Network switching method and device, communication equipment, storage medium and program product

Abstract

The invention relates to a network switching method and device, communication equipment, a storage medium and a program product, and relates to the technical field of communication. The method comprises: a PCF network element sending a 3GPP and non-3GPP interoperation policy to a UE, the 3GPP and non-3GPP interoperation policy being used for instructing the UE to decide whether to switch a session between a 3GPP network and a non-3GPP network. In the method, the content indicated by the interoperation strategy sent by the PCF network element to the UE is whether the session connection supports switching among a plurality of different networks, so that the UE can know which networks can be switched and which networks cannot be switched before switching the networks. Further, the UE decides to switch the session connection to an appropriate network based on the 3GPP and non-3GPP interoperation policy, so as to maintain the continuity of the current session connection of the UE.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a network switching method, apparatus, communication device, storage medium, and program product. Background Art

[0002] With the booming development of communication technologies, the services of user equipment (UE) are usually carried out in a hybrid networking environment. For example, it is a hybrid networking of the 4th generation mobile communication technology network (4G), the 5th generation mobile communication technology network (5G), and WiFi (Wireless Fidelity, mobile hotspot) or cellular network.

[0003] In related technologies, taking the voice service under the current cellular network as an example, during the process of the UE performing a voice service, if the UE moves from the current cellular network to an area without a cellular network, network switching is required to maintain the continuity of the UE's voice call service and avoid UE voice call drops.

[0004] Therefore, how the UE learns about the networks that support switching has become a technical problem to be urgently solved. Summary of the Invention

[0005] Embodiments of this application provide a network switching method, apparatus, communication device, storage medium, and program product that can enable a UE to learn about network switching capabilities.

[0006] In a first aspect, embodiments of this application provide a network switching method applied to a PCF network element. The method includes:

[0007] Sending a 3GPP and non-3GPP interoperability policy to the UE; the 3GPP and non-3GPP interoperability policy is used for the UE to decide whether to switch the session connection between 3GPP and non-3GPP networks.

[0008] In one embodiment, the 3GPP and non-3GPP interoperability policy includes at least one of session switching policy description information, DNN information corresponding to the session switching policy, policy information type indication information, and public land mobile network (PLMN) information corresponding to the 3GPP and non-3GPP interoperability policy.

[0009] In one embodiment, the session switching policy description information includes at least one of the following:

[0010] Whether the session connection supports switching between the EPDG network and the EPC network;

[0011] Whether the session connection supports switching between the N3IWF network and the EPC network;

[0012] Whether the session connection supports switching between the EPDG network and the 5GC network;

[0013] Whether the session connection supports switching between the N3IWF network and the 5GC network.

[0014] In one embodiment, the session switching policy description information includes at least one of the following:

[0015] Whether the session connection supports switching from the EPDG network to the EPC network;

[0016] Whether the session connection supports switching from the EPC network to the EPDG network;

[0017] Whether the session connection supports switching from the N3IWF network to the EPC network;

[0018] Whether the session connection supports switching from the EPC network to the N3IWF network;

[0019] Whether the session connection supports switching from the EPDG network to the 5GC network;

[0020] Whether the session connection supports switching from the 5GC network to the EPDG network;

[0021] Whether the session connection supports switching from the N3IWF network to the 5GC network;

[0022] Whether the session connection supports switching from the 5GC network to the N3IWF network.

[0023] In one embodiment, the PLMN information includes home PLMN information and non-home PLMN information.

[0024] In one embodiment, the DNN information includes a session connection corresponding to a DNN for indicating an interworking policy applicable to 3GPP and non-3GPP.

[0025] In one embodiment, the method includes:

[0026] Receiving a policy update response sent by the UE; the policy update response is sent by the UE when the policy update is completed according to the 3GPP and non-3GPP interworking policy.

[0027] In one embodiment, the method includes:

[0028] Send NAS information to the AMF network element. The NAS information carries the 3GPP and non-3GPP interworking policies to instruct the AMF network element to send the 3GPP and non-3GPP interworking policies to the UE.

[0029] In one embodiment, the method includes:

[0030] In response to a registration request sent by the AMF network element carrying a 3GPP and non-3GPP interworking policy request, send the 3GPP and non-3GPP interworking policies to the UE; the registration request is sent by the UE to the AMF network element.

[0031] In one embodiment, the method includes:

[0032] When the PCF network element is a home PCF network element, receive the 3GPP and non-3GPP interworking policies sent by the UDM network element.

[0033] In one embodiment, the method includes:

[0034] When the PCF network element is a roaming PCF network element, receive the 3GPP and non-3GPP interworking policies sent by the home PCF network element; the 3GPP and non-3GPP interworking policies of the home PCF network element are sent by the UDM network element.

[0035] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0036] In a second aspect, an embodiment of the present application provides a network switching method applied to a UE. The method includes:

[0037] Receive the 3GPP and non-3GPP interworking policies sent by the PCF network element;

[0038] Determine whether to switch the session connection between the 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interworking policies.

[0039] In one embodiment, the 3GPP and non-3GPP interworking policies include policy information type indication information. The method further includes:

[0040] According to the policy information type indication information, save the 3GPP and non-3GPP interworking policies locally and update the policy information of the initial interworking policies with the same policy information type indication information.

[0041] In one embodiment, the method further includes:

[0042] When the policy update is completed according to the 3GPP and non-3GPP interworking policies, send a policy update response to the PCF network element.

[0043] In one embodiment, the 3GPP and non-3GPP interworking policy includes PLMN information, and the method further includes:

[0044] Obtain the current PLMN network to which the UE is currently attached;

[0045] If the PLMN network accessed by the current 3GPP and the PLMN network accessed by the non-3GPP belong to the same PLMN, determine that the 3GPP and non-3GPP interworking policy corresponding to the PLMN network can be applied to the current network.

[0046] In one embodiment, the 3GPP and non-3GPP interworking policy includes session handover policy description information and session handover policy description information, and the method further includes:

[0047] Determine the target handover network according to the session handover policy description information;

[0048] Switch the session connection to the target handover network.

[0049] In one embodiment, the session handover policy description information includes at least one of the following:

[0050] Whether the session connection supports handover between the EPDG network and the EPC network;

[0051] Whether the session connection supports handover between the N3IWF network and the EPC network;

[0052] Whether the session connection supports handover between the EPDG network and the 5GC network;

[0053] Whether the session connection supports handover between the N3IWF network and the 5GC network.

[0054] In one embodiment, the session handover policy description information includes at least one of the following:

[0055] Whether the session connection supports handover from the EPDG network to the EPC network;

[0056] Whether the session connection supports handover from the EPC network to the EPDG network;

[0057] Whether the session connection supports handover from the N3IWF network to the EPC network;

[0058] Whether the session connection supports handover from the EPC network to the N3IWF network;

[0059] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0060] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0061] Whether the session connection supports switching from the N3IWF network to the 5GC network;

[0062] Whether the session connection supports switching from the 5GC network to the N3IWF network.

[0063] In one embodiment, before receiving the 3GPP and non-3GPP interworking policy sent by the PCF network element, the method further includes:

[0064] Sending a registration request carrying a 3GPP and non-3GPP interworking policy request to the AMF network element; the registration request is used to instruct the AMF network element to send the 3GPP and non-3GPP interworking policy to the PCF network element.

[0065] In one embodiment, the method further includes:

[0066] Receiving NAS information sent by the PCF network element through the AMF network element; the NAS information carries the 3GPP and non-3GPP interworking policy.

[0067] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0068] In a third aspect, an embodiment of the present application provides a network switching device, and the device includes:

[0069] A policy sending module, configured to send a 3GPP and non-3GPP interworking policy [Handover policy] to the UE; the 3GPP and non-3GPP interworking policy is used for the UE to determine whether to switch the session connection between the 3GPP and non-3GPP networks.

[0070] In a fourth aspect, an embodiment of the present application provides a network switching device, and the device includes:

[0071] A policy receiving module, configured to receive the 3GPP and non-3GPP interworking policy sent by the PCF network element;

[0072] A policy determining module, configured to determine whether to switch the session connection between the 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interworking policy.

[0073] In a fifth aspect, an embodiment of the present application provides a communication device, including a transmitter,

[0074] The transmitter is configured to send a 3GPP and non-3GPP interworking policy [Handover policy] to the UE; the interworking policy is used for the UE to determine whether to switch the session connection between the 3GPP and non-3GPP networks.

[0075] In a sixth aspect, an embodiment of the present application provides a communication device, including a receiver, a processor, and a memory, where the memory stores a computer program;

[0076] The receiver is configured to receive 3GPP and non-3GPP interoperability policies sent by a PCF network element;

[0077] The processor executes the computer program to determine whether to switch a session connection between 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policies.

[0078] In a seventh aspect, an embodiment of the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method in any one of the above first aspect or second aspect embodiments are implemented.

[0079] In an eighth aspect, an embodiment of the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the method in any one of the above first aspect or second aspect embodiments are implemented.

