WO2023138352A1

WO2023138352A1 - Inter-system interoperation method and device

Info

Publication number: WO2023138352A1
Application number: PCT/CN2023/070032
Authority: WO
Inventors: 孙晓姬; 宗在峰
Original assignee: 华为技术有限公司
Priority date: 2022-01-21
Filing date: 2023-01-03
Publication date: 2023-07-27
Also published as: CN116506837A

Abstract

The present application provides an inter-system interoperation method and device. The method comprises: a mobility management network element determines whether a terminal device supports an inter-system communication interface; the mobility management network element sends first indication information to an access network element or the terminal device, wherein the first indication information is used for indicating whether the terminal device supports the inter-system communication interface, and comprises identity identification information of the terminal device. According to the scheme, when the terminal device needs to perform inter-system interoperation, the terminal device can selectively perform, according to the first indication information, interoperation based on the inter-system communication interface or interoperation without the inter-system communication interface, thereby enhancing the user experience.

Description

A method and device for interoperability between systems

This application claims the priority of a Chinese patent application with application number 202210072349.0 and application title "A Method and Device for Interoperability Between Systems" submitted to the China Patent Office on January 21, 2022, the entire contents of which are incorporated in this application by reference.

technical field

The embodiments of the present application relate to wireless communication, and in particular design a method and device for interoperability between systems.

Background technique

The deployment process of 5G will be a long-term process of replacement, upgrade and iteration based on 4G. For a long period of time, 4G and 5G coexist, and users often need to change from 5G to 4G, or from 4G to 5G. The protocol specifies the N26 interface between the mobility management entity (MME) and the access and mobility management function (AMF). When the N26 interface on the network side has been deployed, issue the instruction information of interoperability between systems based on the N26 interface. When the N26 interface on the network side is not deployed or unavailable, issue the instruction information for interoperability between systems without the N26 interface. That is to say, all users in the network will receive the same indication information.

However, some users who support the N26 interface may use interoperability between systems without the N26 interface, resulting in poor user experience. Therefore, how to provide different solutions for interoperability between systems for different users is an urgent problem to be solved at present.

Contents of the invention

The present application provides a method for interoperability between systems. According to the solution, different solutions for interoperability between systems can be provided for different users.

In a first aspect, a method for interoperability between systems is provided, and the method includes: a mobility management network element determines whether a terminal device supports an intersystem communication interface; the mobility management network element sends first indication information to an access network element or the terminal equipment, where the first indication information is used to indicate whether the terminal equipment supports an intersystem communication interface, and the first indication information includes identity information of the terminal equipment.

In a mobile communication system, a mobility management network element may be responsible for handling terminal equipment connection and mobility management tasks. For example, in an evolved packet system (evolved packet system, EPS), the mobility management network element may be an MME, and in a 5G system (the 5th generation system, 5GS), the mobility management network element may be an AMF. The network element of the access network can be a 4G base station or a 5G base station. The inter-system communication interface can be a communication interface between two mobile communication systems, and can be used to transmit the mobility management state and session management state of the terminal equipment, for example, the communication interface can be the N26 interface between the EPS system and the 5GS system.

It should be understood that in the scenario where the inter-system communication interface has been deployed, the mobility management network element needs to determine whether the terminal device supports the inter-system communication interface, and then determine the mode for the terminal device to perform inter-system interoperability.

Based on the above technical solution, the mobility management network element can determine whether each terminal device registered in the network supports the inter-system communication interface, and issue the first indication information. In the process of possible inter-system interoperability in the future, the network element of the access network can query the first indication information of the terminal device, and selectively perform interoperability based on an inter-system communication interface or interoperability without an inter-system communication interface according to the first indication information, so as to change the access network of the terminal device. In this way, different interoperability solutions between systems can be provided for different users, while service continuity of different users can be guaranteed, and user experience can be improved. In addition, the system can more flexibly control the strategy of each terminal device for interoperability between systems, improving control accuracy. In addition, the first indication information includes the identity information of the terminal equipment, and the network element of the access network can distinguish the first indication information of different terminal equipments, so as to initiate different inter-system interoperability for different terminal equipments.

With reference to the first aspect, in a possible implementation manner, the mobility management network element obtains the PLMN information of the terminal device's home public land mobile communication network; the mobility management network element determines whether the terminal device supports the inter-system communication interface according to the home PLMN information.

Based on the above technical solution, the mobility management network element can determine which network the terminal device belongs to, thereby determining which network users support the inter-system communication interface and which network users do not support the inter-system communication interface. In this way, different interoperability solutions between systems can be provided for users belonging to different networks, while ensuring service continuity of different users and improving user experience.

With reference to the first aspect, in a possible implementation manner, when the home PLMN information is on the first PLMN list, the mobility management network element determines that the terminal device supports the inter-system communication interface; or, when the home PLMN information is not on the first PLMN list, the mobility management network element determines that the terminal device does not support the inter-system communication interface.

It should be understood that the first PLMN list may be pre-configured, for example, the first PLMN list may be pre-configured as (PLMN1, PLMN2), and when the PLMN to which the terminal device belongs is PLMN1 or PLMN2, it is determined that the terminal device supports the inter-system communication interface. Otherwise, it is determined that the terminal device does not support the inter-system communication interface.

Based on the above technical solution, it is beneficial to manage PLMNs that support or do not support inter-system communication interfaces.

With reference to the first aspect, in a possible implementation manner, the mobility management network element acquires the subscription data of the terminal device, and the subscription data includes inter-system interoperability indication information; the mobility management network element determines whether the terminal equipment supports the inter-system communication interface according to the inter-system interoperability indication information.

Based on the above technical solution, it can be signed whether the terminal device supports the inter-system communication interface. In this way, different capability indication information for interoperability between systems can be delivered to different terminal devices at a finer granularity.

With reference to the first aspect, in a possible implementation manner, the mobility management network element sends an initial context establishment request to the access network element, where the initial context establishment request includes the first indication information.

Based on the above technical solution, the first indication information can be carried in the initial context establishment request message during the registration process of the terminal device in the network, which can save signaling overhead.

Optionally, the mobility management network element sends an attach accept message to the terminal device, where the attach accept message includes the first indication information.

Optionally, when the access network element associated with the terminal device is changed, the first indication information is sent to the changed access network element.

Based on the above technical solution, when the access network element associated with the terminal device changes, for example, when the terminal device moves from the coverage area of the source base station to the target base station, and the terminal device switches or reselects from the source base station to the target base station, the mobility management network element may send the first indication information to the target base station. In this way, the base station where the terminal device is currently located can obtain the first indication information, so that in the future possible interoperability between systems, the base station where the terminal equipment is currently located can change the access network of the terminal device according to the first indication information.

In a second aspect, a method for interoperability between systems is provided. The method includes: a network element of an access network acquires PLMN information selected by a terminal device; and the network element of the access network determines whether the terminal device supports an intersystem communication interface according to the PLMN information.

Based on the above technical solution, the network elements of the access network can also independently determine whether the terminal device supports the communication interface between the systems. In this way, the participation of the network elements of the core network is not required, and signaling consumption can be reduced. At the same time, different interoperability solutions between systems can be provided for different users, while ensuring business continuity for different users and improving user experience. In addition, the system can more flexibly control the strategy of each terminal device for interoperability between systems, improving control accuracy.

Optionally, the network element of the access network sends the first indication information to the terminal device, where the first indication information is used to indicate whether the terminal device supports the inter-system communication interface, and the first indication information includes the identity information of the terminal device.

Based on the above technical solution, the terminal device can initiate correct inter-system inter-operation according to the first indication information when inter-system inter-operation is required, so as to ensure service continuity and improve user experience.

In a third aspect, a method for interoperability between systems is provided. The method includes: a network element of an access network receives first indication information, the first indication information is used to indicate whether a terminal device supports an inter-system communication interface, and the first indication information includes identification information of the terminal device.

Based on the foregoing technical solution, the network element of the access network may receive the first indication information of the terminal device. During possible interoperability between systems in the future, the network element of the access network may selectively perform interoperability based on an intersystem communication interface or interoperability without an intersystem communication interface according to the first indication information, so as to change the access network of the terminal device. In this way, different interoperability solutions between systems can be provided for different users, while service continuity of different users can be guaranteed, and user experience can be improved. In addition, the system can more flexibly control the strategy of each terminal device for interoperability between systems, improving control accuracy.

With reference to the third aspect, in a possible implementation manner, an access network element stores the first indication information.

Based on the above technical solution, the network element of the access network can store the first indication information of multiple terminal devices, so as to query the first indication information corresponding to the terminal devices in the interoperability process between systems in the future, so as to initiate correct intersystem interoperation.

With reference to the third aspect, in a possible implementation manner, the method further includes: an access network element receiving an initial context establishment request, where the initial context establishment request includes the first indication information.

Based on the above technical solution, the first indication information can be carried in the initial context establishment request message in the process of the terminal device registering in the network, which can save signaling overhead.

With reference to the third aspect, in a possible implementation manner, the method further includes: when the first indication information indicates that the terminal device supports the inter-system communication interface, the access network element initiates a first interoperation based on the inter-system communication interface to change the access network of the terminal device; or, when the first indication information indicates that the terminal device does not support the inter-system communication interface, the access network element initiates a second interoperation without an inter-system communication interface to change the access network of the terminal device.

Based on the above technical solution, in the interoperability process between systems, the network element of the access network can selectively perform interoperability based on an intersystem communication interface or interoperability without an intersystem communication interface according to the first indication information, so as to change the access network of the terminal device. In this way, service continuity of different users can be guaranteed at the same time, and user experience can be improved.

Optionally, the network element of the access network queries the first indication information of the terminal device.

