Roaming method, device and system

Abstract

The embodiment of the invention provides a roaming method, device and system. The method comprises: when a terminal device cannot access a first PLMN, the terminal device accesses a second PLMN, and a dynamic roaming protocol between the second PLMN and the first PLMN is activated; the terminal equipment receives indication information from the second PLMN, wherein the indication information is used for indicating that a dynamic roaming protocol between the second PLMN and the first PLMN is deactivated; and the terminal equipment sends an access request message to the first PLMN according to the indication information.

Description

[0001] This application is a divisional application. The application number of the original application is 201980103216.1, and the original application date is December 30, 2019. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The embodiments of the present application relate to the field of communication technology, and in particular, to a roaming method, device, and system. Background Art

[0003] In existing communication networks, when the Home Public Land Mobile Network (HPLMN) corresponding to a terminal device fails, the terminal device cannot access the HPLMN. Usually, there are other operator networks in the area where the HPLMN fails, but these operator networks may not have a roaming agreement with the HPLMN. In this case, current technology does not provide a method for terminal devices to access other operator networks. Summary of the invention

[0004] The embodiments of the present application provide a roaming method, apparatus and system, which enable the device to access other operator networks in the fault area when the HPLMN corresponding to the terminal device fails.

[0005] In a first aspect, an embodiment of the present application provides a roaming method including: when a terminal device cannot access a first PLMN, the terminal device accesses a second PLMN, and a dynamic roaming agreement between the second PLMN and the first PLMN is activated; the terminal device receives indication information from the second PLMN, and the indication information is used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; and the terminal device sends an access request message to the first PLMN according to the indication information.

[0006] In a possible implementation manner, the terminal device receives the indication information from the second PLMN, including: the terminal device receives a broadcast message from the second PLMN, where the broadcast message includes the indication information.

[0007] In a possible implementation manner, the broadcast message further includes identification information of the first PLMN and / or area information that does not allow the terminal device to access the second PLMN.

[0008] In a possible implementation manner, the method further includes: the terminal device deregistering in the second PLMN.

[0009] In a possible implementation manner, the terminal device receives the indication information from the second PLMN, including: the terminal device receives a deregistration request message from the second PLMN, the deregistration request message including the indication information.

[0010] In a possible implementation manner, the deregistration request message further includes area information that does not allow the terminal device to access the second PLMN.

[0011] In a possible implementation manner, the method further includes: before the terminal device accesses the second PLMN, the terminal device receives indication information from the second PLMN indicating that a dynamic roaming agreement between the second PLMN and the first PLMN is activated.

[0012] In a possible implementation manner, the method further includes: before the terminal device accesses the second PLMN, the terminal device obtains information of the second PLMN.

[0013] In a possible implementation, the information of the second PLMN further includes at least one of the following information: an access technology type allowing the terminal device to access the second PLMN, area information allowing the terminal device to access the second PLMN, and priority information of the second PLMN.

[0014] In a second aspect, an embodiment of the present application provides a roaming method including: when a terminal device cannot access a first PLMN, a core network element in a second PLMN obtains first indication information, wherein the first indication information is used to indicate activation of a dynamic roaming agreement between the second PLMN and the first PLMN; and the core network element sends the first indication information to the terminal device.

[0015] In a possible implementation manner, the core network network element obtaining the first indication information includes: the core network network element obtaining a first notification message, and the first notification message includes the first indication information.

[0016] In a possible implementation manner, the first notification message further includes information about the first PLMN, and the information about the first PLMN includes identification information of the first PLMN.

[0017] In a possible implementation, the first notification message further includes at least one of the following information: an access technology type allowing the terminal device to access the second PLMN, area information allowing the terminal device to access the second PLMN, and priority information of the second PLMN.

[0018] In a possible implementation, the method further includes: the core network element determines the access network device according to the area information allowing the terminal device to access the second PLMN, wherein the access network device is located in the area allowing the terminal device to access the second PLMN.

[0019] In a possible implementation, the core network element is an access management network element, and the core network element obtains the first notification message, including: the access management network element obtains the first notification message from the network management network element through the network open function network element in the second PLMN.

[0020] In a possible implementation, the method also includes: the core network network element obtains second indication information, and the second indication information is used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; the core network network element sends the second indication information to the terminal device through the access network device.

[0021] In a third aspect, an embodiment of the present application provides a communication device, comprising: a processing unit, used to connect the communication device to a second PLMN when the communication device cannot access the first PLMN, and the dynamic roaming agreement between the second PLMN and the first PLMN is activated; a receiving unit, used to receive indication information from the second PLMN, the indication information being used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; and a sending unit, used to send an access request message to the first PLMN according to the indication information.

[0022] In a possible implementation manner, the communication device may be a terminal device.