[0080] In the above network switching method, device, communication device, storage medium, and program product, the PCF network element sends 3GPP and non-3GPP interoperability policies to the UE, and the 3GPP and non-3GPP interoperability policies are used to instruct the UE to decide whether to switch a session connection between 3GPP and non-3GPP networks. In this method, the content indicated by the interoperability policy sent by the PCF network element to the UE is whether session connection switching is supported between multiple different networks, so that the UE can know which networks can be switched and which networks cannot be switched before switching networks. Further, the UE decides to switch the session connection to a suitable network based on the 3GPP and non-3GPP interoperability policies to maintain the continuity of the UE's current session connection. Description of the Drawings

[0081] Figure 1 It is an application environment diagram of the network switching method in an embodiment;

[0082] Figure 2 It is a flowchart of the network switching method in an embodiment;

[0083] Figure 3 It is a flowchart of the network switching method in another embodiment;

[0084] Figure 4 It is a flowchart of the policy determination step in an embodiment;

[0085] Figure 5Schematic flowchart of a network switching method in another embodiment;

[0086] Figure 6 Schematic signaling interaction diagram of a network switching method in an embodiment;

[0087] Figure 7 Structural block diagram of a network switching device in an embodiment;

[0088] Figure 8 Structural block diagram of a network switching device in another embodiment;

[0089] Figure 9 Internal structure diagram of a communication device in an embodiment;

[0090] Figure 10 Internal structure diagram of a communication device in another embodiment. Detailed implementation manners

[0091] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0092] As the commercial maturity of 5G Standalone (SA) networking gradually progresses, the services of terminals are gradually migrated from 4G networks to 5G networks. 5G networks can provide voice services based on Voice over New Radio (VoNR) or EPS Fallback. Among them, EPS fallback means that when a user needs to use voice services, 5G users switch or redirect from 5G networks to 4G networks and use VOLTE voice services through 4G networks.

[0093] However, there are still great challenges in forming continuous wide-area coverage for the high-frequency deployment of 5G New Radio (NR) networks. Based on this, compensating for the lack of cellular coverage through Voice over WiFi (VoWiFi) indoors can provide users with seamless, full-coverage, and highly reliable voice call services, which can complement the cellular network and further leverage the advantages of the integration of fixed and mobile networks.

[0094] The network switching method, apparatus, communication device, storage medium, and program product provided by the embodiments of this application can be applied to scenarios where a UE needs to perform network switching due to factors such as poor or unstable current call signals. For example, when the UE is in a call, it switches from an area covered by a cellular network to an area without cellular network coverage and covered by a VoWiFi network, or from an area covered by a VoWiFi network to an area without VoWiFi network coverage and covered by a cellular network, or from an area covered by a cellular / VoWiFi network to a hybrid network.

[0095] Among them, when the UE is in a call in an area covered by a cellular network, the UE can provide voice services through a Protocol Data Unit (PDU) session or a Packet Data Network (PDN) connection under the 3rd Generation Partnership Project (3GPP) access network, such as the Evolved Packet Core (EPC) or the 5th generation mobile communication Core (5GC). When the UE is in a call in an area covered by a VoWiFi network, the UE can provide voice services through a PDU session or a PDN connection under a non-3GPP access network through a Non-3GPP Inter Working Function (N3IWF) network element or an Evolevd Packet Data Gateway (ePDG).

[0096] However, in an environment where 4G, 5G networks and WiFi are in a hybrid network, there may be a situation where the network only supports interoperability between 4G and WiFi, but does not support interoperability between 5G and WiFi. In addition, as more and more applications support interoperability between WiFi and cellular networks, different session connections / PDN connections may have different WiFi and cellular switching strategies, and there may also be differences in switching strategies in different roaming areas.

[0097] In the related art, the UE cannot know whether the cellular network supports switching with the VoWiFi network, or whether the VoWiFi network supports switching with the cellular network. Then, in some network environments that do not support switching between the cellular network and the VoWiFi network, if the UE still tries to switch the network, it may cause the UE switching to fail.

[0098] Based on this, an embodiment of the present application provides a network switching method. When the UE coexists with the cellular network and the WiFi network, the network issues a policy on the WiFi and cellular interoperability capabilities to the UE. When the UE knows the interoperability capabilities between the networks, it selects a suitable target network for switching to continue the voice service and avoid call drops for the UE.

[0099] Figure 1 A schematic diagram of the scenario of a network switching method is provided. This application scenario may include a UE 10, an Access and Mobility Management Function (AMF) network element 20, and a Policy Control Function (PCF) network element 30. There is a communication connection between the UE 10 and the AMF network element 20, and a communication connection between the AMF network element 20 and the PCF network element 30.

[0100] Among them, the UE 10 can be a wireless terminal. A wireless terminal can be a device that provides voice and / or other service connectivity to users, or a handheld device with wireless connection capabilities, or other processing devices connected to a wireless modem. The wireless terminal can communicate with one or more core networks via a Radio Access Network (RAN). The wireless terminal can be a mobile terminal, such as a mobile phone and a computer with a mobile terminal. For example, it can be a portable, pocket-sized, handheld, computer-integrated, or vehicle-mounted mobile device that exchanges language and / or data with the wireless access network. The wireless terminal can also be referred to as a system, a Subscriber Unit, a Subscriber Station, a Mobile Station, a Mobile, a Remote Station, a Remote Terminal, an Access Terminal, a User Terminal, a User Agent, etc., which is not limited herein.

[0101] The AMF network element 20 is responsible for functions such as UE authentication, authorization, registration, mobility management, and connection management; the PCF network element 30 is a terminal policy control network element that provides terminal policies for the UE.

[0102] In the embodiments of the present application, the PCF network element may send an interworking policy to the UE through the AMF network element to inform the UE of the network that supports session connection switching. The UE feeds back the result of the switching policy update to the PCF network element through the AMF network element, so that after the UE learns about the network capabilities, it can more accurately select a suitable target network for switching to continue the voice service and avoid UE network switching failures.

[0103] It should be noted that the beneficial effects brought by the embodiments of the present application or the technical problems solved are not limited to this one, and there may also be other implicit or related problems. For specific details, please refer to the descriptions of the following embodiments.

[0104] The following uses specific embodiments to elaborate in detail on the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems. These several specific embodiments may be combined with each other, and concepts or processes that are the same or similar may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0105] In one embodiment, as Figure 2 shown, a flowchart of a network switching method is provided. Taking the method applied to the Figure 1 PCF network element as an example, the method includes the following steps:

[0106] S201: Send 3GPP and non-3GPP interworking policies to the UE; the 3GPP and non-3GPP interworking policies are used for the UE to decide whether to switch the session connection between 3GPP and non-3GPP networks.

[0107] Among them, 3GPP network access means accessing the 5G core network through a standard 3GPP access network in accordance with the protocol standards formulated by 3GPP. For example, a base station accesses the 5G core network according to a standard interface; non-3GPP network access means accessing the 5G core network through a network that is not defined by 3GPP, such as WiFi, through a special network element (3GPP standard).

[0108] The 3GPP and non-3GPP interworking policies in the embodiments of the present application are used to indicate whether the session connection supports switching between 3GPP and non-3GPP networks, so that the UE can decide whether to switch the session connection between 3GPP and non-3GPP networks.

[0109] It should be noted that due to different ways of accessing the network, a UE can have multiple different types of session connections. For example, the UE accesses the 5GC network through a Protocol Data Unit (PDU) session, and the UE accesses the EPS network through a Public Data Network (PDN) connection. Moreover, due to the diversification of services accessed by the UE, the number of session connections corresponding to the UE can also be multiple.

[0110] In one embodiment, the session connection includes a PDU session or a PDN connection.

[0111] In practical applications, when the UE has multiple PDN / PDU connections and different PDN / PDU connections have different UE IP addresses, in the case of downlink data arrival, the core network selects to send data on different connections according to the IP address of the downlink data.

[0112] Moreover, the UE usually provides service under a hybrid network composed of the coverage of a cellular network and a WiFi network, and the UE can access the 5G core network through the corresponding session connection under different networks. Taking the voice call service as an example, under the 5G network, it supports providing voice services through VoNR or EPS FALLBACK in a stand-alone network.

[0113] In this case, to maintain the continuity of the service, when the hybrid network where the UE is located changes, for example, the UE moves from the current cellular network to an area without a cellular network, or moves from an area covered by WiFi to an area without WiFi coverage, etc., the UE needs to timely perform network switching on the session connection to maintain the continuity of the service.

[0114] In the embodiment of the present application, before the UE performs network switching, the PCF network element sends the 3GPP and non-3GPP interoperability policies to the UE to inform the UE of the network switching capabilities, specifically including which networks the session connection supports switching between and which networks it does not support switching between. In this way, the UE determines the target switching network based on the 3GPP and non-3GPP interoperability policies and switches the session connection to the target switching network to maintain the continuity of the current session connection of the UE.

[0115] It should be noted that when the UE completes the registration request, the PCF network element can send the 3GPP and non-3GPP interoperability policies to the UE through any reachable channel. The embodiment of the present application does not limit the triggering condition and the sending channel for the PCF network element to send the 3GPP and non-3GPP interoperability policies to the UE.

[0116] In a scenario, when the PCF network element receives the 3GPP and non-3GPP interoperability policy, it spontaneously sends the 3GPP and non-3GPP interoperability policy to the UE.

[0117] In the embodiments of the present application, the PCF network element sends the 3GPP and non-3GPP interoperability policy to the UE. The 3GPP and non-3GPP interoperability policy is used to instruct the UE to determine whether to switch the session connection between the 3GPP and non-3GPP networks. In this method, the content indicated by the interoperability policy sent by the PCF network element to the UE is whether the session connection supports switching between multiple different networks, so that the UE can know which networks can be switched and which networks cannot be switched before switching the network. Further, the UE determines to switch the session connection to a suitable network based on this 3GPP and non-3GPP interoperability policy to maintain the continuity of the UE's current session connection.