In a fourth aspect, a method for interoperability between systems is provided. The method includes: a terminal device receives first indication information, the first indication information is used to indicate whether the terminal device supports an intersystem communication interface, and the first indication information includes identification information of the terminal device.

Based on the above technical solution, the terminal device can receive the first indication information, which is beneficial for the terminal device to initiate a correct registration process according to the first indication information during interoperability between systems, which is beneficial for reducing time delay and improving user experience.

With reference to the fourth aspect, in a possible implementation manner, the method further includes: when the first indication information indicates that the terminal device supports the inter-system communication interface, the terminal device accesses the network by means of mobility registration; or, when the first indication information indicates that the terminal device does not support the inter-system communication interface, the terminal device accesses the network by means of switching registration.

Based on the above technical solution, the terminal device can initiate a correct registration process during interoperability between systems according to the first indication information, which is beneficial to reduce time delay and improve user experience.

According to a fifth aspect, there is provided a device for interoperability between systems, the device comprising: a processing unit configured to determine whether a terminal device supports an inter-system communication interface; a transceiver unit configured to send first indication information to an access network element or a terminal device, where the first indication information is used to indicate whether the terminal device supports the inter-system communication interface, and the first indication information includes identification information of the terminal device.

The apparatus for interoperability between systems provided in this application can deliver different interoperability indication information for intersystems to different terminal devices. When the terminal device needs to perform system intercommunication, different intersystem interoperability can be targetedly initiated based on the first indication information of the terminal device. In this way, it is possible to prevent all terminal devices in the system from changing access networks in the same way. For example, when all interoperability between systems is performed without inter-system communication interfaces, some users who support inter-system communication interfaces will experience poor experience.

With reference to the fifth aspect, in a possible implementation manner, the processing unit is specifically configured to: obtain information about the public land mobile communication network PLMN to which the terminal device belongs; and determine whether the terminal device supports the inter-system communication interface according to the home PLMN information.

With reference to the fifth aspect, in a possible implementation manner, the processing unit is specifically configured to: determine that the terminal device supports the inter-system communication interface when the home PLMN information is on the first PLMN list; or, when the home PLMN information is not on the first PLMN list, determine that the terminal device does not support the inter-system communication interface.

With reference to the fifth aspect, in a possible implementation manner, the processing unit is specifically configured to: acquire the subscription data of the terminal device, where the subscription data includes inter-system interoperability indication information; determine whether the terminal device supports the inter-system communication interface according to the inter-system interoperability indication information.

With reference to the fifth aspect, in a possible implementation manner, the transceiving unit is specifically configured to: send an initial context establishment request to an access network element, where the initial context establishment request includes the first indication information.

According to the sixth aspect, a device for interoperability between systems is provided, the device includes: a transceiver unit, configured to acquire PLMN information selected by a terminal device; a processing unit, configured to determine whether the terminal device supports an inter-system communication interface according to the PLMN information.

The device can independently judge whether the terminal equipment supports the communication interface between systems, so that the participation of network elements of the core network is not required, and signaling consumption can be reduced.

With reference to the sixth aspect, in a possible implementation manner, the transceiver unit is further configured to: send first indication information, where the first indication information is used to indicate whether the terminal device supports an inter-system communication interface, where the first indication information includes the terminal device's identity information.

In a seventh aspect, there is provided an apparatus for interoperability between systems, the apparatus comprising: a transceiver unit configured to receive first indication information, the first indication information is used to indicate whether a terminal device supports an intersystem communication interface, and the first indication information includes identity information of the terminal equipment. The apparatus may receive first indication information of the terminal device. During possible future intersystem interoperability, interoperability based on an intersystem communication interface or interoperability without an intersystem communication interface can be selectively performed according to the first indication information, so as to change the access network of the terminal device. In this way, different interoperability solutions between systems can be provided for different users, while service continuity of different users can be guaranteed, and user experience can be improved. In addition, the system can more flexibly control the strategy of each terminal device for interoperability between systems, improving control accuracy.

With reference to the seventh aspect, in a possible implementation manner, the device further includes a storage unit, configured to store the first indication information.

With reference to the seventh aspect, in a possible implementation manner, the transceiving unit is specifically configured to receive an initial context establishment request, where the initial context establishment request includes the first indication information.

With reference to the seventh aspect, in a possible implementation manner, the apparatus further includes a processing unit, configured to, when the first indication information indicates that the terminal device supports the inter-system communication interface, initiate a first interoperation based on the inter-system communication interface to change the access network of the terminal device; or, when the first indication information indicates that the terminal device does not support the inter-system communication interface, initiate a second interoperation without an inter-system communication interface to change the access network of the terminal device.

In an eighth aspect, there is provided an apparatus for interoperability between systems, the apparatus including: a transceiver unit, configured to receive first indication information, the first indication information is used to indicate whether the terminal device supports an intersystem communication interface, and the first indication information includes identification information of the terminal equipment.

The apparatus can receive the first indication information, which is beneficial for the terminal device to initiate a correct registration process according to the first indication information during interoperability between systems, which is beneficial for reducing time delay and improving user experience.

With reference to the eighth aspect, in a possible implementation manner, the apparatus further includes a processing unit, configured to, when the first indication information indicates that the terminal device supports the inter-system communication interface, access the network by means of mobility registration; when the first indication information indicates that the terminal device does not support the inter-system communication interface, access the network by means of switching registration.

In a ninth aspect, an apparatus for interoperability between systems is provided, and the apparatus for interoperability between systems has a function of implementing the method in the first aspect or any possible implementation thereof. The functions may be implemented by hardware, or may be implemented by executing corresponding software through hardware. Hardware or software includes one or more units corresponding to the functions described above.

In a tenth aspect, there is provided an apparatus for interoperability between systems, wherein the apparatus for interoperability between systems has the function of implementing the method in the second aspect or any possible implementation thereof, or has the function of implementing the method in the third aspect or any possible implementation thereof. The functions may be implemented by hardware, or may be implemented by executing corresponding software through hardware. Hardware or software includes one or more units corresponding to the functions described above.

In an eleventh aspect, an apparatus for interoperability between systems is provided, wherein the apparatus for interoperability between systems has the function of implementing the method in the fourth aspect or any possible implementation thereof.

A twelfth aspect provides an apparatus for interoperability between systems, including at least one processor, the at least one processor is coupled to at least one memory, the at least one memory is used to store computer programs or instructions, and the at least one processor is used to call and run the computer programs or instructions from the at least one memory, so that the communication device executes the method in the first aspect or any possible implementation thereof.

In an example, the device may be an access and mobility management functional network element or a mobility management entity.

In another example, the device may be a component (such as a chip or an integrated circuit) installed in an access and mobility management functional network element or a mobility management entity.

A thirteenth aspect provides an apparatus for interoperability between systems, including at least one processor, the at least one processor is coupled to at least one memory, the at least one memory is used to store computer programs or instructions, and the at least one processor is used to call and run the computer program or instructions from the at least one memory, so that the communication device executes the method in the second aspect or any possible implementation thereof, or executes the method in the third aspect or any possible implementation thereof.

In an example, the device for use may be a 4G base station or a 5G base station.

In another example, the device may be a component (such as a chip or an integrated circuit) installed in a 4G base station or a 5G base station.

A fourteenth aspect provides an apparatus for interoperability between systems, including at least one processor, the at least one processor is coupled to at least one memory, the at least one memory is used to store computer programs or instructions, and the at least one processor is used to call and run the computer program or instructions from the at least one memory, so that the communication device executes the method in the third aspect or any possible implementation thereof.

In an example, the apparatus may be a terminal device.

In another example, the apparatus may be a component (such as a chip or an integrated circuit) installed in a terminal device.

A fifteenth aspect provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program runs on a computer, the computer executes the method described in any one of the first to fourth aspects.

A sixteenth aspect provides a computer program product, the computer program product includes computer program instructions, and when the computer program instructions run on a computer, the computer executes the method described in any one of the first aspect to the fourth aspect.

Description of drawings

Fig. 1 is a schematic diagram of a network structure applicable to the embodiment of the present application.

FIG. 2 shows an exemplary flow chart of a method for interoperability between systems provided by an embodiment of the present application.

Fig. 3 shows an exemplary flow chart of another method for interoperability between systems provided by the embodiment of the present application.

Fig. 4 shows an exemplary flow chart of a method for interoperability between systems provided by an embodiment of the present application.

Fig. 5 shows an exemplary flow chart of another method for interoperability between systems provided by the embodiment of the present application.

FIG. 6 shows an exemplary flow chart of another method for interoperability between systems provided by the embodiment of the present application.

FIG. 7 shows a schematic block diagram of an apparatus for interoperability between systems provided by an embodiment of the present application.

FIG. 8 shows a schematic block diagram of another apparatus for interoperability between systems provided by an embodiment of the present application.

FIG. 9 shows a schematic block diagram of another apparatus for interoperability between systems provided by an embodiment of the present application.

FIG. 10 shows a schematic block diagram of another apparatus for interoperability between systems provided by an embodiment of the present application.

FIG. 11 shows a schematic structural diagram of a device for interoperability between systems provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

The technical solutions provided in this application can be applied to various communication systems. In a communication system, the part operated by the operator may be called a public land mobile network (public land mobile network, PLMN) (also called an operator network, etc.). PLMN is a network established and operated by the government or its approved operators for the purpose of providing land mobile communication services to the public. It is mainly a public network where mobile network operators (MNO) provide users with mobile broadband access services. The PLMN described in this application may specifically be a network conforming to the standard requirements of the third generation partnership project (3rd generation partnership project, 3GPP), referred to as the 3GPP network. The 3GPP network generally includes but is not limited to the fifth-generation mobile communication (5th-generation, 5G) network (referred to as 5G network), the fourth-generation mobile communication (4th-generation, 4G) network (referred to as 4G network), and other future communication systems such as 6G network. For convenience of description, a 4G network or a 5G network will be used as an example for description in this embodiment of the application. Specifically in our country, the network of each mobile communication operator is counted as a PLMN, so the networks of China Mobile, China Unicom and China Telecom are different PLMNs.

