 1403 when executing the program implements the method on the terminal device side in the above method embodiments. It is noted that the memory 1402 may be non-volatile or volatile, and may be located within the modulation subsystem or within the processing device 1400, as long as the memory 1402 is connected to the processor 1403.

As another form of the embodiment of the present application, there is provided a computer-readable storage medium having stored thereon instructions that, when executed, perform the method on the terminal device side in the above-described method embodiment.

As another form of the embodiments of the present application, there is provided a computer program product containing instructions that, when executed, perform the method on the terminal device side in the above-described method embodiments.

When the communication apparatus in this embodiment of the present application is a network device, the network device may be as shown in fig. 15, and the communication apparatus 1500 includes one or more radio frequency units, such as a Remote Radio Unit (RRU) 1510 and one or more baseband units (BBUs) (which may also be referred to as digital units, DUs) 1520. The RRU 1510 may be referred to as a transceiver module, which corresponds to the transceiver module 1001 in fig. 10, and optionally may also be referred to as a transceiver, a transceiver circuit, or a transceiver, which may include at least one antenna 1511 and a radio frequency unit 1512. The RRU 1510 is mainly used for transceiving radio frequency signals and converting the radio frequency signals into baseband signals, for example, for sending a random access response message to a terminal device. The BBU 1510 is mainly used for performing baseband processing, controlling a base station, and the like. The RRU 1510 and the BBU 1520 may be physically disposed together or may be physically disposed separately, i.e., distributed base stations.

The BBU 1520 is a control center of the base station, and may also be referred to as a processing module, and may correspond to the processing module 1002 in fig. 10, and is mainly used for completing baseband processing functions, such as channel coding, multiplexing, modulating, spreading, and the like. For example, the BBU (processing module) may be configured to control the base station to perform an operation procedure related to the network device in the foregoing method embodiment, for example, to generate the foregoing random access response message.

In an example, the BBU 1520 may be formed by one or more boards, and the boards may support a radio access network of a single access system (e.g., an LTE network) together, or may support radio access networks of different access systems (e.g., an LTE network, a 5G network, or other networks) respectively. The BBU 1520 also includes a memory 1521 and a processor 1522. The memory 1521 is used to store necessary instructions and data. The processor 1522 is configured to control the base station to perform necessary actions, for example, to control the base station to execute the operation procedure related to the network device in the foregoing method embodiment. The memory 1521 and the processor 1522 may serve one or more boards. That is, the memory and processor may be provided separately on each board. Multiple boards may share the same memory and processor. In addition, each single board can be provided with necessary circuits.

It should be understood that the processor mentioned in the embodiments of the present application may be a Central Processing Unit (CPU), and may also be other general purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will also be appreciated that the memory referred to in the embodiments of the application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. 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 SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (memory module) is integrated in the processor.

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter associated objects are in an "or" relationship.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a portable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method of communication, comprising:

the communication device determines a first cell; the first cell is a cell satisfying an execution condition of a conditional handover;

the communication device determining a second cell; the second cell is the cell indicated by the handover command;

if the first cell is consistent with the second cell, the communication device continues to execute the process of establishing connection with the first network equipment; the first network device is a network device corresponding to the first cell.
The communication method according to claim 1, wherein if the first cell is consistent with the second cell, the communication apparatus continues to perform the procedure of establishing a connection with a first network device, and includes:

and if the first cell is consistent with the second cell and the connection establishment process of the communication device and the first network equipment reaches a first condition, the communication device continues to execute the process of establishing connection with the first network equipment.
The communication method of claim 2, wherein the method further comprises:

and if the first cell is consistent with the second cell and the connection establishment process of the communication device and the first network equipment does not reach a first condition, the communication device re-executes the connection establishment process with the first network equipment according to the switching command.
A communication method according to any of claims 1 to 3, characterized in that the method further comprises:

and if the first cell is inconsistent with the second cell, the communication device executes a process of establishing connection with a second network device according to the switching command, wherein the second network device is a network device corresponding to the second cell.
The communication method according to any one of claims 1 to 4, wherein the first cell is a cell to which a connection between the communication apparatus and the first network device is being established.
A method of communication, comprising:

the communication apparatus determines a third cell, which is a cell satisfying an execution condition of the conditional handover;

and if the communication device determines that the connection establishment between the network equipment corresponding to a fourth cell fails, the communication device executes a process of establishing connection with the network equipment corresponding to the third cell, wherein the fourth cell is the cell indicated by the handover command.
The communication method according to claim 6, wherein the third cell is one of the cells satisfying the condition for performing the conditional handover except for the fourth cell.
The communication method according to claim 6 or 7, wherein before the communication apparatus determines that the connection establishment between the network devices corresponding to the fourth cell fails, the method further comprises:

the communication apparatus postpones performing a procedure of establishing a connection with a network device corresponding to the third cell.
The communication method according to any one of claims 6 to 8, characterized in that the method further comprises:

the communication device records the time length of the third cell meeting the execution condition of the conditional switch;

wherein a duration of the third cell meeting the execution condition of the conditional handover is less than or equal to a preset time length.
A communication method according to any one of claims 6 to 9, characterized in that the method further comprises:

if the communication device determines that the connection establishment between the network equipment corresponding to the fourth cell fails and the third cell does not exist, the communication device executes a connection reestablishment process of the network equipment corresponding to the target cell;

wherein the target cell is a cell determined by the communication device.
A communications apparatus, comprising: means for performing the steps of any of claims 1 to 5.
A communications apparatus, comprising: a processor for invoking a program in a memory for performing the communication method of any of claims 1 to 5.
A communications apparatus, comprising: a processor and an interface circuit for communicating with other devices, the processor being configured to perform the communication method of any one of claims 1 to 5.
A communications apparatus, comprising: means for performing the steps of any of claims 6 to 10.
A communications apparatus, comprising: a processor for invoking a program in a memory for performing the communication method of any one of claims 6 to 10.
A communications apparatus, comprising: a processor and an interface circuit for communicating with other devices, the processor being configured to perform the communication method of any one of claims 6 to 10.
A computer-readable storage medium characterized in that the computer-readable storage medium stores a program that when called by a processor, the communication method of any one of claims 1 to 5 is executed, or the communication method of any one of claims 6 to 10 is executed.
A computer program, characterized in that a communication method according to any one of claims 1 to 5 is executed or a communication method according to any one of claims 6 to 10 is executed when the program is called by a processor.
A communication system, comprising: a communication device and a first network apparatus;

the communication device is configured to determine a first cell; the first cell is a cell meeting the execution condition of conditional handover, and the first network device is a network device corresponding to the first cell;

the communications apparatus further configured to determine a second cell; the second cell is the cell indicated by the handover command;

the communication device is further configured to continue to perform a process of establishing a connection with the first network device if the first cell is consistent with the second cell.
The communication system according to claim 19, wherein the communication device is specifically configured to: and if the first cell is consistent with the second cell and the connection establishment process with the first network equipment reaches a first condition, continuing to execute the process of establishing connection with the first network equipment.
The communication system of claim 20,

the communication device is further configured to, if the first cell is consistent with the second cell and the connection establishment procedure with the first network device does not reach the first condition, re-execute the procedure of establishing connection with the first network device according to the handover command.
The communication system according to any of claims 19 to 21, characterized in that the system further comprises: a second network device; the second network device is a network device corresponding to the second cell;

the communication device is further configured to execute a process of establishing a connection with the second network device according to the handover command if the first cell is inconsistent with the second cell.
The communication system according to any of claims 19 to 22, wherein the first cell is a cell to which the connection between the first network device and the communication apparatus is being established.
A communication system, comprising: a communication device, a third network device and a fourth network device;

the communication apparatus is configured to determine a third cell, where the third cell is a cell that satisfies an execution condition of a conditional handover, and the third network device is a network device corresponding to the third cell;

the communication device is further configured to perform a process of establishing a connection with a fourth network device; the fourth network device is a network device corresponding to a fourth cell; the fourth cell is the cell indicated by the handover command;

the communication device is further configured to execute a process of establishing a connection with the third network device when it is determined that the connection with the fourth network device fails to be established.
The communication system according to claim 24, wherein the third network device is a network device corresponding to one of the cells except the fourth cell in the third cell.
The communication system according to claim 24 or 25,

the communication device is further configured to postpone performing a procedure of establishing a connection with the third network device before determining that the connection with the fourth network device has failed to be established.
The communication system according to any of the claims 24 to 26,

the communication device is further configured to record a duration that the third cell meets the execution condition of the conditional handover;

wherein a duration of the third cell meeting the execution condition of the conditional handover is less than or equal to a preset time length.
The communication system according to any of claims 24 to 27, wherein the system further comprises: a fifth network device; the fifth network device is a network device corresponding to a target cell, and the target cell is a cell determined by the communication apparatus;

the communication device is further configured to execute a connection reestablishment procedure with the fifth network device if the communication device determines that the connection establishment with the fourth network device fails and the third cell does not exist.