[0118] In the foregoing embodiments, the function of the 3GPP and non-3GPP interoperability policy is described, that is, the 3GPP and non-3GPP interoperability policy is used to instruct the UE to determine whether to switch the session connection between the 3GPP and non-3GPP networks. Next, through an embodiment, the content of the 3GPP and non-3GPP interoperability policy will be described.

[0119] Then in one embodiment, the 3GPP and non-3GPP interoperability policy includes at least one of session switching policy description information, DNN information corresponding to the session switching policy, policy information type indication information, and PLMN information corresponding to the 3GPP and non-3GPP interoperability policy.

[0120] Among them, the session switching policy description information is used to provide the UE with the policy on whether the session connection can be switched between the 3GPP network and the non-3GPP network.

[0121] In practical applications, considering the switching between the 3GPP network and the non-3GPP network, the session switching policy description information includes information on both the switching network and the switching direction.

[0122] Then in a scenario, the session switching policy description information can be unidirectional switching policy description information, which is used to indicate that the session connection can be switched from one network to another network, or bidirectional switching policy description information, which is used to indicate that the session connection is switched between two networks.

[0123] The data network name (DNN) information corresponding to the session switching policy is used to indicate the session connection corresponding to the DNN to which the 3GPP and non-3GPP interoperability policy applies.

[0124] If the 3GPP and non-3GPP interworking policy does not include the DNN, it means that the 3GPP and non-3GPP interworking policy applies to all session connections.

[0125] The policy information type indication is used to indicate that the interworking policy is the 3GPP and non-3GPP interworking handover policy. That is to say, the UE can, through the 3GPP and non-3GPP interworking policy, switch the services accessed through the 3GPP network to the non-3GPP network, or switch the session connection accessed through the non-3GPP network to the 3GPP network.

[0126] The PLMN (Public Land Mobile Network) information corresponding to the 3GPP and non-3GPP interworking policy is used to indicate the network identifier corresponding to the 3GPP and non-3GPP interworking policy.

[0127] The PLMN information corresponding to the 3GPP and non-3GPP interworking policy can be home PLMN information or non-home PLMN information.

[0128] Specifically, the home PLMN information (Home PLMN, HPLMN) refers to the information of the home network of the operator, and one UE corresponds to one HPLMN. The non-home PLMN information refers to the information of other networks outside the home operator, such as the Visited Public Land Mobile Network (VPLMN), the Equivalent Home PLMN (EHPLMN), etc.

[0129] The PCF network element sends the 3GPP and non-3GPP interworking policy carrying the PLMN information to the UE, instructing the UE to perform a validity judgment on the 3GPP and non-3GPP interworking policy, and then select whether to adopt the 3GPP and non-3GPP interworking policy. The specific judgment method will be described in detail in the subsequent embodiments and will not be elaborated here.

[0130] It should be noted that the 3GPP and non-3GPP interworking policy information includes at least one of the session handover policy description information, the DNN information corresponding to the session handover policy, the policy information type indication information, and the PLMN information, and may also include two, multiple, or all of them. In this regard, the embodiments of the present application do not make any restrictions.

[0131] In the embodiments of the present application, the 3GPP and non-3GPP interworking policy information includes session handover policy description information, DNN information corresponding to the session handover policy, policy information type indication information, and PLMN information corresponding to the 3GPP and non-3GPP interworking policy, covering the session handover capabilities of session connections, session handover directions, network handover types, operator affiliations, etc. in multiple dimensions, providing a complete and comprehensive session connection handover policy for the UE.

[0132] The following uses an embodiment to illustrate the session handover policy description information in the 3GPP and non-3GPP interworking policy in the foregoing embodiments.

[0133] In one embodiment, the session handover policy description information includes at least one of the following:

[0134] Whether the session connection supports handover between the EPDG network and the EPC network;

[0135] Whether the session connection supports handover between the N3IWF network and the EPC network;

[0136] Whether the session connection supports handover between the EPDG network and the 5GC network;

[0137] Whether the session connection supports handover between the N3IWF network and the 5GC network.

[0138] In the case where the interworking policy is the 3GPP and non-3GPP interworking policy, the 3GPP access network includes the EPC network and the 5GC network, and the non-3GPP access network includes the EPDG network accessed through the EPDG network element and the N3IWF network accessed through the N3IWF gateway.

[0139] Based on this, the specific scenarios for handover between the 3GPP access network and the non-3GPP access network include handover between the EPDG network / N3IWF network in the non-3GPP access network and the EPC network / 5GC network in the 3GPP access network.

[0140] The handover between every two networks includes two handover directions. The session handover policy description information in the embodiments of the present application can be used to describe whether the session connection supports mutual handover between two networks.

[0141] Taking the EPDG network and the EPC network as examples, if the session connection supports the handover from the EPDG network to the EPC network and also supports the handover from the EPC network to the EPDG network, the corresponding session handover policy description information is: The session connection supports handover between the EPDG network and the EPC network. If the session connection does not support the handover from the EPDG network to the EPC network or does not support the handover from the EPC network to the EPDG network, the corresponding session handover policy description information is: The session connection does not support handover between the EPDG network and the EPC network.

[0142] In the embodiments of the present application, considering the interaction between multiple networks under the 3GPP access network and multiple networks under the non-3GPP access network, the network handover policies of the UE under multiple hybrid network deployments are covered to the greatest extent, so that the UE has multiple candidate handover network policies, and then a suitable network is determined for handover.

[0143] The session handover policy description information in the above embodiments describes the bidirectional handover capability between two networks through one piece of information. Hereinafter, another description method of the session handover policy description information will be described through an embodiment.

[0144] In one embodiment, the session handover policy description information includes at least one of the following:

[0145] Whether the session connection supports handover from the EPDG network to the EPC network;

[0146] Whether the session connection supports handover from the EPC network to the EPDG network;

[0147] Whether the session connection supports handover from the N3IWF network to the EPC network;

[0148] Whether the session connection supports handover from the EPC network to the N3IWF network;

[0149] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0150] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0151] Whether the session connection supports handover from the N3IWF network to the 5GC network;

[0152] Whether the session connection supports handover from the 5GC network to the N3IWF network.

[0153] Whether the session connection supports handover between the 3GPP network and the non-3GPP network can be further refined according to the session handover direction into whether the session connection supports handover from the 3GPP network to the non-3GPP network and whether it supports handover from the non-3GPP network to the 3GPP network.

[0154] Taking whether a session connection supports handover between an EPDG network and an EPC network as an example, it can be subdivided into whether a session connection supports handover from an EPDG network to an EPC network and whether a session connection supports handover from an EPC network to an EPDG network in combination with the handover direction between the EPDG network and the EPC network.

[0155] The session handover policy description information about the handover ability between the EPDG network and the EPC network in the embodiments of the present application includes the following four situations: supporting handover from the EPDG network to the EPC network, not supporting handover from the EPDG network to the EPC network, supporting handover from the EPC network to the EPDG network, and not supporting handover from the EPC network to the EPDG network.

[0156] For the handover ability between the N3IWF network and the EPC network, the handover ability between the EPDG network and the 5GC network, and the handover ability between the N3IWF network and the 5GC network, reference can be made to the above description of the handover between the EPDG network and the EPC network, which will not be elaborated here.

[0157] In the embodiments of the present application, considering that the handover between the 3GPP access network and the non-3GPP access network is directional, based on this, through the session handover policy description information, the handover ability between every two networks is subdivided into two unidirectional handover ability indications to comprehensively cover the network handover strategies of the UE between different networks, so that the UE has multiple candidate handover network strategies, and then determine a suitable network for handover.

[0158] Based on the description of the 3GPP and non-3GPP interoperability policy information in the foregoing embodiments, the construction steps of the 3GPP and non-3GPP interoperability policy information will be described below through an embodiment.

[0159] The interoperability policy sent by the PCF network element to the UE includes policy information under multiple different PLMNs.

[0160] Among them, the PLMN is represented by a Mobile Country Code (MCC) and a Mobile Network Code (MNC), and occupies 3 bytes through BCD coding, as shown in Table 1 below. Table 1 is the management sublist of the terminal policy part.

[0161] Table 1

[0162]

[0163] Furthermore, a PLMN can contain multiple groups of terminal policy information, as shown in Table 2. Table 2 is the content of the management sublist of the terminal policy part.

[0164] Table 2

[0165]

[0166] Furthermore, each group of policy information is uniquely identified by the UPSC. As shown in Table 3, Table 3 is a group of terminal policy information.

[0167] Table 3

[0168]

[0169] In Table 3, the UPSC includes the binary encoding of the UPSC, and the value of the UPSC is set by the PCF network element.

[0170] Next, each group of policy information contains different types of UE policies, such as slice policies, session policies and other types of UE policies, as shown in Table 4. Taking the inclusion of UE policy part1~N as an example, Table 4 is the content of the terminal policy part.

[0171] Table 4

[0172]

[0173] Furthermore, in order to distinguish different types of policy information, it is indicated by a terminal policy type, which occupies 4 bits, as shown in Table 5. Table 5 is a schematic representation of the columns of the content of the terminal policy part.

[0174] Table 5

[0175]

[0176] Finally, the specific content included in the terminal policy information is shown in Table 6. Table 6 is the 3GPP-non-3GPP interworking policy content.

[0177] Table 6

[0178]

[0179] In Table 6, the Data Network Name (DNN) is used to select the SMF and UPF for the PDU session and determine the interworking policy applied to this PDU session.

