CN112788584A

CN112788584A - Communication method and device

Info

Publication number: CN112788584A
Application number: CN202010018645.3A
Authority: CN
Inventors: 陆长奇; 宗在峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-11-08
Filing date: 2020-01-08
Publication date: 2021-05-11
Anticipated expiration: 2040-01-08
Also published as: CN112788584B; WO2021088554A1

Abstract

A communication method and device, the method includes: the method comprises the steps that a mobility management network element of a first network receives a first request message from a session management network element, the first request message comprises first ARP information, the mobility management network element allocates a first identifier for a default QoS flow of a first connection in the first network, the first identifier is used for identifying a bearer corresponding to the default QoS flow in a second connection in a second network, and the mobility management network element sends a first response message to the session management network element, wherein the first response message comprises the first identifier. The first request message indicates the ARP information corresponding to the default QoS flow, so that the mobility management network element can identify the default QoS flow of the first connection of the first network, and the corresponding identifier is assigned to the default QoS flow, thereby ensuring the service continuity. In addition, the method does not need to restrict the planning of the ARP, and has better flexibility and applicability.

Description

Communication method and device

Technical Field

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

Background

Current third generation partnership project (3 GPP) protocols support interworking between Evolved Packet System (EPS) networks and fifth generation mobile communication technology system (5th GS) networks. Because the EPS network performs quality of service (QoS) control through the EPS bearer, the 5GS network performs QoS control through the QoS flow, and the interworking between the EPS network and the 5GS network requires mapping between the EPS bearer and the QoS flow.

However, in general, the number of EPS bearers that the EPS network can create for one user is not equal to the number of QoS flows that the 5GS network can create for one user. When the number of the QoS flows created by the 5GS network for a certain user is larger than the maximum number of EPS bearers which can be created by the EPS network for the user, only part of the QoS flows can be selected to be switched to the EPS network. Whether a QoS flow can be handed over to the EPS network can be achieved by whether an EPS Bearer Identity (EBI) is allocated to the QoS flow.

In the conventional technical solution, whether a QoS flow can be switched to an EPS network is determined according to an Allocation and Retention Priority (ARP) of the QoS flow. Thus, strict constraints on the ARP planning are required to ensure that the default QoS flow of a PDU session can be switched to the EPS network. That is, the ARP information of the default QoS flow must be set to the non-preemptive type and the priority is highest, otherwise the entire PDU session cannot be switched to the EPS network due to the failure to allocate EBI to the default QoS flow or the failure to cancel the EBI of the default QoS flow. But strict ARP constraints are difficult to guarantee in real-world service deployment.

Disclosure of Invention

The embodiment of the application provides a communication method and device, which are used for allocating a corresponding bearer identifier in a second connection of a second network to a default QoS flow in a first connection of a first network under the condition of no dependency on ARP (Address resolution protocol) planning, so that service continuity during switching between the first network and the second network is ensured.

In a first aspect, an embodiment of the present application provides a communication method, where the method is applicable to a mobility management network element in a first network, and the method includes: a mobility management network element of a first network receives a first request message from a session management network element, the first request message including first allocation retention priority, ARP, information; after receiving the first request message, the mobility management network element allocates a first identifier for a default QoS flow of a first connection in a first network, wherein the first identifier is used for identifying a bearer corresponding to the default QoS flow in a second connection in a second network; the mobility management network element sends a first response message to the session management network element, wherein the first response message comprises the first identifier.

The above-mentioned default quality of service QoS flow may be an implementation of a default first data channel of a first connection in a first network, and the present invention is equally applicable to other forms of first data channels. The bearer may be an implementation manner of a second data channel corresponding to the first data channel in the second connection in the second network, and the present invention is also applicable to other forms of second data channels.

In one implementation, the first request message indicates that the first ARP information is ARP information corresponding to a default quality of service, QoS, flow for a first connection in the first network. By the method, the first request message sent by the session management network element to the mobility management network element of the first network can indicate that the first ARP information carried by the first request message is the ARP information corresponding to the default QoS flow in the first connection of the first network, so that the mobility management network element can identify the default QoS flow of the first connection of the first network, thereby identifying the corresponding identifier for the default QoS flow and ensuring service continuity. In addition, the method does not need to restrict the planning of the ARP, and has better flexibility and applicability.

With reference to the first aspect, in a possible design of the first aspect, the first request message includes only the first ARP information, and correspondingly, the first response message includes only the first identifier.

With reference to the first aspect, in a possible design of the first aspect, the first request message may further include ARP information corresponding to at least one other QoS flow of the first connection, and a position of the first ARP information in the first request message is before a position of the ARP information corresponding to the at least one other QoS flow in the first request message.

With reference to the first aspect, in a possible design of the first aspect, the first response message may include a first identifier and an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

With reference to the first aspect, in a possible design of the first aspect, the first request message further includes first indication information, where the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

With reference to the first aspect, in a possible design of the first aspect, the first response message includes a first identifier and second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection.

With reference to the first aspect, in a possible design of the first aspect, the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

With reference to the first aspect, in a possible design of the first aspect, the first response message further includes second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection, or the first response message may further include an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

With reference to the first aspect, in a possible design of the first aspect, the first request message is a first request message after a first connection is created, where the first connection is a connection of a terminal device.

With reference to the first aspect, in one possible design of the first aspect, the method further includes: and the mobility management network element determines that the identifier allocated for the default QoS flow is the last revoked identifier in the identifiers allocated for the QoS flows of the first connection.

In a second aspect, an embodiment of the present application provides a communication method, where the method is applicable to a session management network element, and the method includes: a session management network element sends a first request message to a mobility management network element of a first network, wherein the first request message comprises first allocation retention priority ARP information; the session management network element receives a first response message from the mobility management network element, where the first response message includes a first identifier allocated by the mobility management network element for a default QoS flow of a first connection in a first network, and the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in a second network.

In one implementation, the first request message indicates that the first ARP information is ARP information corresponding to a default quality of service, QoS, flow for a first connection in the first network. Through the method, the session management network element indicates that the first ARP information carried by the session management network element is the ARP information corresponding to the default QoS flow in the first connection of the first network through the first request message sent to the mobility management network element of the first network, so that the mobility management network element can identify the default QoS flow of the first connection of the first network, thereby identifying the corresponding identifier for the default QoS flow and ensuring the service continuity. In addition, the method does not need to restrict the planning of the ARP, and has better flexibility and applicability.

With reference to the second aspect, in a possible design of the second aspect, only the first ARP information is included in the first request message; accordingly, only the first identity is included in the first response message.

With reference to the second aspect, in a possible design of the second aspect, the first request message further includes ARP information corresponding to at least one other QoS flow of the first connection, and a position of the first ARP information in the first request message is before a position of the ARP information corresponding to the at least one other QoS flow in the first request message.

With reference to the second aspect, in a possible design of the second aspect, the first response message includes a first identifier and an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

With reference to the second aspect, in a possible design of the second aspect, the first request message further includes first indication information, where the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

With reference to the second aspect, in a possible design of the second aspect, the first response message includes a first identifier and second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection.

With reference to the second aspect, in a possible design of the second aspect, the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

With reference to the second aspect, in a possible design of the second aspect, the first response message further includes second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection, or the first response message further includes an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

With reference to the second aspect, in a possible design of the second aspect, the first request message is a first request message after the first connection is created, and the first connection is a connection of a terminal device.

In a third aspect, an embodiment of the present application provides a communication method, where the method is applicable to a mobility management network element in a first network, and the method includes: a mobility management network element of a first network receives a request message from a session management network element, wherein the request message is used for requesting allocation of an identifier for a first quality of service (QoS) flow of a first connection of a terminal device in the first network, and the identifier is used for identifying a bearer corresponding to the first QoS flow in a second connection in a second network; the mobile management network element determines that the identifier distributed to the terminal equipment needs to be cancelled; the mobility management network element revokes the second identifier of the second QoS flow from the allocated identifiers according to a policy, and allocates the second identifier to the first QoS flow, wherein the policy is: in the identifiers allocated to the QoS flows connected in a first network of the terminal equipment, the identifier allocated to the default QoS flow is the identifier which is finally revoked; and the mobility management network element sends a response message to the session management network element, wherein the response message comprises the second identifier.

By the method, when the identifier allocated to the terminal device needs to be cancelled, the mobility management network element of the first network can select the QoS flow with the cancelled identifier according to the policy of preferentially cancelling the identifier allocated to the non-default QoS flow in the connection of the first network, so that the problem that the connection of the first network where the default QoS flow is located cannot be switched to the second network due to the fact that the identifier allocated to the default QoS flow is cancelled can be avoided, and the service continuity of the terminal device can be effectively guaranteed.

With reference to the third aspect, in a possible design of the third aspect, the second QoS flow is a non-default QoS flow of the first connection.

With reference to the third aspect, in a possible design of the third aspect, the second QoS flow is a non-default QoS flow that has a lowest priority in the first connection and can be preempted.

With reference to the third aspect, in a possible design of the third aspect, the second QoS flow is a QoS flow of a connection other than the first connection for the terminal device.

With reference to the third aspect, in a possible design of the third aspect, the second QoS flow is a lowest priority preemptible QoS flow in a connection in the first network of the terminal device.

