CN117880900A

CN117880900A - Communication method and device

Info

Publication number: CN117880900A
Application number: CN202211237047.0A
Authority: CN
Inventors: 李浩然; 徐艺珊
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-10-10
Filing date: 2022-10-10
Publication date: 2024-04-12
Also published as: WO2024078224A1

Abstract

A communication method and device relate to the technical field of communication. The method comprises the following steps: when the first core network equipment determines that the terminal meets the condition of the first localization service, acquiring the access type of the network currently accessed by the terminal and the access type allowed by the first network, if the access type allowed by the first network is the same as the first access type, the first core network equipment instructs the terminal to switch from the access network corresponding to the first access type to the access network corresponding to the second access type, and when the first core network equipment determines that the terminal is switched, the core network is triggered to send first network selection information to the terminal. The first network is a network for providing a first localization service, and the access type of the network currently accessed by the terminal is a first access type. The method can reduce the influence of the network reselection operation on the ongoing service of the terminal.

Description

Communication method and device

Technical Field

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

Background

The localization service (localized service) is a special network service that can be provided by an operator or a third party service provider. The localized services have a flexible deployment approach that facilitates third party service providers to deploy specific localized services within a defined time and/or place range. The localization service is provided with a connection by a hosting network (a network that provides localization services for terminals, which may also be referred to as a managed network). When a terminal subscribes to a localization service, the localization service may be used at a particular time and/or place.

In the related art, when a terminal meets the condition of a localization service (for example, meets the time and/or place requirements of the localization service) and is within the coverage area of a home network that provides the localization service, the terminal executes a reselection procedure to access the home network. After the terminal accesses the nesting network, the terminal can use the localization service provided by the nesting network. Based on the network selection mechanism, the terminal releases all sessions in the current network, performs the de-registration operation, enters an idle state, and then performs network selection again, and if the terminal is executing the service at this time, the service currently being executed is interrupted, and the service continuity is affected.

Therefore, how to reduce or avoid the influence of the re-networking operation on the currently ongoing service is a technical problem that needs to be solved at present.

Disclosure of Invention

The embodiment of the application provides a communication method and device for reducing the influence of network reselection operation on services in progress of a terminal.

In a first aspect, a communication method is provided, which may include the steps of: when a first core network device determines that a terminal meets the condition of a first localization service, acquiring the access type of a network currently accessed by the terminal and the access type allowed by a first network, wherein the first network is a network for providing the first localization service, and the access type of the network currently accessed by the terminal is the first access type; if the allowed access type of the first network is the same as the first access type, the first core network device instructs the terminal to switch from an access network corresponding to the first access type to an access network corresponding to a second access type, wherein the second access type is different from the first access type; and after the first core network equipment determines that the terminal is switched to the access network corresponding to the second access type, triggering the core network to send first network selection information to the terminal.

In the above implementation manner, when the terminal meets the condition of the localization service, if the access type allowed by the first network (i.e., the network providing the localization service, that is, the home network) is the same as the access type allowed by the first network (i.e., the access type of the network currently accessed by the terminal (i.e., the service network)), which indicates that the two access types conflict, the first core network device may instruct the terminal to switch from the access network corresponding to the first access type to the access network corresponding to the access type different from the first access type, and trigger the core network to send the first network selection information to the terminal after the switching is completed, so that, because the switching of the access network is already performed before the terminal performs network reselection based on the network selection information, when the terminal selects the first network based on the network selection information, the access type of the first network is different from the access type of the service currently executed by the terminal, so that the service currently executed by the terminal is not interrupted, and continuity of the service is ensured.

In a possible implementation manner, the determining, by the first core network device, that the terminal is switched to the access network corresponding to the second access type includes: the first core network device sends first indication information to the terminal and receives second indication information sent by the terminal, wherein the first indication information is used for indicating the terminal to send the second indication information to the first core network device after the terminal finishes the switching, and the second indication information is used for indicating the terminal to finish the switching; or the first core network device determines that the terminal is switched to the access network corresponding to the second access type according to the access network connection information of the terminal.

The implementation manner can ensure that the first core network equipment triggers the core network to send the first network selection information to the terminal after determining that the terminal is switched to the access network corresponding to the second access type, thereby ensuring that the network selection information sent by the network side is received after the switching is finished, further performing network reselection according to the selection information, and further ensuring the continuity of the service of the terminal side.

In one possible implementation manner, when the first core network device determines that the terminal meets a condition of a first localization service, the method further includes: the first core network equipment acquires the service state of the terminal; the obtaining the access type allowed by the first network includes: and if the service state of the terminal indicates that the terminal has service in progress, the first core network equipment acquires the access type allowed by the first network.

In the above implementation manner, only if the terminal currently has a service in progress, the first core network device acquires the access type allowed by the first network, and then performs subsequent operations (including, when the access type allowed by the first network is the same as the first access type, indicating that the terminal is switched from the access network corresponding to the first access type to the access network corresponding to the second access type), otherwise, the operation of acquiring the access type allowed by the first network is not performed, and then the operation of indicating that the terminal is switched is not performed. That is, only if the terminal currently has a service in progress, it is necessary to instruct the terminal to switch to ensure service continuity, and for the case that the terminal currently does not have a service in progress, the terminal may not be instructed to switch, so that processing costs on the network side and the terminal side may be saved, and network resource costs may be saved.

Optionally, the obtaining, by the first core network device, the service state of the terminal includes: the first core network device sends first request information to the terminal, wherein the first request information is used for requesting to inquire the service state of the terminal; the first core network device receives first response information sent by the terminal based on the first request information, wherein the first response information is used for indicating the service state of the terminal.

Optionally, the first response message includes third indication information, where the third indication information is used to indicate a service state of the terminal.

In one possible implementation manner, the obtaining, by the first core network device, the access type allowed by the first network includes: the first core network device sends second request information to second core network device, wherein the second request information comprises the identification of the terminal and the identification of the first network; the first core network device receives second response information sent by the second core network device based on the second request information, wherein the second response information comprises indication information of an access type allowed by the first network.

In the above implementation manner, the first core network device may acquire, from the second core network device, an access type allowed by the first network.

Optionally, the second request information further includes fourth indication information, where the fourth indication information is used to indicate the second core network device to return, to the first core network device, the access type allowed by the first network.

In one possible implementation manner, when the first core network device determines that the terminal meets a condition of the first localization service, the method further includes: if the access type allowed by the first network includes a second access type, where the second access type is different from the first access type, the first core network device triggers a core network to send second network selection information to the terminal, where the second network selection information is used to indicate the second access type.

In the above implementation manner, when the terminal meets the condition of the localization service, if the first network (i.e., the network providing the localization service) includes a second access type different from the first access type (i.e., the access type of the service network currently accessed by the terminal) in the allowed access types, which indicates that the two access types do not collide or are likely to occur/not collide, the first core network device may trigger the core network to send network selection information to the terminal, where the network selection information is used to indicate the second access type, so, after the terminal selects the localization network based on the network selection information, the localization network is accessed through the access network corresponding to the second access type according to the second access type, thereby ensuring that the access type of the localization network is different from the access type of the service network currently executed by the terminal, and ensuring continuity of the service.

In a possible implementation manner, the second network selection information includes information of the first network, so that the terminal can select the first network when performing network reselection, and thus the first localization service provided by the first network can be used.

In a possible implementation manner, the second network selection information is further used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes the first network, and the priority of the first network is highest, so that the terminal can preferentially select the first network when performing network reselection, and thus the first localization service provided by the first network can be used.

Optionally, the second network selection information includes a network selection list, where the network selection list includes at least one network recommended to the terminal to perform network reselection and information indicating an access type of the first network.

In a possible implementation manner, the first core network device triggers a core network to send second network selection information to the terminal, including: the first core network device sends the identification of the terminal, the identification of the first network and the indication information of the second access type to the second core network device; the second core network device is configured to obtain a network selection list corresponding to the terminal according to the identifier of the terminal and the identifier of the first network, and generate the second network selection information according to the network selection list and the indication information of the second access type; the first core network device receives the second network selection information sent by the second core network device; and the first core network equipment sends the second network selection information to the terminal.

Optionally, the first core network device further sends fifth indication information to the second core network device, where the fifth indication information is used to instruct the second core network device to generate the second network selection information according to the indication information of the second access type and a network selection list corresponding to the terminal.

In one possible implementation, the first access type is a 3GPP access type, and the second access type is a non-3 GPP access type; or, the first access type is a non-3 GPP access type, and the second access type is a 3GPP access type.

In a second aspect, a communication method is provided, including: when a first core network device determines that a terminal meets the condition of a first localization service, acquiring the access type of a network currently accessed by the terminal and the access type allowed by a first network, wherein the first network is a network for providing the first localization service, and the access type of the network currently accessed by the terminal is the first access type; if the access type allowed by the first network includes a second access type, where the second access type is different from the first access type, the first core network device triggers a core network to send network selection information to the terminal, where the network selection information is used to indicate the second access type.

In one possible implementation, the network selection information includes information of the first network.

In a possible implementation manner, the network selection information is further used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes the first network, and the priority of the first network is highest.

In a possible implementation manner, the network selection information includes a network selection list, where the network selection list includes the at least one network recommended to the terminal for network reselection and information indicating an access type of the first network.

In a possible implementation manner, the first core network device triggers a core network to send network selection information to the terminal, including: the first core network device sends the identification of the terminal, the identification of the first network and the indication information of the second access type to the second core network device; the second core network device is configured to obtain a network selection list corresponding to the terminal according to the identifier of the terminal and the identifier of the first network, and generate the network selection information according to the network selection list and the indication information of the second access type; the first core network device receives the network selection information sent by the second core network device; and the first core network equipment sends the network selection information to the terminal.

In a possible implementation manner, the first core network device further sends fifth indication information to the second core network device, where the fifth indication information is used to instruct the second core network device to generate the network selection information according to the indication information of the second access type and a network selection list corresponding to the terminal.

In a possible implementation manner, the obtaining, by the first core network device, a service state of the terminal includes: the first core network device sends first request information to the terminal, wherein the first request information is used for requesting to inquire the service state of the terminal; the first core network device receives first response information sent by the terminal based on the first request information, wherein the first response information is used for indicating the service state of the terminal.

In a possible implementation manner, the first response message includes third indication information, where the third indication information is used to indicate a service state of the terminal.

