WO2021147003A1

WO2021147003A1 - Communication method and apparatus

Info

Publication number: WO2021147003A1
Application number: PCT/CN2020/073827
Authority: WO
Inventors: 李娇娇; 张向东
Original assignee: 华为技术有限公司
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2021-07-29
Also published as: CN114586466A

Abstract

Provided are a communication method and apparatus. The method and apparatus relate to the technical field of communications, and can reduce the delay for a terminal device to access a network device. The method comprises: a terminal device determining a first cell; the terminal device determining a second cell; and if the first cell is consistent with the second cell, the terminal device ignoring a handover command, and continuing to execute the process of establishing a connection with a first network device, wherein the first cell is a cell that satisfies an execution condition of conditional handover, and 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.

Description

Communication method and device

Technical field

This application relates to the field of communication technology, and in particular to a communication method and device.

Background technique

In a wireless communication system, when the quality of the wireless link between the terminal device and the source cell gets worse, and/or the quality of the wireless link between the terminal device and other cells other than the source cell gets better, The terminal device switches from the source cell to the target cell to ensure the link quality during message transmission between the terminal device and the 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 moves to the network device corresponding to the cell that meets the execution conditions of the conditional handover Initiate a random access channel (RACH) process, and then receive a handover (HO) command (command) from the network device corresponding to the source cell, and the terminal device stops corresponding to the cell that meets the execution conditions of the conditional handover RACH process between network devices, and initiate the RACH process between network devices corresponding to the cell indicated by the handover command. In the above process, when the cell indicated by the handover command and the cell meeting the execution condition of the conditional handover are the same cell, unnecessary time delay may be introduced.

Summary of the invention

The embodiments of the present application provide a communication method and device, which can shorten the time for a terminal device to access a cell and reduce unnecessary time delay.

In order to achieve the foregoing objectives, the following technical solutions are adopted in the embodiments of this application:

In the first aspect, an embodiment of the present application provides a communication method. The method includes: a terminal device determines a first cell. The terminal device determines the second cell. If the first cell is consistent with the second cell, the terminal device continues to perform the process of establishing a connection with the first network device. That is to say, if the first cell is consistent with the second cell, the terminal device ignores the handover command. The first cell is a cell that meets the execution condition of the conditional handover, the second cell is the cell indicated by the handover command, and the first network device is a network device corresponding to the first cell.

In this way, after the terminal device receives the handover command, the terminal device determines the cell that satisfies the execution conditions of the conditional handover and the cell indicated by the handover command. If the two are consistent, the terminal device ignores the handover command and continues to execute with the first network The process of equipment connection establishment so that the terminal equipment can access the cell indicated by the handover command without re-executing the process of establishing a connection with the first network device, thereby shortening the time for the terminal equipment to access the cell indicated by the handover command and reducing unnecessary Time delay.

In a possible design, if the first cell is consistent with the second cell, the terminal device continues to perform the process of establishing a connection with the first network device, including: if the first cell is consistent with the second cell, and the terminal device is consistent with the second cell When the connection establishment process of a network device reaches the first condition, the terminal device continues to execute the process of establishing a connection with the first network device. That is, if the first cell and the second cell are consistent, and the connection establishment process 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 process 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.

In a possible design, the communication method of the embodiment of the present application further includes: if the first cell is consistent with the second cell, and the connection establishment process between the terminal device and the first network device does not meet the first condition, the terminal device according to the handover Command to re-execute the process of establishing a connection with the first network device. That is to say, in the case that the connection establishment process between the terminal device and the first network device does not meet the first condition, since the cell indicated by the handover command has the latest configuration information, the terminal device re-executes the connection with the first network device according to the handover command. The RACH process of the network equipment is to access the cell indicated by the handover command, thereby ensuring the quality of the wireless link between the terminal equipment and the network equipment.

In a possible design, the communication method of the embodiment of the present application further includes: if the first cell is inconsistent with the second cell, the terminal device executes the process of establishing a connection with the second network device according to the handover command, and the second network device is Network equipment corresponding to the second cell. Here, since the priority of the handover command is relatively high, in the case where the first cell and the second cell are inconsistent, the terminal device preferentially accesses the second cell. In addition, the cell indicated by the handover command is the newly determined cell, and the cell indicated by the handover command has the latest configuration information, thereby ensuring the reliability of the connection between the terminal device and the network device.

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

In a second aspect, an embodiment of the present application provides a communication method. The method includes: a terminal device determines a third cell, and if the terminal device determines that a connection between a network device corresponding to the fourth cell fails to be established, the terminal device executes a communication with the network device corresponding to the fourth cell. The process in which network devices corresponding to the three cells establish a connection. Among them, the third cell is a cell that meets the execution condition of the conditional handover, and the fourth cell is the cell indicated by the handover command.

That is, the terminal device determines the third cell before determining that the connection establishment with the fourth network device fails. Even if the terminal equipment determines the third cell, the connection between the network equipment corresponding to the third cell is not immediately established, but the terminal equipment determines the network equipment corresponding to the fourth cell (that is, the fourth network equipment). Only when the connection establishment fails, the terminal device establishes a connection with the network device corresponding to the third cell (that is, the third network device). After determining that the connection establishment with the fourth network device fails, the terminal device does not need to determine the cell that meets the execution conditions of the conditional handover, but executes the network device corresponding to the third cell based on the determined third cell (ie The third network device) establishes a connection process, thereby shortening the time for the terminal device to access the cell and reducing unnecessary time delay.

In a possible design, the third cell is one of the cells other than the fourth cell among the cells that meet the execution conditions of the conditional handover. In this way, the terminal device first removes the fourth cell from the cells that meet the execution conditions of the conditional handover, so as to prevent the terminal device from performing the process of establishing a connection with the network device corresponding to the fourth cell, and accordingly increase the probability of successful connection establishment. This helps to shorten the time for the terminal device to successfully establish a connection with the network device and reduce the time delay.

In a possible design, before the terminal device determines that the connection establishment between the network device corresponding to the fourth cell fails, the communication method of the embodiment of the present application further includes: the terminal device postpones the establishment of the network device corresponding to the third cell The process of connecting. In this way, when the terminal device determines the connection establishment process between the network devices corresponding to the fourth cell, even if the terminal device determines the third cell, the terminal device does not access the third cell, thereby ensuring that the terminal device has a higher access priority. The cell indicated by the high handover command to ensure the link quality between the terminal equipment and the network equipment.

In a possible design, the communication method of the embodiment of the present application further includes: the terminal device records the length of time that the third cell satisfies the execution condition of the conditional handover. Wherein, the length of time that the third cell satisfies the execution condition of the conditional handover is less than or equal to the preset time length. Since the terminal device may be in a mobile state, here, the terminal device can measure whether the cell meets the execution condition of the conditional handover by recording the length of time that the third cell satisfies the execution condition of the conditional handover.

In a possible design, the communication method of the embodiment of the present application further includes: if the terminal device determines that the connection establishment between the network device corresponding to the fourth cell fails, and the third cell does not exist, then the terminal device performs a communication with the target cell The connection re-establishment process of the corresponding network device. Among them, 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 with the fourth network device (ie, 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 execute the connection with the target cell. The connection re-establishment process of the network equipment corresponding to the cell enables the terminal equipment to access the network.