[0180] As can be seen from Table 6, the 3GPP-non-3GPP interworking policy contains n + 1 bytes. The first byte is the DNN flag. Different DNNs can correspond to different policy types. The specific policy information occupies 8 bits:

[0181] When bit 1 is set to 0, it means that the handover from ePDG to EPC is not supported. When it is set to 1, it means that the handover from ePDG to EPC is supported;

[0182] The Bit bit position set to 0 indicates that the handover from EPC to ePDG is not supported, and set to 1 indicates that the handover from ePDG to EPC is supported;

[0183] And so on, the remaining bit positions respectively represent different interworking scenarios, with a total of 8 interworking scenarios.

[0184] Exemplarily, the interworking policy sent by the PCF network element to the UE includes:

[0185] (1) The interworking policy information corresponding to PLMN 46011.

[0186] The PDU session with DNN as ims supports the handover between Epdg and EPC, as well as the handover between Epdg and 5GC. After receiving the policy information, the terminal can switch to VoWiFi during VoNR calls and also during VoLTE calls according to the indication of the information; the PDU session with DNN as ctnet does not support the handover between 3GPP and non-3GPP networks. The terminal should not switch the session connection to the wifi network after establishing a ctnet network connection in the cellular network.

[0187] (2) The interworking policy information corresponding to PLMN 46001.

[0188] The PDU session with DNN as ims supports the handover between Epdg and EPC, but does not support the handover between Epdg and 5GC. After receiving the policy information, the terminal cannot switch to VoWiFi during VoNR calls and needs to switch to VoLTE calls first and then switch to VoWiFi according to the indication of the information.

[0189] Then in one embodiment, the method further includes:

[0190] Receiving a policy update response sent by the UE; the policy update response is sent by the UE when the policy update is completed according to the 3GPP and non-3GPP interworking policies.

[0191] The policy update response can be generated when the UE updates the local initial 3GPP and non-3GPP interworking policies according to the 3GPP and non-3GPP interworking policies.

[0192] In one scenario, the UE updates the initial 3GPP and non-3GPP policy information in the local storage that is the same as the policy information type indication information according to the policy information type indication information in the 3GPP and non-3GPP interworking policies, generates a policy update response, and sends it to the PCF network element.

[0193] In the embodiments of the present application, through the interaction between the UE and the PCF network element, the 3GPP and non-3GPP interoperability policy information between the PCF network element and the UE is synchronized, avoiding the PCF network element from sending duplicate interoperability policy information to the UE, and reducing the communication burden to a certain extent.

[0194] In the foregoing embodiments, the PCF network element may send the 3GPP and non-3GPP interoperability policies to the UE through any reachable channel. That is to say, the PCF network element may send the 3GPP and non-3GPP interoperability policies in multiple ways. Based on this, through an embodiment below, an implementable way for the PCF network element to send the 3GPP and non-3GPP interoperability policies will be described.

[0195] In one embodiment, sending the 3GPP and non-3GPP interoperability policies to the UE includes:

[0196] Sending NAS information to the AMF network element, where the NAS information carries the 3GPP and non-3GPP interoperability policies, to instruct the AMF network element to send the 3GPP and non-3GPP interoperability policies to the UE.

[0197] In the embodiments of the present application, the PCF network element sends the 3GPP and non-3GPP interoperability policies to the AMF network element, instructing the AMF network element to send the 3GPP and non-3GPP interoperability policies to the UE.

[0198] Further, to improve the security of the interoperability policy transmission, the PCF network element encapsulates the 3GPP and non-3GPP interoperability policies to obtain Non-Access Stratum (NAS) information, and sends the NAS information to the AMF network element to instruct the AMF network element to transparently transmit the 3GPP and non-3GPP interoperability policies to the UE.

[0199] In the embodiments of the present application, through the communication channel of the PCF network element, the AMF network element, and the UE, it supports the PCF network element to send the 3GPP and non-3GPP interoperability policies. Such a communication method conforms to the transmission channels of each network element in the actual communication process, reducing the communication burden of the communication network to a certain extent. At the same time, the 3GPP and non-3GPP interoperability policies are encapsulated in the NAS information for transmission, improving the security of the 3GPP and non-3GPP interoperability policies during transmission.

[0200] In the foregoing embodiments, the triggering conditions for the PCF network element to send the 3GPP and non-3GPP interoperability policies to the UE are not limited. That is to say, in the actual scenario, there are multiple ways to trigger the PCF network element to send the 3GPP and non-3GPP interoperability policies. Based on this, through an embodiment below, a triggering method for the PCF network element to send the 3GPP and non-3GPP interoperability policies will be described.

[0201] In one embodiment, the method includes:

[0202] In response to a registration request carrying a 3GPP and non-3GPP interoperability policy request sent by the AMF network element, the interoperability policy is sent to the UE; the registration request is sent by the UE to the AMF network element.

[0203] Among them, the registration request is a request instruction sent by the UE to the core network for accessing the network. If the UE's registration request is approved, it means that the UE can access the 5G core network through the 3GPP network or the non-3GPP network, and naturally a session connection can be established between the UE and the 5G core network.

[0204] The UE carries the 3GPP and non-3GPP policy requests in the registration request and sends them to the AMF network element, and the AMF network element sends the registration request to the PCF network element to instruct the PCF network element to send the 3GPP and non-3GPP interoperability policies to the UE.

[0205] In response to the registration request sent by the AMF network element, the PCF network element sends the 3GPP and non-3GPP interoperability policies to the UE through any reachable channel.

[0206] In the embodiment of the present application, the UE sends a policy request to the PCF network element through the AMF network element, and the PCF network element sends the 3GPP and non-3GPP interoperability policies to the UE in response to the policy request. It is equivalent to that the PCF sends the 3GPP and non-3GPP interoperability policies to the UE according to the UE's policy request. Such an interaction method enables the UE to timely learn the 3GPP and non-3GPP interoperability policies.

[0207] In the scenario of network handover, when the PCF network element sends the 3GPP and non-3GPP interoperability policies to the UE, then before the PCF network element sends the 3GPP and non-3GPP interoperability policies, the PCF network element naturally also needs to obtain the 3GPP and non-3GPP interoperability policies first. Based on this, the steps for the PCF network element to obtain the 3GPP and non-3GPP interoperability policies will be described through an embodiment below.

[0208] In one embodiment, before sending the 3GPP and non-3GPP interoperability policies to the UE, the method further includes:

[0209] In the case where the PCF network element is the home PCF network element, receive the 3GPP and non-3GPP interoperability policies sent by the UDM network element.

[0210] Among them, the Unified Data Management (UDM) network element is responsible for the management of user identities, subscribed data, authentication data, and the registration management of the user's serving network elements. The UDM network element in the embodiments of this application is the UDM network element under the home operator of the UE, and is used to provide 3GPP and non-3GPP interworking policies to the UE through the PCF network element.

[0211] Since the UE is usually mobile, it means that the UE can provide services in its home location, such as call services, or may provide call services in a non-home location, that is, roaming.

[0212] Then when the UE provides service in its home location, the UE provides services through a session connection in its home location, and the home PCF network element establishes communication with the UE. In this case, the home PCF directly receives the 3GPP and non-3GPP interworking policies sent by the UDM network element.

[0213] The embodiments of this application provide a downlink transmission channel including the UDM, the home PCF network element, and the UE. The 3GPP and non-3GPP interworking policies sent by the UDM network element are sent down to the UE through the home PCF, so that the UE can timely learn the ability to support switching between multiple different networks for the session connection, and then decide whether to switch the session connection to avoid service interruption.

[0214] In the foregoing embodiments, the content of the home PCF network element obtaining the 3GPP and non-3GPP interworking policies when the UE provides service in its home location is described. The following describes the steps for the roaming PCF network element to obtain the 3GPP and non-3GPP interworking policies when the UE provides service in a non-home location through an embodiment parallel to the above embodiments.

[0215] Then in one embodiment, before sending the 3GPP and non-3GPP interworking policies to the UE, the method further includes:

[0216] When the PCF network element is a roaming PCF network element, receiving the 3GPP and non-3GPP interworking policies sent by the home PCF network element; the 3GPP and non-3GPP interworking policies of the home PCF network element are sent by the UDM network element.

[0217] The UE does not provide services through a session connection in its home location, and the roaming PCF network element establishes communication with the UE. In this case, the UDM network element sends the 3GPP and non-3GPP interworking policies to the home PCF network element, and then the home PCF network element sends the 3GPP and non-3GPP interworking policies to the roaming PCF network element.

[0218] In the embodiment of the present application, the UDM network element distributes the 3GPP and non-3GPP interoperability policies to the home PCF network element, and then the home PCF network element distributes the 3GPP and non-3GPP interoperability policies to the roaming PCF network element, and then the roaming PCF network element distributes the 3GPP and non-3GPP interoperability policies to the UE. In the roaming state, a downlink transmission channel including the UDM network element, the home PCF network element, the roaming PCF network element, and the UE is provided, so that the UE can timely learn whether the session connection supports switching between multiple different networks, and then decide whether to switch the session connection to avoid service interruption.

[0219] Combining the above two embodiments, it can be seen that when the UE is roaming, the roaming PCF network element receives the 3GPP and non-3GPP interoperability policies sent by the UDM network element through the home PCF network element; when the UE is not roaming, the home PCF network element receives the interoperability policies sent by the UDM network element. It is equivalent to determining the type of the PCF network element communicating with the UE according to whether the UE is roaming, and for different types of PCF network elements, the ways of receiving the 3GPP and non-3GPP interoperability policies are correspondingly provided and sent to the UE, which means that the UE can learn the networks that the session connection supports switching in both roaming and non-roaming cases.

