WO2020164470A1

WO2020164470A1 - Communication method, apparatus, and system

Info

Publication number: WO2020164470A1
Application number: PCT/CN2020/074721
Authority: WO
Inventors: 张宏平; 耿婷婷; 曾清海
Original assignee: 华为技术有限公司
Priority date: 2019-02-14
Filing date: 2020-02-11
Publication date: 2020-08-20
Also published as: CN111565479B; CN111565479A

Abstract

Embodiments of the present application provide a communication method, apparatus, and system. The method comprises the following steps: when a first access network device receives an RRC re-establishment request message from a terminal device, the first access network device determines that an access mobility management entity providing a service to the terminal device changes, and then sends an RRC establishment message to the terminal device, wherein the RRC establishment message is used for the terminal device to establish an RRC connection with the first access network device. By means of the embodiments of the present application, when an access mobility management entity providing a service to a terminal device changes, the duration of user data interruption and signaling overhead can be reduced.

Description

Communication method and its device and system

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201910118279.6, and the application name is "communication method and its device and system" on February 14, 2019, the entire content of which is incorporated into this application by reference .

Technical field

The embodiments of the present application relate to the field of communication technology, and in particular to a communication method, device, and system.

Background technique

In a mobile communication system, for a terminal device in an idle state (for example, user equipment (UE)), the context information (context) of the UE does not exist on the base station. When the UE in the idle state needs to communicate with the network, the UE needs to initiate an initial access process to enter the connected state. Refer to the initial access process of the idle UE shown in FIG. 1. The initial access process may include, for example, establishing a radio resource control (Radio Resource Control, RRC) connection, activating security, and establishing a bearer. After the UE establishes an RRC connection with the base station, the base station establishes a connection with a core network (core network, CN), the base station establishes context information of the UE, and then executes the process of activating security and establishing a bearer, and then the UE and the network can perform data transmission.

After the UE establishes an RRC connection with the network and enters the connected state, if there are radio link failure, handover failure, integrity protection check failure, RRC reconfiguration failure, etc., the UE will trigger the RRC connection re-establishment process. The RRC connection re-establishment process aims to re-establish the RRC connection, restore the signaling radio bearer (SRB) 1, reactivate security, and restore service continuity. In this process, the UE can select a suitable cell (suitable cell) through the cell selection process and initiate the RRC connection re-establishment process. Before the fifth generation mobile communication (5 ^th -generation, 5G) system, if the UE context information is present on the target cell base station, then the re-establishment successfully; otherwise re-establishment fails. In the current 5G system, even if the UE context information does not exist on the target base station, the target base station can still support RRC connection re-establishment.

Although the target base station supports RRC connection re-establishment, in the process of RRC connection re-establishment, once the access and mobility management function (AMF) serving the UE changes, the RRC connection re-establishment will fail.

Summary of the invention

The embodiments of the present application provide a communication method, a device, and a system, which can reduce the duration of user data interruption and reduce signaling overhead when the access mobility management entity that provides services for the terminal device changes.

The first aspect of the embodiments of the present application provides a communication method, including:

When the first access network device receives the RRC re-establishment request message from the terminal device, it determines that the access mobility management entity that provides services for the terminal device has changed;

The first access network device sends an RRC setup message to the terminal device, where the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.

In the first aspect of the embodiments of the present application, after receiving the RRC re-establishment request message from the terminal device, the first access network device determines whether the access mobility management entity that provides services for the terminal device has changed, and when the change occurs Next, send an RRC setup message to the terminal device so that the terminal device can establish an RRC connection with the first access network device, so as to clarify how to establish the terminal when the access mobility management entity serving the terminal device changes The RRC connection between the device and the first access network device can reduce the duration of user data interruption and reduce signaling overhead.

In a possible implementation manner, before determining that the access mobility management entity providing services for the terminal device is changed, the first access network device obtains the access to which the second access network device belongs from the second access network device. Enter the mobility management entity information, the second access network device is the access network device that provides services for the terminal device before the terminal device initiates the RRC connection re-establishment process; the first access network device is based on the first access network device to which it belongs It is determined that the access mobility management entity information to which the second access network device belongs and the access mobility management entity information to which the second access network device belongs has changed.

According to the access mobility management entity information, when it is determined that the access mobility management entity providing services for the terminal device has changed, the duration of user data interruption can be minimized.

In a possible implementation manner, the access mobility management entity information to which the second access network device belongs includes a list of access mobility management entity sets to which the second access network device belongs, and the first access network device belongs to The access mobility management entity information includes a list of access mobility management entity sets to which the first access network device belongs;

The first access network device determines whether the list of the access mobility management entity set to which the first access network device belongs and the list of the access mobility management entity set to which the second access network device belongs have the same access mobility Management entity collection;

If the same set of access mobility management entities does not exist, the first access network device determines that the access mobility management entity providing services for the terminal device changes.

Specifically, according to the list of the access mobility management entity set, it is determined that the access mobility management entity providing services for the terminal device has changed, which can also minimize the duration of user data interruption.

In a possible implementation manner, the access mobility management entity information to which the second access network device belongs includes the access mobility management entity list to which the second access network device belongs, and the access mobility management entity to which the first access network device belongs The incoming mobility management entity information includes a list of access mobility management entities to which the first access network device belongs;

The first access network device judges whether the access mobility management entity list to which the first access network device belongs and the access mobility management entity list to which the second access network device belongs have the same access mobility management entity;

If the same access mobility management entity does not exist, the first access network device determines that the access mobility management entity that provides services for the terminal device changes.

Specifically, according to the list of access mobility management entities, it is determined that the access mobility management entity providing services for the terminal device has changed, which can also minimize the duration of user data interruption.

In a possible implementation manner, the first access network device may obtain the access mobility management entity information to which the second access network device belongs from the second access network device in the following manner: the first access network device passes through Receive the Xn interface establishment request message or the Xn interface establishment response message from the second access network device to obtain the access mobility management entity information to which the second access network device belongs, the Xn interface establishment request message or the Xn interface establishment response The message includes the access mobility management entity information to which the second access network device belongs.

In a possible implementation manner, the first access network device may obtain the access mobility management entity information to which the second access network device belongs from the second access network device in the following manner: the second access network device actively Informing the first access network device of the access mobility management entity information to which it belongs can improve the initiative of the second access network device and reduce signaling overhead.

In a possible implementation manner, when the first access network device determines that the access mobility management entity that provides services for the terminal device changes, the first access network device does not perform the notification to the second access network device. The step of sending the context information acquisition request message is to directly send the RRC establishment message to the terminal device, which can minimize the duration of user data interruption and reduce signaling overhead.

In a possible implementation manner, the first access network device sends a context information acquisition request message to the second access network device before determining that the access mobility management entity providing services for the terminal device changes, and the second access network device The network device is an access network device that provides services for the terminal device before the terminal device initiates the RRC connection re-establishment process; receives a context information acquisition response message from the second access network device, and the context information acquisition response message includes the access mobile A mobility management entity identifier, where the access mobility management entity identifier is used to identify an access mobility management entity that provides services for the terminal device when the terminal device accesses the second access network device;

If the first access network device cannot connect to the access mobility management entity identified by the access mobility management entity identifier, the first access network device determines that the access mobility management entity that provides services for the terminal device has changed.

In the process of acquiring the context information of the terminal device, it is determined whether the access mobility management entity providing services for the terminal device has changed, so that when the change is determined, the RRC establishment message is sent to the terminal device to reduce user data The duration of the interruption reduces the signaling overhead.

The aforementioned context information acquisition response message may also include context information of the terminal device, so that the first access network device can learn the context information of the terminal device.

In a possible implementation manner, the first access network device sends a context information acquisition request message to the second access network device before determining that the access mobility management entity providing services for the terminal device changes, and the second access network device The network device is an access network device that provides services for the terminal device before the terminal device initiates the RRC connection re-establishment process; receiving a context information acquisition failure message from the second access network device, where the context information acquisition failure message includes the reason for the failure, The failure reason is used to indicate that the access mobility management entity that provides services for the terminal device has changed;

The first access network device determines that the access mobility management entity providing services for the terminal device has changed according to the failure cause.

A second aspect of the embodiments of the present application provides a communication device that has the function of implementing the method provided in the first aspect. The function can be realized by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a possible implementation manner, the communication device includes: a transceiving module and a processing module; the processing module is configured to determine that the terminal device provides services when the transceiving module receives an RRC re-establishment request message from the terminal device The access mobility management entity changes; the transceiver module is used to send an RRC setup message to the terminal device, and the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.