In a third aspect, an embodiment of the present application provides a communication device, the communication device including: a unit for executing each step in any of the foregoing aspects. The communication device may be the terminal device in the foregoing first aspect, or a device including the foregoing terminal device; or, the communication device may be the terminal device in the foregoing second aspect, or a device including the foregoing terminal device.

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

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

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

In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium that stores instructions in the computer-readable storage medium, and when it runs on a computer, the computer can execute any one of the above-mentioned communications. method.

In an eighth aspect, embodiments of the present application provide a computer program product containing instructions, which when run on a computer, enable the computer to execute the communication method of any one of the foregoing aspects.

In a ninth aspect, an embodiment of the present application provides a circuit system, the circuit system includes a processing circuit, and the processing circuit is configured to execute the communication method according to any one of the foregoing aspects.

In a tenth aspect, an embodiment of the present application provides a chip. The chip includes a processor, and the processor is coupled to a memory. The memory stores program instructions. When the program instructions stored in the memory are executed by the processor, any one of the above aspects is implemented. Communication method.

In an eleventh aspect, an embodiment of the present application provides a communication system. The communication system includes a terminal device and a first network device. The terminal device is used to determine the first cell. The first cell is a cell that meets the execution condition of the conditional handover, and the first network device is a network device corresponding to the first cell. The terminal device is also used to determine the second cell. Among them, the second cell is the cell indicated by the handover command. The terminal device is further configured to continue to perform the 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 also used to ignore the handover command if the first cell is consistent with the second cell.

In a possible design, 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 device has reached the first condition, continue to perform the connection establishment with the first network device the process of. That is to say, the terminal device is specifically configured to ignore the handover command if the first cell is consistent with the second cell, and the connection establishment process with the first network device has reached the first condition.

In a possible design, the terminal device is also used for if the first cell is consistent with the second cell, and the connection establishment process with the first network device does not meet the first condition, then according to the handover command, re-execute the connection with the first network The process by which a device establishes a connection.

In a possible design, the communication system in the embodiment of the present application further includes a second network device. The second network device is a network device corresponding to the second cell. The terminal device is also configured to perform a process of establishing a connection with the second network device according to the handover command if the first cell is not consistent with the second cell.

In a twelfth aspect, an embodiment of the present application provides a communication system, which includes a terminal device, a third network device, and a fourth network device. The terminal device is used to determine the third cell. The third cell is a cell that meets 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 also used to perform the process of establishing a connection with the 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 also used to execute the process of establishing a connection with the third network device when the connection with the fourth network device fails to be established.

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

In a possible design, the terminal device is also used to postpone the process of establishing a connection with the third network device before determining that the connection establishment with the fourth network device fails.

In a possible design, the terminal device is also used to record the length of time that the third cell satisfies the execution condition of the conditional handover. Wherein, the length of time that the third cell satisfies the execution condition of the conditional handover is less than or equal to the preset time length.

In a possible design, the communication system in the embodiment of the present application 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 perform a connection re-establishment 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. Among them, the target cell is a cell determined by the terminal device.

Among them, the technical effects brought about by any of the design methods in the second aspect to the twelfth aspect can be referred to the technical effects brought about by the different design methods in the first aspect, which will not be repeated here.

Description of the drawings

Figure 1 is a schematic flow chart of a cell handover method provided by related technologies;

Figure 2 is a schematic flowchart of another cell handover method provided by related technologies;

FIG. 3 is a schematic flowchart of another cell handover method provided by related technologies;

FIG. 4 is a schematic diagram of a wireless communication network architecture provided by an embodiment of this application;

FIG. 5 is a schematic flowchart of a communication method provided by an embodiment of this application;

FIG. 6 is a schematic flowchart of a random access process provided by an embodiment of this application;

FIG. 7 is a schematic flowchart of another communication method provided by an embodiment of this application;

FIG. 8 is a schematic flowchart of yet another communication method provided by an embodiment of this application;

FIG. 9 is a schematic flowchart of yet another communication method provided by an embodiment of this application;

FIG. 10 is a schematic structural diagram of a communication device provided by an embodiment of this application;

FIG. 11 is a schematic diagram of the hardware structure of a communication device provided by an embodiment of this application;

FIG. 12 is a schematic structural diagram of another communication device provided by an embodiment of this application;

FIG. 13 is a schematic structural diagram of another communication device provided by an embodiment of this application;

FIG. 14 is a schematic structural diagram of another communication device provided by an embodiment of this application;

FIG. 15 is a schematic structural diagram of another communication device provided by an embodiment of this application.

Detailed ways

The terms "first" and "second" in the description of the application and the drawings are used to distinguish different objects, or to distinguish different processing of the same object, rather than describing a specific order of the objects. In addition, the terms "including" and "having" and any variations thereof mentioned in the description of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units that are not listed, or optionally also Including other steps or units inherent to these processes, methods, products or equipment. In the embodiments of the present application, words such as "exemplary" or "for example" are used as examples, illustrations, or illustrations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferable or advantageous than other embodiments or design solutions. To be precise, words such as "exemplary" or "for example" are used to present related concepts in a specific manner.

First, introduce the technical terms involved in related technologies:

Switch:

In a wireless communication system, when a terminal device moves from one cell to another, or due to network reasons, business load adjustments, equipment failures, etc., the terminal device may switch from the source cell to the target cell to protect the terminal equipment and the network Continuity of communication between. The above process is called "handover". Among them, the cell that the terminal device accessed before the handover occurs due to reasons such as movement, network reasons, service load adjustment, equipment failure, etc., is called the source cell. The cell that the terminal device accesses after handover due to reasons such as movement, network reasons, business load adjustment, equipment failure, etc., is called the target cell. In related technologies, there are the following three handover processing methods:

The first, conventional handover (handover, HO)

Referring to Figure 1, the conventional handover process includes the following steps:

S100. The terminal device 10 determines a trigger event.

Exemplarily, the trigger event may be that the signal quality of the source cell is lower than a preset value.

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

Among them, the network device 11 is a network device corresponding to the source cell. The measurement report includes information such as the receiving quality of the reference signal of the source cell and the receiving quality of the reference signal 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 the cell to be accessed.

Among them, the cell to be accessed is a cell.

S103. The network device 11 sends a switching request (request) to the network device 12. Correspondingly, the network device 12 receives the handover request from the network device 11.

Among them, the network device 12 is a network device corresponding to the cell to be accessed. The switching request is used to request to switch the connection between the terminal device 10 and the network device from the network device 11 to a network device 12. The network device 12 determines whether to establish a connection with the terminal device 10 according to its current state, and if so, the corresponding network device 12 executes S104:

S104. The network device 12 sends a handover request acknowledgement (acknowledgement, ACK) to the network device 11. Correspondingly, the network device 11 receives the handover request confirmation from the network device 12.

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

Wherein, the handover command includes the configuration information of the cell to be accessed determined in S102.

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

S107. The terminal device 10 initiates a random access (RACH) process to the network device corresponding to the target cell according to the handover command. Correspondingly, the network equipment corresponding to the target cell and the terminal equipment 10 execute the RACH process.