[0023] In a fourth aspect, an embodiment of the present application provides a communication device, comprising: a receiving unit, used to obtain first indication information when a terminal device cannot access a first PLMN, the first indication information being used to indicate activation of a dynamic roaming agreement between a second PLMN and the first PLMN, and the communication device being a device in the second PLMN; and a sending unit, used to send the first indication information to the terminal device.

[0024] In a possible implementation manner, the receiving unit is used to obtain a first notification message, where the first notification message includes the first indication information.

[0025] In a possible implementation manner, the first notification message further includes information about the first PLMN, and the information about the first PLMN includes identification information of the first PLMN.

[0026] In a possible implementation, the first notification message further includes at least one of the following information: an access technology type allowing the terminal device to access the second PLMN, area information allowing the terminal device to access the second PLMN, and priority information of the second PLMN.

[0027] In a possible implementation, the communication device further includes a processing unit, configured to determine the access network device according to the area information allowing the terminal device to access the second PLMN, wherein the access network device is located within the area allowing the terminal device to access the second PLMN.

[0028] In a possible implementation manner, the receiving unit is configured to obtain the first notification message from a network management network element through a network open function network element in the second PLMN.

[0029] In a possible implementation, the receiving unit is further used to obtain second indication information, where the second indication information is used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; the sending unit is further used to send the second indication information to the terminal device through the access network device.

[0030] In a possible implementation manner, the communication device may be a core network element, such as an access management network element.

[0031] In the present application, the second PLMN and the first PLMN have the same mobile country code, and the mobile network code of the second PLMN is different from the mobile network code of the first PLMN.

[0032] In the present application, the dynamic roaming agreement between the second PLMN and the first PLMN includes: if the terminal device can access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is deactivated; if the terminal device cannot access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is activated.

[0033] In the present application, the first PLMN is a home public land mobile network HPLMN, and the second PLMN is a visited public land mobile network VPLMN.

[0034] In a fifth aspect, the present application provides a communication device, comprising a processor, which reads computer-readable instructions stored in a memory so that the communication device executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect.

[0035] In a sixth aspect, the present application provides a communication device, comprising a processor, which reads computer-readable instructions stored in a memory so that the communication device executes the method in the above-mentioned second aspect or any possible implementation manner of the second aspect.

[0036] In a seventh aspect, the present application provides a communication system. The communication system includes the communication device in the fourth aspect or the sixth aspect and an access network device connected to the communication device. The communication device communicates with a terminal device through the access network device.

[0037] In an eighth aspect, the present application provides a computer-readable storage medium, comprising computer-readable instructions, which, when executed on a computer, enable the computer to execute any one of the methods in the first or second aspect above.

[0038] In a ninth aspect, the present application provides a computer program product, including a computer program, which, when executed on a computer, enables the computer to execute any one of the methods in the first or second aspect above.

[0039] In a tenth aspect, the present application provides a chip or a chip system. The chip or chip system includes at least one processor and a communication interface, the communication interface is coupled to the at least one processor, the processor is used to run a computer program or instruction to execute the method in the first aspect or any possible implementation of the first aspect, and the communication interface is used to communicate with other modules outside the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a scenario applicable to an embodiment of the present application;

[0041] Figure 2 A schematic diagram of a 5G network to which an embodiment of the present application is applicable;

[0042] Figure 3 is a schematic diagram of a roaming method according to an embodiment of the present application;

[0043] Figure 4 is a schematic diagram of another roaming method according to an embodiment of the present application;

[0044] Figure 5 is a schematic diagram of another roaming method according to an embodiment of the present application;

[0045] Figure 6 is a schematic diagram of another roaming method according to an embodiment of the present application;

[0046] Figure 7 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0047] Figure 8A schematic diagram of the structure of another communication device provided in an embodiment of the present application;

[0048] Fig. 9 A schematic diagram of the structure of a chip or chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish similar contents. For example, the first PLMN and the second PLMN are only used to distinguish different PLMNs, and do not limit their order. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0050] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0051] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art can appreciate that with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0052] In the present application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0053] In a communication network, if a terminal device wants to obtain services provided by the network, it needs to select a PLMN, reside in a suitable cell, and successfully complete the registration process. Among them, PLMN selection can be divided into two modes: automatic mode and manual mode according to the operation mode.

[0054] Automatic mode: The terminal device automatically tries the PLMN with the highest priority according to the priority order of each PLMN in the PLMN list. If successful, it selects a suitable cell in the PLMN to reside. If a high-priority PLMN selection fails, the terminal device tries the PLMN with the second priority until the terminal device can successfully register with a PLMN.

[0055] Manual mode: The terminal device will present a list of currently available PLMNs to the user (for example, in order of priority). The user selects the appropriate PLMN to access based on the presented list of PLMNs.

[0056] In the automatic mode, the PLMN selection can be divided into PLMN selection based on prior information and initial PLMN selection according to whether prior information exists.