[0220] The above is the description of the related embodiments on the side of the PCF network element as the execution subject. The embodiment of the present application also provides an embodiment corresponding to the above process with the UE as the execution subject on this basis. Since all the implementation principles, detailed processes, and achievable technical effects of the following embodiments with the UE as the execution subject are the same as those of the above embodiments with the PCF network element as the execution subject, for the sake of simplicity and clarity, the following embodiments will not be described in detail one by one, and the implementation processes and implementation effects of each embodiment can refer to the descriptions of the foregoing embodiments.

[0221] Then as Figure 3 shown, the embodiment of the present application provides a network switching method applied to the UE. The method includes:

[0222] S301, receiving the 3GPP and non-3GPP interoperability policies sent by the PCF network element.

[0223] S302, determining whether to switch the session connection between the 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policies.

[0224] Among them, the 3GPP and non-3GPP interoperability policies are used to indicate whether the session connection supports switching between the 3GPP and non-3GPP networks. The session connection includes a PDU session or a PDN connection.

[0225] In the embodiments of the present application, the UE communicates with the PCF network element through the session connection established with the core network, specifically by receiving the 3GPP and non-3GPP interworking policies sent by the PCF network element.

[0226] When the UE receives the 3GPP and non-3GPP interworking policies sent by the PCF network element, it decides whether to switch the session connection between the 3GPP and non-3GPP networks by parsing the content of the 3GPP and non-3GPP interworking policies.

[0227] In the embodiments of the present application, the UE receives the 3GPP and non-3GPP interworking policies sent by the PCF network element, and determines whether to switch the session connection between the 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interworking policies. In this method, the content indicated by the 3GPP and non-3GPP interworking policies sent by the PCF network element to the UE is whether the session connection supports switching between multiple different networks, so that the UE can know which networks can be switched and which networks cannot be switched before switching the network. Further, the UE decides to switch the session connection to a suitable network based on this 3GPP and non-3GPP interworking policy to maintain the continuity of the UE's current session connection.

[0228] The 3GPP and non-3GPP interworking policies sent by the PCF network element to the UE may include session switching policy description information, DNN information corresponding to the session switching policy, or policy information type indication information, or PLMN information corresponding to the 3GPP and non-3GPP interworking policies. Correspondingly, after the UE receives the 3GPP and non-3GPP interworking policies, it can decide whether to adopt the 3GPP and non-3GPP interworking policies according to the information in the 3GPP and non-3GPP interworking policies and make a response, etc.

[0229] The following describes the corresponding response scenarios when the UE makes corresponding responses according to different policy information in the 3GPP and non-3GPP interworking policies.

[0230] In one embodiment, the 3GPP and non-3GPP interworking policy includes policy information type indication information, and the method further includes:

[0231] Save the 3GPP and non-3GPP interworking policy to the local according to the policy information type indication information for policy information update.

[0232] The policy information type indication information in the embodiments of the present application carries the policy type indication that the policy is about the interworking policy between the 3GPP and non-3GPP networks.

[0233] After receiving the 3GPP and non-3GPP interoperability policies, the UE replaces the content of the initial 3GPP and non-3GPP interoperability policies with the content of the latest received 3GPP and non-3GPP interoperability policies according to the policy information type indication information, so as to implement the information update of the initial 3GPP and non-3GPP interoperability policies.

[0234] In the embodiment of the present application, the UE updates the initially saved 3GPP and non-3GPP interoperability policies locally according to the policy information type indication information, avoiding conflicts between the UE's local initial 3GPP and non-3GPP interoperability policies and the new 3GPP and non-3GPP interoperability policies sent by the PCF network element, and maintaining the effectiveness of the UE's local 3GPP and non-3GPP interoperability policies.

[0235] After the UE saves the 3GPP and non-3GPP interoperability policies sent by the PCF network element, it can also feedback the result to the PCF network element to maintain the consistency between the 3GPP and non-3GPP interoperability policies sent by the PCF network element and the 3GPP and non-3GPP interoperability policies saved locally by the UE.

[0236] In one embodiment, when the policy update is completed according to the 3GPP and non-3GPP interoperability policies, a policy update response is sent to the PCF network element.

[0237] The UE updates the initial 3GPP and non-3GPP policies in the local storage that are the same as the policy information type indication information according to the policy information type indication information in the 3GPP and non-3GPP interoperability policies, generates a policy update response, and sends it to the PCF network element.

[0238] In the embodiment of the present application, through the interaction between the UE and the PCF network element, the interoperability policy information between the PCF network element and the UE is synchronized, avoiding the PCF network element from sending duplicate interoperability policy information to the UE, and reducing the communication burden to a certain extent.

[0239] The foregoing embodiments illustrate the steps for the UE to respond according to the policy information type indication information in the 3GPP and non-3GPP interoperability policies. In practical applications, the 3GPP and non-3GPP interoperability policies can be policies under different operators in different regions. Then, the 3GPP and non-3GPP interoperability policies can also include home PLMN information and non-home PLMN information, so that the UE can judge the effectiveness of the 3GPP and non-3GPP interoperability policy information according to the PLMN information of each different policy in the 3GPP and non-3GPP interoperability policy information, and determine whether to adopt the policy information of the 3GPP and non-3GPP interoperability policies. Based on this, through an embodiment below, another response scenario of the UE to the 3GPP and non-3GPP interoperability policies is illustrated.

[0240] In one embodiment, as Figure 4 shown, the 3GPP and non-3GPP interworking policy includes PLMN information, and the method further includes:

[0241] S401, obtain the current PLMN network to which the UE is currently attached.

[0242] Obtain the PLMN information of the network to which the current UE is attached, and then, according to the PLMN information of the current network, determine and select the corresponding policy information from the 3GPP and non-3GPP interworking policies.

[0243] S402, if the PLMN network accessed by the current 3GPP and the PLMN network accessed by the non-3GPP belong to the same PLMN, determine that the 3GPP and non-3GPP interworking policy corresponding to the PLMN can be applied to the current network.

[0244] It should be noted that, in the case where it is determined that the 3GPP and non-3GPP interworking policy corresponding to the current 3GPP-accessed PLMN network can be applied to the current network, the UE can choose to switch the session connection according to the 3GPP and non-3GPP interworking policy, or can also not perform the switch.

[0245] In the embodiment of the present application, the UE determines the effectiveness of the 3GPP and non-3GPP interworking policy information according to the PLMN information in the 3GPP and non-3GPP interworking policy information, and determines the handover policy that matches the current access network, so as to facilitate the UE to select a more suitable network for the session connection.

[0246] In one scenario, the UE determines to switch the network according to the 3GPP and non-3GPP interworking policy information, which requires that the 3GPP and non-3GPP interworking policy includes multiple candidate access networks and the handover capabilities between different networks.

[0247] In one embodiment, as Figure 5 shown, the 3GPP and non-3GPP interworking policy includes session handover policy description information, and the method further includes:

[0248] S501, determine the target handover network according to the session handover policy description information.

[0249] Among them, the session handover policy description information is used to indicate whether the session connection can be mutually handed over between different networks. The UE determines, according to the session handover policy description information, between which networks the session connection supports handover, and between which networks the session connection does not support handover.

[0250] In one embodiment, the session handover policy description information includes at least one of the following:

[0251] Whether the session connection supports switching between the EPDG network and the EPC network;

[0252] Whether the session connection supports switching between the N3IWF network and the EPC network;

[0253] Whether the session connection supports switching between the EPDG network and the 5GC network;

[0254] Whether the session connection supports switching between the N3IWF network and the 5GC network.

[0255] The description of the session switching policy description information here is the same as that in the above embodiment with the PCF network element as the execution entity side. For details, please refer to the description of the foregoing embodiments and will not be repeated here.

[0256] In another scenario, the session switching policy description information is used to indicate whether the session connection can switch from one network to another network. That is, on the basis of the session switching policy description information, the switching direction of the network is further clarified. The UE determines, according to the session switching policy description information, from which network the session connection can be switched to another network and from which network the session connection cannot be switched to another network.

[0257] In one embodiment, the session switching policy description information includes at least one of the following:

[0258] Whether the session connection supports switching from the EPDG network to the EPC network;

[0259] Whether the session connection supports switching from the EPC network to the EPDG network;

[0260] Whether the session connection supports switching from the N3IWF network to the EPC network;

[0261] Whether the session connection supports switching from the EPC network to the N3IWF network;

[0262] Whether the session connection supports switching from the EPDG network to the 5GC network;

[0263] Whether the session connection supports switching from the 5GC network to the EPDG network;

[0264] Whether the session connection supports switching from the N3IWF network to the 5GC network;

[0265] Whether the session connection supports switching from the 5GC network to the N3IWF network.

[0266] The description of the session switching policy description information here is the same as that in the above embodiment with the PCF network element as the execution entity side. For details, please refer to the description of the foregoing embodiments and will not be repeated here.

[0267] S502, switch the session connection to the target switching network.

[0268] In the embodiments of the present application, considering the interaction between multiple networks under the 3GPP access network and multiple networks under the non-3GPP access network, and the switching between the 3GPP access network and the non-3GPP access network is directional, the UE determines the switching capabilities between networks through the session switching policy description information in the 3GPP and non-3GPP interoperability policies, and then determines a suitable network for switching.

[0269] In the foregoing embodiments, the triggering conditions for the PCF network element to send 3GPP and non-3GPP interoperability policies to the UE are not limited. That is to say, the UE can actively trigger the PCF network element to send 3GPP and non-3GPP interoperability policies and receive them, or the UE can passively receive the interoperability policies sent by the PCF network element. Based on this, through an embodiment below, an implementation manner for the UE to trigger the PCF network element to issue 3GPP and non-3GPP interoperability policies is described.