However, in the above process, due to wireless network reasons, two phenomena often occur: first, the measurement report cannot reach the network device corresponding to the source cell; second, the handover command cannot reach the terminal device 10. In this way, the connection between the terminal device and the network device is interrupted, which affects the user experience.

The second type, conditional handover (CHO)

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

S201. The terminal device 20 sends a measurement report to the network device 21. Correspondingly, the network device 21 receives the measurement report from the terminal device 20.

Among them, the network device 21 is a network device corresponding to the source cell.

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

Among them, the cell to be accessed may be one cell or multiple cells.

S203: The network device 21 sends a handover request to the network device 22. Correspondingly, the network device 22 receives the handover request from the network device 21.

Among them, the network device 22 is a network device corresponding to the 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 multiple cells, the number of network devices 22 may be one or multiple. Exemplarily, two network devices are shown in FIG. 2, namely, a network device 22a and a network device 22b. Each of the multiple 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 confirmation to the network device 21. Correspondingly, the network device 21 receives the handover request confirmation from the network device 22.

Exemplarily, referring to FIG. 2, the network device 22a sends a handover request confirmation to the network device 21. Correspondingly, the network device 21 receives the handover request confirmation from the network device 22a. The network device 22b sends a handover request confirmation to the network device 21. Correspondingly, the network device 21 receives the handover request confirmation from the network device 22b.

S205: The network device 21 sends a condition switching command to the terminal device 20. Correspondingly, the terminal device 20 receives the condition switching command from the network device 21.

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

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 lower than the threshold 1, and the signal quality of the candidate cell is higher than the threshold 2.

In the above two examples, the signal may be a synchronization signal block (synchronization signal block, SSB) or a channel state information reference signal (channel state information-reference signals, CSI-RS). When the signal is SSB, the signal quality can be the reference signal receiving power (RSRP) of the SSB, the reference signal receiving quality (RSRQ), or the reference signal signal-to-interference and noise ratio (reference signal-to-noise ratio). signal to interference plus noise ratio, RS-SINR). When the signal is a CSI-RS, the signal quality can also be RSRP, RSRQ, or RS-SINR of the CSI-RS. Among them, SSB includes primary synchronization signals (PSS), secondary synchronization signals (SSS), and physical broadcast channels (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 a cell that meets the execution condition of the conditional handover.

S207: The terminal device 20 initiates a RACH process to the network device 22a. Correspondingly, the RACH process is executed between the network device 22a and the terminal device 20.

Among them, 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 (such as the network device 22a), it can transmit uplink (UL) information and/or downlink (downlink, DL) Information.

In the above process, the network device pre-configures one or more candidate cells for the terminal device. In addition, the network device pre-configures the execution condition of the condition switch for the terminal device. After the terminal device determines the cell that meets the execution condition of the conditional handover, it can initiate the RACH process without waiting to receive the handover command from the network device. Since the above process can be performed before the network condition becomes worse, the possibility of interruption of the connection between the terminal device and the network device can be reduced, and the successful message transmission between the terminal device and the network device can be ensured.

3. Dual active protocol stack handover (dual active protocol stack handover, DAPS HO)

During the DAPS handover, the terminal device uses two protocol stacks. Among them, one protocol stack is used to communicate with the network device corresponding to the source cell, and the other protocol stack is used to communicate with the network device corresponding to the target cell. The network device corresponding to the source cell sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from the network device corresponding to the source cell. The cell indicated by the handover command is the target cell to be accessed by the terminal device. The terminal equipment still maintains the connection between the network equipment corresponding to the source cell. At the same time, the terminal equipment initiates the RACH process to the network equipment corresponding to the target cell indicated by the handover command according to the handover command. The terminal device releases the connection of the network device corresponding to the source cell only after the process of establishing the connection between the terminal device and the network device corresponding to the target cell is completed. If the handover 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 achieved.

4. Switch between configuration condition switching mechanism and DAPS mechanism

In order to reduce the interruption time between the terminal equipment and the network equipment, and meet the business requirements of low delay and high reliability, the wireless communication system introduces a conditional switching mechanism and a DAPS mechanism. Referring to Figure 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. Correspondingly, the network device 31 receives the measurement report from the terminal device 30.

Among them, the network device 31 is a network device corresponding to the source cell.

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

Among them, the cell to be accessed may be one cell or multiple cells.

S303. The network device 31 sends a handover request to the network device 32. Correspondingly, the network device 32 receives the switching request from the network device 31.

Among them, the network device 32 is a network device corresponding to the 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 multiple cells, the number of network devices 32 may be one or multiple. Illustratively, FIG. 3 shows two network devices 32, namely a network device 32a and a network device 32b. Each of the multiple 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 executes S304:

S304. The network device 32 sends a handover request confirmation to the network device 31. Correspondingly, the network device 31 receives the handover request confirmation from the network device 32.

Exemplarily, referring to FIG. 3, the network device 32a sends a handover request confirmation to the network device 31. Correspondingly, the network device 31 receives the handover request confirmation from the network device 32a. The network device 32b sends a handover request confirmation to the network device 31. Correspondingly, the network device 31 receives the handover request confirmation from the network device 32b.

S305. The network device 31 sends a condition switching command to the terminal device 30. Correspondingly, the terminal device 30 receives the condition switching command from the network device 31.

Among them, the conditional handover command includes the configuration information of the candidate cell and the execution condition of the conditional handover. For the related description of the conditional switching command, please refer to the related introduction of S205, which will not be repeated here.

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 a cell that meets the execution condition of the conditional handover.

S307. The terminal device 30 initiates a RACH process to the network device 32a. Correspondingly, the RACH process is executed between the network device 32a and the terminal device 30.

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

S308: The terminal device 30 releases the connection with the network device 31. Correspondingly, the network device 31 also releases the connection with the terminal device 30.

It should be noted that before the end of the RACH process, the terminal device 30 and the network device 31 are still transmitting information. 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. information. After the RACH process ends, information transmission is performed between the terminal device 30 and the network device 32a. For example, the terminal device 30 sends uplink information to the network device 32a, and the network device 32a sends downlink information to the terminal device 30. After the RACH process ends and before the connection between the terminal device 30 and the network device 32a is released, the network device 31 still sends downlink information to the terminal device 30. Correspondingly, 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, the network device 31 and the terminal device 30 no longer transmit information.

During the RACH process between the terminal device 30 and the network device 32a, since the terminal device 30 is still connected to the network device 31, the network device 31 can still send information to the terminal device 30, for example, the network device 31 sends a switching command to the terminal device 30 . Correspondingly, the terminal device 30 receives the switching command from the network device 31. Since the priority of the handover command is higher, the terminal device 30 stops the RACH process between the network devices 32a, and initiates the RACH process between the network devices corresponding to the cell indicated by the handover command. In the above process, when the cell indicated by the handover command and the cell where the terminal device 30 is establishing a connection are the same cell, the terminal device 30 also re-initiates the RACH process to the network device 32a. In this way, unnecessary time delay is introduced.