With reference to the third aspect, in a possible design of the third aspect, when all QoS flows that have been allocated with identifications in a connection in the first network of the terminal device are default QoS flows, the second QoS flow is a default QoS flow of other connections of the terminal device except the first connection.

With reference to the third aspect, in one possible design of the third aspect, the method further includes: the mobility management network element determines that the first QoS flow has preemption capability.

With reference to the third aspect, in one possible design of the third aspect, the method further includes: and the mobility management network element sends a response message, wherein the response message comprises the second identifier.

With reference to the third aspect, in a possible design of the third aspect, the request message further includes ARP information corresponding to at least one other QoS flow of the first connection, and the response message further includes an identifier allocated to the other QoS flow;

with reference to the third aspect, in a possible design of the third aspect, if the first QoS flow is a default QoS flow of the first connection, the response message further includes second indication information, where the second indication information is used to indicate that a second identifier is an identifier allocated by a mobility management network element for the default QoS flow of the first connection, or a position of the second identifier in the response message is located before a position of the identifier allocated by the other QoS flows in the response message.

With reference to the third aspect, in one possible design of the third aspect, the method further includes: and the mobility management network element receives an update message from the session management network element, wherein the update message is used for updating the corresponding relation between the ARP and the identifier.

With reference to the third aspect, in one possible design of the third aspect, the method further includes: the mobility management network element receives a message from the source mobility management network element or the session management network element, the message including the assigned identity for the terminal device.

With reference to the third aspect, in a possible design of the third aspect, the allocated identification includes an identification of QoS flow allocation in connections of one or more first networks of the terminal device.

With reference to the third aspect, in a possible design of the third aspect, the allocated identifier includes an identifier allocated for a default QoS flow, and may also include an identifier allocated for a non-default QoS flow.

With reference to the third aspect, in a possible design of the third aspect, the identifier of the default QoS flow assignment is located in the message before the identifier of the non-default QoS flow assignment in the connection to the first network is located in the message.

With reference to the third aspect, in a possible design of the third aspect, the message includes indication information, where the indication information is used to indicate an identifier corresponding to a default QoS flow.

With reference to the third aspect, in a possible design of the third aspect, the indication information is an identifier corresponding to the default QoS flow.

In a fourth aspect, the present application provides a communication apparatus, which may be a mobility management network element or a chip in the mobility management network element. The apparatus may include a processing unit and a transceiver unit. When the apparatus is a mobility management network element, the processing unit may be a processor, and the transceiving unit may be a communication interface; the mobility management network element may further comprise a storage unit, which may be a memory; the storage unit is configured to store instructions, and the processing unit executes the instructions stored by the storage unit to cause the mobility management network element to perform the method according to the first aspect or the third aspect. When the apparatus is a chip within a mobility management network element, the processing unit may be a processor, and the transceiving unit may be an input/output interface, a pin, a circuit, or the like; the processing unit executes instructions stored by a storage unit, which may be a storage unit (e.g., a register, a cache, etc.) within the chip or a storage unit (e.g., a read-only memory, a random access memory, etc.) located outside the chip within the mobility management network element, so as to cause the mobility management network element to perform the method of the first aspect or the third aspect.

In a fifth aspect, an embodiment of the present application provides a communication apparatus, where the communication apparatus may be a session management network element, and may also be a chip in the session management network element. The communication device may include a processing unit and a transceiving unit. When the apparatus is a session management network element, the processing unit may be a processor, and the transceiving unit may be a communication interface; the session management network element may further comprise a storage unit, which may be a memory; the storage unit is configured to store instructions, and the processing unit executes the instructions stored by the storage unit to cause the session management network element to execute the method according to the second aspect. When the apparatus is a chip in a session management network element, the processing unit may be a processor, and the transceiving unit may be an input/output interface, a pin, a circuit, or the like; the processing unit executes instructions stored by a storage unit, which may be a storage unit (e.g., a register, a cache, etc.) within the chip or a storage unit (e.g., a read-only memory, a random access memory, etc.) located outside the chip, so as to cause the session management network element to perform the method according to the second aspect.

In a sixth aspect, an embodiment of the present application provides a chip system, including: a processor coupled to a memory for storing a program or instructions which, when executed by the processor, cause the system-on-chip to implement the method in the first aspect or any one of the possible designs of the first aspect, or the second aspect or any one of the possible designs of the second aspect, or the third aspect, or any one of the possible designs of the third aspect.

Optionally, the chip system further comprises an interface circuit for receiving the code instructions and transmitting them to the processor.

Optionally, the number of processors in the chip system may be one or more, and the processors may be implemented by hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

Optionally, the memory in the system-on-chip may also be one or more. The memory may be integrated with the processor or may be separate from the processor, which is not limited in this application. For example, the memory may be a non-transitory processor, such as a read only memory ROM, which may be integrated with the processor on the same chip or separately disposed on different chips, and the type of the memory and the arrangement of the memory and the processor are not particularly limited in this application.

In a seventh aspect, this application provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, causes the processor to perform the method in the first aspect or any one of the possible designs of the first aspect, or the method in the second aspect or any one of the possible designs of the second aspect, or the method in any one of the possible designs of the third aspect.

In an eighth aspect, an embodiment of the present application provides a computer program product, including: computer program code which, when executed by a processor, causes the processor to perform the method in the first aspect or any one of the possible designs of the first aspect, or the second aspect or any one of the possible designs of the second aspect, or the third aspect.

In a ninth aspect, an embodiment of the present application provides a communication system, where the communication system includes a session management network element and a mobility management network element in a first network. Optionally, the communication system further comprises a terminal device.

Drawings

Fig. 1 is a schematic diagram of a network architecture suitable for use in the embodiment of the present application;

fig. 2 is a flowchart illustrating a communication method according to an embodiment of the present application;

fig. 3 is a schematic flowchart of another communication method according to an embodiment of the present application;

fig. 4 is a schematic flowchart of allocating an EBI for a first QoS flow in an example provided by an embodiment of the present application;

fig. 5 is a schematic diagram of a 5GS EBI allocation flow provided in the first embodiment of the present application;

fig. 6 is a schematic diagram of a 5GS EBI allocation flow provided in the second embodiment of the present application;

fig. 7 is a schematic diagram of a 5GS EBI allocation flow provided in a third embodiment of the present application;

fig. 8 is a schematic diagram of an EPS to 5GS Registration or Handover procedure provided in the fourth embodiment of the present application;

fig. 9 is a schematic diagram of an EPS to 5GS Registration or Handover procedure provided in the fifth embodiment of the present application;

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

fig. 11 is another schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: global system for mobile communications (GSM) systems, Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD), universal mobile telecommunications system (universal mobile telecommunications system, UMTS), Worldwide Interoperability for Microwave Access (WIMAX) communication systems, fifth generation (5G) or new NR systems, etc., or other similar communication systems applied to future communications.

The technical scheme provided by the embodiment of the application is suitable for a scenario supporting interoperation between a first network and a second network, wherein the first network and the second network are systems supporting different communication systems, and thus the first network may also be referred to as a first system and the second network may also be referred to as a second system. For example, the first network may be a 5G communication system, and the second network may be a 4G communication system, where the 5G communication system may also be referred to as a 5GS network or simply as a 5G system, and the 4G communication system may also be referred to as an EPS network or simply as a 4G system. It should be understood that the first network and the second network in the embodiment of the present application may also be other types of communication systems, and the present application is not limited thereto.

Please refer to fig. 1, which is a schematic diagram of a possible network architecture in which a 5GS network and an EPS network coexist according to an embodiment of the present application. The main network elements involved in the network architecture are explained below.

The EPS network may include the following network elements:

1. (radio access network, (R) AN) network element: the method and the device are used for providing a network access function for authorized terminal equipment in a specific area, and can use transmission tunnels with different qualities according to the grade of the terminal equipment, the service requirement and the like.

The (R) AN network element can manage radio resources, provide access services for the terminal device, and then complete forwarding of control signals and terminal device data between the terminal device and the core network, and the (R) AN network element can also be understood as a base station in a conventional network. In a 4G communication system, the (R) AN network element may also be referred to as evolved universal terrestrial radio access network (E-UTRAN) or evolved base station (eNB), as shown in fig. 1.

It should be noted that the "network element" may also be referred to as an entity, a device, an apparatus, a module, or the like, and the present application is not particularly limited. Also, in the present application, for convenience of understanding and explanation, a description of "network element" is omitted in some descriptions, for example, AN (R) AN network element is abbreviated as RAN, in which case the "(R) AN network element" is understood as AN (R) AN network element or AN (R) AN entity, and explanation of the same or similar cases is omitted below.

2. A Mobility Management Entity (MME) for providing mobility management functions. In addition, the MME may also provide functions such as lawful interception and access authorization/authentication.

3. A Serving Gateway (SGW) is used for providing functions such as user data forwarding.

4. A packet data network gateway user plane function (PGW-U) for providing a user plane function of a PDN gateway.

5. A packet data network gateway control plane function (PGW-C) for providing a control plane function of the PDN gateway.

6. A Policy and Charging Rules Function (PCRF) for providing a unified policy framework for guiding network behavior, providing policy and charging rules information for a control plane function network element, and the like.

7. A Home Subscriber Server (HSS) includes a subscriber profile for performing authentication and authorization of a subscriber and may provide information about the physical location of the subscriber.