In a possible implementation manner, the communication device includes: a processor, a transceiver, and a memory. The transceiver is used to receive and send information. The memory stores a computer program. The computer program includes program instructions. The processor communicates with the memory via a bus. Connected to the transceiver, the processor executes the program instructions stored in the memory, so that the first access network device performs the following operations: when the transceiver receives the RRC re-establishment request message from the terminal device, it is determined to be the terminal device The access mobility management entity providing the service changes; the control transceiver sends an RRC setup message to the terminal device, and the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.

Based on the same inventive concept, since the principle and beneficial effects of the communication device for solving the problem can be referred to the method described in the first aspect and the beneficial effects brought about, the implementation of the device can be referred to the implementation of the method, and the repetition will not be repeated. .

The third aspect of the embodiments of the present application provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, the computer program includes program instructions, and the program instructions when executed by a processor cause the processor to execute the first The method described in the aspect.

The fourth aspect of the embodiments of the present application provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method described in the first aspect.

A fifth aspect of the embodiments of the present application provides a communication method, including:

The terminal device sends an RRC re-establishment request message to the first access network device;

When the access mobility management entity providing services for the terminal device changes, the terminal device receives the RRC establishment message from the first access network device;

The terminal device establishes an RRC connection with the first access network device based on the RRC setup message.

In the fifth aspect of the embodiments of the present application, when the access mobility management entity that provides services for the terminal device changes, the terminal device receives an RRC setup message from the first access network device to establish a connection with the first access network device. The RRC connection between devices reduces the duration of user data interruption and reduces signaling overhead.

A sixth aspect of the embodiments of the present application provides a communication device, which has a function of implementing the method provided in the fifth aspect. The function can be realized by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a possible implementation manner, the communication device includes: a transceiver module and a processing module; the transceiver module is used to send an RRC re-establishment request message to the first access network device; when the terminal device provides services for access mobility The management entity changes and receives the RRC establishment message from the first access network device; the processing module is configured to establish an RRC connection with the first access network device based on the RRC establishment message.

In a possible implementation manner, the communication device includes: a processor, a transceiver, and a memory. The transceiver is used to receive and send information. The memory stores a computer program. The computer program includes program instructions. The processor communicates with the memory via a bus. Connected to the transceiver, the processor executes the program instructions stored in the memory to enable the terminal device to perform the following operations: control the transceiver to send an RRC re-establishment request message to the first access network device; when the terminal device provides service access The mobility management entity changes and controls the transceiver to receive the RRC establishment message from the first access network device; and establishes an RRC connection with the first access network device based on the RRC establishment message.

Based on the same inventive concept, since the principle and beneficial effects of the communication device for solving the problem can be referred to the method described in the fifth aspect and the beneficial effects brought about, the implementation of the device can refer to the implementation of the method, and the repetition will not be repeated. .

A seventh aspect of the embodiments of the present application provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, the computer program includes program instructions, and the program instructions when executed by a processor cause the processor to execute the fifth The method described in the aspect.

The eighth aspect of the embodiments of the present application provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method described in the fifth aspect.

A ninth aspect of the embodiments of the present application provides a communication method, including:

The second access network device receives a context information acquisition request message from the first access network device, where the context information acquisition request message is used to request to acquire the context information of the terminal device;

The second access network device determines that the access mobility management entity that provides services for the terminal device has changed according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device;

The second access network device sends a context information acquisition failure message to the first access network device.

In the ninth aspect of the embodiments of the present application, the second access network device determines whether the access mobility management entity that provides services for the terminal device has changed, and sends context information to the first access network device when the change occurs Obtain the failure message so that the first access network device can determine that the access mobility management entity providing services for the terminal device has changed, and execute the step of sending an RRC setup message to the terminal device, thereby reducing the duration of user data interruption and reducing signaling overhead .

In a possible implementation manner, the above context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that the access mobility management entity providing services for the terminal device has changed, so that the first access network device can determine the failure reason according to the failure reason. When the access mobility management entity providing services for the terminal device changes, the step of sending an RRC establishment message to the terminal device is executed.

In a possible implementation manner, the second access network device determines the access mobility management that provides services for the terminal device according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device Before the entity changes, the access mobility management entity information to which the first access network device belongs can be obtained by the following method: the second access network device receives the Xn interface establishment request message or Xn from the first access network device An interface establishment response message, where the Xn interface establishment request message or the Xn interface establishment response message includes the access mobility management entity information to which the first access network device belongs.

In a possible implementation manner, the context information of the terminal device includes the access mobility management entity identifier, and the access mobility management entity identifier is used to identify the terminal device when it accesses the second access network device and provide the terminal device with Service access mobility management entity;

The second access network device searches whether there is an access mobility management entity identified by the access mobility management entity identifier in the access mobility management entity information to which the first access network device belongs, and if it is not found, it determines The access mobility management entity that provides services for terminal devices has changed.

A tenth aspect of the embodiments of the present application provides a communication device, which has a function of implementing the method provided in the ninth aspect. The function can be realized by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

In a possible implementation manner, the communication device includes: a transceiver module and a processing module; the transceiver module is configured to receive a context information acquisition request message from the first access network device, and the context information acquisition request message is used to request acquisition Context information of the terminal device; a processing module for determining that the access mobility management entity providing services for the terminal device has changed according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device; The transceiver module is also configured to send a context information acquisition failure message to the first access network device.

In a possible implementation manner, the communication device includes: a processor, a transceiver, and a memory. The transceiver is used to receive and send information. The memory stores a computer program. The computer program includes program instructions. The processor communicates with the memory via a bus. Connected to the transceiver, the processor executes the program instructions stored in the memory to make the second access network device perform the following operations: control the transceiver to receive the context information acquisition request message from the first access network device, and the context information acquisition The request message is used to request to obtain the context information of the terminal device; according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device, it is determined that the access mobility management entity providing services for the terminal device has changed ; Control the transceiver to send a context information acquisition failure message to the first access network device.

Based on the same inventive concept, since the principle and beneficial effects of the communication device to solve the problem can be referred to the method described in the ninth aspect and the beneficial effects brought about, the implementation of the device can refer to the implementation of the method, and the repetition will not be repeated. .

The eleventh aspect of the embodiments of the present application provides a computer-readable storage medium in which a computer program is stored. The computer program includes program instructions. The program instructions, when executed by a processor, cause the processor to execute the foregoing The method described in the nine aspects.

The twelfth aspect of the embodiments of the present application provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method described in the ninth aspect.

A thirteenth aspect of the embodiments of the present application provides a communication system, which includes the first access network device related to the first aspect and the terminal device related to the fifth aspect,

The terminal device is configured to send an RRC re-establishment request message to the first access network device;

The first access network device is configured to determine that the access mobility management entity providing services for the terminal device has changed in the case of receiving the RRC re-establishment request message from the terminal device; send an RRC establishment message to the terminal device;

The terminal device is also configured to receive an RRC setup message from the first access network device, and establish an RRC connection with the first access network device based on the RRC setup message.

In a possible implementation manner, the communication system further includes the second access network device involved in the ninth aspect.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the following will describe the drawings that need to be used in the embodiments of the present application or the background art.

Figure 1 is a simplified flow chart of the initial access process of an idle UE;

Figure 2 is a schematic flow chart of the RRC connection re-establishment process;

Figure 3 is a schematic diagram of a network architecture applying an embodiment of the present application;

4 is a schematic flowchart of a communication method provided in Embodiment 1 of this application;

Fig. 5a is a schematic diagram of a process for obtaining AMF information provided by an embodiment of the application;

FIG. 5b is a schematic diagram of the process of updating AMF information according to an embodiment of the application;

FIG. 6 is a schematic flowchart of a communication method provided in Embodiment 2 of this application;

FIG. 7 is a schematic flowchart of a communication method provided in Embodiment 3 of this application;

Figure 8 is a schematic flow chart of the RRC connection recovery process;

FIG. 9 is a schematic flowchart of a communication method provided in Embodiment 4 of this application;

FIG. 10 is a schematic diagram of the logical structure of a communication device provided by an embodiment of the application;

FIG. 11 is a simplified schematic diagram of the physical structure of a communication device provided by an embodiment of the application.

detailed description

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Wherein, in the description of this application, unless otherwise specified, "/" means that the objects associated before and after are in an "or" relationship, for example, A/B can mean A or B; in this application, "and/or "It's just an association relationship that describes the associated objects. It means that there can be three kinds of relationships. For example, A and/or B can mean: A alone exists, A and B exist at the same time, and B exists alone. , B can be singular or plural. Also, in the description of this application, unless otherwise specified, "plurality" means two or more than two. "The following at least one item (a)" or similar expressions refers to any combination of these items, including any combination of a single item (a) or plural items (a). For example, at least one item (a) of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple . In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with substantially the same function and effect. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and order of execution, and words such as "first" and "second" do not limit the difference.