In view of this, the embodiment of the present application provides a communication method, and the communication method of the embodiment of the present application is applicable to various communication systems. The communication method provided in the embodiments of the present 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 structural diagram of a communication system applicable to the communication method of the embodiment of the present application. The communication system may include a terminal device 40 and a network device 41. Among them, the terminal device 40 and the network device 41 are wirelessly connected. The number of terminal devices 40 may be one or more, and the number of network devices 41 may also be one or more. Figure 4 shows only one network device and two terminal devices. In Figure 4, an ellipse represents a cell. FIG. 4 is only a schematic diagram, and does not constitute a limitation on the application scenario of the communication method of the embodiment of the present application.

The terminal device 40, also known as user equipment (UE), mobile station (MS), mobile terminal (MT), etc., is a device that provides users with voice/data connectivity, such as , Handheld devices or vehicle-mounted devices with wireless connectivity. The terminal equipment can specifically be: mobile phone (mobile phone), tablet computer, notebook computer, palm computer, mobile internet device (mobile internet device, MID), wearable device, virtual reality (virtual reality, VR) device, augmented reality (augmented) Reality (AR) equipment, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, and wireless terminals in smart grids Terminals, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes, terminal devices in future 5G communication networks or communication networks after 5G And so on, the embodiment of the present invention does not limit this.

The network device 41 is a device in a wireless communication network, for example, a radio access network (RAN) node that connects the terminal device 40 to the wireless communication network. At present, some examples of RAN nodes are: gNB, transmission reception point (TRP), evolved Node B (evolved Node B, eNB), radio network controller (RNC), Node B (Node B) B, NB), base station controller (BSC), base transceiver station (BTS), home base station (for example, home evolved NodeB, or home Node B, HNB), baseband unit (base Band unit, BBU), or wireless fidelity (Wifi) access point (AP), or network side equipment in the future 5G communication network or communication network after 5G, etc.

The communication systems and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art knows that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems.

The communication method provided by the embodiment of the present application will be described in detail below.

It should be noted that the name of the message between each network element or the name of each parameter in the message in the following embodiments of the present application is just an example, and other names may also be used in specific implementations, which are explained here in a unified manner and will not be described below. Go into details.

The embodiment of the present application provides a communication method, which is applied in a cell handover process. Referring to Figure 5, the communication method includes the following steps:

S501: The terminal device determines the first cell.

Among them, the first cell is a cell that satisfies the execution condition of the conditional handover. The first cell may be one cell or multiple cells.

Exemplarily, for the specific implementation process of S501, please refer to the relevant descriptions of S301 to S306, which will not be repeated here.

S502: The terminal device executes a process of establishing a connection with the first network device.

Wherein, the first network device is a network device corresponding to the first cell.

Here, if there is one cell that meets the execution condition of the conditional handover, the terminal device executes the process of establishing a connection with the network device corresponding to the first cell (that is, the first network device). If there are multiple cells that meet the execution conditions of the conditional handover, the terminal device selects a cell that meets the execution conditions of the conditional handover from the multiple cells that meet the execution conditions of the conditional handover according to preset conditions or rules, and then executes it. The process of establishing a connection with the network device (that is, the first network device) corresponding to the cell. That is to say, in the conditional handover mechanism, after the terminal device determines the cell that meets the execution condition of the conditional handover, the terminal device always executes the process of establishing a connection with the network device corresponding to a cell to access an execution condition that meets the conditional handover. Of the cell.

Exemplarily, a contention-based random access process is taken as an example to describe the specific implementation process of S502. Referring to Figure 6, S502 can be specifically implemented as the following steps:

S5021. The terminal device sends a random access preamble (random access preamble, RAP) to the first network device. Correspondingly, the first network device receives the RAP from the terminal device.

Among them, RAP is used to request access to the first network device. The first network device estimates the transmission delay between itself and the terminal device according to the RAP, and allocates transmission resources for the terminal device. After that, the first network device executes S5022:

S5022. The first network device sends a random access response (random access response, RAR) to the terminal device. Correspondingly, the terminal device receives the RAR from the first network device.

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

S5023: The terminal device transmits the 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.

Among them, message 3 includes the identification of the terminal device.

Exemplarily, the message 3 may be a radio resource control (radio resource control, RRC) link establishment request (connection request), or an RRC connection re-establishment request (connection re-establishment request).

S5024. The first network device sends a message 4 to the terminal device. Correspondingly, the terminal device receives the message 4 from the first network device.

Among them, the message 4 includes the identification of the terminal device. In the case that the identification of the terminal device in the message 4 is consistent with the identification of the terminal device in the message 3, the terminal device determines that the establishment of the connection with the first network device is completed.

S503: The terminal device determines the second cell.

Among them, the second cell is the cell indicated by the handover command.

Exemplarily, the terminal device receives a handover command from a network device corresponding to the source cell. Among them, the handover command includes the cell identity. The cell identified by the cell identifier is the cell to be accessed by the terminal device instructed by the handover command.

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

Exemplarily, the first cell and the second cell have corresponding cell identifiers. The terminal device compares the cell identity of the first cell with the cell identity of the second cell to determine whether the first cell is consistent with the second cell. If the cell identity of the first cell is the same as the cell identity of the second cell, the terminal device determines that the first cell is consistent with the second cell. If the cell identity of the first cell is different from the cell identity of the second cell, the terminal device determines that the first cell is inconsistent with the second cell.

Since the priority of the handover command is higher, when the first cell is consistent with the second cell, the cell accessed by the connection being executed by the terminal device is the cell on which the handover command received by the terminal device is executed. The terminal device does not need to initiate the RACH process to the network device corresponding to the second cell (ie, the first network device) according to the handover command, and the terminal device can continue to perform S502.

In the case that the first cell is not consistent with the second cell, the terminal device executes S505. The specific description of S505 is as follows:

S505: The terminal device executes a process of establishing a connection with the second network device according to the handover command.

Wherein, the second network device is a network device corresponding to the second cell.

Here, due to the high priority of the handover command, in the case where the first cell and the second cell are inconsistent, the terminal device preferentially accesses the second cell. Even if the terminal device is accessing the first cell, the terminal device will give priority to The second network device initiates the RACH process and does not perform S502 any more. In this way, the terminal device can always access the cell indicated by the handover command with a higher priority. In addition, the cell indicated by the handover command is the newly determined cell, and the cell indicated by the handover command has the latest configuration information, thereby ensuring the reliability of the connection between the terminal device and the network device.

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

For the communication method provided by the embodiments of the present application, for a terminal device configured with a conditional handover mechanism and a DAPS mechanism, after the terminal device receives a handover command, the terminal device determines the cell that meets the execution condition of the conditional handover and the cell indicated by the handover command In the cell, when the two are the same, the terminal device ignores the handover command and continues to perform the process of establishing a connection with the first network device, so that the terminal device can access the cell indicated by the handover command without re-executing the connection with the first network device The process of establishing a connection can shorten the time for the terminal device to access the cell indicated by the handover command and reduce unnecessary time delay.

In some embodiments, in addition to determining "whether the first cell is consistent with the second cell", the terminal device also determines "whether the connection establishment process between the terminal device and the first network device meets the first condition" to determine whether Continue to perform the process of establishing a connection with the first network device. Referring to FIG. 7, in a case where the terminal device determines that the first cell is consistent with the second cell, the terminal device executes S506:

S506: The terminal device determines whether the connection establishment process with the first network device meets the first condition: if so, the terminal device continues to execute S502; if not, the terminal device re-executes S502 according to the switching command.