In a possible implementation manner, the second request information further includes fourth indication information, where the fourth indication information is used to instruct the second core network device to return, to the first core network device, an access type allowed by the first network.

In a third aspect, a communication method is provided, the method comprising: when a first core network device determines that a terminal meets the condition of a first localization service, the first core network device notifies the first core network device when the first core network device indicates that the terminal does not have an ongoing service; and after the first core network equipment receives the indication information which is sent by the terminal and used for informing the terminal that the ongoing service does not exist, triggering a core network to send network selection information to the terminal.

In one possible implementation, the network selection information includes information of the first network, the first network being a network providing the first localization service.

In one possible implementation manner, the network selection information is used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes the first network, and the priority of the first network is highest.

In a fourth aspect, a communication method is provided, including: when a terminal determines that the condition of a first localization service is met, acquiring the access type of a network currently accessed by the terminal and the access type allowed by a first network, wherein the first network is a network for providing the first localization service, and the access type of the network currently accessed by the terminal is a first access type; if the access type allowed by the first network is the same as the first access type, the terminal is switched from the access network corresponding to the first access type to the access network corresponding to the second access type, and after switching to the access network corresponding to the second access type, the terminal selects the first network for access; wherein the second access type is different from the first access type.

In one possible implementation, the method further includes: if the access type allowed by the first network comprises a second access type, wherein the second access type is different from the first access type, the terminal selects the first network and accesses the first network through an access network corresponding to the second access type.

In a fifth aspect, a communication method is provided, including: when a terminal meets the condition of a first localization service, determining whether a service is currently in progress or not; if the terminal has a service currently in progress, the terminal determines whether to switch the access type according to the selection of the user, if the access type is determined to be switched, the terminal switches from the access network corresponding to the first access type to the access network corresponding to the second access type, and performs network reselection according to the network selection information after the switching is completed, wherein the second access type is different from the first access type.

In one possible implementation, the method further includes: and if the access type is not switched according to the selection of the user, the terminal performs network reselection according to the network selection information after the currently executing service is ended.

In one possible implementation, the method further includes: and if the terminal does not currently have the service in progress, the terminal performs network reselection according to the network selection information.

In a sixth aspect, a communication device is provided, including a processing unit and a transceiver unit; the processing unit is used for: when the terminal meets the condition of a first localization service, acquiring the access type of a network which is accessed by the terminal currently and the access type allowed by a first network, wherein the first network is used for providing the first localization service, and the access type of the network which is accessed by the terminal currently is the first access type; if the allowed access type of the first network is the same as the first access type, the receiving-transmitting unit indicates the terminal to switch from the access network corresponding to the first access type to the access network corresponding to a second access type, wherein the second access type is different from the first access type; and triggering a core network to send first network selection information to the terminal after determining that the terminal is switched to an access network corresponding to the second access type.

In a seventh aspect, a communication apparatus is provided, including a processing unit and a transceiver unit; the processing unit is used for: when the terminal meets the condition of a first localization service, acquiring the access type of a network which is accessed by the terminal currently and the access type allowed by a first network, wherein the first network is used for providing the first localization service, and the access type of the network which is accessed by the terminal currently is the first access type; and if the access type allowed by the first network comprises a second access type, wherein the second access type is different from the first access type, triggering a core network to send network selection information to the terminal, and the network selection information is used for indicating the second access type.

An eighth aspect provides a communication system comprising: the first core network device is configured to execute the method of any one of the first aspects, and the second core network device is configured to trigger, according to the notification of the first core network device, the core network to send first network selection information to the terminal.

A ninth aspect provides a communication system comprising: the first core network device is configured to perform the method according to any one of the second aspect, and the second core network device is configured to trigger, according to the notification of the first core network device, a core network to send second network selection information to the terminal.

In a tenth aspect, there is provided a communication apparatus comprising: one or more processors; wherein the instructions of the one or more computer programs, when executed by the one or more processors, cause the communications apparatus to perform the method of any of the first aspects, or the method of any of the second aspects, or the method of any of the third aspects, or the method of any of the fourth aspects, or the method of any of the fifth aspects.

In an eleventh aspect, there is provided a computer readable storage medium comprising a computer program which, when run on a computing device, causes the computing device to perform the method of any one of the first aspects, or to perform the method of any one of the second aspects, or to perform the method of any one of the third aspects, or to perform the method of any one of the fourth aspects, or to perform the method of any one of the fifth aspects.

A twelfth aspect, there is provided a chip coupled to a memory for reading and executing program instructions stored in the memory to implement the method of any one of the first aspect, or the method of any one of the second aspect, or the method of any one of the third aspect, or the method of any one of the fourth aspect, or to perform the method of any one of the fifth aspect.

A thirteenth aspect provides a computer program product which, when invoked by a computer, causes the computer to perform the method of any of the above first aspects, or to perform the method of any of the above second aspects, or to perform the method of any of the above third aspects, or to perform the method of any of the above fourth aspects, or to perform the method of any of the above fifth aspects.

The advantages of the second aspect to the thirteenth aspect are described above with reference to the advantages of the first aspect, and the description is not repeated.

Drawings

FIG. 1 is a diagram of an interworking architecture between a home network and a third party in the related art;

FIG. 2 is a schematic diagram of a priority order of candidate networks in the related art;

FIG. 3 is a schematic diagram of a handover procedure of a PDU session from a non-3GPP access to a 3GPP access in the related art;

FIG. 4 is a diagram of a PDU session handover procedure from 3GPP access to non-3GPP access in the related art;

fig. 5 is a flow of updating a network selection list to a terminal by an HPLMN in the related art;

FIG. 6 is a schematic flow chart of temporary network reselection in the related art;

FIG. 7 is a schematic diagram of a related art 3GPP system;

fig. 8 is a flow chart of a communication method according to an embodiment of the present application;

FIG. 9 is a schematic diagram of an example flow of the flow shown in FIG. 8 in an embodiment of the present application;

fig. 10 is a flow chart of another communication method according to an embodiment of the present application;

FIG. 11 is a schematic diagram of an example flow of the flow shown in FIG. 10 in an embodiment of the present application;

fig. 12 is a flow chart of another communication method according to an embodiment of the present application;

Fig. 13 is a flow chart of another communication method according to an embodiment of the present application;

fig. 14 is a flow chart of another communication method according to an embodiment of the present application;

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

fig. 16 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

It should be understood that in this application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. In the text description of the present application, the character "/" generally indicates that the front-rear association object is an or relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b, and c may represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Wherein a, b and c can be single or multiple respectively. The terms "first," "second," and the like, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such as a series of steps or elements. The method, system, article, or apparatus is not necessarily limited to those explicitly listed but may include other steps or elements not explicitly listed or inherent to such process, method, article, or apparatus.

The related art related to the embodiments of the present application will be described first.

And (one) localization services and a localization network architecture.

The localization service (localized service) is a network service provided by an operator or a third party service provider, and can be used at a designated time and/or place when the terminal subscribes to the localization service. The localization service is provided with connection by the localization network, and the terminal needs to access the localization network and meets the time and/or place requirements of the localization service so as to use the localization service. The localized services have a flexible deployment approach that facilitates third party service providers to deploy specific services within a defined time and/or place range.

The nesting network is a network for providing services for the terminal in the localization service. Fig. 1 illustrates an architecture of a nesting network. A hosting network is a network that provides connectivity to obtain localized services. The nesting network may be a non-public network (NPN) or a public land mobile network (public land mobile network, PLMN) network. The network may provide coverage (which may be associated with localized services) only at a particular geographic location and/or for a particular time. The localization service may be provided by a hosting network operator or by a third party service provider.

When a user wants to acquire a localization service through a nesting network, the user needs to access the nesting network first and then acquire the localization service through the nesting network. Since the localization service may be available at a specific geographic location and/or a specific time, or the localization network is covered at a specific geographic location and/or a specific time, the terminal needs to access the localization network at a specific geographic location and/or a specific time, so as to obtain the localization service.

And (II) network reselection and network selection priority.

Network selection is divided into two cases: one is automatic network selection, i.e. the terminal automatically selects one network (e.g. one PLMN or NPN) according to the priority order of available candidate networks (e.g. comprising PLMNs and/or NPN), under which the best cell is selected for registration; another is manual network selection, i.e. all candidate networks are presented to the user, and the user selects one network under which the best cell is selected for registration.

The automatic net selection mainly comprises three processes: network selection, cell selection, location registration. Briefly, when a terminal selects a network, it starts to select cells belonging to that network. After searching (or scanning) for cells belonging to the network, information of neighboring cells is acquired from the system information broadcast, the terminal selects a cell with the best signal among all the cells for camping, and then the terminal initiates a location registration process. After successful location registration, the terminal successfully enters the network, i.e. successfully resides in the cell.

When selecting a network, the terminal selects a network with a high priority from the candidate networks in the network selection list according to the priority order of the candidate networks. Fig. 2 illustrates a network priority order. The networks in the net-selection list follow the following priority order:

registered PLMN (RPLMN): refers to the last registered PLMN with the highest priority;

equivalent PLMN (equivalent PLMN, EPLMN): is an equivalent PLMN of the RPLMN, and since the terminal may store cell information (such as frequency points, scrambling codes, etc.) of the RPLMN, these information may help the speed of subsequent cell selection, the EPLMN priority is lower than that of the RPLMN;

home PLMN (HPLMN)/equivalent home PLMN (equivalent home PLMN, EHPLMN): the EHPLMN is an equivalent PLMN of the HPLMN, stored in a global subscriber identity card (universal subscriber identity module, USIM) of the terminal, and has the same priority as the HPLMN; if the RPLMN is HPLMN, the EPLMN is the same as the EHPLMN, and if the RPLMN is not HPLMN, the EPLMN is different from the EHPLMN;

user controlled PLMN (UPLMN): the PLMN controlled by the user is the PLMN registered by the terminal during manual network selection, and UPLMN information is stored in the USIM of the terminal;

Operator controlled PLMN (operator controlled PLMN, OPLMN): for an operator controlled PLMN, information of the OPLMN is stored in the USIM of the terminal, and when the user signs a roaming agreement with the home operator, information of the operator's PLMN is stored in the USIM of the terminal;

a Visited PLMN (VPLMN);

forbidden PLMN (FPLMN): refers to a PLMN that inhibits PLMNs and that the terminal cannot register.