The 5GS network may comprise the following network elements:

1. (R) AN network element: the method and the device are used for providing a network access function for authorized terminal equipment in a specific area, and can use transmission tunnels with different qualities according to the grade of the terminal equipment, the service requirement and the like.

In a 5G communication system, the (R) AN network element may also be referred to as a next generation access network (NG-RAN, as shown in fig. 1) or a next generation base station (gNB).

2. An access and mobility management function (AMF) for functions of access management and mobility management. In addition, the AMF may also provide functions such as lawful interception and access authorization/authentication.

In one possible design, the AMF may communicate with the MME over an N26 interface. In fig. 1, letters and numbers of the line attachments between the network elements indicate names of communication interfaces between the network elements, however, the communication interfaces between the network elements may have other names, and the present application is not limited thereto.

3. User Plane Function (UPF), which is used for packet routing and forwarding, quality of service (QoS) processing of user plane data, and the like.

4. A Session Management Function (SMF), which is mainly used for session management, IP (internet protocol) address allocation and management of terminal devices, and user plane selection and management. The SMF may also be the termination point of the policy control and charging function interface.

5. A Policy Control Function (PCF), a unified policy framework for guiding network behavior, providing policy rule information for control plane function network elements (e.g., AMFs, SMFs, etc.), and the like.

6. A Unified Data Management (UDM) network element for managing subscription data. In addition, the method is also used for user service registration management, terminal equipment identification processing, access authentication and the like.

In the above network architecture, network elements with the same or similar functions may be jointly configured. For example, UPF and PGW-U may be combined, SMF and PGW-C may be combined, PCF and PCRF may be combined, HSS and UDM may be combined, and the "+" in fig. 1 indicates that two devices may be combined.

It should be understood that the network architecture applied to the present application is only an exemplary network architecture described in the service architecture, and the network architecture to which the embodiments of the present application are applied is not limited thereto, and any network architecture capable of implementing the functions of the network elements described above is applicable to the embodiments of the present application.

The network element or the function may be a network element in a hardware device, a software function running on dedicated hardware, or a virtualization function instantiated on a platform (e.g., a cloud platform).

The terminal device may be switched from the 4G communication system to the 5G communication system, or may be switched from the 5G communication system to the 4G communication system. The terminal equipment has a wireless communication function, can be deployed on land and comprises an indoor or outdoor, handheld or vehicle-mounted terminal; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal may be a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned driving (self driving), a wireless terminal in remote medical treatment (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), etc.; but also various forms of User Equipment (UE), Mobile Station (MS), and terminal equipment (terminal device).

For convenience of description, in the following description, a mobility management network element is taken as an access and mobility management function AMF network element, and a session management network element is taken as a session management function SMF network element, for example. Further, the AMF network element is abbreviated as AMF, and the SMF network element is abbreviated as SMF. That is, the AMFs described later in this application may be replaced by a mobility management network element, and the SMFs may be replaced by a session management network element.

Please refer to fig. 2, which is a flowchart illustrating a communication method provided in an embodiment of the present application, where the method specifically includes the following steps:

step S201, the session management network element sends a first request message to a mobility management network element of the first network, where the first request message includes first ARP information, and the first request message indicates that the first ARP information is ARP information corresponding to a default QoS flow of a first connection in the first network.

The first request message is configured to request a mobility management network element of the first network to allocate an identifier for a default QoS flow of a first connection in the first network, where the identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in the second network, for example, the identifier may be an identifier of a bearer corresponding to the default QoS flow in the second connection in the second network.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the first connection in the first network may refer to a PDU session in the 5GS network, and the second connection in the second network may refer to a PDN connection in the EPS network, and for convenience of description, the first connection in the first network is respectively referred to as a first PDU session and a first PDN connection in the following of the present application.

In the embodiment of the present application, a PDU session at least includes a default QoS flow (default QoS flow), and optionally, the PDU session may further include one or more other QoS flows, where the one or more other QoS flows are non-default QoS flows, or may also be referred to as dedicated QoS flows (default QoS flows). That is, if only one QoS flow is included in one PDU session, the QoS flow must be a default QoS flow, if a plurality of QoS flows are included in one PDU session, one default QoS flow must exist in the plurality of QoS flows, and the other QoS flows are all non-default QoS flows. Similarly, at least one default EPS bearer is included in one PDN connection, and optionally, one or more other EPS bearers may also be included in the PDN connection, where the one or more other EPS bearers are non-default EPS bearers or may also be referred to as dedicated EPS bearers.

As such, the first request message may be understood as that the session management network element (e.g. SMF) requests the mobility management network element (e.g. AMF) in the 5GS network to allocate an EBI to the default QoS flow of the first PDU session, where the EBI refers to an identification of an EPS bearer corresponding to the default QoS flow in the first PDN connection in the EPS network. The first request message may also be referred to as a first EBI allocation request message, or may have another name, and the present application is not limited thereto. It will be appreciated that if a QoS flow is allocated an EBI, this indicates that the QoS flow can be successfully handed over from the 5GS network to the EPS network.

It can be understood that, in the embodiment of the present application, the first connection in the first network and the second connection in the second network are connections for the same terminal device. I.e. the first PDU session is a PDU session of the terminal device and the first PDN connection is also a PDN connection of the terminal device.

Optionally, the session management network element may send the first request message to the mobility management network element of the first network in a process of creating the first connection in the first network. Further, the first request message may also be a first request message after the first connection is created. That is to say, after a first PDU session in the 5GS network is created, the SMF first applies for EBI for a default QoS flow in the first PDU session, so that when the terminal device performs handover from the 5GS network to the EPS network, the default QoS flow in the PDU session can be successfully handed over to the EPS network, thereby ensuring service continuity of the terminal device.

In this embodiment of the application, the ARP information indicating that the first ARP information is the ARP information corresponding to the default QoS of the first connection in the first network may have a variety of possible implementations.

In a first possible implementation, only the first ARP information may be included in the first request message. That is, only ARP information of the default QoS flow of the first connection may be carried in the first request message, thereby facilitating the mobility management network element to identify the default QoS flow in the first connection. It should be noted that, the first request message may only include the first ARP information, which means that the first request message does not include ARP information of other QoS flows of the first connection, and of course, according to different scenarios, the first request message may also include other information.

For example, after the first connection of the first network is created, the mobility management network element may receive, from the session management network element, the first ARP information carried in the first request message, and determine that the ARP information corresponds to the default QoS flow of the first connection.

In a second possible implementation manner, the first request message may include the first ARP information and ARP information corresponding to at least one other QoS flow of the first connection. In order to facilitate the mobility management network element to identify ARP information corresponding to a default QoS flow of the first connection, the location of the first ARP information in the first request message precedes the location of ARP information corresponding to at least one other QoS flow of the first connection in the first request message.

For example, the first ARP information and ARP information corresponding to the at least one other QoS flow of the first connection may be included in different fields in the first request message, and the field including the first ARP information precedes the field including ARP information corresponding to the at least one other QoS flow of the first connection. Optionally, the first ARP information may be located in one field in the first request message, and the ARP information corresponding to at least one other QoS flow of the first connection is located in another field or fields in the first request message; alternatively, the ARP information corresponding to each QoS flow may have an independent field in the first request message, which is not limited in this application.

For another example, the first ARP information and ARP information corresponding to the at least one other QoS flow of the first connection may be included in the same field in the first request message, and the location of the first ARP information in this field precedes the location of the ARP information corresponding to the at least one other QoS flow of the first connection in this field.

For another example, the first request message may include a list of ARP information, the first ARP information is located at a first position of the list of ARP information, and the ARP information corresponding to at least one other QoS flow of the first connection is located after the first ARP information in the list of ARP information.

In a third possible implementation manner, the first request message may include first ARP information and first indication information, where the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

Optionally, the first request message may further include ARP information corresponding to at least one other QoS flow of the first connection, and a position of the first ARP information in the first request message is before ARP information corresponding to at least one other QoS flow of the first connection. For a specific implementation of the location of the first ARP information in the first request message corresponding to the first ARP information and the at least one other QoS flow of the first connection, reference may be made to the description in the second possible implementation, which is not described herein again.

In this embodiment of the application, the first indication information may be represented as information carried in a certain field in the first request message, for example, if the first ARP information and ARP information corresponding to at least one other QoS flow of the first connection are located in different fields in the first request message, the first indication information may be used to indicate a field where the first ARP information is located, and the first indication information may be located in the field where the first ARP information is located, or may be located in a separate field, which is not limited in this application. For another example, if the first ARP information is located in the same field in the first request message as at least one other QoS flow of the first connection, the first indication information may be used to indicate that the first ARP information contained in the field is the first ARP information. For another example, the first request message includes an ARP list, where the ARP list includes the ARP corresponding to all QoS flows that need to allocate the EBI, and in addition to the ARP list, the first request message also includes the ARP corresponding to the default QoS flow, and the ARP corresponding to the default QoS flow is used as the first indication information. For another example, if the first request message includes a list of ARP information, the first indication information is used to indicate that the first ARP information in the list of ARP information is the first ARP information. Alternatively, the first indication information may exist in an implicit manner, for example, the existence of a specific field for indicating the first ARP information in the first request message may be regarded as the first indication information.