In addition, the network architecture and business scenarios described in the embodiments of this application are intended to illustrate the technical solutions of the embodiments of this application more clearly, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. Those of ordinary skill in the art will know that With the evolution of the 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 names or terms involved in the embodiments of the present application will be introduced below.

Terminal equipment may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to wireless modems with wireless communication functions; it may also include user equipment (UE) and subscriber units (subscriber). unit), cellular phone (cellular phone), smart phone (smart phone), wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem (modem), handheld device (handheld), laptop Laptop computer, cordless phone or wireless local loop (WLL) station, machine type communication (MTC) terminal, UE, mobile station (MS) , Terminal device (terminal device) or relay user equipment, etc. The relay user equipment may be, for example, a 5G residential gateway (RG). The terminal device in the embodiment of the present application is introduced by taking the UE as an example.

An access network (access network, AN) device may also be a radio access network (radio access network, RAN) device. The access network equipment is used to connect the terminal equipment to the core network to realize the transmission of signals and data between the data network and the terminal equipment. The access network equipment can be an evolved base station (evolution node B, eNB) in a long term evolution (LTE) system, or a next-generation node B (gNB) in a 5G system. It can be a base station in a future communication system. In the embodiments of this application, the access network equipment is introduced by taking gNB as an example.

The first access network device is the terminal device in the process of initiating the RRC connection re-establishment process, the terminal device selects the access network device on which the RRC connection re-establishment process is initiated, and establishes an RRC connection with the access network device. In other words, the first access network device is the access network device corresponding to the RRC connection re-establishment, that is, the access network device that re-establishes the RRC connection with the terminal device. The name of the first access network device does not constitute a limitation to the embodiment of the present application. For example, the first access network device may also be referred to as a target base station or a target access network device.

The second access network device is an access network device that provides services for the terminal device before the terminal device initiates the RRC connection re-establishment process, that is, the serving base station accessed by the terminal device before the RRC connection re-establishment process is initiated. That is, the terminal device establishes an RRC connection (communicates) with the second access network device, and the terminal device triggers the RRC connection re-establishment process due to reasons such as radio link failure. The second access network device may have context information of the terminal device with which the RRC connection is established. The name of the second access network device does not constitute a limitation to the embodiment of the present application. For example, the second access network device may also be referred to as a source base station or a source access network device.

The access mobility management entity belongs to the core network element and is responsible for the access and mobility management of terminal equipment. The access mobility management entity may be the AMF in the core network of the 5G system, or it may be an entity with the same functions as the AMF in the future core network. The name of the access mobility management entity does not constitute a limitation to the embodiments of the present application. For example, the access mobility management entity may be called AMF, access management network element, or access management entity. In the embodiments of this application, the access mobility management entity is introduced by taking the AMF as an example.

Xn interface refers to the interface between the access network equipment and the access network equipment. The process of establishing the Xn interface between access network device 1 and access network device 2 is: access network device 1 sends an Xn interface establishment request to access network device 2, and when access network device 2 receives the Xn interface establishment request, Send an Xn interface establishment response to the access network device 1; or the access network device 2 sends an Xn interface establishment request to the access network device 1, and the access network device 1 sends an Xn interface establishment response to the access network device 2. Xn interface can refer to the interface between 5G base station and 5G base station, such as the interface between gNB and gNB. With the development of communication system, the name of the interface between access network equipment and access network equipment may change The name of the Xn interface does not constitute a limitation on the embodiment of this application.

Refer to Figure 2, which is a schematic flow diagram of the RRC connection re-establishment process. The schematic flow diagram includes the following steps:

Step 1. The UE sends an RRC re-establishment request to the target base station to request the establishment of an RRC connection with the target base station.

Step 2: The target base station sends a context information acquisition request to the source base station for requesting to acquire the context information of the UE.

Step 3: The source base station sends a context information acquisition response to the target base station for responding to the context information acquisition request. The context information acquisition response includes the context information of the UE.

Step 4: The target base station sends an RRC re-establishment to the UE, so that the UE establishes an RRC connection with the target base station.

Step 4a: The UE establishes an RRC connection with the target base station based on RRC re-establishment, and sends the RRC re-establishment completion to the target base station.

Optionally, step 5 and step 5a are included after step 4, and the target base station configures radio resources for the UE. In step 5, the target base station sends the RRC reconfiguration to the UE, and in step 5a, the UE sends the RRC reconfiguration complete to the target base station.

Optionally, after step 4a, step 6 is further included: the target base station sends a data forwarding address indication to the source base station, so that the source base station stops forwarding data to the UE.

Step 7. The target base station sends a path switching request to the AMF for requesting that the forwarding path is forwarded through the source base station to be forwarded through the target base station.

Step 8. The AMF sends a path switching response to the target base station to respond to the path switching request.

Step 9. The target base station notifies the source base station to release the context information of the UE. At this point, the RRC connection re-establishment process is complete.

In Figure 2, the target base station supports the RRC connection re-establishment by obtaining the context information of the UE through the source base station, and successfully obtains the context information of the UE.

At present, in a 5G system, for a UE, in addition to the base station maintaining the context information of the terminal device, the AMF also maintains the context information of the terminal device. In Figure 2, in one case, the AMF serving the UE has not changed (for example, the AMF connected to the target base station and the AMF connected to the source base station are the same), so the data flow direction (ie, path switching) can be changed. The network sends data to the UE through the source base station instead of sending data to the UE through the target base station. However, if the AMF serving the UE changes, for example, no interface is established between the target base station and the AMF connected to the source base station (this interface can be called an N2 interface or an NG interface, taking the N2 interface as an example), the target base station cannot Connect to the AMF connected to the source base station, or establish an interface between the target base station and the AMF connected to the source base station, but the AMF is overloaded, the target base station does not select the AMF, the target base station 402 will fail to perform path switching, and then execute Figure 1 again The flow chart shown is to re-establish the RRC connection, which increases the duration of user data interruption and correspondingly increases the signaling overhead.

In view of this, the embodiments of the present application provide a communication method, apparatus, and system. When the first access network device receives the RRC re-establishment request message, it determines whether the AMF serving the terminal device has changed, and In the case of a change, the RRC setup message is directly sent to the terminal device, and the RRC connection does not need to be re-established after the RRC connection re-establishment process is completed and the path switching fails, thereby reducing the duration of user data interruption and reducing signaling overhead.

Please refer to FIG. 3, which is a schematic diagram of a network architecture applying an embodiment of the present application. The schematic diagram of the network architecture includes a first access network device 402 and a terminal device 401.

The embodiment of this application is applied to the scenario of RRC connection re-establishment. The terminal device 401 selects the first access network device 402 to initiate the RRC connection re-establishment process. In one possible manner, the terminal device 401 sends an RRC re-establishment request message to the first access network device 402; after receiving the RRC re-establishment request message, the first access network device 402 determines that the terminal device 401 provides services If the AMF changes, the first access network device 402 sends an RRC setup message to the terminal device 401; when the terminal device 401 receives the RRC setup message, it establishes a connection with the first access based on the RRC setup message RRC connection between network devices 402. How the first access network device 402 specifically determines whether the AMF provided by the terminal device 401 has changed will be described in detail in subsequent embodiments.

Optionally, the network architecture shown in FIG. 3 may also include a second access network device 403. The second access network device 403 may determine whether the AMF provided by the terminal device 401 has changed. If there is a change, it will notify the first An access network device 402, so that the first access network device 402 executes the step of sending an RRC setup message to the terminal device 401. How the second access network device 403 specifically determines whether the AMF provided by the terminal device 401 has changed will be described in detail in subsequent embodiments.

The communication method provided in the embodiment of the present application will be described in detail below. In the introduction process, the terminal equipment takes the UE as an example, and the access mobility management entity takes the AMF as an example. It should be noted that the name of each message in the embodiment of the present application is used as an example, and does not constitute a limitation to the embodiment of the present application.

Taking the application of the embodiment of the present application to the schematic diagram of the network architecture shown in FIG. 3 as an example, as shown in FIG. 4, the schematic flowchart of the communication method provided in the first embodiment of the present application may include but not limited to the following steps:

Step S501: The UE sends an RRC re-establishment request message to the first access network device.

Correspondingly, the first access network device receives the RRC re-establishment request message from the UE.

Wherein, the UE may be any UE within the network coverage of the first access network device. After the UE establishes an RRC connection with the second access network device and enters the connected state, if radio link failure, handover failure, integrity protection check failure, or RRC reconfiguration failure occurs, the UE will trigger the RRC connection re-establishment process. The UE selects a cell under the first access network device through a cell selection process, and sends an RRC re-establishment request message to the first access network device to initiate an RRC connection re-establishment process. The RRC reestablishment request message may be, for example, RRC reestablishment request.