[0270] In one embodiment, before receiving the 3GPP and non-3GPP interoperability policies sent by the PCF network element, the method further includes:

[0271] Send a registration request carrying a 3GPP and non-3GPP interoperability policy request to the AMF network element; the registration request is used to instruct the AMF network element to send 3GPP and non-3GPP interoperability policies to the PCF network element.

[0272] The registration request sent by the UE to the core network requests to access the core network. If the UE's registration request is approved, the UE can access the core network through different access network methods and establish a session connection with the core network.

[0273] It should be known that due to different access network methods, the UE can have multiple different types of session connections. For example, the UE accesses the 5GC network through a PDU session, and the UE accesses the EPS network through a PDN connection. Moreover, due to the diversification of the services accessed by the UE, the number of session connections corresponding to the UE can also be multiple.

[0274] The UE carries the 3GPP and non-3GPP interoperability policy request in the registration request and sends it to the PCF network element through the AMF network element to instruct the PCF network element to issue the 3GPP and non-3GPP interoperability policies in the registration request to the UE.

[0275] In the embodiments of the present application, the UE sends a registration request to the PCF network element through the AMF network element, and the PCF network element, in response to the registration request, sends 3GPP and non-3GPP interworking policies to the UE. That is, the PCF sends 3GPP and non-3GPP interworking policies to the UE according to the UE's registration request, which to a certain extent avoids resource waste caused by the PCF repeatedly sending 3GPP and non-3GPP interworking policies, and at the same time enables the UE to timely learn about 3GPP and non-3GPP interworking policies.

[0276] During the downlink transmission of 3GPP and non-3GPP interworking policies, multiple communication nodes are involved. At this time, in order to improve the comprehensiveness and security of 3GPP and non-3GPP interworking policy information, the 3GPP and non-3GPP interworking policies can be encapsulated.

[0277] Then in one embodiment, the method further includes:

[0278] Receiving NAS information sent by the PCF network element through the AMF network element; the NAS information carries 3GPP and non-3GPP interworking policies.

[0279] The PCF network element encapsulates the 3GPP and non-3GPP interworking policies to obtain NAS information, and sends the NAS information to the AMF network element to instruct the AMF network element to transparently transmit the interworking policies to the UE.

[0280] In the embodiments of the present application, through the communication channel of the PCF network element, the AMF network element, and the UE, it supports the PCF network element to send 3GPP and non-3GPP interworking policies. Such a communication method conforms to the transmission channels of each network element in the actual communication process, and to a certain extent reduces the communication burden on the communication network. At the same time, the 3GPP and non-3GPP interworking policies are encapsulated in the NAS information for transmission, which improves the security of the 3GPP and non-3GPP interworking policies during transmission.

[0281] In one embodiment, Figure 6 Provide a signaling interaction flowchart of a network switching method. Figure 6 The shown signaling interaction flowchart involves the UE, the AMF network element, and the PCF network element. In the case where the network environment where the UE is located changes and the UE switches the network for a service session, the network switching method provided by the embodiments of the present application includes the following steps:

[0282] S601, Obtain 3GPP and non-3GPP interworking policies.

[0283] S602, The PCF network element encapsulates the 3GPP and non-3GPP interworking policies into NAS information and sends it to the AMF network element.

[0284] Specifically, the PCF network element encapsulates the 3GPP and non-3GPP interworking policies in the NAS information and sends them to the AMF network element through the N1 / N2 interface.

[0285] S603, the AMF transparently forwards the NAS information to the UE.

[0286] When the UE is in a 3GPP access or non-3GPP access and connection established situation, the AMF transparently transmits the NAS information to the UE through any reachable channel.

[0287] S604, the UE updates the policy information and sends a policy update response to the AMF network element.

[0288] S605, the AMF network element sends the policy update response sent by the UE to the PCF network element.

[0289] The network switching method provided by the embodiments of this application can solve the problem that the network does not support switching and causes the UE switching to fail during the process of VoWiFi to cellular handover and cellular to VoWiFi handover by the PCF network element sending the interworking policy to the UE, and is compatible with different heterogeneous network combinations. In addition, the non-3GPP and 3GPP interworking policies provided by the embodiments of this application include various scenarios such as 4G / 5G and Epdg / N3IWF interworking. On this basis, the UE can send different handover policies according to different PDU sessions, so that the UE can implement different handover policies according to different visited networks.

[0290] In one embodiment, the network switching method includes the following steps:

[0291] (1) The UE sends a registration request carrying a 3GPP and non-3GPP interworking policy request to the AMF network element.

[0292] (2) The AMF network element sends a registration request carrying a 3GPP and non-3GPP interworking policy to the PCF network element.

[0293] (3) The PCF network element encapsulates the 3GPP and non-3GPP interworking policies into the NAS information and sends them to the AMF network element.

[0294] (4) The AMF network element sends the NAS information carrying a 3GPP and non-3GPP interworking policy to the UE.

[0295] (5) When the UE completes the policy update according to the 3GPP and non-3GPP interworking policies, the UE sends a policy update response to the AMF network element.

[0296] At the same time, after receiving the interworking policy, the UE saves it locally and replaces the existing initial 3GPP and non-3GPP interworking policies of the same type.

[0297] When the UE applies the policy information sent by the network, the UE obtains the PLMN information of the current network, and determines that the corresponding interoperability policy takes effect when the 3GPP and non-3GPP networks belong to the same PLMN.

[0298] Furthermore, the UE may also determine a target switching network according to the 3GPP and non-3GPP interoperability policy, and decide whether to switch a session to the target switching network.

[0299] (6) The AMF network element sends a policy update response to the PCF network element.

[0300] In an embodiment of the present application, the PCF network element sends a 3GPP and non-3GPP interoperability policy to the UE, and the 3GPP and non-3GPP interoperability policy is used to instruct the UE to decide whether to switch the session connection between the 3GPP and non-3GPP networks. In this method, the interoperability policy sent by the PCF network element to the UE indicates whether the session connection supports switching between multiple different networks, so that the UE can know which networks can be switched and which networks cannot be switched before switching networks. Furthermore, based on this 3GPP and non-3GPP interoperability policy, the UE decides to switch the session connection to an appropriate network to maintain the continuity of the UE's current session connection.

[0301] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0302] In one embodiment, Figure 7 As shown, a network switching device is provided, including: a policy sending module 701, wherein:

[0303] The policy sending module 701 is used to send the 3GPP and non-3GPP interoperability policy to the UE; the 3GPP and non-3GPP interoperability policy is used by the UE to decide whether to switch the session connection between the 3GPP and non-3GPP networks.

[0304] In one embodiment, the 3GPP and non-3GPP interworking policy includes at least one of session handover policy description information, DNN information corresponding to the session handover policy, policy information type indication information, and public land mobile network (PLMN) information corresponding to the 3GPP and non-3GPP interworking policy.

[0305] In one embodiment, the session handover policy description information includes at least one of the following:

[0306] Whether the session connection supports handover between the EPDG network and the EPC network;

[0307] Whether the session connection supports handover between the N3IWF network and the EPC network;

[0308] Whether the session connection supports handover between the EPDG network and the 5GC network;

[0309] Whether the session connection supports handover between the N3IWF network and the 5GC network.

[0310] In one embodiment, the session handover policy description information includes at least one of the following:

[0311] Whether the session connection supports handover from the EPDG network to the EPC network;

[0312] Whether the session connection supports handover from the EPC network to the EPDG network;

[0313] Whether the session connection supports handover from the N3IWF network to the EPC network;

[0314] Whether the session connection supports handover from the EPC network to the N3IWF network;

[0315] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0316] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0317] Whether the session connection supports handover from the N3IWF network to the 5GC network;

[0318] Whether the session connection supports handover from the 5GC network to the N3IWF network.

[0319] In one embodiment, the DNN information includes the session connection corresponding to the DNN to which the 3GPP and non-3GPP interworking policy applies.

[0320] In one embodiment, the PLMN information includes home PLMN information and non-home PLMN information.

[0321] In one embodiment, the network switching device further includes a response receiving module, configured to receive a policy update response sent by a UE; the policy update response is sent by the UE when the UE completes policy update according to the 3GPP and non-3GPP interoperability policy.

[0322] In one embodiment, the policy sending module 701 further includes an information sending unit, configured to send NAS information to an AMF network element, where the NAS information carries the 3GPP and non-3GPP interoperability policy, so as to instruct the AMF network element to send the 3GPP and non-3GPP interoperability policy to the UE.

[0323] In one embodiment, the network switching device further includes a request response module, configured to, in response to a registration request sent by the AMF network element and carrying a 3GPP and non-3GPP interoperability policy request, send down the 3GPP and non-3GPP interoperability policy to the UE; the registration request is sent by the UE to the AMF network element.

[0324] In one embodiment, the network switching device further includes a first receiving module, configured to receive the 3GPP and non-3GPP interoperability policy sent by a UDM network element when the PCF network element is a home PCF network element.

[0325] In one embodiment, the network switching device further includes a second receiving module, configured to receive the 3GPP and non-3GPP interoperability policy sent by a home PCF network element when the PCF network element is a roaming PCF network element; the 3GPP and non-3GPP interoperability policy of the home PCF network element is sent by a UDM network element.