Exemplarily, when the connection establishment process between the terminal device and the first network device is implemented as a RACH process, the first condition may be implemented as the following two examples:

Example 1: The first condition may be that the terminal device has completed S5022, that is, the terminal device has received the RAR from the first network device. At this time, the terminal device determines whether the process of establishing a connection with the first network device meets the first condition, which can be implemented as follows: in the RACH process between the terminal device and the first network device, the terminal device determines whether the terminal device has received the communication from the first network device. RAR. If the terminal device determines that it has not received the RAR from the first network device, the terminal device determines that the connection establishment process with the first network device does not meet the first condition; if the terminal device determines that it has received the RAR from the first network device, then The terminal device determines that the connection establishment process with the first network device has reached the first condition.

Example 2: The first condition may also be that the terminal device executes S5023 to end, that is, the terminal device sends message 3 to the first network device. At this time, the terminal device determines whether the connection establishment process with the first network device meets the first condition, which can be implemented as: in the RACH process between the terminal device and the first network device, the terminal device determines whether a message is sent to the first network device 3. If the terminal device has not sent message 3 to the first network device, or is sending message 3 to the first network device, the terminal device determines that the connection establishment process with the first network device has not reached the first condition; When the network device sends message 3, the terminal device determines that the connection establishment process with the first network device has reached the first condition.

It should be noted that the terminal device can also execute S504 and S506 at the same time. In the case of executing S504 and S506 at the same time, there can be the following four situations:

First, the first cell is consistent with the second cell, and the connection establishment process between the terminal device and the first network device has reached the first condition. In this case, the terminal device continues to execute S502.

Second, the first cell is consistent with the second cell, and the connection establishment process between the terminal device and the first network device does not meet the first condition. In this case, the terminal device re-executes S502 according to the switching command.

Third, the first cell is not consistent with the second cell, and the connection establishment process between the terminal device and the first network device has reached the first condition. In this case, the terminal device executes S505.

Fourth, the first cell is not consistent with the second cell, and the connection establishment process between the terminal device and the first network device does not meet the first condition. In this case, the terminal device executes S505. That is, in the case where the first cell and the second cell are not consistent, the terminal device executes S505.

In this way, when the connection establishment process 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 establish a connection with the first network device To shorten the connection establishment time between terminal equipment and network equipment. 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 the case that the connection establishment process between the terminal device and the first network device does not meet the first condition, since the cell indicated by the handover command has the latest configuration information, the terminal device re-executes the RACH with the first network device according to the handover command, By accessing the cell indicated by the handover command, the quality of the wireless link between the terminal device and the network device is guaranteed.

In addition, in the related art, for a wireless communication system configured with a conditional switching mechanism, after the terminal device receives the conditional switching command from the network device corresponding to the source cell, the terminal device determines the execution condition of the conditional switching in the conditional switching command. The cell that meets the execution conditions of the conditional handover. If the terminal device receives the handover command from the network device corresponding to the source cell before determining the cell that meets the execution condition of the conditional handover, the terminal device initiates the RACH process to the network device corresponding to the cell indicated by the handover command. In the case that the RACH process 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. The terminal device accesses the new cell in such a way as but not limited to the following three Ways:

Method 1: The terminal device performs the connection re-establishment process. During the connection re-establishment process, the process of "the terminal equipment determines a new cell" introduces unnecessary time delay. Among them, the connection re-establishment process refers to the RRC connection re-establishment process triggered by handover failure, radio link failure, etc. when the terminal device is in the RRC connection state, including the restoration of signaling radio bearers (SRB) 1, And the safe reactivation of the access stratum (AS).

Method 2: The terminal device determines a new cell according to the S criterion. The terminal device determines whether the new cell is consistent with the candidate cell in the conditional switching command: if it is, the terminal device executes the handover process of conditional switching; if not, the terminal device executes the connection re-establishment process. Since the terminal device determines that the RACH process between the network devices corresponding to the cell indicated by the handover command fails (that is, the terminal device determines that the execution of the handover command fails), the terminal device starts to determine a new cell. In this way, the process of "the terminal equipment determines a new cell" introduces unnecessary time delay.

Manner 3: The terminal device detects the cell that meets the execution condition of the conditional handover. If there is a cell that satisfies the execution condition of the conditional handover, the terminal device initiates the RACH process to the network device corresponding to the cell that satisfies the execution condition of the conditional handover, so that the terminal device can access the cell that satisfies the execution condition of the conditional handover; If the cell of the conditional handover is executed, the terminal device executes the connection re-establishment process. After the terminal device determines that the RACH process between the network devices corresponding to the cell indicated by the handover command fails (that is, the terminal device determines that the execution of the handover command fails), the terminal device starts to detect the cell that meets the execution condition of the conditional handover. In this way, the process of "the terminal device determines the cell that meets the execution condition of the conditional handover" introduces unnecessary time delay.

In the technical solution of the third manner, further, if the cell meeting 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 process between the network devices corresponding to the cell. In this case, the probability of failure of the RACH process between the terminal equipment and the network equipment corresponding to the cell that meets the execution conditions of the conditional handover is relatively high, which further introduces unnecessary delays and easily leads to the communication between the terminal equipment and the network equipment. The connection is interrupted, which affects the user experience.

In view of this, the embodiment of the present application also provides another communication method. Referring to FIG. 8, the communication method includes the following steps:

S801. The terminal device determines the third cell.

Among them, the third cell is a cell that satisfies the execution condition of the conditional handover.

Exemplarily, for the specific implementation process of S801, please refer to the relevant descriptions of S301 to S306, which will not be repeated here.

S802. The terminal device determines that the establishment of the connection with the fourth network device fails.

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

Exemplarily, the terminal device receives a handover command from a network device corresponding to the source cell. The handover command includes the cell identification. The cell identified by the cell identifier is the cell to be accessed by the terminal device instructed by the handover command.

S803: The terminal device executes a process of establishing a connection with the third network device.

Wherein, the third network device is a network device corresponding to the third cell.

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

It should be noted that, due to the high priority of the handover command, the terminal device does not immediately determine that the connection between the network device corresponding to the fourth cell fails and the cell that satisfies the execution condition of the conditional handover. The process of establishing a connection with a network device corresponding to the third cell is performed, and the process of establishing a connection with a network device corresponding to the third cell is postponed until the terminal device performs S802, and the terminal device performs S803 based on the third cell. In this way, the time for the terminal equipment to access the 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 establishment with the fourth network device fails. Even if the terminal device determines the third cell, it does not immediately perform the process of establishing a connection with the network device corresponding to the third cell. Instead, the terminal device determines the network device corresponding to the fourth cell (that is, the fourth network device). Only when the connection establishment fails, the terminal device performs the process of establishing a connection with the network device corresponding to the third cell (that is, the third network device). That is, the terminal device determines the cell that meets the execution condition of the conditional handover before the process of establishing the connection with the fourth network device starts, or during the process of establishing the connection with the fourth network device. After determining that the connection establishment with the fourth network device fails, the terminal device does not need to determine the cell that meets the execution conditions of the conditional handover, but executes the network device corresponding to the third cell based on the determined third cell (ie The third network device) establishes a connection process, thereby shortening the time for the terminal device to access the cell and reducing unnecessary time delay.