Step S502: The first access network device determines whether the AMF serving the UE has changed.

After receiving the RRC re-establishment request message from the UE, the first access network device determines whether the AMF serving the UE has changed. If there is a change, step S503 is performed; if there is no change, it can be performed according to FIG. 2, that is, the step of sending a context information acquisition request message to the second access network device is performed.

Wherein, there is one AMF serving the UE, but there may be more than one AMF establishing an N2 interface with the access network device, that is, the first access network device and the second access network device may be connected to more than one AMF. In a possible manner, one access network device can establish N2 interfaces with multiple AMF sets, one AMF set includes multiple AMFs, and one access network device can connect to all AMFs included in one AMF set. Or, in another possible manner, in the case that there is no AMF set, one access network device can be connected to multiple AMFs.

A change in the AMF serving the UE can be understood as the AMF serving the UE when the UE accesses the second access network device. When the UE initiates the RRC connection re-establishment process with the first access network device, the first An access network device cannot connect to the AMF, for example, the first access network device has not established an N2 interface with the AMF; it can also be understood as the AMF that provides services for the UE when the UE accesses the second access network device, the first access The network device has established an N2 interface with the AMF, but the first access network device cannot select the AMF to provide services for the UE. For example, the AMF may be overloaded and the first access network device cannot select the AMF to provide the UE. The service or the operator’s policy causes the first access network device to be unable to select the AMF to provide the service for the UE.

Exemplarily, the first access network device may determine whether the AMF serving the UE has changed in the following three ways:

Manner 1: The first access network device determines whether the AMF serving the UE has changed according to the AMF information to which the first access network device belongs and the AMF information to which the second access network device belongs. Among them, the AMF information to which the first access network device belongs refers to the information of the AMF that establishes the N2 interface with the first access network device.

In a possible implementation, the AMF information to which the first access network device belongs may include a list of AMF Set (AMF Set) to which the first access network device belongs, that is, the AMF Set to which the first access network device belongs. The network equipment establishes a list of AMF sets of the N2 interface, and the list includes one or more AMF sets. The AMF information to which the second access network device belongs includes a list of AMF sets to which the second access network device belongs, that is, a list of AMF sets that establish an N2 interface with the second access network device.

The first access network device can determine whether the list of AMF sets to which the first access network device belongs and the list of AMF sets to which the second access network device belongs have the same AMF set. If the same AMF set does not exist, it can be understood Because the AMF sets to which they belong are completely different, or the lists of the AMF sets to which the two belong do not have an intersection, indicating that the first access network device cannot connect to the AMF set to which the second access network device belongs, then the first access network device can determine The AMF serving the UE has changed. For example, the list of AMF sets to which the first access network device belongs includes AMF set 1 and AMF set 2, and the list of AMF sets to which the second access network device belongs includes AMF set 3 and AMF set 4. Then the first access The network equipment can determine that the AMF serving the UE has changed.

Further, if there is a partial intersection between the list of the AMF set to which the first access network device belongs and the list of the AMF set to which the second access network device belongs, the same AMF set exists, for example, the first access network device belongs to The list of AMF sets includes AMF set 1 and AMF set 2, and the list of AMF sets to which the second access network device belongs includes AMF set 2 and AMF set 3. There is an intersection, and the intersection is AMF set 2, then the first access The network equipment can further use Method 2 or Method 3 to determine whether the AMF serving the UE has changed, or according to the interactive public land mobile network (PLMN) list to determine whether the AMF serving the UE has occurred change. For the method of judging based on the interactive PLMN list, please refer to the paragraph before the introduction method 2.

Further, if the list of AMF sets to which the first access network device belongs is exactly the same as the list of AMF sets to which the second access network device belongs, for example, the list of AMF sets to which the first access network device belongs only includes the AMF set 1 and AMF set 2, and the list of AMF sets to which the second access network device belongs only includes AMF set 1 and AMF set 2, then the first access network device can determine that the AMF serving the UE does not change.

The access network equipment will connect to all AMFs in an AMF set, so it is sufficient to judge according to the list of the AMF set.

In a possible implementation manner, the AMF information to which the first access network device belongs may include a list of AMFs to which the first access network device belongs, that is, a list of AMFs that establish an N2 interface with the first access network device. The AMF information to which the second access network device belongs includes a list of AMFs to which the second access network device belongs.

The first access network device determines whether the AMF list to which the first access network device belongs and the AMF list to which the second access network device belongs have the same AMF. If the same AMF does not exist, it can be understood that the AMF to which it belongs is complete If the AMFs to which they belong are different, or there is no intersection between the AMFs to which they belong, it indicates that the first access network device cannot connect to the AMF to which the second access network device belongs, and the first access network device can determine that the AMF serving the UE has changed.

Further, if there is a partial intersection between the list of AMFs to which the first access network device belongs and the list of AMFs to which the second access network device belongs, the first access network device may further adopt method 2 or method 3 to determine that it is Whether the AMF served by the UE has changed, or judge whether the AMF served by the UE has changed according to the PLMN list. For the method of judging based on the interactive PLMN list, please refer to the paragraph before the introduction method 2.

Further, if the list of AMFs to which the first access network device belongs is exactly the same as the list of AMFs to which the second access network device belongs, the first access network device can determine that the AMF serving the UE does not change.

Wherein, the first access network device obtains the AMF information to which the second access network device belongs from the second access network device. For details, refer to the schematic flow chart for obtaining AMF information shown in FIG. 5a. The process in which the first access network device obtains the AMF information to which the second access network device belongs from the second access network device can be performed independently or in combination with the embodiment shown in FIG. 4, which is not limited in the embodiment of the present application. If performed in combination, generally, the process of the first access network device acquiring the AMF information to which the second access network device belongs from the second access network device is performed before step S501.

In Figure 5a, in the process of establishing the Xn interface by the first access network device, acquiring the AMF information of the second access network device may include: the first access network device sends an Xn interface establishment request to the second access network device Message, the Xn interface establishment request message carries the AMF information to which the first access network device belongs; after receiving the Xn interface establishment request message, the second access network device sends an Xn interface establishment response to the first access network device Message, the Xn interface establishment response message carries the AMF information to which the second access network device belongs. The schematic diagram of the flow of acquiring AMF information shown in FIG. 5a is applicable to any two access network devices, that is, it is also applicable to swapping the positions of the first access network device and the second access network device. In other words, the second access network device may also send an Xn interface establishment request message to the first access network device, and the Xn interface establishment request message carries the AMF information to which the second access network device belongs; After receiving the Xn interface establishment request message, the network device sends an Xn interface establishment response message to the second access network device, where the Xn interface establishment response message carries the AMF information to which the first access network device belongs. The processes shown in FIG. 5a and FIG. 5b can be combined with the embodiment method shown in FIG. 4, or can be used as an independent embodiment, which is not limited here.

After the Xn interface is established between the first access network device and the second access network device, the AMF information to which the access network device belongs may change. If there is a change, the peer end can be notified through the update process to avoid inconsistencies leading to the first An error in the judgment of the access network equipment caused re-establishment failure or increased user data interruption time. Please refer to the flowchart of updating AMF information shown in Figure 5b. In Figure 5b, assuming that the AMF information to which the first access network device belongs has changed, the update process may include: the first access network device sends a configuration update message to the second access network device, and the configuration update message includes the updated AMF information For example, a newly added AMF set or a deleted AMF set, or the configuration update message includes the updated complete AMF information; when the second access network device receives the configuration update message, it can update according to the configuration update message And save the updated AMF information to which the first access network device belongs. After the update, the second access network device sends a configuration update confirmation message to the first access network device. The configuration update confirmation message is used to indicate the second access The network equipment has been updated. Similarly, the schematic flow chart of updating AMF information shown in FIG. 5b is applicable to any two access network devices.

Optionally, the second access network device may actively inform the first access network device of the AMF information to which the second access network device belongs, that is, the trigger of the Xn interface establishment request message is not required. The message carried by the AMF information to which the second access network device belongs is not limited in the embodiment of this application.

It should be noted that in the case where it is determined that the AMF serving the UE has changed through method 1, the first access network device does not need to execute the step of sending the context information acquisition request message to the second access network device, that is, it does not execute Step 2 in the embodiment shown in Fig. 2 is executed directly instead of step S503. Here, the step of sending the context information acquisition request message to the second access network device is not performed, and it can also be referred to as skipping or ignoring the step of sending the context information acquisition request message to the second access network device. This is not limited. In this way, neither the acquisition of the UE context shown in Figure 2 nor the path switching process shown in Figure 2 is performed, but the RRC setup message sent to the UE in Figure 1 is directly executed, which can minimize the duration of user data interruption. , Reduce signaling overhead.