[0326] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0327] In one embodiment, as Figure 8 shown, a network switching device is provided, including: a policy receiving module 801 and a policy determining module 802, where:

[0328] The policy receiving module 801 is configured to receive the 3GPP and non-3GPP interoperability policy sent by a PCF network element;

[0329] The policy determining module 802 is configured to determine whether to switch the session connection between the 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policy.

[0330] In one embodiment, the network switching device further includes a policy update module, configured to save the 3GPP and non-3GPP interoperability policy to the local according to the policy information type indication information, and update the initial interoperability policy with the same policy information type indication information.

[0331] In one embodiment, the network switching device further includes a response sending module, configured to send a policy update response to the PCF network element when the policy update is completed according to the 3GPP and non-3GPP interoperability policy.

[0332] In one embodiment, the network switching device further includes a third receiving module and a policy determination module, where:

[0333] An information receiving module, configured to obtain the current PLMN network to which the UE is currently attached;

[0334] A policy determination module, configured to determine that the 3GPP and non-3GPP interoperability policy corresponding to the PLMN network can be applied to the current network if the PLMN network accessed by the current 3GPP is the same as the PLMN network accessed by the non-3GPP.

[0335] In one embodiment, the network switching device further includes a network determination module and a network switching module, where:

[0336] A network determination module, configured to determine a target switching network according to the session switching policy description information;

[0337] A network switching module, configured to switch the session connection to the target switching network.

[0338] In one embodiment, the session switching policy description information includes at least one of the following:

[0339] Whether the session connection supports switching between the EPDG network and the EPC network;

[0340] Whether the session connection supports switching between the N3IWF network and the EPC network;

[0341] Whether the session connection supports switching between the EPDG network and the 5GC network;

[0342] Whether the session connection supports switching between the N3IWF network and the 5GC network.

[0343] In one embodiment, the session switching policy description information includes at least one of the following:

[0344] Whether the session connection supports switching from the EPDG network to the EPC network;

[0345] Whether the session connection supports switching from the EPC network to the EPDG network;

[0346] Whether the session connection supports switching from the N3IWF network to the EPC network;

[0347] Whether the session connection supports switching from the EPC network to the N3IWF network;

[0348] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0349] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0350] Whether the session connection supports handover from the N3IWF network to the 5GC network;

[0351] Whether the session connection supports handover from the 5GC network to the N3IWF network.

[0352] In one embodiment, the network handover device further includes a request sending module, configured to send a registration request carrying a 3GPP and non-3GPP interworking policy request to the AMF network element; the registration request is used to instruct the AMF network element to send a 3GPP and non-3GPP interworking policy to the PCF network element.

[0353] In one embodiment, the network handover device further includes a third receiving module, configured to receive NAS information sent by the PCF network element through the AMF network element; the NAS information carries a 3GPP and non-3GPP interworking policy.

[0354] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0355] For the specific limitations of the network handover device, reference can be made to the limitations on the network handover method in the foregoing text, which will not be elaborated here. Each module in the foregoing network handover device can be implemented in whole or in part by software, hardware, and their combination. The foregoing modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory of the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the foregoing modules.

[0356] Figure 9Schematic diagram of the communication device 900 provided by the embodiment of the present application. The communication device 900 may be a PCF network element device, including a receiver 901, a memory 902, a processor 903, at least one communication bus 904, and a transmitter 905. The communication bus 904 is used to implement communication connections between components. The memory 902 may contain a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk memory. Various programs may be stored in the memory 902 to complete various processing functions and implement the method steps of this embodiment. In this embodiment, the transmitter 905 may be a radio frequency processing module or a baseband processing module in the PCF network element device, and the receiver 901 may also be a radio frequency processing module or a baseband processing module in the PCF network element device. The transmitter 905 and the receiver 901 may be integrated together to form a transceiver. Both the transmitter 905 and the receiver 901 may be coupled to the processor 903, and may perform receive or transmit operations under the instruction or control of the processor 903.

[0357] In the embodiment of the present application, the transmitter 905 is used to send 3GPP and non-3GPP interoperability policies to the UE; the 3GPP and non-3GPP interoperability policies are used for the UE to determine whether to switch the session connection between 3GPP and non-3GPP networks.

[0358] In one embodiment, the 3GPP and non-3GPP interoperability policies include at least one of session handover policy description information, DNN information corresponding to the session handover policy, policy information type indication information, and public land mobile network PLMN information corresponding to the 3GPP and non-3GPP interoperability policies.

[0359] In one embodiment, the session handover policy description information includes at least one of the following:

[0360] Whether the session connection supports switching between the EPDG network and the EPC network;

[0361] Whether the session connection supports switching between the N3IWF network and the EPC network;

[0362] Whether the session connection supports switching between the EPDG network and the 5GC network;

[0363] Whether the session connection supports switching between the N3IWF network and the 5GC network.

[0364] In one embodiment, the session handover policy description information includes at least one of the following:

[0365] Whether the session connection supports switching from the EPDG network to the EPC network;

[0366] Whether the session connection supports handover from the EPC network to the EPDG network;

[0367] Whether the session connection supports handover from the N3IWF network to the EPC network;

[0368] Whether the session connection supports handover from the EPC network to the N3IWF network;

[0369] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0370] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0371] Whether the session connection supports handover from the N3IWF network to the 5GC network;

[0372] Whether the session connection supports handover from the 5GC network to the N3IWF network.

[0373] In one embodiment, the PLMN information includes home PLMN information and non-home PLMN information.

[0374] In one embodiment, the DNN information includes session connections corresponding to DNNs for which the 3GPP and non-3GPP interworking policies apply.

[0375] In one embodiment, the receiver 901 is configured to receive a policy update response sent by the UE; the policy update response is sent by the UE when the UE completes policy update according to the 3GPP and non-3GPP interworking policies.

[0376] In one embodiment, the transmitter 905 is further configured to send NAS information to the AMF network element, where the NAS information carries the 3GPP and non-3GPP interworking policies, to instruct the AMF network element to send the 3GPP and non-3GPP interworking policies to the UE.

[0377] In one embodiment, the transmitter 905 is further configured to, in response to a registration request carrying a 3GPP and non-3GPP interworking policy request sent by the AMF network element, send down the 3GPP and non-3GPP interworking policies to the UE; the registration request is sent by the UE to the AMF network element.

[0378] In one embodiment, the receiver 901 is further configured to receive the 3GPP and non-3GPP interworking policies sent by the UDM network element when the PCF network element is the home PCF network element.

[0379] In one embodiment, the receiver 901 is further configured to receive the 3GPP and non-3GPP interworking policies sent by the home PCF network element when the PCF network element is a roaming PCF network element; the 3GPP and non-3GPP interworking policies of the home PCF network element are sent by the UDM network element.

[0380] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0381] Figure 10 FIG. is a schematic structural diagram of a communication device provided by an embodiment of the present invention, and the communication device may be a terminal. Figure 10 The illustrated communication device 1000 includes: at least one processor 1001, a memory 1002, and at least one network interface 1004. Each component in the communication device 1000 is coupled together through a bus system 1005. It can be understood that the bus system 1005 is used to implement the connection and communication between these components. In addition to the data bus, the bus system 1005 further includes a power bus, a control bus, and a status signal bus. However, for the sake of clear illustration, in Figure 10 all kinds of buses are labeled as the bus system 1005. In addition, in the embodiments of the present application, a transceiver 1003 is further included, and the transceiver may be multiple elements, that is, including a transmitter and a receiver, and provides a unit for communicating with various other devices on a transmission medium.

[0382] It can be understood that the memory 1002 in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM). The memory 702 of the systems and methods described in the embodiments of the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0383] In some embodiments, the memory 1002 stores the following elements, executable modules, or data structures, or subsets thereof, or extended sets thereof: an operating system 1002a. Among them, the operating system 1002a includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., for implementing various basic services and processing hardware-based tasks.

[0384] In the embodiments of the present invention, by calling the programs or instructions stored in the memory 1002, the receiver in the transceiver 1003 receives the interoperability policy sent by the PCF network element when the registration request is completed; the interoperability policy is used to indicate whether the session connection supports handover between multiple different networks.

[0385] Some or all of the methods disclosed in the embodiments of the present invention can also be applied to the processor 1001, or implemented by the processor 1001, or implemented in cooperation with other components (such as a transceiver) by the processor 1001. The processor 1001 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor 1001 or instructions in the form of software. The above-mentioned processor 1001 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 1002, and the processor 1001 reads the information in the memory 1002 and combines its hardware to complete the steps of the above method.

[0386] It can be understood that these embodiments described in the embodiments of the present invention can be implemented by hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or a combination thereof.

[0387] For software implementation, the techniques described in the embodiments of the present invention can be implemented by modules (such as procedures, functions, etc.) that execute the functions described in the embodiments of the present invention. The software code can be stored in a memory and executed by the processor 1001. The memory can be implemented inside or outside the processor 1001.

[0388] In one embodiment, a receiver is configured to receive 3GPP and non-3GPP interoperability policies sent by a PCF network element;

[0389] The processor 1001 is configured to determine whether to switch a session connection between 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policies.

[0390] In one embodiment, the processor 1001 is configured to save the 3GPP and non-3GPP interoperability policies locally according to the policy information type indication information, and update the policy information of the initial interoperability policy under the same policy information type indication information.

[0391] In one embodiment, a transmitter is configured to send a policy update response to the PCF network element when the policy update is completed according to the 3GPP and non-3GPP interoperability policies.