It should be noted that the third possible implementation manner may be applied to a scenario in which, in the PDU session creation process, the PCF issues multiple rules and needs to map the rules into QoS rules, or a scenario in which the terminal device originally does not support the interoperation between the first network and the second network but the subsequent subscription is modified to support the interoperation between the first network and the second network.

In a fourth possible implementation manner, the first request message may include the first ARP information and ARP information corresponding to at least one other QoS flow of the first connection. The first ARP information is ARP information corresponding to a default QoS (quality of service) flow of the first connection in the first network. In other words, the first ARP itself may be used as the indication information to indicate that the first ARP information is the ARP information corresponding to the default QoS flow of the first connection in the first network. For example, the priority of the first ARP is set to a specific value indicating that this ARP is the ARP for the default quality of service QoS flow. In one implementation, a value of a priority of an ARP corresponding to the default QoS flow is predefined, and an ARP corresponding to another QoS flow cannot be set to the predefined value, and in another implementation, whether the ARP supports a preempted attribute (Pre-preemption virtual) may be set to distinguish the ARP corresponding to the default QoS flow from the ARP of the other QoS flow, for example, the ARP of the default QoS flow is set to be unable to be preempted, and the ARP of the other QoS flow is set to be preempted. Of course, other manners may also be adopted to distinguish the ARP of the default QoS flow from the ARP of other QoS flows, which is not limited in this embodiment. This implementation may not require additional indication information, nor may it require the first ARP be placed before the other ARP. The mobility management network element can determine whether the ARP is the ARP corresponding to the default QoS flow according to the ARP.

In addition, it should be understood that, the ARP information corresponding to the QoS flows mentioned in the embodiments of the present application does not limit that one ARP information corresponds to one QoS flow, and one ARP information may correspond to one or more QoS flows. That is to say, the ARP information corresponding to different QoS flows may be the same, and when the first request message includes ARP information corresponding to multiple QoS flows, if the ARP information corresponding to some of the QoS flows is the same, the same ARP information may be repeated multiple times in the first request message, that is, one ARP information corresponds to one QoS flow one to one; the same ARP information may also occur only once in the first request message, i.e. there are one or more QoS flows corresponding to the same ARP information.

The first and second possible implementations may be understood as indicating, in an implicit form, that the first APR information in the first request message is ARP information corresponding to the default QoS flow, and the third possible implementation may be understood as indicating, in an explicit form, that the first APR information in the first request message is ARP information corresponding to the default QoS flow.

Step S202, the mobility management network element receives the first request message from the session management network element.

Step S203, after receiving the first request message, the mobility management network element allocates a first identifier to a default QoS flow of a first connection in the first network, where the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in the second network.

In this embodiment of the present application, a mobility management network element may allocate, according to a policy, a first identifier to a default QoS flow of a first connection in a first network. The strategy comprises the following steps: if the terminal device currently has an identification of the bearer of the second connection in the available second network, the mobility management network element may assign an identification to the default QoS flow of the first connection from the identification of the bearer of the available second connection. If the terminal device does not currently have the identifier of the bearer of the second connection in the available second network, the identifier of the second bearer of the second connection already allocated to the terminal device needs to be revoked, and the mobility management network element may reallocate the revoked identifier of the second bearer of the second connection to the default QoS flow of the first connection. However, when the identifier of the bearer of the second connection already allocated to the terminal device is revoked, it should be noted that, among the identifiers allocated to the QoS flows of one first connection, the identifier allocated to the default QoS flow is the last identifier to be revoked.

It should be understood that, if the first request message further includes, in addition to the first ARP information, ARP information corresponding to at least one other QoS flow of the first connection, the mobility management network element may preferentially allocate an EBI to the default QoS flow. That is, when the mobility management element confirms that EBIs cannot be allocated for all requested QoS flows, the mobility management element first allocates the available EBIs to the default QoS flow.

It is further understood that if the first request message includes, in addition to the first ARP information, ARP information corresponding to at least one other QoS flow of the first connection, the mobility management network element may allocate an identification of the corresponding bearer in the second connection for some or all of the at least one other QoS flow of the first connection in a similar manner as the allocation of the first identification for the default QoS flow. That is, since the identities of the bearers in the second connection that can be allocated for the QoS flows of one terminal device are limited, there may be a case where some non-default QoS flows cannot be allocated with identities.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the first request message may include ARP information corresponding to the default QoS flow in the first PDU session, and after receiving the first request message, a mobility management network element (e.g., AMF) in the 5GS network may allocate a first EBI to the default QoS flow in the first PDU session, where the first EBI is an identifier of an EPS bearer corresponding to the default QoS flow in the first PDU session in the first PDN connection in the EPS network. If the first request message may include ARP information corresponding to one or more non-default QoS flows of the first PDU session, the AMF may allocate EBI for some or all of the one or more non-default QoS flows of the first PDU session in the same manner.

It should be noted that the revocation referred to in the embodiments of the present application may also be expressed as recovery, cancellation, release, and the like, and the present application is not limited thereto.

How the mobility management network element allocates an identifier for a default QoS flow of a first connection in a first network according to a policy will be described in detail in another communication method provided in this embodiment of the present application.

Step S204, the mobility management element sends a first response message to the session management element, where the first response message includes the first identifier.

In a first possible implementation manner of the method, the first response message may include only the first identifier allocated for the default QoS flow of the first connection in the first network. Similarly, the fact that the first response message may include only the first identifier allocated to the default QoS flow means that the first response message does not include identifiers allocated to other QoS flows, and of course, the first response message may include other information according to different scenarios.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the first response message may include only the first EBI allocated for the default QoS flow of the first PDU session.

In a second possible implementation manner of the method, the first response message may include the first identifier and an identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection in the first response message.

Taking the example that the first network is a 5GS network and the second network is an EPS network, the first response message may include the first EBI allocated by the AMF for the default QoS flow of the first PDU session and the EBI allocated by the AMF for the at least one other QoS flow of the first PDU session, and the position of the first EBI in the first response message is before the position of the EBI allocated by the AMF for the at least one other QoS flow of the first PDU session in the first response message.

The specific implementation manner of the location of the first identifier in the first response message is similar to the specific implementation manner of the location of the first ARP information in the first request message, that is, the field containing the first identifier may be located before the field containing the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection, or may be in a field, the location of the first identifier in the field may be located before the location of the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection in the field, or there may be a list of identifiers of bearers of the second connection in the first response message, where the first identifier is in a first location in the list of identifiers, for specific please refer to the description in the foregoing.

Corresponding to a third possible implementation manner of indicating that the first ARP information is ARP information corresponding to a default QoS flow of the first connection in the first network, the first response message may include a first identifier and second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for the default QoS flow of the first connection.

Optionally, the first response message may further include an identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection, and a location of the first identifier in the first response message is before a location of the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection in the first response message. The specific implementation of the location of the first identifier in the first response message is similar to the specific implementation of the location of the first ARP information in the first request message, see the description above.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the first response message may include first EBI and second indication information allocated by the AMF for the default QoS flow of the first PDU session, where the second indication information is used to indicate that the first EBI is the EBI allocated by the AMF for the default QoS flow of the first PDU session. Optionally, the first response message may include the EBI allocated by the AMF for the at least one other QoS flow of the first PDU session, and the position of the first EBI in the first response message is before the position of the EBI allocated by the AMF for the at least one other QoS flow of the first PDU session in the first response message.

The specific implementation of the second indication information is similar to the specific implementation of the first indication information, that is, the second indication information may be represented as information carried in a certain field in the first response message, or as an Information Element (IE) in the first response message. For example, if the first identifier and the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection are located in different fields in the first response message, the second indication information may be used to indicate the field where the first identifier is located, where the second indication information may be located in the field where the first identifier is located, or may be located in a separate field, which is not limited in this application; for another example, if the first identifier and the identifier allocated by the mobility management network element for the at least one other QoS flow of the first connection are located in the same field in the first response message, the first indication information may be used to indicate that the first identifier contained in the field is the first identifier of the default QoS flow allocated to the first connection. For another example, the first response message includes a list of the correspondence between the ARP corresponding to all QoS flows to which EBIs allocated and the EBI allocated to the QoS flow, and in addition, the first response message also includes the EBI allocated to the default QoS flow, and the EBI serves as the second indication information. For another example, if the first response message includes a list of identities of bearers in the second connection, the second indication information is used to indicate that the first identity in the list of identities is the first identity of the default QoS flow allocated to the first connection. Alternatively, the first indication information may exist in an implicit manner, for example, the existence of a specific field for indicating the first identifier of the default QoS flow allocated to the first connection included in the first response message may be regarded as the second indication information.

Optionally, if the first response message includes the identifier allocated by the mobility management network element for the multiple QoS flows, an order of the identifier allocated for the multiple QoS flows in the first response message may be the same as or different from an order of the ARP information corresponding to the multiple QoS flows in the first request message, which is not limited in this application.

It may be understood that, after step S204, the mobility management network element may further allocate, to other QoS flows in the first connection, an identifier of a bearer corresponding to the second connection in the second network, and may also allocate, to QoS flows in other connections in the first network, an identifier of a bearer corresponding to the second connection in the second network, where the other connections in the first network and the aforementioned first connection are all connections of the same terminal device.