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

Step 1: The terminal device determines whether the cell that meets the execution condition of the conditional handover is consistent with the fourth cell: if so, the terminal device performs step two, and if not, the terminal device performs step three. Among them, the specific instructions of step two and step three are as follows:

Step 2: The terminal device executes a process of establishing a connection with a network device corresponding to one of the cells other than the fourth cell among the cells that meet the execution condition of the conditional handover.

Exemplarily, there are three cells that meet the execution conditions of the conditional handover, which are denoted as cell 1, cell 2, and cell 3, respectively. The fourth cell is cell 1. In this case, the terminal device selects a cell from cell 2 and cell 3 based on preset conditions or criteria, and then executes the process of establishing a connection with the network device corresponding to the cell. In the case that the selected cell is cell 2, the terminal device performs a process of establishing a connection with the network device corresponding to cell 2. In the case where the selected cell is cell 3, the terminal device performs a process of establishing a connection with the network device corresponding to cell 3.

Step 3: The terminal device executes a process of establishing a connection with a network device corresponding to one of the cells that meet the execution condition of the conditional handover.

Exemplarily, there are three cells that meet the execution conditions of the conditional handover, which are denoted as cell 1, cell 2, and cell 3, respectively. The fourth cell is cell 4. In this case, the terminal device selects a cell from cell 1, cell 2, and cell 3, and then establishes a connection with the network device corresponding to the cell.

In this way, the terminal device first removes the fourth cell from the cells that meet the execution conditions of the conditional handover, so as to prevent the terminal device from performing the process of establishing a connection with the network device corresponding to the fourth cell, and accordingly increase the probability of successful connection establishment. This helps to shorten the time for establishing a connection between the terminal device and the network device and reduce 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 length of time that the third cell satisfies the execution condition of the conditional handover.

Wherein, the length of time that the third cell satisfies the execution condition of the conditional handover is less than or equal to the preset time length. The preset time length may be a time length configured by the network device for the terminal device in advance, or may be a time length set by the terminal device according to actual service requirements.

As a possible implementation manner, the terminal device starts a timer after executing S801. If the timer does not expire, the terminal device determines that the cell still satisfies the execution condition of the conditional handover, that is, the third cell exists. If the timer expires, the terminal device determines that the cell no longer meets the execution condition of the conditional handover, that is, the third cell does not exist. Here, the timing duration of the timer is the aforementioned preset duration.

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

Since the terminal device may be in a mobile state, the terminal device can measure whether the cell meets the execution condition of the conditional handover by recording the length of time that the third cell satisfies the execution condition of the conditional handover. In the case that the time length recorded by the terminal device is less than or equal to the preset time length, the terminal device determines that the cell satisfies the execution condition of the conditional handover. In the case that the time length recorded by the terminal device is greater than the preset time length, the terminal device determines that the cell no longer satisfies the execution condition of the conditional handover.

In some embodiments, when the terminal device determines that the connection establishment between the network device corresponding to the fourth cell fails, and the third cell does not exist, referring to FIG. 9, the communication method according to the embodiment of the present application further includes S805:

S805: The terminal device executes a connection re-establishment 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 re-establishment process can refer to the prior art, which will not be repeated here.

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

Case 1: The terminal device does not find a cell that meets the execution conditions of the conditional handover;

Case 2: The terminal device has found a cell that satisfies the execution condition of the conditional handover and is consistent with the fourth cell.

Case 3: The terminal device has found a cell that satisfies the execution condition of the conditional handover, and the recorded time 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 with the fourth network device (ie, 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 execute the connection with the target cell. The connection re-establishment process of the network device corresponding to the cell (that is, the fifth network device) enables the terminal device to access the network.

The foregoing mainly introduces the solutions provided by the embodiments of the present application from the perspective of interaction between various network elements. Correspondingly, an embodiment of the present application also provides a communication device. The communication device may be the network element in the foregoing method embodiment, or a device including the foregoing network element, or a component that can be used for a network element. It can be understood that, in order to realize the above-mentioned functions, the communication device includes hardware structures and/or software modules corresponding to each function. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

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

For example, taking the communication device 1000 as the terminal device in FIG. 5 in the foregoing method embodiment as an example,

Then the processing module 1002 is used to determine the first cell. Among them, the first cell is a cell that satisfies the execution condition of the conditional handover. The processing module 1002 is also used to determine the second cell. Among them, the second cell is the cell indicated by the handover command. The processing module 1002 is further configured to continue to perform the process of establishing a connection with the first network device if the first cell is consistent with the second cell. In other words, the processing module 1002 is also configured to ignore the handover command if the first cell is consistent with the second cell. Wherein, the first network device is a network device corresponding to the first cell. Exemplarily, during the process of establishing a connection with the first network device, the transceiver module 1001 is used to send an RAP to the first network device, or the transceiver module 1001 is used to receive an RAR from the first network device.

In a possible design, the processing module 1002 is specifically configured to continue to establish a connection with the first network device if the first cell is consistent with the second cell and the connection establishment process with the first network device reaches the first condition. That is, the processing module 1002 is specifically configured to: if the first cell is consistent with the second cell, and the connection establishment process with the first network device reaches the first condition, then the handover command is ignored.

In a possible design, the processing module 1002 is further configured to: if the first cell is consistent with the second cell, and the connection establishment process with the first network device does not meet the first condition, then according to the handover command, re-execute the connection with the second cell. A process in which a network device establishes a connection.

In a possible design, the processing module 1002 is further configured to: if the first cell is inconsistent with the second cell, execute the process of establishing a connection with the second network device according to the handover command, and the second network device corresponds to the second cell Network equipment.

For example, taking the communication device 1000 as the terminal device in FIG. 8 in the foregoing method embodiment as an example,

Then the processing module 1002 is used to determine the third cell. Among them, the third cell is a cell that satisfies the execution condition of the conditional handover. The processing module 1002 is further configured to, if it is determined that the connection establishment between the network equipment corresponding to the fourth cell fails, execute a process of establishing a connection with the network equipment corresponding to the third cell. Among them, the fourth cell is the cell indicated by the handover command. Exemplarily, in the process of performing the connection establishment of the network device corresponding to the third cell (that is, the third network device), the transceiver module 1001 is used to send RAP to the network device corresponding to the third cell, or the transceiver module 1001 is used to Receive the RAR from the network device corresponding to the third cell.

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

In a possible design, the processing module 1002 is also used to record the length of time that the third cell satisfies the execution condition of the conditional handover. Wherein, the length of time that the third cell satisfies the execution condition of the conditional handover is less than or equal to the preset time length.

In a possible design, the processing module 1002 is further configured to perform connection reconstruction of the network device corresponding to the target cell if it is determined that the connection establishment between the network device corresponding to the fourth cell fails and the third cell does not exist. Process. Among them, the target cell is a cell determined by the terminal device.

Among them, all relevant content of the steps involved in the above method embodiments can be cited in the functional description of the corresponding functional module, which will not be repeated here.