When the terminal executes network selection, selecting a proper network from the network selection list according to the priority order, if the selected network has coverage at the position, accessing the network by the terminal, otherwise, continuously selecting the network from the network selection list according to the priority order by the terminal. When the terminal executes the network selection flow, the terminal needs to be in an idle state, namely, the terminal releases all current sessions, ends all services, and then performs network reselection.

(III) procedure for switching protocol data unit (protocol data unit, PDU) sessions between third Generation partnership project (3rd generation partnership project,3GPP)/non-3 GPP (non-3 GPP, N3 GPP) accesses.

Currently, handover procedures can be categorized into two types, namely, handover of PDU session from 3GPP access to non-3GPP access, or handover from non-3GPP access to 3GPP access.

As shown in fig. 3, the procedure of switching the PDU session from the non-3GPP connection to the 3GPP connection may include:

step 1: if the terminal has not completed registration through 3GPP access, registration is completed according to the procedure of 4.2.2.2.2 in protocol 23502;

step 2: the terminal establishes a new session through 3GPP access according to the session ID of PDU session to be switched, and the part can refer to the relative content of 4.3.2.2.1 in protocol 23502;

step 3: if the user plane is still active in the non-3GPP access at this time, then resources of the non-3GPP access are released according to the procedures 4.3.4.2 step 4 to step 7 and 4.3.4.2 step 7a in protocol 23502, and no session release at any terminal side is involved in this step since the session is not released at this time in order to release the entire PDU session.

As shown in fig. 4, the procedure of switching the PDU session from the 3GPP connection to the non-3GPP connection may include:

step 1: if the terminal has not completed registration through the non-3GPP access, the registration is completed according to the procedure of 4.12.2 in the protocol 23502;

step 2: the terminal establishes a new session through non-3GPP access according to the session ID of PDU session to be switched, and the part can refer to the relevant content of 4.12.5 in protocol 23502;

Step 3: if the user plane is still active in 3GPP access at this time, 3GPP resources are released according to the procedures of 4.3.4.2 step 3b and 4.3.4.2 step 4 to step 7a/7b in protocol 23502, and no session release at any terminal side is involved in this step since session release is not performed for releasing the entire PDU session at this time.

(IV) roaming handoff (steering of roaming, SOR).

When the terminal registers with the HPLMN or the VPLMN, the HPLMN transmits an updated network selection list to the terminal so that the terminal performs network reselection according to the network selection list, which is called an SOR procedure. Fig. 5 illustrates an SOR process, which may include the steps of:

step 0: if the unified data management function (unifieddata management, UDM) in the HPLMN network supports the retrieval of a selection list (referred to as a list of preferred PLMNs in combination with access technologies (preferred PLMN/access technology combinations)) from the SOR application function (SORapplication function, SOR-AF), the SOR-AF may send the selection list to the HPLMN UDM (i.e., UDM in the HPLMN). The SOR-AF sends an Update request (nudm_parameter_update request) message to the HPLM NUDM, which includes the updated net list.

Step 1: the HPLMN UDM obtains updated net-lists (either sent by the SOR-AF or obtained from a unified data warehouse function (unifieddata repository, UDR)). The HPLMN UDM informs the access and mobility management function (access and mobility management function, AMF) about the user profile update. The AMF is the AMF of the network in which the terminal is registered (i.e., the AMF is the AMF in the HPLMN if the terminal is registered with the HPLMN; the AMF is the AMF in the VPLMN if the terminal is registered with the VPLMN). The HPLMN UDM sends a notification request (nudm_sdm_ Notification request) message to the AMF, which message includes an updated list of networks to be sent to the terminal. In one possible implementation, the updated picklist is included in SOR information (steering of roaming information).

Step 2: the AMF sends a downlink non-access stratum (NAS) message to the terminal, where the message includes information obtained from the UDM. I.e. the AMF transparently passes information acquired from the UDM to the terminal. If the UDM sends the updated picklist to the AMF, the downstream NAS message includes the picklist. If the UDM sends the SOR information to the AMF, where the SOR information includes the updated network selection list, the downstream NAS message sent by the AMF to the terminal includes the SOR information.

Step 3: after the terminal receives the SOR information (or the network selection list), the terminal performs a security check confirming that the information is provided by the HPLMN. If the security check is successful, the terminal uploads the information into the USIM or replaces the OPLMN selection list stored in the terminal, which is called Operator Controlled PLMN Selector with Access Technology list.

Step 4: if the UDM requests the terminal to feed back a response message, the terminal includes the response message in the uplink NAS message. Optionally, the response message includes an SOR transparent container (SOR transparent container) in the upstream NAS message.

Step 5: the AMF sends the information (nudm_sdm_info message) included in the SOR transparent container to the UDM. The information is information included in an SOR transparent container in an uplink NAS message sent by the terminal. The SOR transparent container includes a response message sent by the terminal. The UDM verifies that the response message was sent by the terminal.

Step 6: if the updated net-selection list is provided by the SOR-AF, the HPLMN UDM may send a message to the SOR-AF indicating that the net-selection list has been successfully transmitted to the terminal. The HPLMN UDM sends an Nsoraf_SoR_info message to the SOR-AF, including information of successful transmission.

And (five) a Temporary Network Reselection (TNR) procedure.

Fig. 6 illustrates a TNR procedure, which may include the steps of:

step 0: the terminal has registered with the VPLMN or HPLMN through the AMF.

Step 1: the terminal sends TNR information through NAS information and requests authentication to the network side. In a possible implementation, the terminal sends the information through a registration request. The TNR information includes:

-a start time and end time request of the TNR procedure;

-selecting a localization service identity for use;

-a selected nesting network identification.

Step 2: the AMF updates the terminal context to the UDM according to TNR information provided by the terminal, wherein the TNR information is contained in the terminal context.

Step 3a to step 3d: based on the TNR information received from the AMF, the UDM requests SOR-AF to authenticate the network requested in the TNR information for the terminal. The SOR-AF updates the SOR information to the UDM and protects the SOR information by an authentication service function (authentication server function, AUSF).

Step 4 to step 10: and updating the SOR information of the terminal according to the SOR flow shown in the figure 5.

Step 11: and when the terminal meets the localization service condition, selecting the network according to the network selection list provided by the SOR information. When a network with a higher priority appears, the terminal performs network reselection.

And (six) 3GPP system architecture.

Fig. 7 shows a schematic architecture of a 3GPP system, where the system architecture includes a terminal, (Radio) access network (R) AN, and a core network device. Wherein, the device related to the embodiment of the application may include:

and (3) a terminal: may also be referred to as a terminal device. The terminal device in the embodiment of the present application may be a passive terminal device or a semi-passive terminal device. The terminal device of the embodiment of the present application may also be referred to as a passive (passive) terminal device. The terminal device in the embodiment of the present application may be, for example, a tag, a User Equipment (UE), or the like. The terminal device may be widely applied to various scenarios, such as internet of things (internet of things, IOT), device-to-device (D2D), vehicle-to-device (vehicle to everything, V2X) communication, machine-type communication (machine-type communication, MTC), internet of things (internet of things, IOT), virtual reality, augmented reality, industrial control, autopilot, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, and the like. The embodiment of the application does not limit the specific technology and the specific equipment form adopted by the terminal equipment.

(R) AN apparatus: the system is used for providing network access functions for authorized terminal equipment in a specific area, and can use transmission tunnels with different qualities according to the level of the terminal equipment, the service requirements and the like.

The access network device may be a base station (base station), an evolved node b (eNodeB), a transmission reception point (transmission reception point, TRP), a next generation base station (gNB) in a 5G mobile communication system, a next generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc.; the present invention may also be a module or unit that performs a function of a base station part, for example, a Central Unit (CU) or a Distributed Unit (DU). The CU can complete the functions of a radio resource control protocol and a packet data convergence layer protocol (packet data convergence protocol, PDCP) of the base station and can also complete the functions of a service data adaptation protocol (service data adaptation protocol, SDAP); the DU performs functions of a radio link control layer and a medium access control (medium access control, MAC) layer of the base station, and may also perform functions of a part of physical layers or all physical layers, and for a detailed description of each protocol layer, reference may be made to related technical specifications of 3 GPP. The access network device may be a macro base station, a micro base station, an indoor station, a relay node, a donor node, or the like. The specific technology and specific device configuration adopted by the access network device in the embodiments of the present application are not limited. For ease of description, the access network devices hereinafter will take base stations as examples.

The base station and the terminal device may be fixed in location or may be movable. The base station and terminal equipment may be deployed on land, including indoors or outdoors, hand-held or vehicle-mounted; the device can be deployed on the water surface; but also on aerial planes, balloons and satellites. The embodiment of the application does not limit the application scenes of the base station and the terminal equipment.

Data Network (DN): for providing a network for transmitting data. In future communication systems, the data network may still be a DN, or may have other names, which are not limited in this application. In a 5G communication system, a PDU session may be established after a terminal device accesses a network, and an application function (e.g., an application server) deployed in the DN may be interacted with by accessing the DN through the PDU session.

An access and mobility management function (access and mobility management function, AMF) entity (which may also be referred to as an access and mobility management function, an access and mobility management device, an access and mobility management element, an access management device, a mobility management device) is one of core network devices, and is mainly used for mobility management and access management, etc., and may be used for implementing functions other than session management, such as legal interception, or access authorization (or authentication), registration of a user equipment, mobility management, tracking area update procedure, reachability detection, selection of a session management element, mobility state transition management, etc., in the mobility management entity (mobility management entity, MME) function. For example, in 5G, the access and mobility management element may be an access and mobility management function (access and mobility management function, AMF) element, and in future communications, such as 6G, the access and mobility management element may still be an AMF element, or have other names, which are not limited in this application. When the access and mobility management network element is an AMF network element, the AMF may provide Namf services.

Unified data management (unified data management, UDM) and unified data store (unified data repository, UDR). UDM or UDR may refer to a user database. May exist as a single logical repository storing user data. The UDM is used for handling terminal equipment identities, access authentication, registration, mobility management, etc. In a 5G communication system, the data management network element may be a UDM network element or a unified data management device. In future communication systems, the unified data management may still be a UDM network element, or may have other names, which are not limited in this application. The unified data management device may be a core network device.