[0057] PLMN selection based on prior information means that the terminal device records the most recent (e.g., current) registered PLMN (Registered PLMN, RPLMN). When the terminal device is turned on next time or returns to the coverage area, the RPLMN is selected with the highest priority. If the RPLMN is not available, the PLMN selection is performed according to the initial selection method.

[0058] Initial PLMN selection refers to the selection of a PLMN by a terminal device in the absence of prior information according to the various PLMNs and their priorities recorded in the Universal Subscriber Identity Module (USIM). In a possible implementation, these PLMNs may be arranged in descending order of priority as follows: (1) HPLMN; (2) Equivalent HPLMN (EHPLMN); (3) User Controlled PLMN; (4) Operator Controlled PLMN; (5) PLMN selected according to quality of service requirements; (6) Other PLMNs. User Controlled PLMN refers to a PLMN that a user of a terminal device can select according to preference. Operator Controlled PLMN refers to a PLMN that an operator stores the PLMNs of other operators that have signed a roaming agreement with the operator in the SIM card of the terminal device when making the SIM card. The terminal device may select the corresponding PLMN to access according to the stored PLMN. The PLMN selected according to the service quality requirement may be an indication information for indicating the terminal device to select the corresponding PLMN according to the service quality requirement, for example: selecting a network with a reference signal receiving power (RSRP) not less than -110dBm. If none of the above PLMNs (1) to (5) is accessible, the terminal device may select other accessible PLMNs.

[0059] If there are multiple optional PLMNs in the area where the terminal device is located, but the terminal device fails to register with each of the multiple optional PLMNs, these PLMNs will be set as prohibited PLMNs by the terminal device. For example: If the terminal device receives the reason information "PLMN not allowed", the terminal device will add the PLMN to the "forbidden PLMN" list in the SIM card.

[0060] Normally, if there is no roaming agreement between multiple operators in the same area, and a terminal device of a certain operator fails to access the PLMN of another operator without a roaming agreement, the terminal device will put the failed PLMN into the forbidden PLMN list. If the terminal device is in automatic network selection mode, the terminal device will not try to access any PLMN in the forbidden PLMN list. If the user subsequently tries to access the PLMN manually and the registration is successful, the terminal device will delete the PLMN in the forbidden PLMN list. In automatic network selection mode or manual network selection mode, once the forbidden PLMN list is generated, the PLMN in the forbidden PLMN list will not be automatically deleted even if the terminal device is turned off or the SIM card is removed.

[0061] See also Figure 1 , Figure 1 It is a schematic diagram of a scenario applicable to the embodiment of the present application. When the terminal device cannot access the first PLMN (for example, the first PLMN fails), the terminal device can access the second PLMN according to the dynamic roaming agreement between the first PLMN and the second PLMN.

[0062] In a possible implementation, the first PLMN is a HPLMN, and the second PLMN is a visited public land mobile network (Visited Land Mobile Network, VPLMN).

[0063] In a possible implementation manner, the first PLMN and the second PLMN have the same Mobile Country Code (MCC), and a Mobile Network Code (MNC) of the first PLMN is different from a Mobile Network Code of the second PLMN.

[0064] In various embodiments of the present application, a PLMN failure may refer to a PLMN failure in an area where a terminal device is located, and does not necessarily refer to a PLMN failure in the entire PLMN.

[0065] See also Figure 2 , Figure 2 It is a schematic diagram of a 5G network to which an embodiment of the present application is applicable. Figure 2 The 5G network in the embodiment adopts a service-oriented network architecture. The embodiments of the present application may also adopt other 5G network architectures, which are not limited here.

[0066] Figure 2The 5G network architecture shown includes: access network (AN) nodes, and multiple network function (NF) network elements. Among them, multiple NF network elements may include: user plane function (UPF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, policy control function (PCF) network element, network slice selection function (NSSF) network element, unified data management (UDM) network element, network repository function (NRF) network element, network exposure function (NEF) network element, data storage function network element (UDR), network management network element, etc. In addition, the network architecture may also include terminal equipment, data network (DN) nodes, application function (AF) network elements, etc.

[0067] In the example of the present application, the network management element may be an operation administration and maintenance (OAM) system. The OAM system may communicate with other NF elements through the NEF element. The OAM system may also communicate directly with other NF elements, which is not limited in the embodiment of the present application.

[0068] Figure 2 The network elements in the network can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform).

[0069] It should be noted that in the above Figure 2 The network architecture shown is only an example of the network elements included in the entire network architecture. In the embodiment of the present application, the network elements included in the network architecture are not limited. For example, in the embodiment of the present application, the network architecture may include the above-mentioned Figure 2 Any one or more of the network elements shown.

[0070] Among them, the terminal device is an electronic device with wireless communication function, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can be user equipment (UE), mobile phone, tablet computer (pad), computer with wireless transceiver function, virtual reality (VR) terminal device, augmented reality (AR) terminal device, wireless terminal device in industrial control, wireless terminal device in self driving, wireless terminal device in remote medical, wireless terminal device in smart grid, wireless terminal device in transportation safety, wireless terminal device in smart city, wireless terminal device in smart home, etc.