In order to facilitate understanding of the embodiment of the present application, the network structure applicable to the embodiment of the present application is described in detail first with reference to FIG. 1 .

FIG. 1 is a schematic diagram of a network structure applicable to an embodiment of the present application. As shown in FIG. 1 , the network structure is, for example, a network structure for intercommunication between a 5GS system and an EPS system defined by the 3rd generation partnership project (3GPP). The network structure may include an access network (access network, AN) and a core network (core network, CN), and may also include user equipment (user equipment, UE).

Among them, the access network is used to implement access-related functions, which can provide network access functions for authorized users in a specific area, and can determine transmission links of different qualities to transmit user data according to user levels and service requirements. The access network forwards control signals and user data between the terminal equipment and the core network. The access network may include access network devices, and the access network devices may be devices that provide access for terminal devices, and may include radio access network (radio access network, RAN) devices and AN devices. The (R)AN device is mainly responsible for wireless resource management, quality of service (QoS) management, data compression and encryption on the air interface side. RAN equipment may include various forms of base stations, such as macro base stations, micro base stations (also called small stations), relay stations, access points, and balloon stations. In systems using different wireless access technologies, the names of devices with base station functions may be different. For example, in 5G systems, it is called RAN or next-generation Node basestation (gNB); in long term evolution (LTE) systems, it is called evolved NodeB (eNB or eNodeB).

Among them, the core network is responsible for maintaining the subscription data of the mobile network, and providing functions such as session management, mobility management, policy management, and security authentication for the UE.

The following briefly introduces each network element shown in Figure 1:

1. User equipment (UE): can be called terminal equipment, access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

A terminal device may be a device that provides voice/data connectivity to users, for example, a handheld device with a wireless connection function, a vehicle-mounted device, and the like. At present, examples of some terminals can be: mobile phone (mobile phone), tablet computer (pad), computer with wireless transceiver function (such as notebook computer, palmtop computer, etc.), mobile Internet device (mobile internet device, MID), virtual reality (virtual reality, VR) equipment, augmented reality (augmented reality, AR) equipment, wireless terminals in industrial control (industrial control), wireless terminals in unmanned driving (self driving) Wireless terminal, wireless terminal in remote medical, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, cellular phone, cordless phone, session initiation protocol (session initiation protocol, SIP) phone, wireless local loop (wireless local loop, W LL) station, personal digital assistant (personal digital assistant, PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal device in 5G network or terminal device in the future evolution public land mobile network (PLMN), etc.

In addition, the terminal device may also be a terminal device in an Internet of Things (Internet of things, IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, so as to realize the intelligent network of human-machine interconnection and object interconnection. IoT technology can achieve massive connections, deep coverage, and terminal power saving through, for example, narrow band NB technology.

In addition, terminal equipment can also include sensors such as smart printers, train detectors, and gas stations. The main functions include collecting data (part of terminal equipment), receiving control information and downlink data from network equipment, and sending electromagnetic waves to transmit uplink data to network equipment.

It should be understood that the terminal device may be any device that can access the network. A certain air interface technology may be used to communicate with each other between the terminal device and the access network device.

2. Access network: including the evolved UMTS terrestrial radio access network (evolved UMTS terrestrial radio access network, E-UTRAN) in the LTE system and the next generation radio access network (NG-RAN) in the 5G system. The access network can provide network access functions for authorized users in a specific area, including radio access network (radio access network, RAN) equipment and AN equipment. The RAN device is mainly a 3GPP network wireless network device, and the AN device may be an access network device defined by non-3GPP.

The access network may be an access network using different access technologies. There are currently two types of wireless access technologies: 3GPP access technologies (such as those used in 3G, 4G or 5G systems) and non-3GPP (non-3GPP) access technologies. The 3GPP access technology refers to the access technology that complies with the 3GPP standard specifications. For example, the access network equipment in the 5G system is called the next generation Node Base station (gNB) or RAN. Non-3GPP access technologies refer to access technologies that do not comply with 3GPP standards, such as air interface technologies represented by access point (AP) in wireless fidelity (WiFi), worldwide interoperability for microwave access (WiMAX), code division multiple access (CDMA) networks, etc. The access network equipment (AN equipment) may allow non-3GPP technology interconnection and intercommunication between the terminal equipment and the 3GPP core network.

An access network that implements access network functions based on wireless communication technologies may be called a RAN. The radio access network can be responsible for functions such as radio resource management, quality of service (QoS) management, data compression and encryption on the air interface side. The wireless access network provides access services for terminal equipment, and then completes the forwarding of control signals and user data between the terminal and the core network.

For example, the wireless access network may include but not limited to: a macro base station, a micro base station (also called a small cell), a radio network controller (radio network controller, RNC), a node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (for example, home evolved NodeB, or home Node B, HNB), a baseband unit (base band unit, BBU), AP, wireless relay node, wireless backhaul node, transmission point (transmission point, TP) or transmission and reception point (transmission and reception point, TRP) in the WiFi system, etc., can also be gNB or transmission point (TRP or TP) in the 5G (eg, NR) system, one or a group (including multiple antenna panels) antenna panels of the base station in the 5G system, or, it can also be a network node that constitutes a gNB or transmission point , such as a baseband unit (BBU), or a distributed unit (DU), or a base station in the next-generation communication 6G system, etc. The embodiment of the present application does not limit the specific technology and specific equipment form adopted by the radio access network equipment.

The access network can provide services for the cells. The terminal device can communicate with the cell through the transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the access network device.

3. MME network element: It is the network element of the EPC system core network control plane, mainly used for access control, user registration network, mobility management, session management and routing selection.

4. AMF network element: It is the network element of the core network of the 5GS system, mainly used for mobility management and access management, such as user location update, user registration network, user switching, etc. AMF can also be used to implement other functions in MME except session management. For example, functions such as lawful interception or access authorization (or authentication).

5. SGW network element: mainly responsible for user plane processing, responsible for functions such as routing and forwarding of data packets, used to process service flow, complete service bearer, etc.

6. SMF+PGW-C converged network element: a network entity formed by the combination of session management function (session management function, SMF) and PDN gateway control plane (PDN gate way control plane function, PGW-C). It is mainly used for session management, Internet protocol (internet protocol, IP) address allocation and management of UE, selection of endpoints that can manage user plane functions, policy control, or charging function interfaces, and downlink data notification.

7. UPF+PGW-U converged network element: a network entity formed by the combination of user plane function (UPF) and PDN gateway user plane (PDN gate way user plane function, PGW-U). It is mainly responsible for the forwarding and receiving of user data in the terminal equipment. User data can be received from a data network (DN) and transmitted to a terminal device through an access network device.

8. HSS+UDM integrated network element: a network entity formed by the combination of home subscriber server (HSS) and unified data management (UDM). It is mainly used to generate authentication credentials, user identification processing (such as storing and managing user permanent identities, etc.), access authorization control and contract data management, etc.

9. PCRF+PCF fusion network element: a network entity formed by combining policy and charging rule function (PCRF) and policy control function (PCF).

10. N26 interface: the interface between the AMF network element and the MME network element. It is used for the UE to interoperate between 4G and 5G systems. The target side network obtains UE mobility management and session management related information from the source side network through the N26 interface. The N26 interface is an optional interface, and its application deployment depends on the operator's specific deployment strategy and service requirements.

The network structure shown in Figure 1 supports service continuity during interoperability between the 4G system and the 5G system. In the process of changing from the 4G system to the 5G system or from the 5G system to the 4G system, there is no need to change the user plane anchor point, saving service processing resources.

It should be understood that the network elements in the network structure shown in FIG. 1 can also interact through other interfaces, such as the N1 interface between the AMF network element and the UE. For the sake of brevity, details are not detailed here.

It should be understood that the above-mentioned network structure applied to the embodiment of the present application is only an example network structure described from the perspective of a service-oriented architecture, and the network structure applicable to the embodiment of the present application is not limited thereto. Any network structure that can realize the functions of the above-mentioned network elements is applicable to the embodiment of the present application.

It should also be understood that the MME, AMF, SGW, SMF+PGW-C, UPF+PGW-U, and HHS+UDM shown in Figure 1 can be understood as network elements used to implement different functions in the core network, for example, they can be combined into network slices as needed. These core network elements can be independent devices, or can be integrated into the same device to implement different functions. This application does not limit the specific forms of the above network elements.

It should also be understood that the above names are only defined for the convenience of distinguishing different functions, and shall not constitute any limitation to the present application. This application does not exclude the possibility of using other names in the 5G network and other networks in the future. For example, in a 6G network, some or all of the above network elements may use the terms in 5G, or may use other names. The name of the interface between network elements in FIG. 1 is just an example, and the name of the interface in a specific implementation may be another name, which is not specifically limited in this application. In addition, the name of the message (or signaling) transmitted between the above network elements is only an example, and does not constitute any limitation on the function of the message itself.

In order to facilitate the understanding of the solutions provided by the embodiments of the present application, firstly, a brief introduction is given to the process of interoperability between systems.

In a traditional solution for interoperability between systems, based on whether the N26 interface is deployed on the network side, interoperability between systems can be performed in a manner of handover or redirection.

When the N26 interface is deployed on the network side, during interoperability between systems, for example, when changing from the source-side network to the target-side network, the target-side network element can obtain the mobility management and session management context information of the terminal device from the source-side network element through the N26 interface, and the source-side network element initiates a handover operation for the terminal device to the target-side network element, which can ensure the continuity of user services.