Application function (application function, AF): the system can interact with a 5G system through AF for accessing network open functions or interacting with a policy framework to perform policy control and the like.

Authentication service function (authentication server function, AUSF): the method is used for realizing the bidirectional authentication of the terminal equipment by the authentication service and the generation of the secret key, and supports a unified authentication framework.

The interaction relationship between the network functional entities and the corresponding interfaces are also shown in fig. 7.

It is to be appreciated that the devices or functions described above may be either network elements in a hardware device, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). The device or function may be divided into one or more services, and further, services that exist independently of the network function may also occur. In this application, an instance of the above-described function, or an instance of a service included in the above-described function, or an instance of a service existing independently of a network function may be referred to as a service instance.

It is to be understood that the embodiments of the present application are not limited to the system architecture described above, but may be applied to other communication systems in the future, such as a 6G system architecture, etc. Moreover, the names of the respective devices used in the embodiments of the present application may remain the same in future communication systems, but the names may change.

In order to acquire the localization service, the terminal needs to access a hosting network. At present, when the terminal meets the condition of the localization service and is in the coverage range of the hosting network, the terminal can execute network reselection. In this case, if the terminal is executing some services, based on the network selection mechanism, the terminal will release all sessions in the current network, perform de-registration, enter an idle state, and then re-select the network, which results in that the currently executing services will be interrupted, and the service continuity is affected, so how to reduce or avoid the impact of re-selecting the network on the currently ongoing services is a problem that needs to be solved at present.

For this reason, the embodiments of the present application provide a communication method and a related apparatus, so as to reduce the influence of the reselection operation on the ongoing service of the terminal.

In the embodiment of the present application, the core network may be accessed through different types of access networks, for example, the core network may be accessed through a non-3 GPP access network (for example, access through Wi-Fi), or the core network may be accessed through a 3GPP access network (for example, access through a cellular network, for example, a base station). Based on the difference of the access networks, the access types are different, for example, the corresponding access type is 3GPP access for the case of passing 3GPP access, and the corresponding access type is non-3 GPP access for the case of passing non-3 GPP access. Of course, depending on the access network, more access types may be included, which is not limited by the embodiments of the present application.

Embodiments of the present application are described in detail below with reference to the accompanying drawings.

Referring to fig. 8, a flow chart of a communication method according to an embodiment of the present application is provided. In the flow, after the terminal meets the condition of the localization service, the network side dynamically transmits the network selection information of the localization network to the terminal. In the process, the network side acquires the access type allowed by the nesting network, identifies the access type of the current access service network (serving network) of the terminal, and if the access type allowed by the nesting network conflicts with the access type of the current access service network of the terminal, the network side instructs the terminal to switch the access type, namely, switches from the current access network to another access network to access the serving network, so that when the terminal reselects the network, the access type of the nesting network does not conflict with the access type of the serving network when the nesting network is selected for access, and further the service continuity of the terminal can be ensured.

It is to be understood that "handover" in this context may be understood as a handover of an access network, such as from an access network corresponding to one access type to an access network corresponding to another access type. Taking an example that the access type includes a 3GPP access and a non-3 GPP access, the "switching" includes switching from an access network corresponding to the 3GPP access to an access network corresponding to the non-3 GPP access, or switching from an access network corresponding to the non-3 GPP access to an access network corresponding to the 3GPP access. Since the access type is changed through the above handover operation, in some embodiments of the present application, the above "handover" is simply referred to as an access type handover, for example, the handover may include a handover from a 3GPP access to a non-3 GPP access, or a handover from a non-3 GPP access to a 3GPP access.

The flow may be applied to the system architecture shown in fig. 7, in which case the first core network device in the flow may be an AMF and the second core network device may be a UDM. The process may also be applied to an evolved system architecture or other system architectures, which embodiments of the present application do not limit.

This flow is described in detail below in conjunction with fig. 8. As shown in fig. 8, the process may include the steps of:

S801: the first core network device determines that the terminal satisfies a condition of the first localization service.

The first localization service may be any localization service. The embodiment of the application does not limit the type of the first localization service.

In one possible implementation manner, if the condition that the terminal satisfies the first localization service is that the terminal enters a service area of the first localization service, when the first core network device determines that the terminal moves into the service area of the first localization service, the first core network device determines that the terminal satisfies the condition of the first localization service. For example, the terminal changes a Tracking Area (TA) through mobility registration, and the new TA is in a service area of the first localization service, where the first core network device determines that the terminal meets a condition of the first localization service.

In another possible implementation manner, if the condition that the terminal satisfies the first localization service is that the service start time is reached, when the first core network device determines that the time is reached, the first core network device determines that the terminal satisfies the condition of the first localization service.

In another possible implementation manner, if the condition that the terminal satisfies the first localization service is that the terminal enters a service area of the first localization service and reaches a service start time, when the first core network device determines that the terminal moves into the service area of the first localization service and currently reaches the service start time, the first core network device determines that the terminal satisfies the condition of the first localization service.

S803: the first core network equipment acquires the access type of the network currently accessed by the terminal and the access type allowed by the first network.

The network to which the terminal is currently connected is also called a serving network (serving network) of the terminal, for example, the serving network may be an HPLMN. In this embodiment, for convenience of description, an access type of a network to which the terminal is currently accessed is referred to as a first access type. The first access type may be, for example, a 3GPP access or a non-3 GPP access.

The first network is a network for providing a first localization service. Based on the nesting network architecture shown in fig. 1, it can be appreciated that the first network is a nesting network that provides the first localized service.

It will be appreciated that the access type allowed by the first network is the type of access that the first network may use, or what type of access may be used to access the first network. The access types allowed by the first network may include only one access type, and may also include multiple access types. Alternatively, the access types allowed by the first network may be the same or different for different terminals.

In one possible implementation manner, the first core network device may obtain, according to the context of the terminal stored in the first core network device, an access type of a network to which the terminal is currently accessed.

In one possible implementation, the first core network device may obtain the access type allowed by the first network from the second core network device. The first core network device sends request information (for convenience of distinction from other request information hereinafter, referred to herein as second request information) to the second core network device, the second request information including an identity of the terminal and an identity of the first network; and the second core network equipment sends second response information to the first core network equipment based on the second request information, wherein the second response information comprises indication information of the access type allowed by the first network. Optionally, the type of access allowed by the first network is indicative of the terminal.

Optionally, the indication information of the allowed access types of the first network may be an identifier of the access type (different access types may be distinguished by using different identifiers), or may be a coded value, which is used to indicate one or more access types. For example, in the case where the total number of access types is two, the code value may be 3 bits of information, and when the code value is equal to 0, 3GPP access is indicated, when the code value is equal to 1, non-3 GPP access is indicated, and when the code value is equal to 2, 3GPP access and non-3 GPP access are indicated. The embodiments of the present application are not limited in this regard.

Optionally, the second request information may further include indication information (for convenience of distinguishing from other indication information hereinafter, the indication information is referred to as fourth indication information), where the fourth indication information is used to instruct the second core network device to return the access type allowed by the first network to the first core network device, and the second core network device may query the access type allowed by the first network according to the fourth indication information and return the query result to the first core network device.

S805: if the first core network device determines that the access type allowed by the first network is the same as the first access type, the terminal is instructed to switch from an access network corresponding to the first access type (namely, a current access network) to an access network corresponding to a second access type according to the second access type, wherein the second access type is different from the first access type.

The case where the access type allowed by the first network is the same as the first access type includes: the first network allows one access type, and the access type is the same as the first access type. For example, the first network may allow an access type of 3GPP access, the first access type may also be 3GPP access, or the first network may allow an access type of non-3 GPP access, the first access type may also be non-3 GPP access.

If the access type allowed by the first network is the same as the first access type, it indicates that the access type allowed by the first network conflicts with the access type of the network currently accessed by the terminal, and in this case, when the terminal performs network reselection, the service in progress by the terminal may be interrupted. In order to ensure service continuity of the terminal, the first core network device instructs the terminal to switch from a current access network to an access network corresponding to a second access type, where the second access type is different from the first access type, so that the terminal switches from the access network corresponding to the first access type (i.e., the current access network) to the access network corresponding to the second access type, i.e., accesses the serving network through the access network corresponding to the second access type. For example, if the first access type is 3GPP, the first core network device instructs the terminal to switch to the non-3 GPP access network, and if the first access type is non-3 GPP access network, the first core network device instructs the terminal to switch to the 3GPP access network. In a possible implementation manner, the procedure of switching the terminal from the non-3 GPP access to the 3GPP access may refer to the procedure shown in fig. 3, and since the procedure does not involve PDU session release at the terminal side, continuity of the service currently performed by the terminal may be ensured. In a possible implementation manner, the procedure of switching the terminal from the 3GPP access to the non-3 GPP access may refer to the procedure shown in fig. 4, and since the procedure does not involve PDU session release at the terminal side, continuity of the service currently performed by the terminal may be ensured.

In one possible implementation, the first core network device may send a notification to the terminal, where the notification is used to instruct the terminal to switch from an access network corresponding to the current first access type to an access network corresponding to the second access type. Optionally, the notification may further include indication information of the second access type.

S807: after the first core network equipment determines that the terminal is switched to the access network corresponding to the second access type, the first core network equipment triggers the core network to send first network selection information to the terminal.

In a possible implementation manner, the first network selection information includes information of the first network, such as an identifier of the first network, so that the terminal may select the first network (i.e. a hosting network of the first localization service) to access according to the first network selection information, so as to adapt to the localization service provided by the first network.

In another possible implementation manner, the first network selection information is further used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes a first network, and the priority of the first network is highest, so that the terminal can preferentially select the first network (i.e. the hosting network of the first localization service) for access according to the first network selection information, and thus the localization service provided by the first network can be used. Optionally, the first network selection information is a network selection list, where the network selection list includes one or more networks recommended to the terminal to perform network reselection, and the network selection list includes a first network with a highest priority. Alternatively, in the network selection list, the priority order of other networks except the first network may be set according to the priority order shown in fig. 2.