[0071] AN nodes can be devices that provide wireless access to UEs, including but not limited to evolved Node B (evolvednode B, eNB for short), wireless-fidelity access point (WiFiAP for short), worldwide interoperability for microwave access base station (WiMAX BS for short), base stations in 5G networks (e.g., gNodeB, gNB), etc. AN nodes can also be (radio access network, RAN) nodes or access nodes in subsequent evolved networks.

[0072] UPF network elements can process messages. For example, UPF can perform functions such as user data forwarding, routing, data statistics, rate limiting, and statistical reporting.

[0073] AMF network elements can perform mobility management in mobile networks, such as user location update, user registration network, user switching, etc. AMF network elements can access the UE's non-access stratum (NAS) signaling (including session management (SM) signaling) through the N1 interface, and can also access the RAN's signaling through the N2 interface to complete the user's registration process and the forwarding of SM signaling and mobility management. AMF network elements can forward messages between SMF network elements and UE.

[0074] SMF network elements can manage sessions in mobile networks, such as session establishment, session modification, and session release.

[0075] The PCF network element can manage user policies, including mobility-related policies, Protocol Data Unit (PDU) session-related policies, such as Quality of Service (QoS) policies, charging policies, etc.

[0076] NSSF network elements are used to select network slices. A network slice is a logically isolated network used to support specific network capabilities and network characteristics. It can include the entire network end-to-end (E2E), or some network functions can be shared in multiple network slices. It is a key technology to meet the network differentiation requirements of the fifth-generation 5G mobile communication technology proposed by 3GPP. Usually, the network characteristics of different network slices are not the same, and the network slices are required to be isolated from each other and not affect each other. For example, the network slices for augmented reality (AR) or virtual reality (VR) services require large bandwidth and low latency; the network slices for the Internet of Things (IOT) services require support for massive terminal access, but the bandwidth is small and there is no requirement for latency.

[0077] The UDM network element is responsible for managing the user's contract data and other information. The UDM network element can provide the user's contract data to network elements such as AMF and SMF.

[0078] The UDR network element stores structured data in the network, including user subscription data information and user policies. UDM can read terminal subscription data from UDR, and PCF can read user policy information from UDR. UDR can also be divided into two parts and merged with UDM and PCF network elements respectively, instead of being deployed independently.

[0079] The NRF network element stores the registration information of other functional network elements and provides mutual search and discovery services between network functional network elements based on this registration information.

[0080] NEF network elements are responsible for the authorization and control of the network's externally exposed services and capabilities. AF network elements located outside the operator's network can provide network data to the network through NEF network elements, and can also obtain the network's externally exposed services and data through NEF.

[0081] DN is used to provide data services to UE and can be the access destination of the user's PDU session. DN can be a PDN network, such as the Internet, IP Multimedia Service (IMS), etc.

[0082] AF network elements can send requests to influence SMF routing policies and are responsible for selecting and relocating applications in local DNs. AF mainly performs dynamic policy / billing control on forwarding plane behavior. These services require dynamic policy and billing control. AF transmits dynamic session information required by PCF.

[0083] In the embodiment of the present application, the first PLMN and the second PLMN may both adopt Figure 2 Of course, the first PLMN and the second PLMN may also adopt other network architectures, such as: Evolved Packet Core network (EPC) architecture or future evolved system architecture, which is not limited here.

[0084] See also Figure 3 , Figure 3 is a schematic diagram of a roaming method according to an embodiment of the present application. The roaming method includes:

[0085] 301. When a terminal device cannot access a first PLMN, a core network element in a second PLMN obtains first indication information, where the first indication information is used to indicate that a dynamic roaming agreement between the first PLMN and the second PLMN is activated.

[0086] In an embodiment of the present application, a dynamic roaming agreement is provided between the first PLMN and the second PLMN. In a possible implementation, a dynamic roaming agreement is provided between the first PLMN and the second PLMN, including: if the terminal device can access the first PLMN, the roaming agreement between the first PLMN and the second PLMN is deactivated; if the terminal device cannot access the first PLMN, the roaming agreement between the first PLMN and the second PLMN is activated. For example, the first PLMN may be the HPLMN of the terminal device, and the second PLMN may be the VPLMN of the terminal device.

[0087] If the terminal device can access the first PLMN, deactivation of the roaming agreement between the first PLMN and the second PLMN may mean that there is no roaming agreement between the first PLMN and the second PLMN, or the roaming agreement between the first PLMN and the second PLMN is unavailable.

[0088] If the terminal device cannot access the first PLMN, the activation of the roaming agreement between the first PLMN and the second PLMN means that a roaming agreement exists between the first PLMN and the second PLMN, or the roaming agreement between the first PLMN and the second PLMN is available.