Optionally, in FIG. 5a, in the process of establishing the Xn interface between the access network devices, the public land mobile network (PLMN) lists that they broadcast can also be exchanged. The exchange of PLMN lists between access network devices can be independent of the exchange of AMF information. For example, the PLMN list broadcast by a certain access network device and the AMF information to which it belongs are not carried in the same message, or a certain access network device broadcasts The PLMN list is not included in the AMF information to which the access network device belongs. The interactive PLMN list and the interactive AMF information can also be combined. For example, the PLMN list broadcast by a certain access network device and the AMF information to which it belongs are carried in the same message, or the PLMN list broadcast by a certain access network device is included in the access In the AMF information to which the network device belongs. Whether it is independent or combined is not limited in the embodiment of the present application. The first access network device may also directly determine based on the PLMN list broadcast by the first access network device and the PLMN list broadcast by the second access network device: the first access network device is receiving the second access network device broadcast After the PLMN list, if it is found that the target cell of the UE (that is, the cell covered by the first access network device) does not broadcast any of the PLMN lists broadcast by the UE’s source cell (that is, the cell covered by the second access network device) One, the first access network device determines that the PLMN of the UE must change, and then determines that the AMF serving the UE will change. The first access network device may also be able to determine that the AMF serving the UE has changed based on the AMF information to which the first access network device belongs and the AMF information to which the second access network device belongs, such as the first access The list of AMFs to which the network device belongs and the list of AMFs to which the access network device belongs overlaps, and the judgment is made based on the PLMN list broadcast by the first access network device and the PLMN list broadcast by the second access network device.

Manner 2: After receiving the RRC re-establishment request message, the first access network device sends a context information acquisition request message to the second access network device, and determines that it is provided by the UE according to the context acquisition response message from the second access network device. Whether the AMF of the service changes, please refer to the specific description of the second embodiment shown in FIG. 7, which will not be repeated here.

Manner 3: After receiving the RRC re-establishment request message, the first access network device sends the context information acquisition request message to the second access network device, and the second access network device determines whether the AMF serving the UE has changed. If a change occurs, a context information acquisition failure message is sent to the first access network device. The context information acquisition failure message includes a failure reason. The failure reason is used to indicate that the AMF serving the UE has changed. The reason for the failure is determined to be that the AMF serviced by the UE has changed. For details, refer to the specific description of Embodiment 3 shown in FIG. 8, and details are not described herein again.

Step S503: If a change occurs, the first access network device sends an RRC setup message to the UE. Correspondingly, the UE receives the RRC setup message from the first access network device.

If the AMF serving the UE changes, the first access network device directly sends an RRC setup message to the UE. After receiving the RRC setup message, the UE can send an RRC setup complete message to the first access network device. The RRC establishment complete message is used to indicate that the RRC connection between the UE and the first access network device has been established.

In the embodiment shown in FIG. 4, after receiving the RRC re-establishment request message from the UE, the first access network device determines that the AMF serving the UE has changed, and executes the step of sending the RRC establishment message to the UE. Avoid re-executing the flow chart shown in FIG. 1 after the path switching process fails, thereby reducing the duration of user data interruption and reducing signaling overhead.

Taking the application of the embodiment of this application to the schematic diagram of the network architecture shown in FIG. 3 as an example, as shown in FIG. 6, the schematic flow chart of the communication method provided in the second embodiment of this application may include but not limited to the following steps:

Step S701: The UE sends an RRC re-establishment request message to the first access network device. Correspondingly, the first access network device receives the RRC re-establishment request message from the UE.

For the implementation process of step S701, please refer to the specific description of step S501 in the embodiment shown in FIG. 4, which will not be repeated here.

Step S702: The first access network device sends a context information acquisition request message to the second access network device.

Correspondingly, the second access network device receives the context information acquisition request message from the first access network device.

The second access network device extracts the context information of the UE when receiving the context information acquisition request message.

Step S703: The second access network device sends a context information acquisition response message to the first access network device. Correspondingly, the first access network device receives the context information acquisition response message from the second access network device.

Wherein, the context information acquisition response message includes an AMF identifier, and the AMF identifier is used to identify the AMF that provides services for the UE when the UE accesses the second access network device. The AMF identifier may be a globally unique AMF identifier (GUAMI).

Optionally, the context information acquisition response message further includes context information of the UE.

In step S704, the first access network device determines whether the AMF serving the UE has changed according to GUAMI.

The first access network device determines whether the AMF identified by GUAMI can be connected. It is understandable that the first access network device or, in other words, determines whether an N2 interface has been established with the AMF identified by GUAMI, or in the list of AMF sets or AMF lists that have established an N2 interface with the first access network device Find out if there is an AMF identified by GUAMI. If the first access network device establishes an N2 interface with the AMF identified by GUAMI, or finds the AMF identified by GUAMI, it is determined that the first access network can connect to the AMF identified by GUAMI; otherwise, it cannot connect to the AMF identified by GUAMI AMF.

If it cannot be connected, it is judged that the AMF serving the UE has changed, and step S705 is executed; if it can be connected, it is judged that the AMF serving the UE has not changed, and an RRC re-establishment message is sent to the UE, that is, as shown in Figure 2 Step 4 in.

Step S705: If a change occurs, the first access network device sends an RRC setup message to the UE.

Correspondingly, the UE receives the RRC setup message from the first access network device.

In the embodiment shown in FIG. 6, after the first access network device receives the RRC re-establishment request message from the UE, it determines that the GUAMI included in the response message is the UE through the context information acquisition response message sent by the second access network device. Whether the AMF that provides the service is changed, and in the case of a change, directly perform the steps of sending the RRC establishment message to the UE, that is, skip or ignore the steps 4 to 9 in Figure 2 and do not need to complete the steps shown in Figure 2 The RRC connection re-establishment process and the RRC connection is re-established after the path switching process fails, thereby reducing the duration of user data interruption and reducing signaling overhead.

Taking the application of the embodiment of the present application to the schematic diagram of the network architecture shown in FIG. 3 as an example, as shown in FIG. 7, the schematic flowchart of the communication method provided in the third embodiment of this application may include but not limited to the following steps:

Step S801: The UE sends an RRC re-establishment request message to the first access network device. Correspondingly, the first access network device receives the RRC re-establishment request message from the UE.

For the implementation process of step S801, please refer to the specific description of step S501 in the embodiment shown in FIG. 4, which will not be repeated here.

Step S802: The first access network device sends a context information acquisition request message to the second access network device.

When the second access network device receives the context information acquisition request message, it searches for the context information of the UE according to the identification information of the UE carried in the context information acquisition request message. The identification information of the UE may be an identification such as a device identification or an international mobile subscriber identification number (IMSI).

Step S803: The second access network device determines whether the AMF serving the UE has changed according to the context information of the UE and the AMF information to which the first access network device belongs.

Wherein, the context information of the UE includes an AMF identifier, and the AMF identifier is used to identify the AMF that serves the UE when the UE accesses the second access network device. The AMF logo can be GUAMI.

The second access network device searches for the AMF identified by GUAMI in the AMF information to which the first access network device belongs. Specifically, it can be searched in the list of AMF sets to which the first access network device belongs, or in the first The access network device is searched in the list of AMFs to which the access network device belongs. If it is not found, the second access network device can determine that the AMF serving the UE has changed.

The AMF information to which the first access network device belongs can be notified to the second access network device through the process shown in Figure 5a, that is, the first access network device carries the Xn interface establishment request message to which the first access network device belongs AMF information. Alternatively, the second access network device sends an Xn interface establishment request message to the first access network device, and the first access network device sends an Xn interface establishment response message to the second access network device, and the Xn interface establishment response message carries the first access network device. 1. AMF information to which the access network device belongs. In other words, the second access network device obtains the AMF information to which the first access network device belongs from the first access network device in the process of establishing the Xn interface with the first access network device.

Step S804: When the second access network device determines that the AMF serving the UE has changed, the second access network device sends a context information acquisition failure message to the first access network device.

Correspondingly, the first access network device receives the context information acquisition failure message from the second access network device.

Optionally, the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that the AMF serving the UE has changed. The reason for the failure may be a reason value, which may be represented by one or more bits, and the reason value is used to indicate that the AMF serving the UE has changed. In practical applications, the context information acquisition failure message may include other types of reason values, for example, a reason value used to indicate the UE's context information acquisition failure. However, the cause value in the embodiment of this application is used to indicate that the AMF serving the UE has changed. The reason value can also be used for the failure statistics of the first access network device. For example, the reason value is used to indicate the UE's context information acquisition failure. Then the first access network device can know the number of occurrences through the reason value. Failed to obtain the context information of the UE.