It should be understood that the processing module 1002 in the embodiment 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 device 1100. When the communication device is implemented as a terminal device, the communication device 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 used to perform the operations performed by the processing module 1002 in the foregoing embodiment, and the transceiver 1130 is used to perform the operations performed by the transceiver module 1001 in the foregoing embodiment.

It should be understood that the communication device 1000 or the communication device 1100 of the embodiment of the present application may correspond to the terminal device in the communication method of FIG. 5 in the embodiment of the present application, and the operation and/or function of each module in the communication device 1000 or the communication device 1100 Respectively in order to achieve the corresponding process of each method in FIG. 5. Alternatively, the communication device 1000 or the communication device 1100 in the embodiment of the present application may correspond to the terminal device in the communication method of FIG. 8 in the embodiment of the present application, and the operations and/or functions of the respective modules in the communication device 1000 or the communication device 1100 are respectively In order to realize the corresponding process of each method in FIG. 8, for the sake of brevity, details are not repeated here.

When the communication device is a terminal device, FIG. 12 shows a simplified schematic diagram of the structure of the terminal device. It is easy to understand and easy to illustrate. In FIG. 12, the terminal device uses a mobile phone as an example. As shown in Figure 12, the terminal equipment includes a processor, a memory, a radio frequency circuit, an antenna, and an input and output device. The processor is mainly used to process the communication protocol and communication data, and to control the terminal device, execute the software program, and process the data of the software program. The memory is mainly used to store software programs and data. The radio frequency circuit is mainly used for the conversion of baseband signals and radio frequency signals and the processing of radio frequency signals. The antenna is mainly used to send and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are mainly used to receive data input by users and output data to users. It should be noted that some types of terminal devices may not have input and output devices.

When data needs to be sent, the processor performs baseband processing on the data to be sent, and then outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and sends the radio frequency signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor, and the processor converts the baseband signal into data and processes the data. For ease of description, only one memory and processor are shown in FIG. 12. In an actual terminal 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 storage device. The memory may be set independently of the processor, or may be integrated with the processor, which is not limited in the embodiment of the present application.

In the embodiments of the present application, the antenna and radio frequency circuit with the transceiving function can be regarded as the transceiving unit of the terminal device, and the processor with the processing function can be regarded as the processing unit of the terminal device. As shown in FIG. 12, the terminal device includes a transceiver unit 1210 and a processing unit 1220. The transceiving unit 1210 may also be referred to as a transceiver, a transceiver, a transceiving device, and so on. The processing unit 1220 may also be referred to as a processor, a processing board, a processing module, a processing device, and the like. Optionally, the device for implementing the receiving function in the transceiver unit 1210 can be regarded as the receiving unit, and the device for implementing the sending function in the transceiver unit 1210 as the sending unit, that is, the transceiver unit 1210 includes a receiving unit and a sending unit. The transceiving unit 1210 may also be called a transceiver, a transceiver, or a transceiving circuit or the like. The receiving unit may sometimes be called a receiver, a receiver, or a receiving circuit. The transmitting unit may sometimes be called a transmitter, a transmitter, or a transmitting circuit.

It should be understood that the transceiving unit 1210 is used to perform sending and receiving operations on the terminal device side in the foregoing method embodiment, and the processing unit 1220 is used to perform other operations on the terminal device in the foregoing method embodiment except for the transceiving operation.

For example, in an implementation manner, the transceiving unit 1210 is used to perform the transceiving operation on the terminal device side in S502 in FIG. 5, and the transceiving unit 1210 is also used to perform the transceiving operation on the terminal device side in S505 in FIG. 5, and/ Or the transceiving unit 1210 is also used to perform other transceiving steps on the terminal device side in the embodiment of the present application. The processing unit 1220 is configured to execute S501, S503, and S504 in FIG. 5, and/or the processing unit 1220 is also 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 the sending operation on the terminal device side in S5021 and S5023 in FIG. 6, or the receiving operation on the terminal device side in S5022 and S5024, and/or the transceiver unit 1210 also It is used to perform other transceiving 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.

For another example, in another implementation manner, the transceiving unit 1210 is used to perform the transceiving operation on the terminal device side in S502 in FIG. 7, and the transceiving unit 1210 is also used to perform the transceiving operation on the terminal device side in S505 in FIG. 7. And/or the transceiving unit 1210 is also configured to perform other transceiving steps on the terminal device side in the embodiment of the present application. The processing unit 1220 is configured to execute S501, S503, S504, and S506 in FIG. 7, and/or the processing unit 1220 is also 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 transceiving unit 1210 is used to perform the transceiving operations on the terminal device side in S803 in FIG. 8, and/or the transceiving unit 1210 is also used to perform other operations on the terminal device side in the embodiment of the present application. Send and receive steps. The processing unit 1220 is configured to execute S801, S802, and S804 in FIG. 8, and/or the processing unit 1220 is also 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 transceiving unit 1210 is used to perform the transceiving operations on the terminal device side in S805 in FIG. 9, and/or the transceiving unit 1210 is also used to perform other operations on the terminal device side in the embodiment of the present application. Send and receive steps. 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-type device or circuit, the device may include a transceiver unit and a processing unit. Wherein, the transceiving 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 device in the embodiment of the present application is a terminal device, the device shown in FIG. 13 may be referred to. As an example, the device can perform functions similar to the processor 1110 in FIG. 11. In FIG. 13, the device includes a processor 1310, a data sending processor 1320, and a data receiving processor 1330. The processing module 1002 in the foregoing embodiment may be the processor 1310 in FIG. 13 and completes corresponding functions. The transceiver module 1001 in the foregoing embodiment may be the sending data processor 1320 and/or the receiving 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 can be understood that these modules do not constitute a restrictive description of the embodiment of the present application, and are merely illustrative.

Figure 14 shows another form of an embodiment of the present application. The processing device 1400 includes modules such as a modulation subsystem, a central processing subsystem, and a peripheral subsystem. The communication device in the embodiment of the present application may be used as the modulation subsystem therein. Specifically, the modulation subsystem may include a processor 1403 and an interface 1401. Among them, the processor 1403 completes the function of the aforementioned processing module 1002, and the interface 1401 completes the function of the aforementioned transceiver module 1001. As another variation, the modulation subsystem includes a memory 1402, a processor 1403, and a program stored in the memory 1402 and running on the processor. When the processor 1403 executes the program, the terminal device side in the foregoing method embodiment is implemented. Methods. It should be noted that the memory 1402 can be non-volatile or volatile, and its location can be located inside the modulation subsystem or in the processing device 1400, as long as the memory 1402 can be connected to the The processor 1403 is sufficient.

As another form of the embodiment of the present application, a computer-readable storage medium is provided, and an instruction is stored thereon. When the instruction is executed, the method on the terminal device side in the foregoing method embodiment is executed.

As another form of the embodiments of the present application, a computer program product containing instructions is provided, and when the instructions are executed, the method on the terminal device side in the foregoing method embodiment is executed.