When the N26 interface is not deployed on the network side, the target side network element cannot obtain the context information of the terminal device from the source side network element through the N26 interface. At this time, the source-side network element initiates a redirection operation to the target-side network element for the terminal device, for example, the source-side base station releases a radio resource control (radio resource control, RRC) connection, and instructs the terminal device to redirect to the target-side base station. Although it is still possible to ensure the continuity of user services without changing the anchor point of the user plane, since there is no communication interface, the delay of the redirection operation is greater than that of the handover operation.

It is worth noting that in the traditional solution, different inter-system interoperability indication information can be issued based on the availability of the N26 interface. For example, interworking without N26 interface indicator (interworking without N26 interface indicator).

Exemplarily, the network side can only configure the interoperability mode between user systems based on system granularity. That is to say, when the N26 interface is deployed on the network side, all users implement interoperability between systems through switching over the N26 interface. When the N26 interface is not deployed on the network side, all users implement interoperability between systems through redirection.

In some scenarios, some users can implement intersystem interoperability through the N26 interface. However, since the N26 interface is not deployed on the network side, intersystem interoperability can only be implemented without the N26 interface, and the user experience is poor.

In other scenarios, some users cannot implement intersystem interoperability through the N26 interface, but some users initiate intersystem interoperability based on the N26 interface, resulting in being rejected by the network side, increasing signaling consumption, and increasing intersystem interoperability. Latency.

The solution provided by the embodiment of the present application can issue different instruction information based on different terminal devices, which is beneficial to adjust strategies for different users to implement interoperability between systems, and at the same time ensure the continuity of services of different users and improve user experience.

Fig. 2 is an exemplary flow chart of a method for interoperability between systems provided by an embodiment of the present application. The method shown in FIG. 2 includes steps S210 to S240. Each step is described in detail below.

S210. The mobility management network element determines whether the terminal device supports an inter-system communication interface.

The mobility management network element may be the MME in the embodiment shown in FIG. 3 , or the AMF in the embodiment shown in FIG. 4 . The inter-system communication interface may be the N26 interface between the 4G network and the 5G network.

It should be understood that the inter-system communication interface has already been deployed in the embodiment of the present application.

It should be understood that, for each terminal device, the mobility management network element needs to determine whether the terminal device supports the inter-system communication interface.

Optionally, the mobility management network element obtains the home PLMN information of the terminal device; the mobility management network element determines whether the terminal device supports the inter-system communication interface according to the home PLMN information.

For example, the information of the PLMN to which the terminal device belongs can be acquired according to the IMSI or SUPI carried in the attach request. Alternatively, the information of the PLMN to which the terminal device belongs may also be obtained according to the identity request and identity response messages in the embodiment shown in FIG. 3 . Alternatively, the number segment information of the user equipment may also be obtained according to the IMSI, so as to obtain the home PLMN information of the user equipment. The number segment information may indicate the operator network to which the user equipment belongs.

Optionally, when the home PLMN information is on the first PLMN list, determine that the terminal device supports an inter-system communication interface; or, when the home PLMN information is not on the first PLMN list, determine that the terminal device does not support an inter-system communication interface.

For example, the first PLMN list may be the first PLMN list in the embodiment shown in FIG. 3 . For example, the MME may pre-configure the first PLMN list as (PLMN1, PLMN2, PLMN3). When the PLMN to which the user equipment belongs is PLMN1, PLMN2 or PLMN3, the MME determines that the user equipment supports the N26 interface. When the PLMN to which the user equipment belongs is PLMN4, the MME determines that the user equipment supports the N26 interface.

Optionally, acquire the subscription data of the terminal device, where the subscription data includes indication information of inter-system interoperability; and determine whether the terminal equipment supports an inter-system communication interface according to the indication information of inter-system interoperability.

S220, the mobility management network element sends the first indication information to the network element of the access network or the terminal device, and correspondingly, the network element of the access network receives the first indication information.

The first indication information is used to indicate whether the terminal device supports an inter-system communication interface, and the first indication information includes identity information of the terminal device.

For example, the identity information of the terminal device may be an International Mobile Subscriber Identity (IMSI) or a Subscription Permanent Identifier (SUPI) of the terminal device.

For example, the first indication information may be the first indication information in the embodiment shown in FIG. 3 or FIG. 4 .

Optionally, the mobility management network element sends an initial context establishment request to the access network element, where the initial context establishment request includes the first indication information.

For example, the initial context establishment request may be the initial context establishment request in the embodiment shown in FIG. 3 or FIG. 4 . Optionally, the network element of the access network or the terminal device stores the first indication information.

That is to say, after receiving the first indication information, the network element of the access network or the terminal device will store the first indication information, so as to query the first indication information during interoperability between systems.

S240, the mobility management network element sends the first indication information to the terminal device, and correspondingly, the terminal device receives the first indication information.

For example, the initial context establishment request in the embodiment shown in FIG. 3 or FIG. 4 may carry an attach accept message, which is transparently transmitted to the terminal device via the eNB or gNB. The attach accept message may be the attach accept message in the embodiment shown in FIG. 3 , or the registration accept message in the embodiment shown in FIG. 4 .

S250. According to the first indication information, the network element of the access network selectively performs the first interoperation based on the intersystem communication interface or the second interoperation without the intersystem communication interface.

S250 is an optional step, and S250 is executed when the terminal device needs to perform interoperability between systems.

It should be understood that, when the first indication information indicates that the terminal device supports an inter-system communication interface, the network element of the access network initiates a first interoperation based on an inter-system communication interface to change an access network of the terminal device; or, when the first indication information indicates that the terminal device does not support an inter-system communication interface, the network element of the access network initiates a second interoperation without an inter-system communication interface to change an access network of the terminal device.

As shown in the embodiment of FIG. 6 , the first interoperation based on the intersystem communication interface may be a switching operation, and the second interoperation without an intersystem communication interface may be a redirection operation.

Optionally, according to the measurement report reported by the terminal device, the network element of the access network determines that the terminal device needs to perform inter-system interoperability.

Optionally, when the first indication information indicates that the terminal device supports an inter-system communication interface, context information related to the terminal device may be transmitted through the inter-system communication interface.

Optionally, when the terminal device needs to perform interoperability between systems, query the first indication information corresponding to the terminal device.

S260. According to the first indication information, the terminal device selectively performs mobility registration or handover registration.

S260 is an optional step, and S260 is executed when the terminal device needs to perform interoperability between systems.

It should be understood that when the first indication information indicates that the terminal device supports the inter-system communication interface, the terminal device accesses the network by means of mobility registration; or, when the first indication information indicates that the terminal device does not support the inter-system communication interface, the terminal device accesses the network by means of switching registration.

The mobility registration is intersystem interoperability based on intersystem communication interfaces. For example, when moving from a 5G network to a 4G network, the terminal device initiates a tracking area update process and obtains context information in the 5G network through the N26 interface. For another example, when moving from a 4G network to a 5G network, the terminal device initiates a mobility registration update process, and obtains context information in the 4G network through the N26 interface.

The handover is registered as an intersystem interoperability without an intersystem communication interface. For example, if the user equipment needs to change from a 5G network to a 4G network, the type of the attach request carried by the user equipment in the attach request is "handover", carries the 4G-GUTI mapped from the 5G-GUTI, and indicates that the source network of the user equipment is a 5G network. In the subsequent process, the network side will migrate all surviving PDU sessions of the user equipment to the 4G network through this process, and ensure the continuity of the IP address of the user equipment.

For another example, the user equipment carries the 5G-GUTI mapped from the 4G-GUTI to perform a registration process of the type "mobility registration update" on the 5G network, and at the same time indicates that the source network of the user equipment is the 4G network.

Fig. 3 is an exemplary flow chart of a method for interoperability between systems provided by an embodiment of the present application. Each step is introduced below.

It should be noted that the embodiment shown in FIG. 3 may be performed during a 4G network registration process, which is also called an attach process. Through the registration process, the relevant information of the user equipment is registered with the network entity, and the user equipment can access various services in the 4G network.

The embodiment shown in Figure 3 does not describe the complete 4G network registration process in detail, for example, before step S305, it may also include key steps such as authentication and entering a security mode. For details that are not described in detail, please refer to the registration process of the 4G network stipulated in the agreement.

S301, the user equipment sends an attach request to the eNB.

S302, the eNB transparently transmits the attach request to the MME, and correspondingly, the MME receives the attach request.

In S301 and S302, the user equipment sends an attach request (attach request) message at the non-access stratum (non-access stratum, NAS) layer, and the eNB can transparently transmit the attach request to the MME.

It should be understood that when the attach request is transparently transmitted, the attach request is transparent to the eNB, but the eNB does not parse the content of the attach request message, but is only responsible for forwarding it.

The attach request may include: user identity, such as IMSI or globally unique temporary user equipment identity (GUTI); location information of the user equipment, such as tracking area identity (tracking area identity, TAI); attach request type (attach request type); user equipment network capability (user equipment network capability); et Data Network connectivity request, PDN connectivity request), etc.

In the base station sharing scenario, each cell can include available PLMNs in the broadcast message, and each PLMN corresponds to an operator network, for example: China Mobile's PLMN, China Unicom's PLMN.

When the user equipment performs registration with the network, the user equipment may select an available PLMN to perform registration according to a preset network selection rule. For example, a home public land mobile network (home public land mobile network, HPLMN) is preferentially selected for registration. In a scenario where roaming across networks is allowed, if the home PLMN is unavailable, the user equipment may also switch to a PLMN network with better network signals. For example, the home PLMN of the user equipment is the 4G network of China Mobile, the user equipment can preferentially select the home PLMN to perform registration, and when the network signal of China Mobile is not good, it can switch to the network of China Unicom with better signal.