It should also be understood that the mobility management network element may receive, from the same session management network element, a second request message requesting assignment of an identifier for another QoS flow in the first connection or another QoS flow in another connection of the first network, or may receive, from another session management network element, a second request message requesting assignment of an identifier for another QoS flow in the first connection or another QoS flow in another connection of the first network, which is not limited in this application.

That is, after step S204, the AMF may also allocate an EBI for the other QoS flows of the first PDU session or the QoS flow of the second PDU session of the terminal device. If the AMF receives a first request message requesting allocation of an EBI for a default QoS flow of a first PDU session from a first SMF, the AMF may receive a second request message from the first SMF and may also receive the second request message from a second SMF, provided that the request message requesting allocation of an EBI for other QoS flows of the first PDU session or QoS flows of a second PDU session of the terminal device is denoted as the second request message.

It should be noted that, after receiving the first response message, if the ARP corresponding to the first identifier indicated in the first response message is not the ARP corresponding to the default QoS flow (for example, when the mobility management element determines the ARP corresponding to the default QoS flow according to the fourth manner, the mobility management element determines the ARP corresponding to the default QoS flow as the ARP corresponding to the default QoS flow), the session management element may perform the following processing:

and the session management network element determines the first identifier as the EBI corresponding to the default QoS flow.

Assuming that ARP1 and ARP2 are included in the first request message, the first ARP determined by SMF is ARP1, but the first ARP determined by AMF is ARP2, AMF allocates EBI1 to ARP1, ARP2 allocates EBI2, AMF sends < ARP2, EBI2>, < ARP1, EBI1> in the first response message, and indicates that EBI2 is the EBI corresponding to the default QoS flow, SMF takes EBI2 as the EBI corresponding to the default QoS flow, that is, the information actually stored by SMF is < ARP1, EBI2>, < ARP2, EBI1 >.

This may cause inconsistencies in the SMF with the < ARP, EBI > correspondence maintained by the AMF.

Optionally, the session management network element sends an update message to the AMF, so as to update the corresponding relationship between the ARP and the EBI. That is, after re-determining the correspondence relationship, the SMF sends the new correspondence relationship to the AMF. As in the above example, the update message sent by the SMF to the AMF includes: < ARP1, EBI2>, < ARP2, EBI1>, so that the same correspondence is preserved in AMF and SMF. The update operation does not change which EBI determined by the AMF is the EBI corresponding to the default QoS flow.

Please refer to fig. 3, which is a flowchart illustrating another communication method according to an embodiment of the present application, where the method specifically includes the following steps:

step S301, the mobility management network element of the first network receives a request message from the session management network element, where the request message is used to request to allocate an identifier for a first QoS flow of a first connection of the terminal device in the first network, and the identifier is used to identify a bearer corresponding to the first QoS flow in a second connection in a second network.

The request message may include ARP information corresponding to the first QoS flow. The first QoS flow may be a default QoS flow of the first connection, or may be a non-default QoS flow of the first connection, which is not limited in the embodiment of the present application. When the first QoS flow is a default QoS flow of the first connection, the request message may further indicate that the first ARP information is ARP information corresponding to the default QoS flow of the first connection in the first network, where the first ARP information refers to ARP information corresponding to the first QoS flow. Or, the first ARP itself may be used as indication information to indicate that the first ARP information is ARP information corresponding to a default quality of service QoS flow of the first connection in the first network. That is to say, the two communication methods provided in the embodiments of the present application may be combined with each other when applied.

The request message may also include ARP information corresponding to other QoS flows of the first connection, so as to allocate an identifier for the other QoS flows.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the first connection in the first network may refer to a PDU session in the 5GS network, such as a first PDU session, and the second connection in the second network may refer to a PDN connection in the EPS network, such as a first PDN connection. As mentioned above, one or more QoS flows may be included in a PDU session, one default QoS flow is included in the one or more QoS flows, and other QoS flows in the one or more QoS flows except the default QoS flow are non-default QoS flows, which may also be referred to as dedicated QoS flows. One PDN connection may include one or more EPS bearers, where the first one or more EPS bearers include a default EPS bearer, and except for the default EPS bearer, other EPS bearers in the first one or more EPS bearers are non-default EPS bearers or may also be referred to as dedicated EPS bearers, and the identifier used to identify the bearer of the second connection in the second network is an identifier of the EPS bearer, that is, an EBI.

As can be seen, the request message is used to request allocation of an EBI for a first QoS flow of a first PDU session of the terminal device in the 5GS network, where the EBI is an identifier of a corresponding EPS bearer of the first QoS flow in the EPS network, and the first QoS flow may be a default QoS flow or a non-default QoS flow in the first PDU session.

Step S302, the mobility management network element determines that the identifier allocated to the terminal device needs to be revoked.

In this embodiment, a maximum number of identifiers allowed to be allocated to each terminal device may be configured for the terminal device, where the identifier refers to an identifier carried in a second connection in a second network. The maximum number of assignable identifiers corresponding to different terminal devices may be the same or different, and the present application is not limited thereto.

Thus, the determination, by the mobility management network element, that the identifier allocated to the terminal device needs to be revoked may be: the mobility management network element determines that the number of the identifiers allocated to the terminal device reaches a set threshold, the terminal device does not have an available identifier at present, and the set threshold is the maximum number of the allocable identifiers corresponding to the terminal device. It should be understood that the determination by the mobility management network element that the identifier allocated to the terminal device needs to be revoked may also be in other situations, and the application is not limited thereto. For example, the terminal device changes from supporting the interoperation between the first network and the second network to not supporting the interoperation between the first network and the second network, the session management network element requests the mobility management network element to revoke the assigned identity for the terminal device, and then the mobility management network element may determine that the assigned identity for the terminal device needs to be revoked.

Taking the first network as a 5GS network and the second network as an EPS network as an example, each terminal device may correspond to a maximum value of the number of assignable EBIs. If the number of the EBIs currently allocated to the QoS flow of the terminal device is equal to the maximum value of the number of the EBIs, it indicates that the terminal device does not currently have an available EBI, and it is necessary to revoke the EBI allocated to a certain QoS flow of the terminal device.

Step S303, the mobility management network element revokes the second identifier of the second QoS flow from the allocated identifiers according to the policy, and allocates the second identifier to the first QoS flow. Wherein the policy is: among the identifiers allocated to the QoS flows of the connection in the first network of the terminal device, the identifier allocated to the default QoS flow is the last identifier to be revoked.

The second QoS flow may be a non-default QoS flow of the first connection, i.e., the second QoS flow and the first QoS flow may both belong to the first connection, or alternatively, the first QoS flow may preempt the identity of the non-default QoS flow that belongs to the first connection. This scenario requires that the first QoS flow is a non-default QoS flow for the first connection. Optionally, the second QoS flow may be a non-default QoS flow with a lowest priority in the first connection that can be preempted.

Alternatively, the second QoS flow may also be a non-default QoS flow of a connection of the other first network than the first connection of the terminal device, that is, the second QoS flow and the first QoS flow may belong to different connections of the first network, and the first QoS flow may preempt an identifier of the non-default QoS flow of the connection of the other first network. In this case, the first QoS flow may be a non-default QoS flow or a default QoS flow of the first connection, and is not limited. Optionally, the second QoS flow may be a non-default QoS flow with a lowest priority among the connections of other first networks where the second QoS flow is located, and the non-default QoS flow with a lowest priority among the connections of all first networks of the terminal device and that can be preempted.

Still alternatively, the second QoS flow may also be a default QoS flow of a connection of the other first networks than the first connection of the terminal device, that is, the second QoS flow and the first QoS flow may belong to different connections of the first network, and the first QoS flow may preempt the identifier of the default QoS flow of the connection of the other first networks. It should be noted, however, that in this case, it is required that only the second QoS flow is assigned with an identification in the connection of the other first network in which the second QoS flow is located, and that no non-default QoS flow is assigned with an identification. That is, the identifier allocated to the second QoS flow is the last identifier revoked in the connection of the other first network in which the second QoS flow is located. Optionally, the second QoS flow may be a default QoS flow with a lowest priority among all the first connections of the terminal device, and the default QoS flow may be preempted.

In this embodiment of the present application, the mobility management network element may determine, according to the ARP information corresponding to the first QoS flow and the ARP information corresponding to each QoS flow to which the identifier has been allocated to the terminal device, which identifier has been allocated to which QoS flow to revoke, that is, determine the identity of the second QoS flow that needs to revoke the identifier.

In one possible implementation, the mobility management network element may first determine from which of the first network's connections of the terminal device the identity is revoked, i.e. determine the identity of the first network's connection in which the second QoS flow is located. Further, a second QoS flow is determined again in the determined connection of the first network.

Specifically, the mobility management network element may select, according to the ARP information of the connection of each first network to which the identifier has been assigned, a connection of a first network from the connections of each first network to which the identifier has been assigned, where the priority of the QoS flow included in each connection of the first networks is less than or equal to the priority of the QoS flow included in the connection of the other first network. If there is at least one identified assigned non-default QoS flow in the connection of the selected first network, the mobility management network element may select one of the non-default QoS flows from the at least one identified assigned non-default QoS flow as the second QoS flow. Optionally, the AMF may select, as the second QoS flow, a non-default QoS flow with a lowest priority that can be preempted from the at least one non-default QoS flow to which the identification has been allocated.