In one possible implementation manner, the first core network device may determine, according to the access network connection information of the terminal, whether the terminal is switched to the access network corresponding to the second access type, that is, whether the terminal completes switching of the access network. The first core network device may be used for mobility management and access management, so that in the process of switching the access network of the terminal, the first core network device may obtain access network connection information of the terminal (such as information of session establishment through a new access network, information of release of access resources of an original access network, etc.), so as to determine whether the terminal completes switching the access network according to the information. For example, in the process of switching the terminal from the non-3 GPP access to the 3GPP access, the first core network device (such as AMF) may acquire information about a new session established by the terminal through the 3GPP access, and may also acquire information about releasing resources of the non-3 GPP access by the terminal, so as to determine whether the terminal completes the switching process from the non-3 GPP access to the 3GPP access according to the information.

In another possible implementation manner, the first core network device may determine whether the terminal completes handover by: the first core network device sends first indication information to the terminal and receives second indication information sent by the terminal. The first indication information is used for indicating the terminal to send second indication information to the first core network equipment after the terminal completes the switching, and the second indication information is used for indicating the terminal to complete the switching.

Optionally, the first core network device may include the first indication information in a message for instructing the terminal to perform access network switching to send the first indication information to the terminal, or may use a separate message to send the first indication information, which is not limited in this embodiment of the present application.

In one possible implementation manner, the first core network device may trigger the core network to send the first network selection information to the terminal by: after the first core network device determines that the terminal is switched to the access network corresponding to the second access type, the first core network device sends a notification to the second core network device to trigger the second core network device to start the SOR process, so that the first network selection information can be acquired from the second core network device. And after the first core network equipment acquires the first network selection information, the first core network equipment sends the first network selection information to the terminal. In one possible implementation, a specific implementation of the SOR procedure may refer to the procedure shown in fig. 5 or fig. 6.

In one possible implementation manner, when the first core network device determines that the terminal meets a condition of the first localization service, the following steps may be further performed: s802: the first core network device obtains the service state of the terminal. In S803, if the first core network determines that the terminal has a service in progress according to the service status of the terminal, the access type allowed by the first network is obtained.

The service state of the terminal may include a first state indicating that the terminal currently has a service in progress and a second state indicating that the terminal currently has no service in progress. Of course, the first state may be further divided according to the type of the service that the terminal is performing, which is not limited in the embodiment of the present application.

In one possible implementation manner, the first core network device may obtain the service state of the terminal by: the first core network equipment sends first request information to the terminal, wherein the first request information is used for requesting to inquire the service state of the terminal; the terminal transmits first response information based on the first request information, wherein the first response information is used for indicating the service state of the terminal. Optionally, the first response information may include third indication information, where the third indication information is used to indicate a service state of the terminal.

In one possible implementation manner, if the first core network device determines that no service is currently in progress in the terminal according to the service state of the terminal after the first core network device obtains the service state of the terminal, the first core network device skips S803 (i.e., does not execute S803), and directly triggers the core network device to send the first network selection information to the terminal. That is, only if the terminal currently has a service in progress, the first core network device instructs the terminal to switch the access network, so as to ensure continuity of the service in progress, and if the terminal currently does not have a service in progress, the terminal does not need to be instructed to switch the access network, thereby saving the overhead of the terminal side and the network side, and saving the signaling overhead.

In the flow shown in fig. 8, the timing relationship of each step is only an example, and the embodiment of the present application does not limit the timing relationship between each step. For example, the step of the first core network device obtaining the access type of the network to which the terminal is currently connected may also precede S801.

Based on the flow shown in fig. 8, when the terminal satisfies the condition of the localization service, if the access type allowed by the first network (i.e. the network providing the localization service, i.e. the network serving as a network) is the same as the first access type (i.e. the access type of the service network currently accessed by the terminal), which indicates that the two access types conflict, the first core network device may instruct the terminal to switch from the access network corresponding to the first access type to the access network corresponding to the access type different from the first access type, and trigger the core network to send the first network selection information to the terminal after the switching is completed, so that, because the access type has been switched before the terminal performs network reselection based on the network selection information, when the terminal selects the network access based on the network selection information, the service currently performed by the terminal is not interrupted, and continuity of the service is ensured.

An example of the flow shown in fig. 8 may be as shown in fig. 9. The specific implementation of the steps in fig. 9 may refer to the relevant content in the flow shown in fig. 8. As shown in fig. 9, the process may include the steps of:

step 1: the AMF determines that the UE satisfies a condition of the first localized service.

Step 2: when the UE satisfies the condition of the first localization service, the AMF sends first request information to the UE, for initiating a query to the UE to request to acquire a service state of the UE, so as to determine whether the UE currently has a service executing.

In a possible implementation, the AMF sends a NAS message to the UE, where the NAS message includes the first request information.

Step 3: the UE sends first response information to the AMF for feeding back a service status of the UE, so that the AMF determines whether the UE currently has a service in progress.

One possible implementation, the UE sends a NAS message to the AMF, where the first response information is included. Optionally, the first response information includes indication information of a service state of the UE, which is used to indicate whether the UE currently has a service in progress.

Step 4: if the UE currently has a service in progress, the AMF requests from the UDM the type of access that the UE wants to access allowed by the hosting network (i.e. the network providing the first localization service).

In one possible implementation manner, the AMF sends a nudm_sdm_get request message to the UDM, where the message includes an identifier of the UE and an identifier of the nesting network, and further includes indication information for indicating that the UDM returns an access type of the nesting network that is allowed to be used by the UE (i.e. fourth indication information in the flowchart shown in fig. 8).

Step 5: the UDM feeds back the access type allowed by the nesting network to the AMF.

One possible implementation, the UDM sends a nudm_sdm_get response message to the AMF, where the message includes an identifier of the nesting network, an identifier of the UE, and indication information of the type of access allowed by the nesting network.

Step 6: the AMF compares the allowed access type of the nesting network with the access type (called a first access type) of the UE currently accessing the serving network, determines whether the two access types conflict, and if so, instructs the UE to switch the access type, namely to switch to another access network, wherein the access type corresponding to the access network is different from the first access type.

For example, if the first access type is 3GPP access, and the access type allowed by the nesting network is also 3GPP access, the AMF instructs the UE to switch the current first access type (3 GPP access) to non-3 GPP access. If the first access type is a non-3 GPP access, and the access type allowed by the nesting network is also a non-3 GPP access, the AMF instructs the UE to switch the current first access type (non-3 GPP access) to the 3GPP access.

In a possible implementation manner, the AMF sends a NAS message to the UE, where the NAS message includes indication information for instructing the UE to perform access network handover.

Step 7: the UE performs an access type handover procedure.

Step 8: the AMF notifies the UDM and triggers the UDM to start the SOR flow.

In one possible implementation, the AMF sends a namf_eventExposure_notify message to the UDM, where the namf_eventExposure_notify message includes a UE identifier, an identifier of a nesting network, and indication information for indicating that the UDM triggers an SOR procedure.

Step 9: the UDM requests SOR information from the SOR-AF.

In one possible implementation, the UDM sends an nsoraf_sor_getrequest message to the SOR-AF requesting the SOR-AF to issue SOR information.

Step 10: the SOR-AF returns SOR information to the UDM.

In one possible implementation, the SOR-AF sends a nsoraf_sor_getresponse message to the UDM, which is used to send SOR information to the UDM in response to the request from the UDM.

Step 11: the UDM sends SOR information to the AMF.

In a possible implementation, the UDM sends a nudm_sdm_notification message to the AMF, the message containing the first network selection information. Optionally, the first network selection information may include a network selection list, and when the UE uses the network selection list to perform network selection, a serving network may be selected for access.

Step 12: the AMF sends the SOR message to the UE.

In one possible implementation, the AMF sends the SOR information to the UE through a NAS message.

Step 13: and after receiving the SOR information, the UE performs network reselection based on the network selection list according to the SOR information sent by the AMF, so as to access a nesting network.

Based on the flow shown in fig. 9, when the network side dynamically issues the network selection information, whether the UE is currently executing the service and the access type allowed by the serving network are considered, if the access type of the serving network conflicts with the serving network, the serving network is switched to the access type, so that the serving network can use different access types to access the network, and the current service is not affected.

Referring to fig. 10, a flow chart of a communication method according to an embodiment of the present application is provided. In the flow, after the terminal meets the condition of the localization service, the network side dynamically transmits the network selection information of the localization network to the terminal. In the process, the network side acquires the allowed access type of the home network, identifies the access type of the current access service network (service network) of the terminal, and indicates the terminal to access the home network by using an access type different from the access type of the current access service network if the allowed access type of the home network does not conflict with the access type of the current access service network of the terminal or the conflict is possible to occur/not occur, so that when the terminal performs network reselection, the access type of the access home network does not conflict with the access type of the access service network when the terminal selects the home network for access, and further the service continuity of the terminal can be ensured.

This flow is described in detail below in conjunction with fig. 10. As shown in fig. 10, the process may include the steps of:

s1001: the first core network device determines that the terminal satisfies a condition of the first localization service.

For a specific implementation of this step, reference may be made to the relevant content in the flow shown in fig. 8.

S1003: the first core network equipment acquires the access type of the network currently accessed by the terminal and the access type allowed by the first network.

S1005: and if the access type allowed by the first network comprises a second access type, the first core network equipment triggers the core network to send second network selection information to the terminal, wherein the second network selection information is used for indicating the second access type. The first access type and the second access type are different.

It may be appreciated that the second access type indicated by the second network selection information is applied to the first network, i.e. the terminal accesses the first network through the access network corresponding to the second access type according to the second network selection information.

In one possible scenario, the first network allows only one access type, and is different from the first access type, i.e. the first network allows access of the second access type described above. This indicates that the access type allowed by the first network does not conflict with the access type of the terminal currently accessing the serving network. For example, the first network may allow an access type of 3GPP access, and the first access type may be a non-3 GPP access; for another example, the first network may allow access of a type other than 3GPP access, and the first access type may be 3GPP access.

In another possible scenario, the first network may allow multiple access types, including a second access type that is different from the first access type. This indicates that the access type allowed by the first network may or may not conflict with the access type of the terminal currently accessing the serving network. For example, the first network may allow access types including 3GPP access and non-3 GPP access, and the first access type may be non-3 GPP access.

Aiming at the various scenes, in the embodiment of the application, the second network selection information sent to the terminal by the first core network device indicates a second access type different from the first access type, so that the access type of the terminal accessing the first network and the access type accessing the serving network do not conflict, and further the service continuity of the terminal can be ensured.