[0089] It can be understood that: there is a temporary roaming agreement between the first PLMN and the second PLMN. When the terminal device can access the first PLMN, the temporary roaming agreement becomes invalid. When the terminal device cannot access the first PLMN, the temporary roaming agreement takes effect.

[0090] In another possible implementation, the first PLMN and the second PLMN have a dynamic roaming agreement, including: if a first condition is met, the roaming agreement between the first PLMN and the second PLMN is valid. The first condition may be that the first PLMN fails, or the terminal device cannot access the first PLMN.

[0091] In the present application, a dynamic roaming agreement may also be referred to as a temporary roaming agreement, which is not limited in the present application.

[0092] In the present application, the core network element is an access management element. When the first PLMN and the second PLMN adopt a 5G network architecture, the access management element may be an AMF element; when the first PLMN and the second PLMN adopt a 4G network architecture, the access management element may be a mobility management entity (MME). In the embodiment of the present application, the access management element is taken as an AMF element for example.

[0093] In a possible implementation, a core network element in the second PLMN obtains a first notification message, and the first notification message includes first indication information. When the core network element is an AMF element, the AMF element may obtain the first notification message from a network management element (e.g., an OAM element) through a network open function element in the second PLMN. The AMF element may also obtain the first notification message directly from the OAM element, which is not limited in the embodiments of the present application.

[0094] In one possible implementation, when a failure occurs in the first PLMN, the OAM system of the first PLMN may send an indication message to the OAM system of the second PLMN2 to indicate activation of the dynamic roaming agreement between the first PLMN and the second PLMN. In another possible implementation, the dynamic roaming agreement between the first PLMN and the second PLMN may be activated by the second PLMN. For example, when the second PLMN learns that a failure occurs in the first PLMN, the OAM system of the second PLMN decides to activate the dynamic roaming agreement between the first PLMN and the second PLMN.

[0095] In a possible implementation, the first notification message also includes information about the first PLMN. The information about the first PLMN may include identification information of the first PLMN. In this way, the terminal device can determine the PLMN that has a dynamic roaming agreement with the second PLMN. Specifically, the identification information of the first PLMN may be an identifier (identify, ID) of the first PLMN.

[0096] In a possible implementation, the first notification message also includes area information that allows the terminal device to access the second PLMN. Specifically, the area information may be a tracking area (TA) identifier list (TA list), which includes one or more tracking area identifiers. For example, the area information may be area information in the second PLMN that allows the terminal device to access the second PLMN in the area where the first PLMN fails. It can be understood that the area in the second PLMN that allows the terminal device to access the second PLMN overlaps with the area where the first PLMN fails, so that the terminal device located in the area where the first PLMN fails can be allowed to access the second PLMN without moving, thereby improving the service experience of the terminal device.

[0097] In a possible implementation, the first notification message may further include policy information for the terminal device to access the second PLMN. The policy information includes at least one of the following information: the type of access technology that allows the terminal device to access the second PLMN, and the priority information of the second VPLMN. Among them, the priority information of the second PLMN can be understood as the priority of the terminal device to access the second PLMN or the order in which the terminal device accesses the second PLMN among these multiple PLMNs when the terminal device attempts to access multiple PLMNs in sequence. The priority information of the second PLMN can also be referred to as the priority of the second PLMN in the terminal device network selection list, which is not limited here.

[0098] In a possible implementation, the access technology type allowing the terminal device to access the second PLMN includes a third generation partnership project (3rd Generation Partnership Project, 3GPP) access technology and / or a non-3GPP (Non-3GPP) access technology.

[0099] In a possible implementation, the priority information of the second PLMN includes that the priority of the second PLMN is lower than the priority of any of the following PLMNs: the priority of the first PLMN, the priority of the equivalent PLMN (EPLMN) of the first PLMN, the priority of the user controlled PLMN, and the priority of the operator controlled PLMN. When the terminal device attempts to access the PLMN, the network selection order of the terminal device is: (1) the first PLMN, (2) the equivalent PLMN of the first PLMN, (3) the user controlled PLMN, (4) the operator controlled PLMN, and (5) the second PLMN. That is, when the terminal device attempts to access (1) the first PLMN, (2) the equivalent PLMN of the first PLMN, (3) the user controlled PLMN, and (4) the operator controlled PLMN in sequence, but fails to access any of them successfully, the terminal device can try to access the second PLMN.

[0100] In another possible implementation, the priority information of the second PLMN includes that the priority of the second PLMN is higher than the priority of the PLMN selected by the user according to the service quality requirement, or the priority of the second PLMN is lower than the priority of the PLMN controlled by the operator and higher than the priority of the PLMN selected by the user according to the service quality requirement. When the terminal device cannot access the PLMN controlled by the operator, the terminal device can try to access the second PLMN. If the second PLMN cannot be accessed, the terminal device can try to access the PLMN selected by the user according to the service quality requirement.