PLMN can be distinguished by public land mobile network ID (PLMN ID), for example: the PLMN ID of China Mobile's 4G network is 46001, the PLMN ID of China Mobile's 5G network is 46002, and the PLMN ID of China Unicom's 4G network is 47001.

PLMN ID consists of mobile country code (mobile country code, MCC) and mobile network code (mobile network code, MNC). For a user equipment, there is only one PLMN to which it belongs. The MCC and MNC of the home PLMN are consistent with the MCC and MNC in the IMSI of the user equipment.

It should be understood that the home PLMN of the user equipment can be learned through the IMSI of the user equipment.

Optionally, the user equipment may use the IMSI to initiate the registration process for the identity, or use the GUTI to initiate the registration process for the identity.

Exemplarily, the first registration process when the user equipment is turned on may use the IMSI as the identity identifier, and subsequently use the GUTI as the identity identifier to initiate registration.

In some embodiments, the user equipment may first be registered on the 5G network, and then move from the 5G network to the 4G network due to service requirements. At this time, the user equipment can use the mapped GUTI (5G GUTI mapped from the 4G GUTI) as the identity to register on the 4G network.

In some embodiments, the user equipment may send the attach request in a periodic registration process. That is to say, the solution of the embodiment shown in FIG. 3 can also be performed in the periodic registration process.

In some embodiments, when the UE moves to a new tracking area (track area, TA), resulting in a mismatch between the TA where the user equipment is located and the TA supported by the user equipment, it is necessary to initiate a tracking area update (tracking area update, TAU) process, and the user equipment may send a tracking area update request in the TAU process, and then perform subsequent related steps. That is to say, the solution of the embodiment shown in FIG. 3 can also be implemented in the TAU process.

S303. The MME sends an identity request (identity request) to the user equipment.

S304. The user equipment sends an identity response (identity response) to the MME. Correspondingly, the MME receives the identity response from the user equipment.

Step S303 and step S304 are optional steps. When the user equipment registers with the network using the IMSI as the identity, step S303 and step S304 do not need to be performed.

In this embodiment of the present application, the MME to which the user equipment is currently attached may be called a new MME, and the MME to which the user equipment has been attached may be called an old MME.

In some embodiments, the old MME can store the context information of the user equipment. When the user equipment registers to the network with the GUTI as the identity, the new MME learns which old MME the user equipment was registered with according to the GUTI, and the new MME sends an identity request to the old MME. In response to the identity request, the old MME sends the IMSI of the user equipment to the new MME.

In some other embodiments, the old MME does not store the context information of the user equipment, and when the user equipment registers with the network using the GUTI as the identity, the new MME sends an identity request to the old MME. Since the old MME does not store the context information of the user equipment, the old MME notifies the new MME that no context information of the user equipment is found. The new MME then sends an identity request to the user equipment, and in response to the identity request, the user equipment sends an identity response to the new MME to provide the IMSI.

It should be understood that the new MME and the old MME may be the same MME.

S305. The MME sends an update location request (update location request) to the HSS+UDM converged network element.

S306. The HSS+UDM integrated network element sends an update location response (update location response) to the MME.

Step S305 and step S306 are used to obtain the subscription data of the user equipment. The subscription data may include information such as whether to subscribe to 4G, a signed access point (access point name, APN), and a default APN.

In this embodiment of the application, the subscription data includes indication information of interoperability between systems. The indication information can be understood as whether the user equipment has subscribed to the N26 interface, and if the user equipment has subscribed to the N26 interface, the user equipment can implement inter-system interoperability through the N26 interface. Otherwise, the user equipment cannot implement inter-system interoperability through the N26 interface.

It should be understood that the HSS+UDM integrated network element may also be an HSS network element in the 4G core network or a UDM network element in the 5G core network, as long as the network element can be used to manage user subscription data.

Optionally, the subscription data may include a list of PLMNs that the user equipment supports the N26 interface. The information related to the N26 interface may also be a list of PLMNs that the user equipment does not support the N26 interface.

S307. The MME determines whether the user equipment supports the N26 interface.

It should be understood that when the user equipment supports the N26 interface, the user equipment can implement intersystem interoperability through the N26 interface, and when the user equipment does not support the N26 interface, the user equipment cannot implement intersystem interoperability through the N26 interface.

It should also be understood that when the user equipment supports the N26 interface, the context information of the user equipment may be transmitted through the N26 interface during interoperability between systems.

When the user equipment does not support the N26 interface, the context information of the user equipment cannot be transmitted through the N26 interface during interoperability between systems.

The MME can determine whether the user equipment supports the N26 interface in various ways.

In a possible implementation manner, the MME obtains the home PLMN information of the user equipment according to the IMSI of the user equipment.

Alternatively, the number segment information of the user equipment may also be obtained according to the IMSI, so as to obtain the home PLMN information of the user equipment. The number range information may indicate the operator network to which the user equipment belongs, for example, the number range of China Mobile is 134xxxxxxxx or 135xxxxxxxx, and the number range of China Telecom is 133xxxxxxxx, 149xxxxxxxx, etc.

The MME can determine whether the user equipment supports the N26 interface according to the home PLMN information of the user equipment.

For example, the MME may pre-configure the first PLMN list, and when the information of the PLMN to which the user equipment belongs is on the first PLMN list, the MME determines that the user equipment supports the N26 interface. Otherwise, the user equipment does not support the N26 interface.

Exemplarily, the first PLMN list is (PLMN1, PLMN2, PLMN3), and when the PLMN to which the user equipment belongs is PLMN1, PLMN2 or PLMN3, the MME determines that the user equipment supports the N26 interface. When the PLMN to which the user equipment belongs is PLMN4, the MME determines that the user equipment does not support the N26 interface.

Or, the MME configures the second PLMN list, and when the PLMN information of the user equipment is on the second PLMN list, the MME determines that the user equipment does not support the N26 interface. Otherwise, the user equipment supports the N26 interface.

In a possible implementation manner, the MME may determine whether the user equipment supports the N26 interface according to the indication information of intersystem interoperability in the subscription data of the user equipment.

In a possible implementation manner, the MME may determine whether the user equipment supports the PLMN list of the N26 interface according to the list of PLMNs supporting the N26 interface in the subscription data of the user equipment.

For example, when the subscription data indicates that the user equipment supports the N26 interface PLMN list as (PLMN2, PLMN3), the user equipment supports switching from the home PLMN to PLMN2 and PLMN3 through the N26 interface, but the user equipment does not support switching from the home PLMN to PLMN4 through the N26 interface.

It should be understood that for each user equipment that initiates the registration process, the MME needs to determine whether the user equipment supports the N26 interface.

S308, the MME sends a session creation request to the SGW.

S309, the SGW sends a session creation request to the SMF+PGW-C.

S310, SMF+PGW-C sends a session creation response to the SGW.

S311, the SGW sends a session creation response to the MME.

Steps S308 to S311 are mainly the process of establishing a session default bearer, which is not limited in this application.

S312, the MME sends an initial context establishment request to the eNB.

The MME sends an initial context establishment request (initial context request) message to the eNB, and the message includes an attach accept (attach accept) message of the NAS layer.

In this embodiment of the present application, the initial context establishment request may carry first indication information, where the first indication information is used to indicate whether the user equipment supports the N26 interface.

Optionally, the attach accept message may carry the first indication information.

Optionally, the first indication information also includes identity information of the user equipment, for example, IMSI.

Exemplarily, the initial context establishment request includes whether the user equipment supports the N26 interface indication information (interworking without N26 interface indicator), the information indicates interoperability between systems without the N26 interface, when it is determined that the user equipment supports the N26 interface, the indication information can be set to false, when it is determined that the user equipment does not support the N26 interface, the indication information can be set to true. That is to say, when the indication information is set to false, the interoperability between the 4G network and the 5G network can be realized in the future by using the N26 interface. When the indication information is set to true, the interoperability between the 4G network and the 5G network can be realized in the future without the N26 interface.

Optionally, the MME may send the first indication information to the eNB.

In some embodiments, when the base station associated with the user equipment changes, for example, when the user equipment moves from the source base station to the target base station, the MME learns that the base station where the user equipment is currently located is the target base station, and the MME may send the first indication information to the target base station.

In some embodiments, when the user equipment moves from the source base station to the target base station, the MME also changes, for example, the MME changes from the source MME to the target MME. At this time, the target MME may execute S307, and send the first indication information to the base station and the user equipment. For example, the target MME may acquire the IMSI of the user equipment or the subscription data of the user equipment from the source MME to determine whether the user equipment supports the N26 interface. And send the first indication information to the target base station.

Optionally, the target MME may acquire the first indication information of the user equipment from the source MME, and send the first indication information to the target base station.

In this way, it can be ensured that when the user equipment moves to any base station, the base station can receive the first indication information of the user equipment, so that when the user equipment needs to change from the 4G network to the 5G network, the base station initiates correct intersystem interoperation according to the first indication information.

Optionally, the MME sends the first indication information to the user equipment only when the user equipment accesses the network for the first time, such as an initial attachment when the user equipment is turned on.

In this way, the number of times of sending the first indication information to the user equipment can be reduced, saving signaling consumption.

In this embodiment of the present application, the MME may determine whether the user equipment supports the N26 interface during the network registration process of the user equipment, and send the first indication information of the user equipment to the base station, where the first indication information may be used to indicate whether the user equipment supports the N26 interface.

Optionally, when the user equipment needs to perform intersystem interoperation, the base station can selectively perform interoperation based on the N26 interface or interoperation without the N26 interface according to the first indication information, so as to change the access network of the user equipment.

Exemplarily, the user equipment needs to be changed from the 4G network to the 5G network, and if the first indication information indicates that the user equipment supports the N26 interface, then the base station performs a cross-system handover procedure to access the user equipment to the 5G network. At this time, the N26 interface can be used for signaling interaction and data transmission between the 4G core network and the 5G core network, for example, it can be used to transmit context information of the user equipment.