When the communication device in the embodiment of the present application is a network device, the network device may be as shown in FIG. 15. The communication device 1500 includes one or more radio frequency units, such as a remote radio unit (RRU) 1510 and one or Multiple baseband units (BBU) (also referred to as digital units, DU) 1520. The RRU 1510 may be called a transceiver module, which corresponds to the transceiver module 1001 in FIG. 10. Optionally, the transceiver module may also be called a transceiver, a transceiver circuit, or a transceiver, etc., which may include at least one antenna 1511和RF unit 1512. The RRU 1510 part is mainly used for receiving and sending radio frequency signals and converting radio frequency signals and baseband signals, for example, for sending random access response messages to terminal devices. The 1510 part of the BBU is mainly used to perform baseband processing, control the base station, and so on. The RRU 1510 and the BBU 1520 may be physically set together, or may be physically separated, that is, a distributed base station.

The BBU 1520 is the control center of the base station, and may also be called a processing module, which may correspond to the processing module 1002 in FIG. 10, and is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, and spreading. For example, the BBU (processing module) may be used to control the base station to execute the operation procedure of 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 composed of one or more single boards, and multiple single boards may jointly support a radio access network (such as an LTE network) of a single access standard, or support different access standards. Wireless access network (such as LTE network, 5G network or other networks). 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 used to control the base station to perform necessary actions, for example, to control the base station to execute the operation procedure of the network device in the foregoing method embodiment. The memory 1521 and the processor 1522 may serve one or more single boards. In other words, the memory and the processor can be set separately on each board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits can be provided on each board.

It should be understood that the processor mentioned in the embodiments of this application may be a central processing unit (central processing unit, CPU), or other general-purpose processors, digital signal processors (digital signal processors, DSP), and application-specific integrated circuits ( application specific integrated circuit (ASIC), ready-made programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.

It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory can be read-only memory (ROM), programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), and electrically available Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory. The volatile memory may be random access memory (RAM), which is used as an external cache. By way of exemplary but not restrictive description, many forms of RAM are available, such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), and synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous connection dynamic random access memory (synchlink DRAM, SLDRAM) ) And direct memory bus random access memory (direct rambus RAM, DR RAM).

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

It should be noted that the memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

It should be understood that the term "and/or" in this text is only an association relationship describing the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, and both A and B exist. , There are three cases of B alone. In addition, the character "/" in this text generally indicates that the associated objects before and after are in an "or" relationship.

It should be understood that in the various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not correspond to the embodiments of the present application. The implementation process constitutes any limitation.

A person of ordinary skill in the art may realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments of the present application.

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

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other media that can store program code .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

A communication method, characterized in that it comprises:

The communication device determines a first cell; the first cell is a cell that satisfies the execution condition of the conditional handover;

The communication device determines the 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 perform the process of establishing a connection with the first network device; 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 device continues to perform the process of establishing a connection with the first network device, comprising:

If the first cell is consistent with the second cell, and the connection establishment process between the communication device and the first network device reaches the first condition, the communication device continues to perform the establishment with the first network device The process of connecting.
The communication method according to claim 2, wherein the method further comprises:

If the first cell is consistent with the second cell, and the process of establishing a connection between the communication device and the first network device does not meet the first condition, the communication device re-executes the connection according to the handover command. The process of establishing a connection by the first network device.
The communication method according to any one of claims 1 to 3, wherein the method further comprises:

If the first cell and the second cell are inconsistent, the communication device executes a process of establishing a connection with a second network device according to the handover command, and the second network device is corresponding to the second cell Internet equipment.
The communication method according to any one of claims 1 to 4, wherein the first cell is a cell corresponding to a connection being established between the communication apparatus and the first network device.
A communication method, characterized in that it comprises:

The communication device determines a third cell, where the third cell is a cell that satisfies the conditional handover condition handover execution condition;

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

The communication apparatus postpones the execution of the process of establishing a connection with the network device corresponding to the third cell.
The communication method according to any one of claims 6 to 8, wherein the method further comprises:

The communication device records the length of time that the third cell satisfies the execution condition of the conditional handover;

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

If the communication apparatus determines that the connection establishment between the network equipment corresponding to the fourth cell fails, and the third cell does not exist, the communication apparatus executes the connection re-establishment process of the network equipment corresponding to the target cell;

Wherein, the target cell is a cell determined by the communication device.
A communication device, characterized by comprising: a unit for executing each step of any one of claims 1 to 5.
A communication device, characterized by comprising: a processor for calling a program in a memory to execute the communication method according to any one of claims 1 to 5.
A communication device, characterized by comprising: a processor and an interface circuit, the interface circuit is used to communicate with other devices, and the processor is used to execute the communication method according to any one of claims 1 to 5.
A communication device, characterized by comprising: a unit for executing each step of any one of claims 6 to 10.
A communication device, characterized by comprising: a processor, configured to call a program in a memory to execute the communication method according to any one of claims 6 to 10.
A communication device, characterized by comprising: a processor and an interface circuit, the interface circuit is used to communicate with other devices, and the processor is used to execute the communication method according to any one of claims 6 to 10.
A computer-readable storage medium, wherein the computer-readable storage medium stores a program, and when the program is called by a processor, the communication method according to any one of claims 1 to 5 is executed, or The communication method described in any one of 6 to 10 is executed.
A computer program, characterized in that, when the program is called by a processor, the communication method according to any one of claims 1 to 5 is executed, or the communication method according to any one of claims 6 to 10 is executed implement.
A communication system, characterized by comprising: a communication device and a first network device;

The communication device is configured to determine a first cell; the first cell is a cell that satisfies a condition for performing a conditional handover, and the first network device is a network device corresponding to the first cell;

The communication device is also used 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 the 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: if the first cell is consistent with the second cell, and the connection establishment process with the first network device has been completed When the first condition is reached, the process of establishing a connection with the first network device is continued.
The communication system according to claim 20, wherein:

The communication device is further configured to: if the first cell is consistent with the second cell, and the connection establishment process with the first network device does not meet the first condition, re-execute the connection according to the handover command The process of establishing a connection by the first network device.
The communication system according to any one of claims 19 to 21, wherein 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 perform a process of establishing a connection with the second network device according to the handover command if the first cell and the second cell are inconsistent.
The communication system according to any one of claims 19 to 22, wherein the first cell is a cell corresponding to a connection being established between the first network device and the communication device.
A communication system, characterized by comprising: a communication device, a third network device, and a fourth network device;

The communication device is configured to determine a third cell, where the third cell is a cell that satisfies a condition for performing a conditional handover, and the third network device is a network device corresponding to the third cell;

The communication device is also used 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; and the fourth cell is a cell indicated by a 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 establishment of a connection with the fourth network device fails.
The communication system according to claim 24, wherein the third network device is a network device corresponding to one of the third cells except the fourth cell.
The communication system according to claim 24 or 25, wherein:

The communication device is further configured to postpone the process of establishing a connection with the third network device before determining that the connection establishment with the fourth network device fails.
The communication system according to any one of claims 24 to 26, wherein:

The communication device is further configured to record the length of time that the third cell satisfies the execution condition of the conditional handover;

Wherein, the length of time that the third cell satisfies the execution condition of the conditional handover is less than or equal to a preset time length.
The communication system according to any one 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 network device corresponding to a target cell. The cell determined by the communication device;

The communication device is further configured to perform a connection re-establishment process 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 .