[0101] In a possible implementation manner, when there are multiple second PLMNs, the priority information of the second PLMN may further include the priority of each second PLMN.

[0102] 302. The core network element sends the first indication information to the terminal device.

[0103] In a possible implementation, the core network element determines the access network device according to the area information that allows the terminal device to access the second PLMN. The access network device is located in the area that allows the terminal device to access the second PLMN. The core network element sends the first indication information to the terminal device through the determined access network device. Exemplarily, if the area that allows the terminal device to access the second PLMN contains multiple access network devices, the multiple access network devices can send broadcast messages to the terminal device at the same time.

[0104] In a possible implementation, the access network device sends a broadcast message to the terminal device. The broadcast message includes the first indication information. The broadcast message may also include identification information of the first PLMN. In this way, the terminal device can determine the PLMN that has a dynamic roaming agreement with the second PLMN.

[0105] In a possible implementation, the broadcast message further includes area information that allows the terminal device to access the second PLMN. For details of the area information, refer to the description of 301.

[0106] In a possible implementation, the broadcast message may further include policy information for the UE to access the second PLMN. For details of the policy information, refer to the description of 301.

[0107] 303. The terminal device accesses the second PLMN.

[0108] Specifically, the terminal device accesses the second PLMN according to the first indication information.

[0109] In a possible implementation, the terminal device may determine that the first PLMN is the HPLMN according to the identification information of the first PLMN included in the broadcast message. Then, the terminal device sends an access request message to the second PLMN according to the first indication information. The access request message may be a registration request message.

[0110] In a possible implementation, the terminal device sends an access request message to the second PLMN according to the received policy information for accessing the second PLMN. For example, the terminal device determines which access technology to select to send the access request message to the second PLMN according to the policy information. Another example is that the terminal device determines the priority of the second PLMN according to the policy information, and then sends the access request message to the second PLMN according to the priority of the second PLMN.

[0111] Through the above operations 301 to 303, when the first PLMN fails and the terminal device cannot access the first PLMN, the terminal device can access the second PLMN.

[0112] When the first PLMN recovers from a fault, the terminal device can re-access the first PLMN through the following operations 304 to 306.

[0113] 304. The core network element in the second PLMN obtains second indication information, where the second indication information is used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN.

[0114] In a possible implementation, the core network element in the second PLMN obtains a second notification message, where the second notification message includes the second indication information. The core network element obtains the second notification message in a manner similar to the manner in which the core network element obtains the first notification message, and the details are described in 301.

[0115] In one possible implementation, when the first PLMN fails, the OAM system of the first PLMN may send an indication message to the OAM system of the second PLMN to indicate the deactivation of the dynamic roaming agreement between the first PLMN and the second PLMN. In another possible implementation, the dynamic roaming agreement between the first PLMN and the second PLMN may be deactivated by the second PLMN. For example, when the second PLMN learns that the first PLMN fails, the OAM system of the second PLMN decides to deactivate the dynamic roaming agreement between the first PLMN and the second PLMN.

[0116] In a possible implementation, the second notification message further includes information about the first PLMN. The information about the first PLMN may include identification information of the first PLMN. In this way, the terminal device can determine that it cannot roam to the second PLMN.

[0117] In a possible implementation, the second notification message further includes area information that does not allow the terminal device to access the second PLMN. Specifically, the area information may be a tracking area identifier list (TA list), which includes one or more tracking area identifiers. For example, the area information may be area information in the second PLMN that does not allow the terminal device to access the second PLMN after the first PLMN fails and recovers.

[0118] It should be noted that, in step 302, the area information in the second PLMN that allows the terminal device to access the second PLMN can be completely identical, partially identical, or completely different from the area information in step 304 that does not allow the terminal device to access the second PLMN; for example, for the convenience of description, the area information in the second PLMN that allows the terminal device to access the second PLMN is referred to as the first area, and the first area includes a first tracking area identifier list; the area information that does not allow the terminal device to access the second PLMN is referred to as the second area, and the second area includes a second tracking area identifier list. Among them, one or more tracking area identifiers in the first tracking area identifier list can be completely identical, partially identical, or completely different from one or more tracking area identifiers in the second tracking area identifier list, and the present invention does not limit this.

[0119] 305. The core network element sends the second indication information to the terminal device.

[0120] In a possible implementation, the core network element determines the access network device according to the area information that does not allow the terminal device to access the second PLMN. The access network device is located in the area that does not allow the terminal device to access the second PLMN. The core network element sends the second indication information to the terminal device through the determined access network device.

[0121] The core network element sends the second indication information to the access network device. The access network device can send the second indication information to the terminal device in the following two ways.

[0122] Method 1

[0123] The access network device sends a broadcast message to the terminal device. The broadcast message includes the second indication information. Further, the broadcast message may also include identification information of the first PLMN. The terminal device may determine that the first PLMN is an HPLMN according to the identification information of the first PLMN. In this way, the terminal device may determine that it is impossible to dynamically roam to the second PLMN.