If the first indication information indicates that the user equipment does not support the N26 interface, then the base station performs a redirection operation to access the user equipment to the 5G network. For example, release the RRC connection with the user equipment, and notify the user equipment to redirect to the base station of the 5G network. At this time, it is considered that there is no N26 interface between the 4G network and the 5G network.

Optionally, in the above example, the user equipment may be in a connected state, and there is an RRC connection with the base station.

Optionally, the first indication information may indicate a list of PLMNs that the user equipment can handover through the N26 interface. When the user equipment needs to interoperate between systems, the base station learns the information of the PLMN to be accessed by the user equipment according to the RRC message, and determines whether the user equipment supports switching to the PLMN to be accessed through the N26 interface according to the list of PLMNs that the user equipment supports the N26 interface.

Exemplarily, when the user is about to access the PLMN5, and when the PLMN5 is on the list of PLMNs supporting the N26 interface, it is determined that the user equipment supports accessing the PLMN5 through the N26 interface.

S313, the eNB sends an RRC connection reconfiguration message to the user equipment.

The RRC connection reconfiguration information is used to establish a radio bearer between the eNB and the user equipment, and the RRC connection reconfiguration information includes an attach accept message.

Meanwhile, the RRC connection reconfiguration information may include the first indication information.

Optionally, the MME may send the first indication information to the user equipment.

In this way, the user equipment can know whether it can realize intersystem interoperability through the N26 interface according to the first indication information, and when the user equipment needs to perform intersystem interoperability, the user equipment can perform the correct intersystem interoperability process according to the first indication information, thereby reducing unnecessary signaling overhead and reducing the delay of intersystem interoperability.

Exemplarily, if the first indication information indicates that the user equipment supports the N26 interface, and the user equipment needs to change from the 4G network to the 5G network, then the user equipment performs a tracking area update (TAU) process to access the 5G network. If the user equipment needs to change from the 5G network to the 4G network, the user equipment performs a mobility registration update process to access the 4G network.

When the first indication information indicates that the user equipment does not support the N26 interface, the user equipment performs handover registration to access the network. For example, if the user equipment needs to change from a 5G network to a 4G network, the type of the attach request carried by the user equipment in the attach request is "handover", and at the same time indicates that the source network of the user equipment is a 5G network. In the subsequent process, the network side will migrate all surviving PDU sessions of the user equipment to the 4G network through this process, and ensure the continuity of the IP address of the user equipment.

For example, the user equipment carries the 5G-GUTI mapped from the 4G-GUTI to perform a registration process of the type "mobility registration update" on the 5G network, and at the same time indicates that the source network of the user equipment is the 4G network.

Optionally, in the above example, the user equipment is in an idle state, and there is no RRC connection with the base station.

S314, the eNB sends an initial context setup response (initialcontextsetupresponse) to the MME.

The initial context setting response is a response to the initial context setting request in step S312, which is not limited in this application.

S315, the user equipment sends an attach complete (attach complete) message to the MME.

S316, the MME sends a modify bearer request (modifybearer request) to the SGW. Correspondingly, the SGW sends a modify bearer response (modifybearerresponse) to the MME.

Fig. 4 is an exemplary flow chart of another method for interoperability between systems provided by an embodiment of the present application. Each step is introduced below.

It should be noted that the embodiment shown in FIG. 4 may be a process of user equipment registering on a 5G network. The embodiment shown in Figure 4 does not describe the complete 5G network registration process in detail. For example, before the gNB transparently transmits the registration request to the AMF, it also includes the step of selecting an AMF. For details that are not described in detail, please refer to the registration process specified in the protocol.

S401, the user equipment sends a registration request to the gNB.

S402, the gNB sends a registration request to the AMF, and correspondingly, the AMF receives the registration request from the user equipment.

S401 and S402 are similar to S301 and S302 respectively, and for details, refer to related descriptions of S301 and S302.

The registration request is similar to the attach request, and the user equipment can carry SUPI or user concealed identifier (subscription concealed identifier, SUCI) in the attach message to initiate the registration process.

In some embodiments, the user equipment may first be registered on the 4G network, and then move from the 4G network to the 5G network due to service requirements. At this time, the user equipment can use the mapped GUTI (5G GUTI mapped from the 4G GUTI) as the identity to register on the 5G network.

In some embodiments, the user equipment may send the attach request in a periodic registration process. That is to say, the solution of the embodiment shown in FIG. 4 can also be performed in the periodic registration process.

In some embodiments, when the UE moves to a new TA, resulting in a mismatch between the TA where the user equipment is located and the TA supported by the user equipment, it is necessary to initiate a mobility registration update process, and the user equipment may send a registration request during the mobility registration update process, and then perform subsequent related steps. That is to say, the solution claimed in the embodiment shown in FIG. 4 can also be implemented in the mobility registration update process.

S403, the MME sends an identity request to the user equipment.

S404, the user equipment sends an identity response to the MME, and correspondingly, the MME receives the identity response from the user equipment.

S403 and S404 are similar to S303 and S304 respectively, and for details, refer to related descriptions of S303 and S304.

S403 and S404 are optional steps. When the user equipment registers with the network using SUPI or SUCI as an identity, that is, when the registration request sent by the user equipment includes SUPI or SUCI, S403 and S404 do not need to be performed.

If the identity of the user equipment cannot be identified, in S303, the AMF needs to initiate an identity request to the user equipment to obtain the SUPI or SUCI of the user equipment.

In this embodiment of the present application, the AMF to which the user equipment is currently registering may be called a new AMF, and the AMF to which the user equipment has been attached may be called an old AMF.

Optionally, the new AMF sends an identity request to the old AMF to obtain the SUPI or SUCI of the user equipment.

S405. The AMF obtains the subscription data of the user from the HSS+UDM.

S405 is similar to S305 and S306, and for details, refer to related descriptions of S303 and S304.

Specifically, the AMF uses the nudm_sdm_get message to obtain the subscription data of the user in the HSS+UDM converged network element.

Optionally, the subscription data includes a list of PLMNs that the user equipment supports the N26 interface. The information related to the N26 interface may also be a list of PLMNs that the user equipment does not support the N26 interface.

S404, the AMF determines whether the UE supports the N26 interface.

S405, the AMF sends an initial context establishment request to the gNB.

S406, the gNB sends RRC connection reconfiguration information to the UE.

S407, the gNB sends an initial context establishment response to the AMF.

S408, the UE sends registration completion information to the AMF.

S404 to S408 are similar to related steps in the embodiment shown in FIG. 3 , and for details, reference may be made to related descriptions of the embodiment shown in FIG. 3 . For example, S404 is similar to S07, and for S404, refer to the related description of S307. S405 is similar to S312, and for details, refer to related descriptions of S312.

Fig. 5 is an exemplary flow chart of a method for interoperability between systems provided by the present application. Each step is introduced below.

S510, the network element of the access network obtains the PLMN information selected by the terminal device.

It should be understood that the access network element may be a 4G base station or a 5G base station.

It should be understood that the PLMN information selected by the terminal device is the PLMN information selected when the terminal device registers to the network.

Optionally, the network element of the access network may obtain the PLMN information selected by the terminal device according to the TAI of the terminal device.

Optionally, the network element of the access network may obtain the information of the PLMN selected by the terminal device through an RRC message.

Optionally, the network element of the access network may acquire the home PLMN information of the terminal device, and determine whether the terminal device supports the N26 interface according to the home PLMN information.

S520. The network element of the access network determines whether the terminal device supports the N26 interface.

Specifically, according to the PLMN information selected by the terminal device, it is determined whether the terminal device supports the N26 interface.

For example, the network element of the access network may configure the third PLMN list, and when the PLMN selected by the terminal device is on the PLMN list, it is determined that the terminal device supports the N26 interface.

The third PLMN list is (PLMN1, PLMN2, PLMN3). When the PLMN selected by the user equipment is PLMN1, PLMN2 or PLMN3, the MME determines that the user equipment supports the N26 interface. When the PLMN selected by the user equipment is PLMN4, the MME determines that the user equipment does not support the N26 interface.

Optionally, the access network element configures a terminal device list supporting the N26 interface, and when the access network element determines that the terminal device supports the N26 interface, the terminal device is added to the terminal device list.

For example, after it is determined that the terminal device 1 supports the N26 interface, the terminal device 1 is added to the terminal device list.

In this way, the judgment result of the terminal device can be saved, and the capability information of the terminal device for system intercommunication can be saved. When the terminal device needs to perform interoperability between systems, it can be checked whether the terminal device is in the terminal device list, thereby determining whether the terminal device supports the N26 interface.

Optionally, when the terminal device needs to interoperate between systems, the network element of the access network can selectively perform interoperation based on the N26 interface or interoperability without the N26 interface according to the first indication information, so as to change the access network of the terminal device.

Exemplarily, the terminal device needs to change from a 4G network to a 5G network, and if the first indication information indicates that the terminal device supports the N26 interface, then the base station performs a cross-system handover process to connect the terminal device to the 5G network. At this time, the N26 interface can be used for signaling interaction and data transmission between the 4G core network and the 5G core network, for example, it can be used to transmit context information of the terminal device.

If the first indication information indicates that the terminal device does not support the N26 interface, then the base station performs a redirection operation to connect the terminal device to the 5G network. For example, release the RRC connection with the terminal device, and notify the terminal device to redirect to the base station of the 5G network. At this time, it is considered that there is no N26 interface between the 4G network and the 5G network.

Optionally, in the above example, the terminal device may be in a connected state, and there is an RRC connection with the base station.

S530. The network element of the access network sends the first indication information to the terminal device.

S530 is an optional step. S530 is similar to S313, and for details, refer to related descriptions of S313.