Since the AMF serving the UE is changed, the context information acquisition failure message does not carry the context information of the UE, thereby saving signaling overhead between access network devices.

Step S805: The first access network device sends an RRC setup message to the UE. Correspondingly, the UE receives the RRC setup message from the first access network device.

After receiving the context information acquisition failure message, the first access network device directly sends an RRC setup message to the UE. After receiving the RRC setup message, the UE may send an RRC setup complete message to the first access network device. The establishment complete message is used to indicate that the RRC connection between the UE and the first access network device has been established.

In the embodiment shown in FIG. 7, the second access network device determines whether the AMF serving the UE has changed, and in the case of the change, sends a context information acquisition failure message to the first access network device, The first access network device directly executes the step of sending the RRC establishment message to the UE, that is, skips or ignores steps 4 to 9 in Figure 2 and does not need to complete the RRC connection re-establishment process shown in Figure 2 and switch the path. The RRC connection is re-established after the process fails, thereby reducing the duration of user data interruption and reducing signaling overhead.

The embodiments shown in FIG. 4 to FIG. 7 are applied to an RRC connection re-establishment scenario, and the method 1 in the embodiment shown in FIG. 4 can also be applied to an RRC connection resumption scenario.

In the 5G system, a new RRC-inactive state is introduced. Like the idle state, the UE disconnects the RRC connection from the network and does not need to receive downlink data, thus achieving the same power saving as the idle state The effect is different from the idle state: in the inactive state, the UE and the access network device (when entering the inactive state) save the context information of the UE, and when it needs to enter the connected state (for example, the UE has uplink data to send, or The network paging the UE into the RRC-connected state), the UE initiates the RRC connection recovery process, and enters the RRC-connected state based on the saved UE context information, thereby reducing time delay and saving signaling overhead.

In addition, the access network equipment can configure a RAN-based notification area (RNA) for the UE that enters the inactive state. The RNA includes one or more cells. Like the UE in the idle state, the UE in the inactive state will Perform cell reselection. When the UE performs cell reselection and reselects to another cell under the RNA, the UE does not need to notify the network. When the UE reselects to a cell outside the RNA or periodically, the UE initiates the RRC connection recovery process Come to inform the network. Refer to the schematic flow chart of the RRC connection restoration process shown in FIG. 8. The schematic flow chart may include the following steps:

Step 1. In the RRC-inactive state, the UE initiates the RRC connection recovery process by sending an RRC recovery request to the target base station.

Step 4: The target base station sends an RRC recovery to the UE, so that the UE can recover the RRC connection with the target base station.

Step 5: The UE restores the RRC connection with the target base station based on RRC recovery, enters the RRC-connected state, and sends the RRC recovery complete to the target base station.

Optionally, step 5 is further included after step 6, in which the target base station sends a data forwarding address indication to the source base station, so that the source base station stops forwarding data to the UE.

Step 9. The target base station notifies the source base station to release the context information of the UE. At this point, the RRC connection recovery process is complete.

In Figure 8, the target base station obtains the UE context information from the source base station to restore the RRC connection, and successfully obtains the UE context information.

At present, in the process of RRC connection recovery, the AMF serving the UE changes, which will also cause the path switching process to fail, the RRC connection is released, the UE enters the idle state, and then the UE and the first access network device need to re-execute the diagram The flow chart shown in 1 is used to restore the RRC connection again, which increases the duration of user data interruption and correspondingly increases the signaling overhead.

In view of this, applying the method 1 shown in FIG. 4 to the RRC connection recovery scenario can reduce the duration of user data interruption during the RRC connection recovery process and reduce signaling overhead. For details, refer to the flowchart shown in FIG. 9.

Taking the application of the embodiment of the present application to the schematic diagram of the network architecture shown in FIG. 3 as an example, as shown in FIG. 9, the schematic flowchart of the communication method provided in the fourth embodiment of the present application may include but not limited to the following steps:

Step S901: The UE sends an RRC recovery request message to the first access network device.

Correspondingly, the first access network device receives the RRC recovery request message from the UE.

The UE in the inactive state initiates the RRC connection recovery process by sending an RRC recovery request message to the first access network device. Among them, the RRC resume request message may be, for example, RRC resume request.

When the inactive UE needs to enter the RRC-connected state, it can initiate the RRC connection recovery process. When the deactivated UE selects a cell under the first access network device during cell reselection, it can initiate an RRC connection recovery process.

Step S902: The first access network device determines whether the AMF serving the UE has changed.

The first access network device determines whether the AMF serving the UE has changed according to the AMF information to which the first access network device belongs and the AMF information to which the second access network device belongs. For details, see the embodiment shown in FIG. 4 The specific description of mode one will not be repeated here.

Step S903: If a change occurs, the first access network device sends an RRC setup message to the UE. Correspondingly, the UE receives the RRC setup message from the first access network device.

When the first access network device determines that the AMF serving the UE has changed through method 1, the first access network device does not perform the step of sending a context information acquisition request message to the second access network device, but Send an RRC setup message directly to the UE. After receiving the RRC setup message, the UE can send an RRC setup complete message to the first access network device. The RRC setup complete message is used to indicate the connection between the UE and the first access network device. The RRC connection has been established, thereby minimizing the duration of user data interruption.

In the embodiment shown in FIG. 9, after receiving the RRC recovery request message from the UE, the first access network device determines that the AMF serving the UE has changed, and directly executes the step of sending the RRC setup message to the UE. That is, steps 4 to 9 in Figure 8 are skipped or ignored. There is no need to complete the RRC connection recovery process shown in Figure 8 and re-establish the RRC connection after the path switching process fails, thereby reducing the duration of user data interruption and reducing Signaling overhead.

It can be understood that, in the foregoing method embodiments, the methods or steps implemented by the first access network device can also be implemented by components (such as chips or circuits) that can be used for the first access network device, and implemented by the terminal device. The method or step of the method can also be implemented by a component (such as a chip or circuit) that can be used in a terminal device, and a method or step implemented by the second access network device can also be implemented by a component (such as Chip or circuit) implementation.

The foregoing describes the method of the embodiment of the present application in detail, and the device of the embodiment of the present application is provided below.

Please refer to FIG. 10, which is a schematic diagram of a logical structure of a communication device provided by an embodiment of the present application. The communication device 70 includes a transceiver module 701 and a processing module 702. The communication device 70 can be the first access network device 402 in FIG. 3 (or a component that can be used for the first access network device), or the second access network device 403 (or can be used for the second access network device). A component of a networked device), or a terminal device 401 (or a component that can be used for a terminal device).

For the case where the communication device 70 is the first access network device:

The processing module 702 is configured to determine that the access mobility management entity that provides services for the terminal device has changed when the transceiver module 701 receives the RRC re-establishment request message from the terminal device;

The transceiver module 701 is configured to send an RRC setup message to the terminal device, where the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.

In a possible implementation, the transceiver module 701 is also used to obtain the access mobility management entity information to which the second access network device belongs from the second access network device, and the second access network device is the terminal device Before initiating the RRC connection re-establishment process, the access network equipment that provides services for the terminal equipment;

The processing module 702 may be configured to determine the access mobility that provides services for the terminal device based on the access mobility management entity information to which the first access network device belongs and the access mobility management entity information to which the second access network device belongs. The sex management entity has changed.

The processing module 702 may be used to determine whether the list of the access mobility management entity set to which the first access network device belongs and the list of the access mobility management entity set to which the second access network device belongs have the same access mobility If the same set of access mobility management entities does not exist, it is determined that the access mobility management entity providing services for the terminal device changes.

In a possible implementation, the transceiver module 701 may be used to send an Xn interface establishment request message or an Xn interface establishment request message from the second access network device to obtain the interface to which the second access network device belongs. Incoming mobility management entity information, the Xn interface establishment request message or the Xn interface establishment response message includes the access mobility management entity information to which the second access network device belongs.

In a possible implementation manner, the processing module 702 is further configured to control the transceiver module not to perform the notification to the second access network device when the access mobility management entity that provides services for the terminal device changes. The step of the access network device sending the context information acquisition request message.

In a possible implementation, the transceiver module 701 is further configured to send a context information acquisition request message to the second access network device; receive a context information acquisition response message from the second access network device, and the context information acquisition response The message includes an access mobility management entity identifier, which is used to identify the access mobility management entity that provides services for the terminal device when the terminal device accesses the second access network device;

The processing module 702 may be used to determine that the access mobility management entity that provides services for the terminal device changes if the first access network device cannot connect to the access mobility management entity identified by the access mobility management entity identifier.