[0124] In a possible implementation manner, if the area in which the terminal device is not allowed to access the second PLMN includes multiple access network devices, the multiple access network devices may send broadcast messages to the terminal device at the same time.

[0125] In a possible implementation, the broadcast message further includes area information that does not allow the terminal device to access the second PLMN. Specifically, the area information may be a tracking area identifier list (TA list), which includes one or more tracking area identifiers.

[0126] After receiving the broadcast message, the terminal device sends a deregistration request message to the second PLMN, so that the terminal device deregisters in the second PLMN.

[0127] Method 2

[0128] The access network device sends a deregistration request message to the terminal device, wherein the deregistration request message includes the second indication information.

[0129] In a possible implementation manner, the deregistration request message further includes area information that does not allow the terminal device to access the second PLMN. For details, see the description of the first manner.

[0130] 306. The terminal device accesses the first PLMN.

[0131] Specifically, the terminal device sends an access request message to the first PLMN according to the second indication information, thereby accessing the first PLMN. The access request message may be a registration request message.

[0132] In an embodiment of the present application, if a fault occurs in the first PLMN and the terminal device cannot access the first PLMN, the terminal device sends an access request to the second PLMN according to the first indication information from the second PLMN, thereby reducing the service waiting time of the terminal device and improving the service experience of the user. Further, when the first PLMN fault is restored, the terminal device sends an access request to the first PLMN according to the second indication information from the second PLMN, so that the terminal device can return to the first PLMN in time.

[0133] The following takes the first PLMN as HPLMN, the second PLMN as VPLMN, and the terminal device as UE as an example to describe in detail the roaming method of the embodiment of the present application. HPLMN includes access network equipment RAN1 and access management network element AMF1. VPLMN includes access network equipment RAN2, access management network element AMF1. NEF network element and OAM network element. Of course, HPLMN and VPLMN may also include other network elements, which are not limited here.

[0134] exist Figure 4 In the illustrated embodiment, when the HPLMN fails, the VPLMN starts dynamic roaming with the HPLMN. Specifically, the method includes:

[0135] 401. UE cannot access the HPLMN.

[0136] After the UE initially accesses the HPLMN, if a failure occurs in the HPLMN, the UE cannot access the HPLMN.

[0137] 402. The OAM network element sends first indication information to the NEF network element.

[0138] When the VPLMN learns that the HPLMN cannot be accessed due to a fault, the VPLMN activates dynamic roaming with the HPLMN, allowing the UE of the HPLMN to access the VPLMN. In a possible implementation, the OAM network element in the VPLMN obtains a first notification message through a third party or directly through the HPLMN and sends the first notification message to the NEF network element. The first notification message includes first indication information. The first indication information is used to indicate that the dynamic roaming agreement between the HPLMN and the VPLMN is activated. The first notification message may also include identification information of the HPLMN. Through the identification information of the HPLMN, the PLMN that is allowed to roam to the VPLMN can be determined.

[0139] In a possible implementation, the first notification message also includes area information allowing the terminal device to access the VPLMN, and / or policy information for the UE to access the VPLMN. For the area information allowing the terminal device to access the VPLMN and the policy information for the UE to access the VPLMN, refer to the area information allowing the terminal device to access the second PLMN and the policy information for the UE to access the second PLMN in 301.

[0140] 403. The NEF network element sends the first indication information to the AMF2 network element.

[0141] In a possible implementation, after receiving the first notification message from the OAM network element, the NEF network element determines the corresponding AMF2 based on the area information that allows the terminal device to access the VPLMN. The service area of ​​AMF2 is included in the area that allows the terminal device to access the VPLMN. Specifically, the NEF network element can find the identifier of AMF2 based on the network topology. The NEF network element sends the above-mentioned first indication information to the AMF2 network element.

[0142] In a possible implementation, the NEF network element sends a first notification message to the AMF2, and the first notification message includes the first indication information. The first notification message may also include at least one of the following contents: identification information of the HPLMN, area information allowing the terminal device to access the VPLMN, and policy information for the UE to access the VPLMN. See the description of 402 for details.

[0143] In a possible implementation, the OAM network element in step 402 can also find out the identifier of AMF2 according to the network topology and directly send the first indication information to AMF2.

[0144] 404. AMF2 network element sends first indication information to RAN2.

[0145] In a possible implementation, after receiving the first notification message from the NEF network element or the OAM network element, the AMF2 network element determines the corresponding RAN2 according to the area information that allows the terminal device to access the VPLMN. Among them, the service area of ​​RAN2 is included in the area where the terminal device is allowed to access the VPLMN. Specifically, the AMF2 network element can find out the identifier of RAN2 according to the network topology. The AMF2 network element sends the above-mentioned first indication information to RAN2.