The mobility management network element may treat the default QoS flow as the second QoS flow if only the default QoS flow among the connections of the selected first network is assigned the identification and the connection of the selected first network is different from the first connection. Otherwise, if only the default QoS flow of the selected connection of the first network is assigned with the identification, but the selected connection of the first network is the first connection, the mobility management element may determine not to assign the identification for the first QoS flow.

Taking the first network as a 5GS network and the second network as an EPS network as an example, assuming that the PDU session in which the second QoS flow is located is denoted as a second PDU session, the AMF may determine the second PDU session according to the priority of the QoS flow included in each PDU session of the terminal device, where the second PDU session specifically refers to a PDU session in which the priority of the included QoS flow is less than or equal to the priority of the QoS flow included in other PDU sessions. If there is at least one non-default QoS flow allocated with an EBI in the second PDU session, the AMF may select one non-default QoS flow from the at least one non-default QoS flow allocated with an EBI as the second QoS flow. Optionally, the second QoS flow specifically refers to a preemptible non-default QoS flow with a lowest priority among the at least one non-default QoS flow allocated with the EBI.

If only the default QoS flow in the second PDU session is allocated with EBIs and the second PDU session is a different PDU session than the first PDU session, the AMF may treat the default QoS flow for the second PDU session as the second QoS flow. If only the default QoS flow in the second PDU session is allocated with EBI, but the second PDU session is actually the same PDU session as the first PDU session, the AMF may determine that the first QoS flow is not allocated EBI, i.e., the AMF refuses to allocate EBI for the first QoS flow.

In another possible implementation, if there is at least one non-default QoS flow to which an identification has been assigned in all the connections of the first network of the terminal device, the mobility management network element may select one non-default QoS flow from the at least one non-default QoS flow to which an identification has been assigned as the second QoS flow. Optionally, the mobility management network element may select, as the second QoS flow, a non-default QoS flow with a lowest priority that can be preempted from the at least one non-default QoS flow to which the identifier has been allocated. If all the identified QoS flows in all the connections of the first network of the terminal device are default QoS flows, the mobility management network element may select one default QoS flow from the default QoS flows that are assigned with the identifiers as the second QoS flow. Optionally, the mobility management network element may select, from the default QoS flows to which the identifiers have been allocated, a default QoS flow with the lowest priority that can be preempted as the second QoS flow.

Taking the first network as a 5GS network and the second network as an EPS network as an example, the AMF may first determine whether at least one identified non-default QoS flow exists in each PDU session of the terminal device, and if so, the AMF may select one non-default QoS flow from the at least one identified non-default QoS flow as the second QoS flow. Optionally, the second QoS flow is a preemptable non-default QoS flow with a lowest priority among the at least one identified non-default QoS flow that has been assigned. If the QoS flows which are distributed with identification in each PDU session of the terminal equipment are not the default QoS flows, the AMF can select one default QoS flow from the default QoS flows which are distributed with identification as the second QoS flow. Optionally, the second QoS flow is a preemptable default QoS flow with the lowest priority among the default QoS flows assigned with the identifiers.

Optionally, for the two possible manners of determining the second QoS flow, before the mobility management network element withdraws the second identifier of the second QoS flow from the allocated identifiers, it may also be determined that the first QoS flow has preemption capability according to the ARP information corresponding to the first QoS flow, and the priority corresponding to the first QoS flow is greater than the priority corresponding to the second QoS flow. I.e. the first QoS flow can only preempt the identity of QoS flows with lower priority than itself.

If the request message includes the ARP of the other QoS flows of the first connection, the mobility management network element also allocates an identifier for the other QoS flows, and a method for allocating an identifier for the other QoS flows by the mobility management network element may be referred to as a method for allocating an identifier for the first QoS flow, which is not described herein again.

Step S304, the mobility management element sends a response message to the session management element, where the response message includes the second identifier.

If the first QoS flow is the default QoS flow of the first connection, the response message may also be used to indicate that the second identifier is an identifier allocated for the default QoS flow of the first connection, and the specific indication manner may be referred to in step S204. Referring to the flowchart shown in fig. 4, in a specific example, after receiving a request message requesting allocation of EBI for a first QoS flow of a first PDU session of a terminal device from an SMF, an AMF may first determine the number of EBI allocated for the terminal device. If the number of EBIs that have been allocated for the terminal device does not exceed the set threshold, the AMF may select one EBI from the available EBIs to allocate to the first QoS flow. If the number of EBIs that have been allocated for the terminal device exceeds a set threshold, the AMF may determine that the allocated EBI needs to be revoked. Further, the AMF may determine whether the first QoS flow has preemption capability according to ARP information corresponding to the first QoS flow carried in the request message. If the first QoS flow has preemption capability, the AMF may continue to determine whether there is at least one non-default QoS flow that has been allocated an EBI and has a lower priority than the first QoS flow and can be preempted in each PDU session of the terminal device, and if so, the AMF may revoke the EBI of the lowest priority QoS flow among the at least one non-default QoS flow and then allocate the EBI to the first QoS flow. If the first QoS flow does not have preemption capability, or there is no at least non-default QoS flow in each PDU session of the terminal device that has been allocated an EBI and has a lower priority than the first QoS flow and can be preempted, or the AMF cannot find a QoS flow that can revoke the EBI, then the AMF may refuse to allocate an EBI for the first QoS flow. Subsequently, the AMF may send a response message to the SMF, where the response message may include the EBI allocated to the first QoS flow if the AMF successfully allocates the EBI to the first QoS flow, and may include information indicating that the allocation of the EBI to the first QoS flow fails if the AMF does not allocate the EBI to the first QoS flow.

In a possible implementation manner, if the first QoS flow is the default QoS flow, the AMF may not determine whether the ARP corresponding to the first QoS flow indicates that the first QoS flow has preemption capability, and the AMF always regards the first QoS flow as having preemption capability.

Optionally, the mobility management network element may further receive a message from the source mobility management network element, where the message includes the assigned identifier for the terminal device. Specifically, the identifier allocated to the terminal device may include: the source mobility management network element allocates an identifier for a QoS flow in one or more connections of the first network of the terminal device, where the identifier may include an identifier allocated for a default QoS flow and may also include an identifier allocated for a non-default QoS flow, and the application is not limited in this application. It should be understood that the identifier assigned to a QoS flow refers to the identifier of the corresponding bearer of the QoS flow in the second network. Further, for each connection of the first network, the location in the message of the identifier assigned for the default QoS flow in the connection of the first network precedes the location in the message of the identifier assigned for the non-default QoS flow in the connection of the first network.

It will be appreciated that the receipt of the message by the mobility management network element from the source mobility management network element may correspond to a scenario in which context is passed between mobility management network elements of the two first networks.

Optionally, the mobility management element may further receive a message from the session management element, where the message includes the assigned identifier of the terminal device. Specifically, the identifier allocated to the terminal device may include: and the mobility management network element in the second network is used for identifying the QoS flow allocation in the connection of one or more first networks of the terminal equipment. The QoS flow may include an identifier allocated to a default QoS flow, and may also include an identifier allocated to a non-default QoS flow, which is not limited in the present application. It should be understood that the identifier assigned to a QoS flow refers to the identifier of the corresponding bearer of the QoS flow in the second network. Further, for each connection of the first network, the location in the message of the identifier assigned for the default QoS flow in the connection of the first network precedes the location in the message of the identifier assigned for the non-default QoS flow in the connection of the first network.

It is to be understood that the receipt of the message by the mobility management element from the session management element may correspond to a scenario in which the terminal device is handed over from the second network to the first network.

Optionally, the message received by the mobility management network element from the source mobility management network element or the session management network element may further include indication information, where the indication information includes at least one EBI, and the indication information may be used to indicate that a first EBI of the at least one EBI is an EBI corresponding to a default QoS flow of a first connection of the first network. The indication information may be, for example, outside the < ARP, EBI > list, a default EBI is added to indicate which EBI is the EBI corresponding to the default QoS flow. Further, the AMF may save the at least one EBI received from the message.

It should be noted that, before the mobility management network element receives the request message from the session management network element in step S301, the source mobility management network element or the session management network element may receive the message.

The communication method provided by the embodiment of the present application is described in detail below with reference to several specific embodiments.

Specific embodiment one- -5GS EBI distribution flow

As shown in fig. 5, in the first embodiment, the SMF only carries one ARP when it first applies for EBI for a QoS flow under a PDU session. In order to identify the default QoS flow, the SMF fixedly carries the ARP corresponding to the default QoS flow in the first EBI allocation request message; accordingly, the AMF identifies the first allocated EBI under each PDU session as the EBI corresponding to the default QoS flow by default. The detailed process is as follows:

1) and in the PDU session establishing process, the SMF initiates an EBI allocation request message to the AMF, and the message only carries the ARP corresponding to the default QoS flow.

2) And the AMF allocates the EBI for the ARP, identifies the EBI as the EBI corresponding to the default QoS flow and then sends an EBI allocation response message to the SMF, wherein the message carries the allocated EBI. And the AMF judges that the ARP is the ARP corresponding to the default QoS flow according to the condition that the request message is the first EBI request message of the PDU session, and the EBI distributed for the QoS flow is the EBI corresponding to the default QoS flow.

3) The SMF can continue to distribute the EBI for the PDU session application to the AMF, and the AMF can judge that the ARP in the subsequent request message is the ARP corresponding to the non-default QoS flow.