[0392] In one embodiment, the processor 1001 is further configured to obtain the current PLMN network to which the UE is currently attached;

[0393] The processor 1001 is further configured to determine that the 3GPP and non-3GPP interoperability policies corresponding to the PLMN network can be applied to the current network when the PLMN network accessed by the current 3GPP and the PLMN network accessed by the non-3GPP belong to the same PLMN.

[0394] In one embodiment, the processor 1001 is further configured to determine a target handover network according to the session handover policy description information;

[0395] The processor 1001 is further configured to switch the session connection to the target handover network.

[0396] In one embodiment, the session handover policy description information includes at least one of the following:

[0397] Whether the session connection supports handover between an EPDG network and an EPC network;

[0398] Whether the session connection supports handover between an N3IWF network and an EPC network;

[0399] Whether the session connection supports handover between an EPDG network and a 5GC network;

[0400] Whether the session connection supports handover between the N3IWF network and the 5GC network.

[0401] In one embodiment, the session handover policy description information includes at least one of the following:

[0402] Whether the session connection supports handover from the EPDG network to the EPC network;

[0403] Whether the session connection supports handover from the EPC network to the EPDG network;

[0404] Whether the session connection supports handover from the N3IWF network to the EPC network;

[0405] Whether the session connection supports handover from the EPC network to the N3IWF network;

[0406] Whether the session connection supports handover from the EPDG network to the 5GC network;

[0407] Whether the session connection supports handover from the 5GC network to the EPDG network;

[0408] Whether the session connection supports handover from the N3IWF network to the 5GC network;

[0409] Whether the session connection supports handover from the 5GC network to the N3IWF network.

[0410] In one embodiment, a transmitter is configured to send a registration request carrying a 3GPP and non-3GPP interworking policy request to an AMF network element; the registration request is used to instruct the AMF network element to send a 3GPP and non-3GPP interworking policy to a PCF network element.

[0411] In one embodiment, a receiver is configured to receive NAS information sent by a PCF network element through an AMF network element; the NAS information carries a 3GPP and non-3GPP interworking policy.

[0412] In one embodiment, the session connection includes a PDU session connection or a PDN connection.

[0413] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it implements any one of the method steps in the network handover methods in the foregoing embodiments.

[0414] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, it implements any one of the method steps in the network handover methods in the foregoing embodiments.

[0415] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0416] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0417] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A network switching method, characterized in that, applied to a Policy Control Function (PCF) network element, the method includes: sending a 3GPP and non-3GPP interoperability policy to the UE; the 3GPP and non-3GPP interoperability policy is used for the UE to decide whether to switch the session connection between 3GPP and non-3GPP networks.

2. The method according to claim 1, characterized in that, the 3GPP and non-3GPP interoperability policy includes at least one of session switching policy description information, data network name (DNN) information corresponding to the session switching policy, policy information type indication information, and public land mobile network (PLMN) information corresponding to the 3GPP and non-3GPP interoperability policy.

3. The method according to claim 2, characterized in that, the session switching policy description information includes at least one of the following: whether the session connection supports switching between an evolved packet data gateway (EPDG) network and an evolved packet core (EPC) network; whether the session connection supports switching between a non-3GPP interworking function (N3IWF) network and the EPC network; whether the session connection supports switching between the EPDG network and a 5th generation mobile communication core network (5GC) network; whether the session connection supports switching between the N3IWF network and the 5GC network.

4. The method according to claim 2, characterized in that, the session switching policy description information includes at least one of the following: whether the session connection supports switching from the EPDG network to the EPC network; whether the session connection supports switching from the EPC network to the EPDG network; whether the session connection supports switching from the N3IWF network to the EPC network; whether the session connection supports switching from the EPC network to the N3IWF network; whether the session connection supports switching from the EPDG network to the 5GC network; whether the session connection supports switching from the 5GC network to the EPDG network; whether the session connection supports switching from the N3IWF network to the 5GC network; whether the session connection supports switching from the 5GC network to the N3IWF network.

5. The method according to claim 2, characterized in that, the PLMN information includes home PLMN information and non-home PLMN information.

6. The method according to claim 2, characterized in that, the DNN information includes a session connection corresponding to the DNN applicable to the 3GPP and non-3GPP interoperability policy.

7. The method according to any one of claims 1-6, characterized in that, the method further includes: receiving a policy update response sent by the UE; the policy update response is sent when the UE completes policy update according to the 3GPP and non-3GPP interoperability policy.

8. The method according to any one of claims 1-6, characterized in that, sending the interoperability policy to the UE includes: Send non-access stratum (NAS) information to an Access and Mobility Management Function (AMF) network element, where the NAS information carries the 3GPP and non-3GPP interworking policy to instruct the AMF network element to send the 3GPP and non-3GPP interworking policy to the UE.

9. The method according to any one of claims 1-6, characterized in that, the method further includes: In response to a registration request carrying a 3GPP and non-3GPP interworking policy request sent by the AMF network element, send the 3GPP and non-3GPP interworking policy to the UE; the registration request is sent by the UE to the AMF network element.

10. The method according to any one of claims 1-6, characterized in that, Before sending the 3GPP and non-3GPP interworking policy to the UE, the method further includes: When the PCF network element is a home PCF network element, receive the 3GPP and non-3GPP interworking policy sent by the Unified Data Management (UDM) network element.

11. The method according to any one of claims 1-6, characterized in that, Before sending the 3GPP and non-3GPP interworking policy to the UE, the method further includes: When the PCF network element is a roaming PCF network element, receive the 3GPP and non-3GPP interworking policy sent by the home PCF network element; the 3GPP and non-3GPP interworking policy of the home PCF network element is sent by the UDM network element.

12. The method according to any one of claims 1-6, characterized in that, The session connection includes a Protocol Data Unit (PDU) session connection or a Public Data Network (PDN) connection.

13. A network handover method, characterized in that, applied to a UE, the method includes: Receive the 3GPP and non-3GPP interworking policy sent by the PCF network element; Determine whether to switch the session connection between 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interworking policy.

14. The method according to claim 13, characterized in that, The 3GPP and non-3GPP interworking policy includes policy information type indication information, and the method further includes: Save the 3GPP and non-3GPP interworking policy locally according to the policy information type indication information for policy information update.

15. The method according to claim 13, characterized in that, The method further includes: Send a policy update response to the PCF network element when the policy update is completed according to the 3GPP and non-3GPP interworking policy.

16. The method according to any one of claims 13-15, characterized in that, The 3GPP and non-3GPP interworking policy includes Public Land Mobile Network (PLMN) information, and the method further includes: Obtain the current PLMN network to which the UE is currently attached; If the PLMN network accessed by 3GPP currently and the PLMN network accessed by non-3GPP belong to the same PLMN, determine that the 3GPP and non-3GPP interworking policy corresponding to the PLMN network can be applied to the current network.

17. The method according to any one of claims 13-15, wherein, the 3GPP and non-3GPP interworking policy includes session handover policy description information, and the method further includes: determining a target handover network according to the session handover policy description information; switching the session connection to the target handover network.

18. The method according to claim 17, wherein, the session handover policy description information includes at least one of the following: whether the session connection supports handover between an EPDG network and an EPC network; whether the session connection supports handover between an N3IWF network and the EPC network; whether the session connection supports handover between the EPDG network and a 5GC network; whether the session connection supports handover between the N3IWF network and the 5GC network.

19. The method according to claim 17, wherein, the session handover policy description information includes at least one of the following: whether the session connection supports handover from an EPDG network to an EPC network; whether the session connection supports handover from the EPC network to the EPDG network; whether the session connection supports handover from an N3IWF network to the EPC network; whether the session connection supports handover from the EPC network to the N3IWF network; whether the session connection supports handover from the EPDG network to a 5GC network; whether the session connection supports handover from the 5GC network to the EPDG network; whether the session connection supports handover from the N3IWF network to the 5GC network; whether the session connection supports handover from the 5GC network to the N3IWF network.

20. The method according to any one of claims 13-15, wherein, before receiving the 3GPP and non-3GPP interworking policy sent by the PCF network element, the method further includes: sending a registration request carrying a 3GPP and non-3GPP interworking policy request to the AMF network element; the registration request is used to instruct the AMF network element to send the 3GPP and non-3GPP interworking policy to the PCF network element.

21. The method according to any one of claims 13-15, wherein, the method further includes: receiving NAS information sent by the PCF network element through the AMF network element; the NAS information carries the 3GPP and non-3GPP interworking policy.

22. The method according to any one of claims 13-15, wherein, the session connection includes a PDU session connection or a PDN connection.

23. A network handover device, wherein, the device includes: a policy sending module, configured to send a 3GPP and non-3GPP interworking policy to a UE; the 3GPP and non-3GPP interworking policy is used for the UE to determine whether to switch a session connection between 3GPP and non-3GPP networks.

24. A network handover device, wherein, the device includes: A policy receiving module, configured to receive 3GPP and non-3GPP interoperability policies sent by a PCF network element; A policy determining module, configured to determine whether to switch a session connection between 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policies.

25. A communication device, characterized in that, it includes: a transmitter; The transmitter is configured to send 3GPP and non-3GPP interoperability policies to a UE; the interoperability policies are used for the UE to determine whether to switch a session connection between 3GPP and non-3GPP networks.

26. A communication device, characterized in that, it includes: a receiver, a processor and a memory, where the memory stores a computer program; The receiver is configured to receive 3GPP and non-3GPP interoperability policies sent by a PCF network element; The processor executes the computer program to determine whether to switch a session connection between 3GPP and non-3GPP networks according to the 3GPP and non-3GPP interoperability policies.

27. A computer-readable storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 22.

28. A computer program product, including a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 22.

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