In a possible implementation manner, the transceiver module 701 is also used to send a context information acquisition request message to the second access network device. The second access network device is the terminal device before initiating the RRC connection re-establishment process. The access network device that the device provides services; receives a context information acquisition failure message from the second access network device, the context information acquisition failure message includes the failure reason, and the failure reason is used to indicate the access mobility management entity that provides services for the terminal device changes happened;

The processing module 702 may be used to determine that the access mobility management entity providing services for the terminal device has changed according to the failure reason.

For the case where the communication device 70 is a terminal device:

The transceiver module 701 is configured to send an RRC re-establishment request message to the first access network device; when the access mobility management entity providing services for the terminal device changes, receive the RRC establishment message from the first access network device;

The processing module 702 is configured to establish an RRC connection with the first access network device based on the RRC setup message.

For the case where the communication device 70 is the second access network device:

The transceiver module 701 is configured to receive a context information acquisition request message from a first access network device, where the context information acquisition request message is used to request to acquire context information of the terminal device;

The processing module 702 is configured to determine, according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device, that the access mobility management entity providing services for the terminal device has changed;

The transceiver module 701 is further configured to send a context information acquisition failure message to the first access network device.

In a possible implementation manner, the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that the access mobility management entity that provides services for the terminal device has changed.

In a possible implementation, the transceiver module 701 is further configured to receive an Xn interface establishment request message or an Xn interface establishment response message from the first access network device, the Xn interface establishment request message or the Xn interface establishment response message Including the access mobility management entity information to which the first access network device belongs.

It should be noted that, for the functions and operations of each module in the communication device 70, reference may be made to related descriptions in the method embodiments.

For example, in the case where the communication device 70 is the first access network device, the transceiver module 701 is used to perform steps S501 and S503 in the embodiment shown in FIG. 4, and steps S701 to S703 in the embodiment shown in FIG. 6 And step S705, step S801, step S802, step S804, and step S805 in the embodiment shown in FIG. 7; the processing module 702 is used to execute step S502 in the embodiment shown in FIG. 4, and steps in the embodiment shown in FIG. S704.

For another example, for the case where the communication device 70 is a terminal device, the transceiver module 701 is used to execute steps S501 and S503 in the embodiment shown in FIG. 4, and steps S701 and S705 in the embodiment shown in FIG. 6, as shown in FIG. Steps S801 and S805 in the illustrated embodiment; the processing module 702 is used to establish an RRC connection with the first access network device.

For another example, for the case where the communication device 70 is a second access network device, the transceiver module 701 is configured to perform steps S702 and S703 in the embodiment shown in FIG. 6, and steps S802 and S802 in the embodiment shown in FIG. S804: The processing module 702 is used to execute step S803 in the embodiment shown in FIG. 7.

Refer to FIG. 11, which is a simplified schematic diagram of the physical structure of a communication device provided by an embodiment of the present application. The communication device 80 may be the first access network device 402 in FIG. 3 (or may be used as a component of the first access network device ), it can also be the second access network device 403 (or a component that can be used for the second access network device), and it can also be the terminal device 401 (or a component that can be used for a terminal device). The communication device 80 includes one or more transceivers 801, a processor 802, and optionally, a memory 803. The transceiver 801, the processor 802, and the memory 803 may be connected to each other through the bus 804, or may be connected in other ways. The related functions implemented by the processing unit 702 shown in FIG. 10 may be implemented by one or more processors 802. The related functions implemented by the transceiver unit 701 shown in FIG. 10 can be implemented by the transceiver 801. The transceiver 801 may also be an input/output interface.

The memory 803 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (erasable programmable read-only memory, EPROM), or A portable read-only memory (compact disc read-only memory, CD-ROM), the memory 803 is used for related instructions and/or data. The processor 802 may call the instructions in the memory 803 to enable the communication device to implement the corresponding methods in the foregoing various embodiments.

The transceiver 801 is used for sending data and/or signaling, and receiving data and/or signaling.

In the embodiment of the present application, for the case where the communication device 80 is the first access network device, the transceiver 801 is used to communicate with the second access network device and the terminal device, for example, the implementation shown in the embodiment shown in FIG. 4 Steps S501 and S503, steps S701 to S703, and S705 in the embodiment shown in FIG. 6, and steps S801, S802, S804, and S805 in the embodiment shown in FIG. 7.

In the embodiment of the present application, for the case where the communication device 80 is a terminal device, the transceiver 801 is used to communicate with the access network device, for example, performing steps S501 and S503 in the embodiment shown in FIG. 4, as shown in FIG. Steps S701 and S705 in the embodiment are shown, and steps S801 and S805 in the embodiment shown in FIG. 7 are shown.

In the embodiment of the present application, for the case where the communication device 80 is the second access network device, the transceiver 801 is used to communicate with the first access network device and the terminal device. For example, perform the step in the embodiment shown in FIG. 6 Steps S702 and S703 are steps S802 and S804 in the embodiment shown in FIG. 7.

The processor 802 may include one or more processors, such as one or more central processing units (CPU). In the case where the processor 802 is a CPU, the CPU may be a single-core CPU, or It can be a multi-core CPU.

Applied in the embodiment of the present application, for the case where the communication device 80 is the first access network device, the processor 802 is configured to execute step S502 in the embodiment shown in FIG. 4 and step S704 in the embodiment shown in FIG. 6.

In the embodiment of the present application, for the case where the communication device 80 is a terminal device, the processor 802 is configured to establish an RRC connection with the first access network device.

In the embodiment of the present application, for the case where the communication device 80 is the second access network device, the processor 802 is configured to execute step S803 in the embodiment shown in FIG. 7.

The memory 803 is used to store program codes and data of the communication device 80.

Regarding the steps performed by the processor 802 and the transceiver 801, refer to the description of the embodiments shown in FIG. 4, FIG. 6 and FIG. 7 for details, and details are not described herein again.

It can be understood that FIG. 11 only shows a simplified design of the communication device. In practical applications, the communication device may also include other necessary components, including but not limited to any number of transceivers, processors, controllers, memories, communication units, etc., and all the devices that can implement the application are included in this application. Within the scope of protection.

The embodiment of the present application also provides a communication system, which includes a first access network device and a terminal device, and also includes a second access network device.

A person of ordinary skill in the art can understand that all or part of the process in the above-mentioned embodiment method can be realized. The process can be completed by a computer program instructing relevant hardware. The program can be stored in a computer readable storage medium. , May include the processes of the foregoing method embodiments. The aforementioned storage media include: ROM or random storage RAM, magnetic disks or optical discs and other media that can store program codes. Therefore, yet another embodiment of the present application provides a computer-readable storage medium having instructions stored in the computer-readable storage medium, which when run on a computer, cause the computer to execute the methods described in the above aspects.

Another embodiment of the present application also provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the methods described in the above aspects.

A person of ordinary skill in the art may realize that the units and algorithm steps described in the examples in combination with the embodiments disclosed in this application 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 above-described system, device, and unit 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 may be implemented in other ways. For example, the device embodiments described above are only 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 can 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.

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

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be sent from a website, computer, server, or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (such as infrared, wireless, microwave, etc.) Another website site, computer, server or data center for transmission. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, and a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)).

Claims

A communication method, characterized in that it comprises:

When the first access network device receives the radio resource control RRC re-establishment request message from the terminal device, it determines that the access mobility management entity providing services for the terminal device has changed;

The first access network device sends an RRC setup message to the terminal device, where the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.
The method of claim 1, wherein the method further comprises:

The first access network device obtains the access mobility management entity information to which the second access network device belongs from the second access network device, and the second access network device is the terminal device in the initiating office Before the RRC connection re-establishment process, an access network device that provides services for the terminal device;

The determination by the first access network device that the access mobility management entity that provides services for the terminal device has changed includes:

The first access network device determines that it is the terminal according to the access mobility management entity information to which the first access network device belongs and the access mobility management entity information to which the second access network device belongs The access mobility management entity provided by the device has changed.
The method according to claim 2, wherein the access mobility management entity information to which the second access network device belongs includes a list of access mobility management entity sets to which the second access network device belongs , The access mobility management entity information to which the first access network device belongs includes a list of access mobility management entity sets to which the first access network device belongs;

The first access network device determines to provide for the terminal device according to the access mobility management entity information of the first access network device and the access mobility management entity information of the second access network device The service access mobility management entity has changed, including:

The first access network device determines whether the list of the access mobility management entity set to which the first access network device belongs and the list of the access mobility management entity set to which the second access network device belongs exists The same set of access mobility management entities;

If the same set of access mobility management entities does not exist, the first access network device determines that the access mobility management entity providing services for the terminal device has changed.
The method according to claim 2, wherein the first access network device acquiring the access mobility management entity information to which the second access network device belongs from the second access network device comprises:

The first access network device obtains the access mobility management entity information to which the second access network device belongs by receiving an Xn interface establishment request message or an Xn interface establishment response message from the second access network device, The Xn interface establishment request message or the Xn interface establishment response message includes the access mobility management entity information to which the second access network device belongs.
The method according to any one of claims 1 to 4, wherein the method further comprises:

In the case where the first access network device determines that the access mobility management entity providing services for the terminal device has changed, the first access network device does not perform sending to the second access network device Context information acquisition request message step.
The method according to claim 1, wherein before the first access network device determines that the access mobility management entity that provides services for the terminal device is changed, the method further comprises:

The first access network device sends a context information acquisition request message to a second access network device, and the second access network device is the terminal device before the terminal device initiates the RRC connection re-establishment process. Access network equipment that the equipment provides services;

The first access network device receives a context information acquisition response message from the second access network device, where the context information acquisition response message includes an access mobility management entity identifier, and the access mobility management entity identifier Used to identify an access mobility management entity that provides services for the terminal device when the terminal device accesses the second access network device;

The determination by the first access network device that the access mobility management entity that provides services for the terminal device has changed includes:

If the first access network device cannot connect to the access mobility management entity identified by the access mobility management entity identifier, the first access network device determines the access that provides services for the terminal device The mobility management entity has changed.
The method according to claim 1, wherein before the first access network device determines that the access mobility management entity that provides services for the terminal device is changed, the method further comprises:

The first access network device sends a context information acquisition request message to a second access network device, and the second access network device is the terminal device before the terminal device initiates the RRC connection re-establishment process. Access network equipment that the equipment provides services;

The first access network device receives a context information acquisition failure message from the second access network device, where the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that a service is provided for the terminal device The access mobility management entity has changed;

The determination by the first access network device that the access mobility management entity that provides services for the terminal device has changed includes:

The first access network device determines that the access mobility management entity that provides services for the terminal device has changed according to the failure cause.
A communication method, characterized in that it comprises:

The terminal device sends an RRC re-establishment request message to the first access network device;

When the access mobility management entity that provides services for the terminal device changes, the terminal device receives the RRC establishment message from the first access network device;

The terminal device establishes an RRC connection with the first access network device based on the RRC setup message.
A communication device, characterized in that it comprises a transceiver module and a processing module,

The processing module is configured to determine that the access mobility management entity that provides services for the terminal device has changed when the transceiver module receives the RRC re-establishment request message from the terminal device;

The transceiver module is configured to send an RRC setup message to the terminal device, where the RRC setup message is used for the terminal device to establish an RRC connection with the first access network device.
The communication device according to claim 9, wherein:

The transceiver module is further configured to obtain the access mobility management entity information to which the second access network device belongs from the second access network device, where the second access network device is the terminal device Before initiating the RRC connection re-establishment process, an access network device that provides services for the terminal device;

The processing module is specifically configured to determine that it is the terminal according to the access mobility management entity information to which the first access network device belongs and the access mobility management entity information to which the second access network device belongs The access mobility management entity provided by the device has changed.
The communication device according to claim 10, wherein the information of the access mobility management entity to which the second access network device belongs includes information about the access mobility management entity set to which the second access network device belongs A list, where the access mobility management entity information to which the first access network device belongs includes a list of access mobility management entity sets to which the first access network device belongs;

The processing module is specifically configured to determine whether the list of the access mobility management entity set to which the first access network device belongs and the list of the access mobility management entity set to which the second access network device belongs exists The same set of access mobility management entities;

If the same set of access mobility management entities does not exist, it is determined that the access mobility management entity that provides services for the terminal device changes.
The communication device according to claim 10, wherein:

The transceiver module is specifically configured to obtain the access mobility management to which the second access network device belongs by receiving an Xn interface establishment request message or an Xn interface establishment response message sent to the second access network device Entity information, the Xn interface establishment request message or the Xn interface establishment response message includes the access mobility management entity information to which the second access network device belongs.
The communication device according to any one of claims 9-12, wherein the processing unit module is further configured to determine the access mobility of the first access network device to provide services for the terminal device When the management entity changes, the transceiver module is controlled not to execute the step of sending a context information acquisition request message to the second access network device.
The communication device according to claim 9, wherein:

The transceiver module is further configured to send a context information acquisition request message to a second access network device, where the second access network device is the terminal device before initiating the RRC connection re-establishment process. An access network device that the device provides services; receiving a context information acquisition response message from the second access network device, where the context information acquisition response message includes an access mobility management entity identifier, and the access mobility management entity The identifier is used to identify the access mobility management entity that provides services for the terminal device when the terminal device accesses the second access network device;

The processing module is specifically configured to determine the access that provides service for the terminal device if the first access network device cannot connect to the access mobility management entity identified by the access mobility management entity identifier The mobility management entity has changed.
The communication device according to claim 9, wherein:

The transceiver module is further configured to send a context information acquisition request message to a second access network device, where the second access network device is the terminal device before initiating the RRC connection re-establishment process. An access network device that provides services by the device; receiving a context information acquisition failure message from the second access network device, where the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that the terminal device provides The service access mobility management entity changes;

The processing module is specifically configured to determine that the access mobility management entity providing services for the terminal device has changed according to the failure cause.
A communication device, characterized in that it comprises a transceiver module and a processing module,

The transceiver module is configured to send an RRC re-establishment request message to the first access network device; when the access mobility management entity that provides services for the terminal device changes, receive the message from the first access network device RRC establishment message;

The processing module is configured to establish an RRC connection with the first access network device based on the RRC setup message.
A communication method, characterized in that it comprises:

The second access network device receives a context information acquisition request message from the first access network device, where the context information acquisition request message is used to request to acquire the context information of the terminal device;

The second access network device determines the access mobility management entity that provides services for the terminal device according to the access mobility management entity information to which the first access network device belongs and the context information of the terminal device changes happened;

The second access network device sends a context information acquisition failure message to the first access network device.
The method according to claim 17, wherein the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate that an access mobility management entity providing services for the terminal device has changed.
The method according to claim 17, wherein the second access network device is determined to be based on the access mobility management entity information to which the first access network device belongs and the context information of the terminal device Before the access mobility management entity provided by the terminal device is changed, the method further includes:

The second access network device receives an Xn interface establishment request message or an Xn interface establishment response message from the first access network device, and the Xn interface establishment request message or the Xn interface establishment response message includes the first interface Information about the access mobility management entity to which the networked device belongs.
A communication device, characterized in that it comprises a transceiver module and a processing module,

The transceiver module is configured to receive a context information acquisition request message from a first access network device, where the context information acquisition request message is used to request to acquire context information of the terminal device;

The processing module is configured to determine the access mobility management entity that provides services for the terminal device based on the access mobility management entity information to which the first access network device belongs and the context information of the terminal device. change;

The transceiver module is further configured to send a context information acquisition failure message to the first access network device.
The second access network device according to claim 20, wherein the context information acquisition failure message includes a failure reason, and the failure reason is used to indicate an access mobility management entity that provides services for the terminal device changes happened.
The second access network device according to claim 20, wherein:

The transceiver module is further configured to receive an Xn interface establishment request message or an Xn interface establishment response message from the first access network device, where the Xn interface establishment request message or the Xn interface establishment response message includes the first 1. Access mobility management entity information to which the access network device belongs.
A communication system, characterized in that the communication system comprises the communication device according to any one of claims 9-15 and the communication device according to claim 16.
The communication system according to claim 23, wherein the communication system further comprises the communication device according to any one of claims 20-22.
A communication device, characterized in that the communication device comprises a memory and a processor, the memory is used to store instructions, and the processor is used to execute the instructions in the memory, such that the instructions in any one of claims 1-7 are The described method is implemented.
A communication device, wherein the communication device includes a memory and a processor, the memory is used to store instructions, and the processor is used to execute the instructions in the memory, so that the method according to claim 8 is achieve.
A communication device, characterized in that the communication device comprises a memory and a processor, the memory is used to store instructions, and the processor is used to execute the instructions in the memory, such that as any one of claims 17-19 The described method is implemented.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program includes program instructions that, when executed by a processor, cause the processor to execute The communication method according to any one of claims 1-7.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program includes program instructions that, when executed by a processor, cause the processor to execute The communication method of claim 8.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program includes program instructions that, when executed by a processor, cause the processor to execute The communication method of any one of claims 17-19.
A computer chip, wherein the chip is connected to a memory, and the chip is used to read and execute a software program stored in the memory, and execute the method according to any one of claims 1 to 7.
A computer chip, wherein the chip is connected to a memory, and the chip is used to read and execute a software program stored in the memory, and execute the method according to claim 8.
A computer chip, characterized in that the chip is connected to a memory, and the chip is used to read and execute a software program stored in the memory, and execute the method according to any one of claims 17 to 19.