In a possible implementation manner, the second network selection information includes information of the first network, such as an identifier of the first network, so that the terminal can select the first network (i.e. the hosting network of the first localization service) to access according to the second network selection information, so as to adapt to the localization service provided by the first network.

In another possible implementation manner, the second network selection information is further used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes a first network, and the priority of the first network is highest, so that the terminal can preferentially select the first network (i.e. the hosting network of the first localization service) for access according to the second network selection information, and thus the localization service provided by the first network can be used. Alternatively, in the at least one network, the priority order of the other networks except the first network may be set in the priority order shown in fig. 2.

Optionally, the second network selection information is a network selection list, and the network selection list includes at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes a first network with a highest priority and information for indicating an access type of the first network. In this embodiment, the information is used to indicate the second access type, that is, the information is used to indicate that the access type of the first network is the second access type. An example of this net-selection list is shown in table 1.

Table 1: examples of net lists:

the priority IDs are in the order from high to low: 1,2,3, … ….

In one possible implementation manner, the first core network device may trigger the core network to send the second network selection information to the terminal by: the first core network equipment sends the identification of the terminal, the identification of the first network and the indication information of the second access type to the second core network equipment; the second core network device obtains a network selection list corresponding to the terminal according to the identifier of the terminal and the identifier of the first network, for example, the identifier of the terminal and the identifier of the first network are sent to the SOR-AF, and the corresponding network selection list is received from the SOR-AF, wherein the network selection list comprises the identifier of the first network, and the priority of the first network is highest; the second core network device generates second network selection information according to the network selection list and the indication information of the second access type, for example, the second core network device may add the indication information of the second access type to the network selection list to obtain second network selection information, and an example of the second network selection information may be referred to in table 1; the second core network equipment sends second network selection information to the first core network equipment; and the first core network equipment sends the second network selection information to the terminal.

Optionally, the first core network device further sends fifth indication information to the second core network device, where the fifth indication information is used to instruct the second core network device to generate second network selection information according to the indication information of the second access type and the network selection list corresponding to the terminal, for example, instruct the second core network device to add the indication information of the second access type to the network selection list of the terminal.

The first core network device sends a notification to the second core network device to trigger the second core network device to start the SOR flow, so that the second network selection information can be obtained from the second core network device. And after the first core network equipment acquires the second network selection information, the second network selection information is sent to the terminal. In one possible implementation, a specific implementation of the SOR procedure may refer to the procedure shown in fig. 5 or fig. 6.

In one possible implementation manner, when the first core network device determines that the terminal meets a condition of the first localization service, the following steps may be further performed: s1002: the first core network device obtains the service state of the terminal. In S1003, if the first core network determines that the terminal has a service in progress according to the service status of the terminal, the access type allowed by the first network is obtained. Alternatively, the implementation manner of the first core network device to obtain the service state of the terminal may refer to the relevant content in the flow shown in fig. 8.

In one possible implementation manner, if the first core network device determines that the terminal does not currently have a service in progress according to the service state of the terminal after the first core network device obtains the service state of the terminal, the first core network device triggers the core network device to send third network selection information to the terminal. The third network selection information includes information of the first network, such as an identifier of the first network, so that the terminal can select the first network (i.e. the hosting network of the first localization service) to access according to the second network selection information, thereby being suitable for the localization service provided by the first network.

Optionally, the third network selection information is further used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes a first network, and the priority of the first network is highest, so that the terminal can preferentially select the first network (i.e. the hosting network of the first localization service) for access according to the second network selection information, and thus the localization service provided by the first network can be used. Alternatively, in the at least one network, the priority order of the other networks except the first network may be set in the priority order shown in fig. 2.

In the flow shown in fig. 10, the timing relationship of each step is only an example, and the embodiment of the present application does not limit the timing relationship between each step. For example, the step of the first core network device obtaining the access type of the network to which the terminal is currently connected may also precede S1001.

Based on the flow shown in fig. 10, when the terminal satisfies the condition of the localization service, if the first network (i.e., the network providing the localization service) includes a second access type different from the first access type (i.e., the access type of the service network to which the terminal is currently connected) in the allowed access types, which indicates that the first access type and the service type are not conflicted or are likely to occur/not to occur conflicted, the first core network device may trigger the core network to send network selection information to the terminal, where the network selection information is used to indicate the second access type, so, after the terminal selects the localization network based on the network selection information, the terminal accesses the localization network through the access network corresponding to the second access type according to the second access type, thereby ensuring that the access type of the localization network is different from the access type of the service network of the terminal, and ensuring continuity of the service currently executed by the terminal.

An example of the flow shown in fig. 10 may be as shown in fig. 11. The specific implementation of the steps in fig. 11 may refer to the relevant content in the flow shown in fig. 10. As shown in fig. 11, the process may include the steps of:

In one possible implementation manner, the AMF sends a nudm_sdm_get request message to the UDM, where the message includes an identifier of the UE and an identifier of the nesting network, and further includes indication information for indicating that the UDM returns an access type of the nesting network that is allowed to be used by the UE.

Step 6: the AMF compares the allowed access type of the nesting network with the access type (called a first access type) of the UE currently accessing the servingnetwork, determines whether the two access types conflict, and if the conflict does not occur, the AMF informs the UDM to start an SOR flow.

For example, if the first access type is a 3GPP access, and the access type allowed by the nesting network is a non-3 GPP access, the two access types do not collide, and the AMF notifies the UDM to start the SOR procedure. If the first access type is non-3 GPP access and the allowed access type of the nesting network is 3GPP access, the two access types do not generate conflict, and the AMF informs the UDM to start SOR flow.

One possible implementation manner, the AMF sends a namf_eventExposure_notify message to the UDM, where the namf_eventExposure_notify message includes a UE identifier and an identifier of a serving network, and may further include indication information of a second access type (the second access type is different from the first access type described above), and further may further include indication information for indicating that the UDM triggers an SOR procedure.

Step 7: the UDM requests SOR information from the SOR-AF.

Step 8: the SOR-AF returns SOR information to the UDM.

Step 9: the UDM sends SOR information to the AMF.

In a possible implementation, the UDM sends a nudm_sdm_notification message to the AMF, the message containing the second network selection information. Optionally, the second network selection information may include a network selection list, where the network selection list includes indication information of the second access type, and when the UE uses the network selection list to perform network selection, a serving network may be selected and network access may be performed according to the second access type.

Step 10: the AMF sends the SOR message to the UE.

Step 11: and after receiving the SOR information, the UE performs network reselection based on the network selection list according to the SOR information sent by the AMF, so as to select a serving network and perform network access according to the second access type.

Based on the flow shown in fig. 11, when the network side dynamically issues the network selection information, whether the UE is currently executing the service and the access type allowed by the serving network are considered, and when the serving network can access the network with an access type different from the current serving network, the current service is not affected.

In one possible implementation, the flow shown in fig. 8 and the flow shown in fig. 10 may be used in combination. In other words, when the first core network device determines that the terminal satisfies the condition of the first localization service, if it is determined that the access type allowed by the first network is the same as the first access type, the relevant steps are executed with reference to the flowchart shown in fig. 8; if the access type allowed by the first network includes the second access type, the relevant steps are performed with reference to the flowchart shown in fig. 10.

In the method, for the case of dynamic transmission of the network selection information, transmission conditions of the network selection information are enhanced to avoid interruption of the current service of the terminal. For example, when the first core network device determines that the terminal meets the condition of the localization service and no service is currently being executed, the first core network device triggers the core network to send network selection information to the terminal, so that the terminal can select a nesting network for network access.

In one possible implementation, when the first core network device determines that the terminal meets a condition of the first localization service, the first core network device is notified when the terminal is instructed that there is no ongoing service; and after the first core network equipment receives the indication information which is sent by the terminal and used for informing the terminal that the ongoing service does not exist, triggering the core network to send the network selection information to the terminal.

Optionally, the network selection information includes information of a first network, where the first network is a network that provides the first localization service.

Optionally, the network selection information is used for indicating at least one network recommended to the terminal to perform network reselection and a priority of the at least one network, where the at least one network includes a first network (i.e. a network providing the first localization service), and the priority of the first network is the highest.

Fig. 12 illustrates one possible implementation of the above procedure. In the flow, after the terminal meets the condition of the localization service, the network side dynamically transmits the network selection information of the localization network to the terminal. In the process, when the network side determines that the terminal does not have service, the network side triggers the core network to send network selection information to the terminal.

As shown in fig. 12, the process may include the steps of:

step 1: the AMF determines that the UE satisfies the condition of the localization service.

The specific implementation manner of determining whether the UE meets the condition of the localization service by the first core network device may refer to the relevant content in the flow shown in fig. 8.

Step 2: when the UE meets the condition of the localization service, the AMF sends indication information to the UE, wherein the indication information is used for indicating the UE to feed back to the AMF after the current service is completely finished.

In the step, if the UE has the current service in progress, the UE can wait for the complete end of the ongoing service and feed back to the AMF; if the UE does not currently have a service in progress, feedback to the AMF may be performed immediately after receiving the indication information.

In one possible implementation, the indication information may be sent to the UE by a downlink NAS message, for example, when the UE triggers the procedure by mobility registration, the AMF may include the indication information in a registration accept message.

Step 3: and the UE feeds back to the AMF according to the received indication information after finishing all the current services, so as to inform the AMF that the UE does not currently have the services.

One possible implementation, the UE may feed back this information to the AMF through a NAS message.

Step 4: the AMF sends a notice to the UDM, indicates that the current UE has met the condition of network reselection, and triggers the UDM to start an SOR flow.

In one possible implementation, the AMF sends a namf_eventExposure_notify message to the UDM, where the message includes information that the UE currently satisfies the localization service, an identifier of the localization service, and an identifier of a localization network (the localization network is a network that provides the localization service).

Step 5: the UDM requests SOR information from the SOR-AF.

One possible implementation, the UDM sends a nsoraf_sor_get request message to the SOR-AF requesting the SOR-AF to issue SOR information.

Step 6: the SOR-AF returns SOR information to the UDM.

In one possible implementation, the SOR-AF sends a nsoraf_sor_get response message to the UDM, which is used to send SOR information to the UDM in response to the request from the UDM.

Step 7: the UDM issues SOR information to the AMF.

One possible implementation manner, the UDM sends a nudm_sdm_notification message to the AMF, where the message includes a network selection list, the network selection list includes an identifier of a nesting network, and the nesting network has the highest priority, and when the UE performs network selection according to the network selection list, the nesting network may be selected for access.