Fig. 6 is an exemplary flow chart of another example of a method for interoperability between systems provided by the present application. Each step is introduced below.

It should be noted that the embodiment shown in FIG. 6 is an example of how to perform intersystem interoperability when the terminal device needs to perform intersystem interoperability. This example mainly illustrates that terminal equipment needs to perform interoperability between 5G and 4G systems. The same principle can be applied to the interoperability process between systems from 4G to 5G.

S610, the terminal device needs to change from the 5G network to the 4G network.

In some scenarios, the data service of the terminal device is initially established on the 5G network, and the terminal device moves to the edge of the 5G base station. The terminal device performs measurement and reports the measurement results. The base station determines that the terminal device needs to perform interoperability between systems according to the measurement report, so as to change the access network to the 4G network to ensure business continuity when the 5G network has weak coverage.

In other scenarios, the data service of the terminal device is initially established on the 5G network, and the data service of the terminal device needs to be carried on the 4G network to obtain a better user experience. Exemplarily, in the early stage of 5G network construction, the network coverage is discontinuous. When it is detected that the voice service is established, the voice service is dropped back to the 4G network through 5G to 4G interoperability to carry the voice service.

In some scenarios, the terminal device is idle and has not established an RRC connection with the base station. Due to the problem of 5G network coverage, the terminal device also needs to change from the 5G network to the 4G network.

In other scenarios, terminal devices need to be changed from 4G networks to 5G networks. For example, when returning from an area with a weak 5G signal to an area with a good 5G signal, the terminal device needs to change from the 4G network to the 5G network.

S620. The network element of the access network queries the first indication information of the terminal device.

It should be understood that the base station may store the first indication information of multiple terminal devices, and the base station may query the first indication information of the terminal devices that need to perform interoperability between systems. For example, query the corresponding first indication information according to the identity of the terminal device to determine whether the terminal device supports the N26 interface.

S630. If the terminal device supports the N26 interface, the network element of the access network performs switching from the 5G network to the 4G network through the N26 interface.

For example, the gNB sends a handover request (handover required) to the AMF, and the AMF and the MME perform signaling interaction through the inter-system communication interface to notify the eNB that there is a terminal device that needs to be handed over to the eNB. Then the AMF sends a handover command (handover command) to the gNB, and the gNB sends the handover command to the terminal device. In S630, the context information of the user equipment may be transmitted through the N26 interface.

It should be understood that the handover operation is intersystem interoperability based on the N26 interface.

Optionally, according to the first indication information, the terminal equipment knows that it supports the N26 interface, and when the terminal equipment does not establish an RRC connection with the network element of the access network, if the first indication information indicates that the user equipment supports the N26 interface, access to the network by means of mobility registration.

For example, if the user equipment needs to change from a 4G network to a 5G network, then the user equipment performs a TAU process to access the 5G network. Or, if the user equipment needs to change from the 5G network to the 4G network, the user equipment performs a mobility registration update process to access the 4G network.

It should be understood that the manner of registering for mobility includes a TAU process or a mobility registration update process.

S640. If the terminal device does not support the N26 interface, the network element of the access network performs redirection from the 5G network to the 4G network.

For example, the gNB releases the RRC connection, notifies the terminal device to redirect to the eNB, and transmits the context information of the terminal device through the HSS+UDM converged network element to maintain the service continuity of the terminal device. In S630, the context information of the user equipment cannot be transmitted through the N26 interface.

It should be understood that the redirection operation is an interoperability between systems without an N26 interface.

Optionally, according to the first indication information, the terminal device knows that it does not support the N26 interface, and when the terminal device does not establish an RRC connection with the network element of the access network, the terminal device accesses the network by switching registration.

For example, when a terminal device needs to change from a 5G network to a 4G network, the type of the attach request carried in the attach request is "handover", and at the same time indicates that the source network of the user equipment is a 5G network. Alternatively, when the terminal device needs to change from a 4G network to a 5G network, the terminal device initiates a registration process of the type "mobility registration update", and at the same time indicates that the source network of the user equipment is a 4G network.

Above, the method provided by the embodiment of the present application is described in detail with reference to FIG. 2 to FIG. 6 . Hereinafter, the device provided by the embodiment of the present application will be described in detail with reference to FIG. 7 to FIG. 8 . It should be understood that the descriptions of the device embodiments correspond to the descriptions of the method embodiments. Therefore, for details that are not described in detail, reference may be made to the method embodiments above. For brevity, details are not repeated here.

FIG. 7 is a schematic block diagram of an apparatus for interoperability between systems provided by an embodiment of the present application. The device 700 includes a transceiver unit 710 and a processing unit 720 . The transceiver unit 710 can implement a corresponding communication function, and the processing unit 720 is used for data processing. The transceiver bill 710 may also be referred to as a communication interface or a communication unit.

The apparatus 700 may be used to execute actions performed by a mobility management network element in the embodiments shown in FIG. 2 , FIG. 3 , FIG. 4 or FIG. 5 , for example, actions performed by an MME or an AMF. The transceiving unit 710 is configured to perform operations related to sending and receiving of the mobility management network element in the embodiment shown in FIG. 2, FIG. 3, FIG. 4 or FIG. 5, and the processing unit 720 is configured to perform operations related to data processing of the mobility management network element in the embodiment shown in FIG. 2, FIG.

Optionally, the apparatus 700 may further include a storage unit, which may be used to store instructions and/or data, and the processing unit 720 may read the instructions and/or data in the storage unit, so that the apparatus implements the aforementioned method embodiments.

The apparatus 700 may be used to execute the actions performed by the mobility management network element in the above method embodiments, for example, the actions performed by the MME or the AMF. The transceiving unit 710 is configured to perform operations related to transceiving of the mobility management network element in the method embodiments above, and the processing unit 720 is configured to perform operations related to processing of the mobility management network element in the method embodiments above.

In an implementation manner, the processing unit 720 is configured to: determine whether the terminal device supports an inter-system communication interface.

The transceiver unit 710 is configured to: send first indication information to an access network element or a terminal device, the first indication information is used to indicate whether the terminal device supports the inter-system communication interface, and the first indication information includes the identity information of the terminal device.

The apparatus 700 provided in this application can deliver different capability indication information for interoperability between systems to different terminal devices. When the terminal device needs to perform system intercommunication, different intersystem interoperability can be targetedly initiated based on the first indication information of the terminal device. In this way, it is possible to prevent all terminal devices in the system from changing access networks in the same way. For example, when all interoperability between systems is performed without inter-system communication interfaces, some users who support inter-system communication interfaces will experience poor experience.

As an example, the processing unit 720 is specifically configured to: acquire information about the PLMN to which the terminal device belongs; and determine whether the terminal device supports the inter-system communication interface according to the information on the home PLMN.

As another example, the processing unit 720 is specifically configured to: when the home PLMN information is on the first PLMN list, determine that the terminal device supports the inter-system communication interface; or, when the home PLMN information is not on the first PLMN list, determine that the terminal device does not support the inter-system communication interface.

As another example, the processing unit 720 is specifically configured to: acquire the subscription data of the terminal device, where the subscription data includes inter-system interoperability indication information; determine whether the terminal device supports the inter-system communication interface according to the inter-system interoperability indication information.

As yet another example, the transceiving unit 720 is specifically configured to: send an initial context establishment request to an access network element, where the initial context establishment request includes the first indication information.

FIG. 8 is a schematic block diagram of another apparatus for interoperability between systems provided by an embodiment of the present application. The device 800 includes a transceiver unit 810 and a processing unit 820 . The transceiver unit 810 can implement corresponding communication functions. The transceiver unit 810 may also be called a communication interface or a communication unit. The processing unit 820 may be used for data processing.

The apparatus 800 may be used to execute the actions performed by the network element of the access network in the embodiment shown in FIG. 5 or FIG. 6 . The transceiving unit 810 is configured to perform operations related to transceiving of network elements of the access network in the embodiment shown in FIG. 5 or FIG. 6 . The processing unit 820 is configured to perform operations related to processing of network elements of the access network in the embodiment shown in FIG. 5 or FIG. 6 .

In an implementation manner, the transceiving unit 810 is configured to: obtain information about the PLMN selected by the terminal device.

The processing unit 820 is configured to: determine whether the terminal device supports an inter-system communication interface according to the PLMN information.

As an example, the transceiving unit 810 is further configured to: send first indication information, where the first indication information is used to indicate whether the terminal device supports an inter-system communication interface, where the first indication information includes identity information of the terminal device.

FIG. 9 is a schematic block diagram of another apparatus for interoperability between systems provided by an embodiment of the present application. The apparatus 900 includes a transceiver unit 910 . The transceiver unit 910 can implement corresponding communication functions. The transceiver unit 910 may also be called a communication interface or a communication unit.

The apparatus 900 may be used to execute actions performed by network elements of the access network in the embodiments shown in FIG. 2 , FIG. 3 , FIG. 4 or FIG. 6 , for example, actions performed by an eNB or a gNB. The transceiving unit 910 is configured to perform operations related to transceiving of network elements of the access network in the embodiment shown in FIG. 2 , FIG. 3 , FIG. 4 or FIG. 6 .

In an implementation manner, the transceiving unit 910 is configured to: receive first indication information, where the first indication information is used to indicate whether the terminal device supports an inter-system communication interface, where the first indication information includes identity information of the terminal device.

The apparatus 900 may receive first indication information of the terminal device. During possible future intersystem interoperability, interoperability based on an intersystem communication interface or interoperability without an intersystem communication interface can be selectively performed according to the first indication information, so as to change the access network of the terminal device. In this way, different interoperability solutions between systems can be provided for different users, while service continuity of different users can be guaranteed, and user experience can be improved. In addition, the system can more flexibly control the strategy of each terminal device for interoperability between systems, improving control accuracy.