4) And when the number of the EBIs allocated to the user by the AMF reaches the upper limit of the number of the EPS Bearer, if the AMF continuously receives the request for allocating the EBI, the AMF needs to cancel the allocated EBI. It should be appreciated that at this point, the request to allocate an EBI may be used to allocate an EBI for a non-default QoS flow of the PDU session of step 1, or to allocate an EBI for a default QoS flow or a non-default QoS flow of another PDU session.

The procedure of the AMF revoking the allocated EBI may refer to the description in the above method embodiment.

5) And the AMF sends a response message to the SMF, wherein the response message carries the distributed EBI.

Specific example two-5 GS EBI Allocation flow

As shown in fig. 6, the second embodiment differs from the first embodiment in that: when SMF applies for EBI allocation for the first time, a plurality of ARP are carried in the request message at the same time, in order to identify the default QoS flow, the following processing is required, and other processing is consistent with the specific embodiment.

1) And the SMF places the ARP corresponding to the default QoS flow in the first position of all the ARP in the first EBI allocation request message. For example, the EBI allocation request of the SMF carries an ARP list, and the ARP of the default QoS flow is located at the head of the ARP list.

2) And the AMF identifies the EBI corresponding to the first ARP as the EBI corresponding to the default QoS flow.

3) In the response message, the AMF puts the EBI corresponding to the default QoS flow at the first position of all the allocated EBIs; for example, the AMF includes a < ARP, EBI > list in the response message, where the first < ARP, EBI > of the list is the ARP and EBI corresponding to the default QoS flow.

Specific example three-5 GS EBI Allocation flow

As shown in fig. 8, the second embodiment differs from the first embodiment in that: when SMF applies for EBI allocation for the first time, a plurality of ARP are carried in the request message at the same time, in order to identify the default QoS flow, the following processing is required, and other processing is consistent with the specific embodiment.

1) And the SMF carries first indication information in the first EBI allocation request message besides the ARP of each QoS flow needing to be allocated with the EBI, and is used for indicating which ARP is the ARP corresponding to the default QoS flow. For example, an ARP list is included in the request message, wherein the ARP list includes an ARP of each QoS flow that needs to be allocated with an EBI, and the first indication information is an ARP of a default QoS flow.

2) The AMF identifies the EBI corresponding to the first ARP as the EBI corresponding to the default QoS flow;

3) and in the response message, the AMF carries indication information besides each allocated EBI and the ARP corresponding to the EBI, and the indication information is used for indicating which EBI is the EBI corresponding to the default QoS flow. For example, the response message includes an EBI, ARP list, which includes each allocated EBI and an ARP corresponding to the EBI, indicating that the information is the EBI corresponding to the default QoS flow.

Specific example Process four EPS to 5GS Registration or Handover

As shown in fig. 7, the procedure of EPS to 5GS Registration or Handover includes the following steps:

1) and the AMF sends a SmContext Create Request message to the SMF.

2) SMF returns an allocatedEbiList cell carried by the created SmContext response message to AMF, and puts ARP and EBI corresponding to the default QoS flow at a first position; the AMF maintains the EBI/ARP information and identifies the first EBI as the EBI for the default QoS flow.

3) And each network element completes the EPS to 5G Registration/Handover flow subsequent processing.

4) The subsequent EBI allocation flow processing is the same as the 5GS EBI allocation flow.

Specific example flow from five EPS to 5GS Registration or Handover

As shown in FIG. 9, the EPS to 5GS Registration or Handover procedure may include the following steps:

1) in the EPS to 5GS Registration or Handover flow, the AMF sends a SmContext Create Request message to the SMF.

2) The SMF returns an Indicator to the AMF to indicate whether the corresponding EBI is a default QoS flow or not in an allocatedEbiList cell carried by the created SmContext response message; the AMF stores the EBI/ARP information and identifies the corresponding EBI as the EBI of the default QoS flow according to the SMF indication. The Indicator may be a field added in the response message, and the field includes the EBI of the Default QoS Flow.

Referring to fig. 10, a schematic structural diagram of a communication device according to an embodiment of the present application is provided, where the communication device 1000 includes: a transceiver module 1010 and a processing module 1120. The communication device may be configured to implement the functions related to the mobility management element or the session management element in any of the above method embodiments. For example, the communication means may be a network device or a chip included in the network device.

When the communication apparatus is used as a mobility management network element to execute the method embodiment shown in fig. 2, the transceiver module 1010 is configured to receive a first request message from a session management network element, where the first request message includes first allocation retention priority ARP information; a processing module 1020, configured to allocate, after the transceiver module 1010 receives the first request message, a first identifier to a default QoS flow of a first connection in a first network, where the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in a second network; the transceiver module 1010 is further configured to send a first response message to the session management network element, where the first response message includes the first identifier.

In one possible design, the first request message indicates that the first ARP information is ARP information corresponding to a default quality of service, QoS, flow for a first connection in the first network.

In one possible design, only the first ARP information is included in the first request message, and correspondingly, only the first identification is included in the first response message.

In one possible design, the first request message may further include ARP information corresponding to at least one other QoS flow of the first connection, and the position of the first ARP information in the first request message is before the position of the ARP information corresponding to the at least one other QoS flow in the first request message.

In one possible design, the first response message may include a first identifier and an identifier allocated by the mobility management element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management element for the at least one other QoS flow in the first response message.

In one possible design, the first request message further includes first indication information, where the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

In one possible design, the first response message includes a first identifier and second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection.

In one possible design, the first ARP information is ARP information corresponding to a default QoS flow for the first connection.

In a possible design, the first response message further includes second indication information, where the second indication information is used to indicate that the first identifier is an identifier allocated for a default QoS flow of the first connection, or the first response message further includes an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

In one possible design, the first request message is a first request message after the first connection is created, and the first connection is a connection of the terminal device.

With reference to the first aspect, in a possible design of the first aspect, the processing module 1120 is further configured to determine that, among the identifiers allocated to the QoS flows of the first connection, the identifier allocated to the default QoS flow is the last identifier to be revoked.

When the communication apparatus is used as a session management network element to execute the method embodiment shown in fig. 2, the transceiver module 1010 is configured to send a first request message to a mobility management network element of a first network, where the first request message includes first allocation retention priority ARP information; the transceiver module 1010 is further configured to receive a first response message from the mobility management network element, where the first response message includes a first identifier allocated by the mobility management network element for a default QoS flow of a first connection in the first network, and the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in the second network.

In one possible design, only the first ARP information is included in the first request message; accordingly, only the first identity is included in the first response message.

In one possible design, the first request message further includes ARP information corresponding to at least one other QoS flow of the first connection, and the position of the first ARP information in the first request message is before the position of the ARP information corresponding to the at least one other QoS flow in the first request message.

In one possible design, the first response message includes a first identifier and an identifier allocated by the mobility management element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management element for the at least one other QoS flow in the first response message.

When the communication apparatus is used as a mobility management network element to execute the method embodiment shown in fig. 3, the transceiver module 1010 is configured to receive a request message from the session management network element, where the request message is used to request that an identifier for identifying a bearer corresponding to a first quality of service QoS flow in a second connection in a second network be allocated to a first quality of service QoS flow of a first connection in the first network of the terminal device; a processing module 1020, configured to determine that the identifier allocated to the terminal device needs to be revoked; the processing module 1020 is further configured to revoke the second identifier of the second QoS flow from the allocated identifiers and allocate the second identifier to the first QoS flow according to a policy, where the policy is: in the identifiers allocated to the QoS flows connected in a first network of the terminal equipment, the identifier allocated to the default QoS flow is the identifier which is finally revoked; the transceiver module 1010 is further configured to send a response message to the session management network element, where the response message includes the second identifier.

In one possible design, the second QoS flow is a non-default QoS flow of the first connection.

In one possible design, the second QoS flow is a non-default QoS flow that may be preempted with the lowest priority in the first connection.

In one possible design, the second QoS flow is a QoS flow for a connection other than the first connection for the terminal device.

In one possible design, the second QoS flow is a preemptible QoS flow having a lowest priority among connections in the first network of terminal devices.

In one possible design, when the QoS flows that have been assigned the identification in the connection in the first network of the terminal device are all default QoS flows, the second QoS flow is a default QoS flow for the other connections of the terminal device than the first connection.

In one possible design, processing module 1020 may be further configured to determine that the first QoS flow has preemption capability.

In one possible design, the transceiver module 1010 is further configured to receive a message from the source mobility management network element or the session management network element, where the message includes the assigned identifier for the terminal device.

Please refer to fig. 11, which is a schematic structural diagram of a communication device according to an embodiment of the present disclosure. The communication device 1100 may be used to implement the methods described in the method embodiments above. The communication apparatus 1100 may be a chip or a network device.

The communications device 1100 includes one or more processors 1101, and the one or more processors 1001 may enable the communications device 1100 to implement the method of the mobility management network element or the session management network element in fig. 2-9. The processor 1101 may be a general purpose processor or a special purpose processor. For example, the processor 1101 may be a Central Processing Unit (CPU) or a baseband processor. The baseband processor may be used to process communication data, and the CPU may be used to control a communication apparatus (e.g., a network device, a terminal device, or a chip), execute a software program, and process data of the software program. The communication apparatus 1100 may further include a transceiving unit 1105 to enable input (reception) and output (transmission) of signals.