Step 8: the AMF issues the SOR message to the UE.

In one possible implementation, the AMF sends the SOR information to the UE through a NAS message, where the SOR information includes the above-mentioned network selection list.

Step 9: and after receiving the SOR information, the UE performs network reselection according to the SOR information issued by the AMF and the network selection list, so as to access a serving network.

In the above flow, the condition of dynamically transmitting the network selection information on the network side is enhanced, and besides the original condition that the localization service corresponds to needs to be met, the condition that the UE does not have the service executing currently is increased. When the UE meets the conditions corresponding to the localization service, the network side will not immediately send the network selection information of the localization network, but will wait for the end of all the current services of the UE and then issue the network selection information. The additional conditions limit that the UE does not reselect the network when the service is executed, thereby avoiding the influence on the current service of the UE.

Some embodiments of the present application further provide a communication method, where, in the method, for a case that network selection information is preconfigured on a terminal, the terminal itself may determine whether a service is currently in progress, and if the service is in progress, the terminal obtains a selection of a user through interaction with the user, and determines whether to initiate network reselection according to the selection of the user. If the user selects to start network reselection, the terminal starts network reselection after waiting for all the services in use to finish, so that network selection is performed again according to a preconfigured network selection list.

Optionally, the network selection information preconfigured on the terminal may include, but is not limited to, an identifier of the localization service, a condition of the localization service, and a network selection list for selecting a nesting network. Alternatively, the condition of the localization service may be a condition based on a service location required by the localization service, or a condition based on a service start time of the localization service, or a condition based on a service location and a service start time. Optionally, the network selection list includes an identifier of a nesting network, and optionally, the nesting network has the highest priority.

Fig. 13 illustrates one possible implementation flow of the method. As shown, the process may include the steps of:

s1301: the terminal determines that the condition of the first localized service is satisfied.

The method of judging whether the condition of the localized service is satisfied is basically the same as the foregoing embodiment, except that since the relevant information of the condition of the localized service is preconfigured on the terminal, the terminal itself can determine whether the terminal satisfies the condition of the localized service.

S1302: when the terminal determines that the condition of the first localization service is satisfied, it is determined whether a service is currently in progress, and if so, the process proceeds to S1303, otherwise, the process proceeds to S1306.

S1303: the terminal acquires the selection of the user through interaction with the user, wherein the selection of the user comprises the approval of the switching access type or the disapproval of the switching access type. If the user agrees to switch the access type, the process proceeds to S1304, otherwise, the process proceeds to S1305.

Optionally, the terminal may provide a user interface for obtaining a user selection, where the user interface may provide an option to agree to the switch access type and an option to disagree with the switch access type, and the user may submit his own selection to the terminal through man-machine interaction.

The terminal may also obtain the user's selection by other means, such as by means of a voice query, and identify whether the user agrees to switch access types according to the received user response voice.

S1304: the terminal is switched from an access network corresponding to a first access type (namely, the access type of the current access network of the terminal) to an access network corresponding to a second access type, and network reselection is carried out according to preconfigured network selection information after the switching is completed, wherein the second access type is different from the first access type.

For example, if the first access type is a non-3 GPP access, the terminal may switch to the 3GPP access by performing the procedure shown in fig. 3; if the first access type is 3GPP access, the terminal can switch to non-3 GPP access by executing the flow shown in FIG. 4.

S1305: and after the currently executing service is finished, the terminal performs network reselection according to the preconfigured network selection information.

In this step, if there is a service currently executing, the terminal may temporarily close the automatic network selection, and perform network reselection according to the preconfigured network selection information after waiting for the service to end. The terminal may also manually perform network reselection by the user after waiting for the service to end, for example, the user may select a network to be accessed from a preconfigured network selection list.

S1306: and the terminal performs network reselection according to the preconfigured network selection information.

In the above flow, after the UE satisfies the condition of the localization service, it is required to additionally determine whether the UE currently executes the service in the service network. When the UE is executing the service in the service network, the automatic network selection is closed, or the UE is interacted with the user to inquire whether the user needs to switch the access type. By the aid of the flow, when the UE performs network reselection, interruption of the currently executed service of the UE can be avoided, and influence on the current service is reduced.

Some embodiments of the present application further provide a communication method, where, for a case where network selection information is preconfigured on a terminal, when a network is reselected, the selected network is accessed by selecting an access type different from a current access type, so as to reduce or avoid an influence of the network selection on a current service.

In one possible implementation manner, when the terminal determines that the condition of the first localization service is satisfied, an access type of a network to which the terminal is currently connected (hereinafter referred to as a first access type) and an access type allowed by the first network (i.e., a network for providing the first localization service) are acquired; if the access type allowed by the first network is the same as the first access type, the terminal switches from the access network corresponding to the first access type to the access network corresponding to the second access type (the second access type is different from the first access type), and performs network reselection according to the preconfigured network selection information after switching to the access network corresponding to the second access type. Because the preconfigured network selection information includes the first network, the terminal can select the first network to access so as to use the first localization service.

Optionally, if the access type allowed by the first network includes the second access type, the terminal performs network reselection according to the preconfigured network selection information. Because the preconfigured network selection information includes the first network, the terminal can select the first network to access so as to use the first localization service.

Fig. 14 illustrates one possible implementation of the above procedure. Under the condition of pre-configuring the UE network selection information, the judgment of the UE on the access type of the nesting network is compared with the access type of the current service network, and the decision of which access type the UE accesses the nesting network is made, so that the influence on the current service is reduced. The process may include the steps of:

step 1: and the UE judges that the condition of the first localization service is met according to the preconfigured localization service information.

Step 2: the UE compares the allowed access type of the home network (i.e. the first network for providing the first localization service) with the first access type (i.e. the access type of the serving network currently being used by the UE), if the two conflict, step 3 is executed, otherwise step 4 is executed.

Optionally, if the access type allowed by the nesting network is the same as the first access type, the two types are indicated to collide. For example, if the nesting network is only accessible through 3GPP, the first access type is also 3GPP access; alternatively, if the nesting network is only accessible through non-3 GPP, the first access type is also non-3 GPP access.

Optionally, if the access type allowed by the nesting network includes a second access type (the second access type is different from the first access type), it indicates that the two access types do not collide, or there is a possibility that the two access types do not collide.

Step 3: the terminal is switched from the access network corresponding to the first access type to the access network corresponding to the second access type, namely, the access type switching is executed. And after switching to the access network corresponding to the second access type, performing network reselection according to the preconfigured network selection information.

After the terminal finishes the switching of the access types, the access types used by the serving network and the serving network are different, so that no conflict is generated, and at the moment, the UE performs network reselection according to the preconfigured network selection information so as to access the serving network.

Step 4: and the UE performs network re-establishment according to the preconfigured network selection information, and accesses the nesting network through an access network corresponding to the second access type according to the second access type after selecting the nesting network.

The above flow compares the access type allowed by the serving network with the access type of the current serving network of the UE, if a conflict occurs, the access network of the current serving network is switched, so that the access type is switched, and the access type of the current serving network is different from the type allowed by the serving network. When the two do not collide, the connection of the serving network is not affected when the UE reselects the network access serving network. Therefore, by adopting the flow, when the UE reselects the network to access the serving network, the influence on the service in the current serving network can be avoided.

Based on the same technical concept, the embodiment of the present application also provides a communication apparatus, as shown in fig. 15, the communication apparatus 1500 may include a processing unit 1501 and a transceiving unit 1502.

In one possible implementation, the communication apparatus 1500 may implement the functions of the first core network device in fig. 8 or fig. 9. Illustratively, the processing unit 1500 is configured to: when the terminal meets the condition of a first localization service, acquiring the access type of a network which is accessed by the terminal currently and the access type allowed by a first network, wherein the first network is used for providing the first localization service, and the access type of the network which is accessed by the terminal currently is the first access type; if the access type allowed by the first network is the same as the first access type, the transceiver 1502 instructs the terminal to switch from the access network corresponding to the first access type to the access network corresponding to a second access type, where the second access type is different from the first access type; and triggering a core network to send first network selection information to the terminal after determining that the terminal is switched to an access network corresponding to the second access type.

In another possible implementation manner, the communication apparatus 1500 may implement the functions of the first core network device in fig. 10 or fig. 11. The processing unit 1501 is illustrated for: when the terminal meets the condition of a first localization service, acquiring the access type of a network which is accessed by the terminal currently and the access type allowed by a first network, wherein the first network is used for providing the first localization service, and the access type of the network which is accessed by the terminal currently is the first access type; and if the access type allowed by the first network comprises a second access type, wherein the second access type is different from the first access type, triggering a core network to send network selection information to the terminal, and the network selection information is used for indicating the second access type.

In another possible implementation manner, the communication apparatus 1500 may implement the function of the first core network device in fig. 12. The processing unit 1501 is illustrated for: notifying the first core network device when the terminal is instructed by the transceiving unit 1502 that there is no ongoing service when it is determined that the terminal satisfies the condition of the first localization service; after receiving, by the transceiver 1502, the indication information sent by the terminal and used for notifying that the terminal does not have an ongoing service, the core network is triggered to send network selection information to the terminal.

In another possible implementation, the communication device 1500 may implement the functionality of the terminal in fig. 13. The processing unit 1501 is illustrated for: when the condition of the first localization service is met, determining whether the terminal currently has a service; if the service is currently in progress, determining whether to switch the access type according to the selection of the user, if the access type is determined to be switched, switching from the access network corresponding to the first access type to the access network corresponding to the second access type, and performing network reselection according to the network selection information after the switching is completed, wherein the second access type is different from the first access type.

In another possible implementation, the communication device 1500 may implement the functionality of the terminal in fig. 14. The processing unit 1501 is illustrated for: when the condition of meeting the first localization service is determined, acquiring the access type of the network currently accessed by the terminal and the access type allowed by the first network, wherein the first network is a network for providing the first localization service, and the access type of the network currently accessed by the terminal is a first access type; if the allowed access type of the first network is the same as the first access type, switching from an access network corresponding to the first access type to an access network corresponding to a second access type, and selecting the first network for access after switching to the access network corresponding to the second access type; wherein the second access type is different from the first access type.