Optionally, referring to FIG. 10 , the apparatus 900 may further include a storage unit 920 or a processing unit 930, the storage unit 920 may be used to store instructions and/or data, and the processing unit 930 may read the instructions and/or data in the storage unit, so that the apparatus implements the aforementioned method embodiments. The processing unit 930 may be configured to perform operations related to processing of network elements of the access network in the embodiment shown in FIG. 2 , FIG. 3 , FIG. 4 or FIG. 6 .

As an example, the storage unit 920 is configured to: store the first indication information.

As an example, the transceiving unit 910 is specifically configured to: receive an initial context establishment request, where the initial context establishment request includes the first indication information.

As an example, the processing unit 930 is configured to: when the first indication information indicates that the terminal device supports the intersystem communication interface, initiate a first interoperation based on the intersystem communication interface to change the access network of the terminal device; or, when the first indication information indicates that the terminal device does not support the intersystem communication interface, initiate a second interoperation without an intersystem communication interface to change the access network of the terminal device.

The embodiment of the present application also provides another device for interoperability between systems. For brevity, its schematic block diagram still refers to FIG. 9 .

The apparatus 900 may be used to execute the actions of the terminal device in the embodiment shown in FIG. 2 , FIG. 3 , FIG. 4 , FIG. 5 or FIG. 6 . The transceiving unit 910 is configured to perform operations related to transceiving of the terminal device in the embodiment shown in FIG. 2 , FIG. 3 , FIG. 4 , FIG. 5 or FIG. 6 .

Optionally, referring to FIG. 10 , the apparatus 900 may further include a storage unit 920 or a processing unit 930 . The storage unit 920 may be used to store instructions and/or data, and the processing unit 930 may read the instructions and/or data in the storage unit, so that the apparatus implements the aforementioned method embodiments. The processing unit 930 is configured to execute processing-related operations of the terminal device in the embodiment shown in FIG. 2 , FIG. 3 , FIG. 4 or FIG. 5 or FIG. 6 .

As an example, the processing unit 930 is configured to: when the first indication information indicates that the terminal device supports the inter-system communication interface, access the network by means of mobility registration; when the first indication information indicates that the terminal device does not support the inter-system communication interface, access the network by means of handover registration.

FIG. 11 shows a schematic structural diagram of a device interoperable between systems provided by an embodiment of the present application. The device 1000 for interoperability between systems shown in FIG. Wherein, the memory 1010 , the processor 1020 , and the communication interface 1030 are connected to each other through the bus 1040 .

Memory 1010 may be ROM, static storage, dynamic storage, or RAM. The memory 1010 may store a program, and when the program stored in the memory 1010 is executed by the processor 1020, the processor 1020 is configured to execute each step of the method for interoperability between systems in the embodiment of the present application.

The processor 1020 may adopt a general-purpose CPU, a microprocessor, an ASIC, a GPU, or one or more integrated circuits for executing related programs, so as to realize the functions required by the units in the device for interoperability between systems in the embodiment of the present application, or execute the method for interoperability between systems in the method embodiment of the present application.

The processor 1020 may also be an integrated circuit chip, which has a signal processing capability. During implementation, each step of the method for interoperability between systems of the present application may be completed by an integrated logic circuit of hardware in the processor 1020 or instructions in the form of software. The aforementioned processor 1020 may also be a general-purpose processor, DSP, ASIC, FPGA or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. Various methods, steps, and logic block diagrams disclosed in the embodiments of the present application may be implemented or executed. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register. The storage medium is located in the memory 1010, and the processor 1020 reads the information in the memory 1010, and combines its hardware to complete the functions required by the units included in the device for inter-system interoperability according to the embodiment of the present application, or execute the method for inter-system interoperability according to the method embodiment of the present application.

The communication interface 1030 implements communication between the apparatus 700 and other devices or communication networks by using a transceiver device such as but not limited to a transceiver.

Bus 1040 may include pathways for communicating information between various components of device 1000 (eg, memory 1010, processor 1020, communication interface 1030).

It should be noted that although the apparatus 1000 shown in FIG. 10 only shows a memory, a processor, and a communication interface, during a specific implementation, those skilled in the art should understand that the apparatus 1000 also includes other devices necessary for normal operation. Meanwhile, according to specific requirements, those skilled in the art should understand that the apparatus 1000 may also include hardware devices for implementing other additional functions. In addition, those skilled in the art should understand that the device 1000 may also only include the devices necessary to realize the embodiment of the present application, and does not necessarily include all the devices shown in FIG. 11 .

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

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

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

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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

If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product in essence or the part that contributes to the prior art or a part of the technical solution. The computer software product is stored in a storage medium and includes several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the application. The aforementioned storage medium includes: various media that can store program codes such as U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk.

The above is only a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Anyone skilled in the art within the scope of the technology disclosed in this application can easily think of changes or replacements, which should be covered within the scope of protection of the application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

A method for interoperability between systems, comprising:

The mobility management network element determines whether the terminal device supports the inter-system communication interface;

The mobility management network element sends first indication information to the access network element or the terminal device, the first indication information is used to indicate whether the terminal device supports the inter-system communication interface, and the first indication information includes the identity information of the terminal device.
The method according to claim 1, wherein the mobility management network element determines whether the terminal device supports an inter-system communication interface, comprising:

The mobility management network element acquires information about the public land mobile communication network PLMN to which the terminal device belongs;

The mobility management network element determines whether the terminal device supports the inter-system communication interface according to the information of the home PLMN.
The method according to claim 2, wherein the mobility management network element determines whether the terminal device supports the inter-system communication interface according to the information of the PLMN to which it belongs, including:

When the home PLMN information is on the first PLMN list, the mobility management network element determines that the terminal device supports the inter-system communication interface; or,

When the home PLMN information is not in the first PLMN list, the mobility management network element determines that the terminal device does not support the inter-system communication interface.
The method according to any one of claims 1 to 3, wherein the mobility management network element determines whether the terminal device supports an inter-system communication interface, comprising:

The mobility management network element acquires subscription data of the terminal device, where the subscription data includes indication information of interoperability between systems;

The mobility management network element determines whether the terminal device supports the inter-system communication interface according to the inter-system interoperability indication information.
The method according to any one of claims 1 to 4, wherein the mobility management network element sends the first indication information to the access network element, including:

The mobility management network element sends an initial context establishment request to the access network element, where the initial context establishment request includes the first indication information.
A method for interoperability between systems, comprising:

The network element of the access network obtains the PLMN information selected by the terminal device;

The network element of the access network determines whether the terminal device supports an inter-system communication interface according to the PLMN information.
The method of claim 6, comprising:

The network element of the access network sends the first indication information to the terminal device, where the first indication information is used to indicate whether the terminal device supports the inter-system communication interface, and the first indication information includes identity information of the terminal device.
A method for interoperability between systems, comprising:

A network element of the access network receives first indication information, where the first indication information is used to indicate whether the terminal device supports an inter-system communication interface, and the first indication information includes identity information of the terminal device.
The method according to claim 8, characterized in that the method further comprises:

The network element of the access network stores the first indication information.
The method according to claim 8 or 9, wherein the receiving the first indication information by the network element of the access network includes:

The access network element receives an initial context establishment request, where the initial context establishment request includes the first indication information.
The method according to claim 8 or 9, wherein when the terminal device needs to perform interoperability between systems, the method further comprises:

When the first indication information indicates that the terminal device supports the inter-system communication interface, the network element of the access network initiates a first interoperation based on the inter-system communication interface to change the access network of the terminal device; or,

When the first indication information indicates that the terminal device does not support the inter-system communication interface, the network element of the access network initiates a second interoperation without an inter-system communication interface, so as to change the access network of the terminal device.
A method for interoperability between systems, comprising:

The terminal device receives first indication information, where the first indication information is used to indicate whether the terminal device supports an inter-system communication interface, and the first indication information includes an identity of the terminal device.
The method according to claim 12, wherein when the terminal device needs to perform interoperability between systems, the method further comprises:

When the first indication information indicates that the terminal device supports the inter-system communication interface, the terminal device accesses the network by means of mobility registration; or,

When the first indication information indicates that the terminal device does not support the inter-system communication interface, the terminal device accesses the network by switching registration.
A device for interoperability between systems, characterized by comprising a unit for implementing the method according to any one of claims 1 to 5.
A device for interoperability between systems, characterized by comprising a unit for implementing the method according to any one of claims 6 to 11.
A device for interoperability between systems, characterized by comprising a unit for implementing the method according to claim 12 or 13.
A device for interoperability between systems, characterized in that it includes:

processor and memory;

The memory is used to store computer programs;

The processor is configured to execute the computer program stored in the memory, so that the device for interoperability between systems executes the method for interoperability between systems according to any one of claims 1 to 5, or executes the method for interoperability between systems according to claim 6 or 7, or executes the method for interoperability between systems according to any one of claims 8 to 11, or executes the method for interoperation between systems according to claim 12 or 13.
A computer-readable storage medium, wherein computer instructions are stored in the computer-readable storage medium, and when the computer instructions are run on a computer, the method for interoperability between systems according to any one of claims 1 to 5 is executed, or the method for interoperation between systems according to claim 6 or 7 is executed, or the method for interoperation between systems according to any one of claims 8 to 11 is executed, or the method for interoperation between systems according to claim 12 or 13 is executed.
A computer program product, characterized in that the computer program product includes computer program code, and when the computer program code is run on a computer, the method for interoperability between systems according to any one of claims 1 to 5 is executed, or the method for interoperability between systems according to claim 6 or 7 is executed, or the method for interoperation between systems according to any one of claims 8 to 11 is executed, or the method for interoperation between systems according to claim 12 or 13 is executed.