For example, the communication apparatus 1100 may be a chip, and the transceiver 1105 may be an input and/or output circuit of the chip, or the transceiver 1105 may be a communication interface of the chip, and the chip may be a component of a terminal device or a network device or other wireless communication devices.

One or more memories 1102 may be included in the communications apparatus 1100, on which programs 1104 are stored, the programs 1104 being executable by the processor 1101 to generate instructions 1103, such that the processor 1101 performs the methods described in the above-described method embodiments according to the instructions 1103. Optionally, the memory 1102 may also have data stored therein. Alternatively, the processor 1101 may also read data stored in the memory 1102, the data may be stored at the same memory address as the program 1104, or the data may be stored at a different memory address from the program 1104.

The processor 1101 and the memory 1102 may be provided separately or integrated together, for example, on a single board or a System On Chip (SOC).

The communication device 1100 may also include a transceiving unit 1105 and an antenna 1106. The transceiver unit 1105 may be referred to as a transceiver, a transceiver circuit or a transceiver for implementing the transceiving function of the communication device through the antenna 1006.

It should be understood that the steps of the above-described method embodiments may be performed by logic circuits in the form of hardware or instructions in the form of software in the processor 1101. The processor 1101 may be a CPU, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, such as a discrete gate, a transistor logic device, or a discrete hardware component.

The embodiment of the present application further provides a computer program product, and when being executed by the processor 1001, the computer program product implements the communication method described in any method embodiment of the present application.

The computer program product may be stored in the memory 1102, for example, as a program 1104, and the program 1104 is finally converted into an executable object file capable of being executed by the processor 1101 through preprocessing, compiling, assembling and linking.

The embodiments of the present application further provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a computer, implements the communication method described in any method embodiment of the present application. The computer program may be a high-level language program or an executable object program.

An embodiment of the present application provides a communication system, which includes a session management network element and a mobility management network element in a first network. Optionally, the communication system further comprises a terminal device.

Such as memory 1102. Memory 1102 can be either volatile memory or nonvolatile memory, or memory 1102 can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, Synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

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

In the several embodiments provided in the present application, the disclosed system, apparatus and method can be implemented in other ways. For example, some features of the method embodiments described above may be omitted, or not performed. The above-described embodiments of the apparatus are merely exemplary, the division of the unit is only one logical function division, and there may be other division ways in actual implementation, and a plurality of units or components may be combined or integrated into another system. In addition, the coupling between the units or the coupling between the components may be direct coupling or indirect coupling, and the coupling includes electrical, mechanical or other connections.

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

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association relationship describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In short, the above description is only a preferred embodiment of the present disclosure, and is not intended to limit the scope of the present disclosure. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of communication, the method comprising:

a mobility management network element of a first network receives a first request message from a session management network element, the first request message including first allocation retention priority, ARP, information;

after receiving the first request message, the mobility management network element allocates a first identifier to a default quality of service (QoS) flow of a first connection in the first network, where the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in a second network;

and the mobility management network element sends a first response message to the session management network element, wherein the first response message comprises the first identifier.

2. The method of claim 1, wherein the first request message indicates that the first ARP information is ARP information corresponding to a default QoS flow for a first connection in the first network.

3. The method of claim 2, wherein only the first ARP information is included in the first request message;

only the first identity is included in the first response message.

4. The method of claim 2, wherein the first request message further includes ARP information for at least one other QoS flow of the first connection, and wherein the first ARP information is located in the first request message before the ARP information for the at least one other QoS flow is located in the first request message.

5. The method of claim 4, wherein the first response message includes the first identifier and an identifier allocated by the mobility management network element for the at least one other QoS flow, and wherein a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

6. The method of claim 5, further comprising first indication information in the first request message, wherein the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

7. The method of claim 6, wherein the first response message includes the first identifier and second indication information, and the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection.

8. The method of claim 1, wherein the first ARP information is ARP information corresponding to a default QoS flow for the first connection.

9. The method according to claim 8, wherein the first response message further includes second indication information, the second indication information is used to indicate that the first identifier is an identifier allocated for a default QoS flow of the first connection, or the first response message further includes an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

10. The method according to any of claims 1 to 9, wherein the first request message is a first request message after the first connection is created, and the first connection is a connection of a terminal device.

11. The method according to any one of claims 1 to 10, further comprising:

and the mobility management network element determines that, among the identifiers allocated to the QoS flows of the first connection, the identifier allocated to the default QoS flow is the last identifier to be revoked.

12. A method of communication, the method comprising:

a session management network element sends a first request message to a mobility management network element of a first network, wherein the first request message comprises first allocation retention priority ARP information;

the session management network element receives a first response message from the mobility management network element, where the first response message includes a first identifier allocated by the mobility management network element for a default QoS flow of a first connection in the first network, and the first identifier is used to identify a bearer corresponding to the default QoS flow in a second connection in a second network.

13. The method of claim 12, wherein the first request message indicates that the first ARP information is ARP information corresponding to a default quality of service, QoS, flow for a first connection in the first network.

14. The method of claim 13, wherein only the first ARP information is included in the first request message;

only the first identity is included in the first response message.

15. The method of claim 13, wherein the first request message further includes ARP information for at least one other QoS flow of the first connection, and wherein the first ARP information is located in the first request message before the ARP information for the at least one other QoS flow is located in the first request message.

16. The method of claim 15, wherein the first response message includes the first identifier and an identifier allocated by the mobility management network element for the at least one other QoS flow, and wherein a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

17. The method of claim 13, further comprising first indication information in the first request message, wherein the first indication information is used to indicate that the first ARP information is ARP information corresponding to a default QoS flow of the first connection.

18. The method of claim 17, wherein the first response message includes the first identifier and second indication information, and the second indication information is used to indicate that the first identifier is an identifier allocated by the mobility management network element for a default QoS flow of the first connection.

19. The method of claim 12, wherein the first ARP information is ARP information corresponding to a default QoS flow for the first connection.

20. The method of claim 19, wherein the first response message further includes second indication information, and the second indication information is used to indicate that the first identifier is an identifier allocated for a default QoS flow of the first connection, or the first response message further includes an identifier allocated by the mobility management network element for the at least one other QoS flow, and a position of the first identifier in the first response message is before a position of the identifier allocated by the mobility management network element for the at least one other QoS flow in the first response message.

21. The method according to any of claims 12 to 20, wherein the first request message is a first request message after the first connection is created, and the first connection is a connection of a terminal device.

22. A method of communication, comprising:

a mobility management network element of a first network receives a request message from a session management network element, wherein the request message is used for requesting allocation of an identifier for a first quality of service (QoS) flow of a first connection of a terminal device in the first network, and the identifier is used for identifying a bearer corresponding to the first QoS flow in a second connection in a second network;

the mobility management network element determines that the identifier allocated to the terminal equipment needs to be cancelled;

the mobility management network element revokes a second identifier of a second QoS flow from the allocated identifiers according to a policy, and allocates the second identifier to the first QoS flow, wherein the policy is: in the identifiers allocated to the QoS flows connected in a first network of the terminal equipment, the identifier allocated to the default QoS flow is the identifier which is finally revoked;

and the mobility management network element sends a response message to a session management network element, wherein the response message comprises the second identifier.

23. The method of claim 22, wherein the second QoS flow is a non-default QoS flow for the first connection.

24. The method of claim 23, wherein the second QoS flow is a preemptable non-default QoS flow having a lowest priority in the first connection.

25. The method of claim 22, wherein the second QoS flow is a QoS flow of a connection other than the first connection for the terminal device.

26. The method of claim 25, wherein the second QoS flow is a preemptible QoS flow having a lowest priority among connections in the first network of the terminal device.

27. The method of claim 22, wherein when all of the identified QoS flows in the connection in the first network of the terminal device are default QoS flows, the second QoS flow is a default QoS flow for the connection of the terminal device other than the first connection.

28. The method of any one of claims 22 to 27, further comprising:

the mobility management network element determines that the first QoS flow has preemption capability.

29. The method of any one of claims 22 to 28, further comprising:

and the mobility management network element receives a message from a source mobility management network element or a session management network element, wherein the message comprises the allocated identifier for the terminal equipment.

30. A communications apparatus, comprising a processing module and a transceiver module, the processing module being coupled to the transceiver module for performing the method of any one of claims 1 to 11, or causing the apparatus to perform the method of any one of claims 12 to 21, or causing the apparatus to perform the method of any one of claims 22 to 29.

31. An apparatus for communication, the apparatus comprising at least one processor coupled with at least one memory:

the at least one processor configured to execute computer programs or instructions stored in the at least one memory to cause the apparatus to perform the method of any one of claims 1 to 11, or to cause the apparatus to perform the method of any one of claims 12 to 21, or to cause the apparatus to perform the method of any one of claims 22 to 29.

32. A readable storage medium for storing instructions that, when executed, cause a method of any one of claims 1 to 11 to be implemented, or cause a method of any one of claims 12 to 21 to be implemented, or cause a method of any one of claims 22 to 29 to be implemented.

33. A communication device comprising a processor and interface circuitry;

the interface circuit is used for receiving code instructions and transmitting the code instructions to the processor;

the processor is configured to execute the code instructions to perform the method of any one of claims 1 to 11, or to perform the method of any one of claims 12 to 21, or to perform the method of any one of claims 22 to 29.