It can be understood that the communication device provided in this embodiment of the present application can implement all the method steps implemented by the corresponding devices in the method embodiment, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those in the method embodiment in this embodiment are omitted.

The communication device 1500 can implement the method steps in the method embodiment and achieve the same technical effects, and the same parts and advantages as those of the method embodiment in this embodiment are not described in detail herein.

For ease of understanding, only the structures required by communication device 1600 to perform the methods described herein are shown in fig. 16, and the present application is not limited to communication devices that may be provided with more components. The communication apparatus 1600 may be configured to perform the steps performed by the related device in the above method embodiments, for example, the related device may be a first core network device (such as an AMF), or a terminal, etc.

The communication device 1600 may include a transceiver 1601, a memory 1603, and a processor 1602, where the transceiver 1601, the memory 1603, and the processor 1602 may be connected by a bus 1604. The transceiver 1601 may be used for communication by a communication device, such as for transmitting or receiving signals. The memory 1603 is coupled to the processor 1602 and is operable to store programs and data necessary for the communication device 1600 to perform various functions. The above memory 1603 and the processor 1602 may be integrated or independent.

The transceiver 1601 may be, for example, a communication port, such as a communication port (or interface) between network elements for communication. The transceiver 1601 may also be referred to as a transceiver unit or a communication unit. The processor 1602 may be implemented by a processing chip or processing circuit. The transceiver 1601 may receive or transmit information wirelessly or by wire.

In addition, according to the actual use requirement, the communication device provided by the embodiment of the application may include a processor, and the processor invokes an external transceiver and/or a memory to implement the above functions or steps or operations. The communication device may also include a memory that is invoked by the processor and executes a program stored in the memory to perform the functions or steps or operations described above. Alternatively, the communication device may also include a processor and a transceiver (or a communication interface), where the processor invokes and executes a program stored in an external memory to perform the functions or steps or operations described above. Alternatively, the communication device may include a processor, memory, and transceiver.

Based on the same concept as the above method embodiments, a computer readable storage medium is further provided in the embodiments of the present application, where a program instruction (or called a computer program, an instruction) is stored, where the program instruction when executed by a processor causes the computer to execute any one of the possible implementation manners of the above method embodiments, and the method embodiments by the first network element. Operations performed by the radio access network or policy control function.

Based on the same concept as the above method embodiments, the present application further provides a computer program product, including program instructions, which when executed by a computer, can cause the computer to implement the above method embodiments, any one possible implementation of the method embodiments, and the first network element. Operations performed by the radio access network or policy control function.

Based on the same concept as the above method embodiments, the present application further provides a chip or a chip system, the chip being coupled to the transceiver for implementing the above method embodiments, any one of the possible implementation manners of the method embodiments being performed by the first network element. Operations performed by the radio access network or policy control function. The chip system may include the chip, as well as components including memory, communication interfaces, and the like.

Based on the same concept as the method embodiment, the embodiment of the application also provides a communication system. Optionally, the communication system includes a first core network device and a second core network device, where the first core network device may perform the operation of the first core network device in fig. 8 or fig. 9, and the second core network device may perform the operation of the second core network device in fig. 8 or fig. 9.

Based on the same concept as the method embodiment, the embodiment of the application also provides a communication system. Optionally, the communication system includes a first core network device and a second core network device, where the first core network device may perform the operation of the first core network device in fig. 10 or fig. 11, and the second core network device may perform the operation of the second core network device in fig. 10 or fig. 11.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.

Claims

1. A method of communication, comprising:

when a first core network device determines that a terminal meets the condition of a first localization service, acquiring the access type of a network currently accessed by the terminal and the access type allowed by a first network, wherein the first network is a network for providing the first localization service, and the access type of the network currently accessed by the terminal is the first access type;

if the allowed access type of the first network is the same as the first access type, the first core network device instructs the terminal to switch from an access network corresponding to the first access type to an access network corresponding to a second access type, wherein the second access type is different from the first access type;

and after the first core network equipment determines that the terminal is switched to the access network corresponding to the second access type, triggering the core network to send first network selection information to the terminal.

2. The method of claim 1, wherein the first core network device determining that the terminal is handed over to the access network corresponding to the second access type comprises:

the first core network device sends first indication information to the terminal and receives second indication information sent by the terminal, wherein the first indication information is used for indicating the terminal to send the second indication information to the first core network device after the terminal finishes the switching, and the second indication information is used for indicating the terminal to finish the switching; or alternatively

And the first core network equipment determines that the terminal is switched to the access network corresponding to the second access type according to the access network connection information of the terminal.

3. The method according to any of claims 1-2, wherein when the first core network device determines that the terminal fulfils the condition of the first localization service, the method further comprises:

the first core network equipment acquires the service state of the terminal;

the obtaining the access type allowed by the first network includes:

and if the service state of the terminal indicates that the terminal has service in progress, the first core network equipment acquires the access type allowed by the first network.

4. The method of claim 3, wherein the first core network device obtaining the service state of the terminal comprises:

the first core network device sends first request information to the terminal, wherein the first request information is used for requesting to inquire the service state of the terminal;

the first core network device receives first response information sent by the terminal based on the first request information, wherein the first response information is used for indicating the service state of the terminal.

5. The method of claim 4, wherein the first response message includes third indication information, the third indication information being used to indicate a traffic state of the terminal.

6. The method according to any of claims 1-5, wherein the first core network device obtaining the access type allowed by the first network comprises:

the first core network device sends second request information to second core network device, wherein the second request information comprises the identification of the terminal and the identification of the first network;

the first core network device receives second response information sent by the second core network device based on the second request information, wherein the second response information comprises indication information of an access type allowed by the first network.

7. The method of claim 6, wherein the second request information further includes fourth indication information for indicating that the second core network device returns to the first core network device an access type allowed by the first network.

8. The method according to any of claims 1-7, wherein when the first core network device determines that the terminal fulfils the condition of the first localization service, the method further comprises:

If the access type allowed by the first network includes a second access type, where the second access type is different from the first access type, the first core network device triggers a core network to send second network selection information to the terminal, where the second network selection information is used to indicate the second access type.

9. The method of claim 8, wherein the second network selection information comprises information of the first network.

10. The method of claim 8, wherein the second network selection information is further used to indicate at least one network recommended to the terminal for network reselection and a priority of the at least one network, the at least one network including the first network, the first network having a highest priority.

11. The method of claim 10, wherein the second network selection information comprises a network selection list including the at least one network recommended to the terminal for network reselection and information indicating an access type of the first network.

12. The method according to any of claims 8-11, wherein the first core network device triggers a core network to send second network selection information to the terminal, comprising:

The first core network device sends the identification of the terminal, the identification of the first network and the indication information of the second access type to the second core network device; the second core network device is configured to obtain a network selection list corresponding to the terminal according to the identifier of the terminal and the identifier of the first network, and generate the second network selection information according to the network selection list and the indication information of the second access type;

the first core network device receives the second network selection information sent by the second core network device;

and the first core network equipment sends the second network selection information to the terminal.

13. The method of claim 12, wherein the first core network device further sends fifth indication information to the second core network device, the fifth indication information being used to instruct the second core network device to generate the second network selection information according to the indication information of the second access type and the network selection list corresponding to the terminal.

14. The method according to any of claims 1-13, wherein the first access type is a 3GPP access type and the second access type is a non-3 GPP access type; or, the first access type is a non-3 GPP access type, and the second access type is a 3GPP access type.

15. A method of communication, comprising:

if the access type allowed by the first network includes a second access type, where the second access type is different from the first access type, the first core network device triggers a core network to send network selection information to the terminal, where the network selection information is used to indicate the second access type.

16. The method of claim 15, wherein the network selection information comprises information of the first network.

17. The method of claim 15, wherein the network selection information is further used to indicate at least one network recommended to the terminal for network reselection and a priority of the at least one network, the at least one network including the first network, the first network having a highest priority.

18. The method of claim 17, wherein the network selection information comprises a network selection list including the at least one network recommended to the terminal for network reselection and information indicating an access type of the first network.

19. The method according to any of claims 15-18, wherein the first core network device triggering a core network to send network selection information to the terminal, comprising:

the first core network device sends the identification of the terminal, the identification of the first network and the indication information of the second access type to the second core network device; the second core network device is configured to obtain a network selection list corresponding to the terminal according to the identifier of the terminal and the identifier of the first network, and generate the network selection information according to the network selection list and the indication information of the second access type;

the first core network device receives the network selection information sent by the second core network device;

and the first core network equipment sends the network selection information to the terminal.

20. The method of claim 19, wherein the first core network device further sends fifth indication information to the second core network device, the fifth indication information being used to instruct the second core network device to generate the network selection information according to the indication information of the second access type and the network selection list corresponding to the terminal.

21. The method according to any of claims 15-20, wherein when the first core network device determines that the terminal fulfils the condition of the first localization service, the method further comprises:

the first core network equipment acquires the service state of the terminal;

the obtaining the access type allowed by the first network includes:

22. The method of claim 21, wherein the first core network device obtaining the traffic state of the terminal comprises:

23. The method of claim 22, wherein the first response message includes third indication information, the third indication information being used to indicate a traffic state of the terminal.

24. The method according to any of claims 15-23, wherein the first core network device obtaining the access type allowed by the first network comprises:

25. The method of claim 24, wherein the second request information further comprises fourth indication information for indicating that the second core network device returns to the first core network device the type of access allowed by the first network.

26. The method according to any of claims 15-25, wherein the first access type is a 3GPP access type and the second access type is a non-3 GPP access type; or, the first access type is a non-3 GPP access type, and the second access type is a 3GPP access type.

27. A communication device, comprising: one or more processors; wherein the instructions of the one or more computer programs, when executed by the one or more processors, cause the communications apparatus to perform the method of any of claims 1-14 or perform the method of any of claims 15-26.

28. A computer readable storage medium, characterized in that the computer readable storage medium comprises a computer program which, when run on a computing device, causes the computing device to perform the method of any one of claims 1-14 or to perform the method of any one of claims 15-26.

29. A chip, characterized in that the chip is coupled to a memory for reading and executing program instructions stored in the memory for implementing the method according to any of claims 1-14 or for implementing the method according to any of claims 15-26.

30. A computer program product, characterized in that the computer program product, when called by a computer, causes the computer to perform the method according to any of claims 1-14 or to perform the method according to any of claims 15-26.