[0146] In a possible implementation, the AMF2 network element sends a first notification message to RAN2, and the first notification message may also include at least one of the following contents: identification information of the HPLMN, area information allowing the terminal device to access the VPLMN, and policy information for the UE to access the VPLMN. See the description of 402 for details.

[0147] 405. The RAN2 network element sends a notification message to the UE.

[0148] In a possible implementation, after receiving the first indication information, RAN2 sends a broadcast message to the UE according to the first indication information. The notification message is the broadcast message. The broadcast message includes the first indication information.

[0149] In a possible implementation, the broadcast message further includes at least one of the following contents: identification information of the HPLMN, information of an area allowing the terminal device to access the VPLMN, and policy information for the UE to access the VPLMN. For details, see the description of 402.

[0150] 406. The UE selects a VPLMN.

[0151] In a possible implementation manner, after the UE receives the broadcast message, if the HPLMN in the broadcast message is the same as the HPLMN of the UE, the UE selects to access the VPLMN using the corresponding policy information.

[0152] In a possible implementation, if the policy information includes the priority information of the VPLMN, the UE selects to access the VPLMN according to the priority order of the VPLMN. For another example, if the policy information includes the type of access technology, the UE uses the corresponding access technology type to access the VPLMN.

[0153] 407. The UE sends a registration request message to AMF2 in the VPLMN.

[0154] Through the operations 401 to 407 above, when the HPLMN of the UE fails, the UE can access the VPLMN having a dynamic roaming agreement with the HPLMN.

[0155] When the HPLMN failure is restored, Figure 5 The illustrated embodiment provides a method for a UE to return from a VPLMN to an HPLMN. Specifically, the method includes:

[0156] 501~503, when the HPLMN fails, the UE cannot access the HPLMN. The UE can Figure 4 The method of the embodiment successfully accesses the VPLMN. For details, refer to the description of steps 401 to 407.

[0157] 504. The OAM network element sends second indication information to the NEF network element.

[0158] When the VPLMN learns that the HPLMN fault is restored, the VPLMN deactivates dynamic roaming with the HPLMN, and does not allow the UE of the HPLMN to access the VPLMN. In a possible implementation, the OAM network element obtains a second notification message through a third party or directly through the HPLMN. The second notification message includes second indication information. The second indication information is used to indicate that the dynamic roaming agreement between the HPLMN and the VPLMN is deactivated. The second notification message may also include identification information of the HPLMN. Through the identification information of the HPLMN, it can be determined that the PLMN that is not allowed to roam to the VPLMN is not allowed.

[0159] In a possible implementation, the second notification message also does not include area information that allows the terminal device to access the VPLMN. Exemplarily, the area information that does not allow the terminal device to access the VPLMN may be a tracking area identifier list (TAlist), which includes one or more tracking area identifiers.

[0160] 505. The NEF network element sends a second indication message to the AMF2 network element.

[0161] In a possible implementation, after the NEF network element receives the second notification message from the OAM network element, it determines the corresponding AMF2 based on the area information that does not allow the terminal device to access the VPLMN. Among them, the service area of ​​​​AMF2 is included in the above-mentioned area where the terminal device is not allowed to access the VPLMN. Specifically, the NEF network element can find the identifier of AMF2 based on the network topology. The NEF network element sends the above-mentioned second indication information to the AMF2 network element.

[0162] In a possible implementation, the NEF network element sends a second notification message to the AMF2, where the second notification message includes the second indication information. The second notification message may also include at least one of the following contents: identification information of the HPLMN, and information about the area where the terminal device is not allowed to access the VPLMN. See the description of 504 for details.

[0163] In a possible implementation, the OAM network element in step 504 can also find out the identifier of AMF2 according to the network topology and directly send the second indication information to AMF2.

[0164] 506. The AMF2 network element sends second indication information to RAN2.

[0165] In a possible implementation, after receiving the second notification message from the NEF network element or the OAM network element, the AMF2 network element determines the corresponding RAN2 according to the area information that does not allow the terminal device to access the VPLMN. Among them, the service area of ​​RAN2 is included in the above-mentioned area that does not allow the terminal device to access the VPLMN. Specifically, the AMF2 network element can find out the identifier of RAN2 according to the network topology. The AMF2 network element sends the above-mentioned second indication information to RAN2.

[0166] In a possible implementation, the AMF2 network element sends a second notification message to RAN2, and the second notification message may also include at least one of the following contents: identification information of the HPLMN, and information about the area in which the terminal device is not allowed to access the VPLMN. See the description of 504 for details.

[0167] 507. The RAN2 network element sends a second notification message to the UE.

[0168] In a possible implementation, after receiving the second indication information, RAN2 sends a broadcast message to the UE according to the second indication information. The second notification message may be the broadcast message. The broadcast message includes the second indication information.

[0169] In a possible implementation, the broadcast message further includes at least one of the following contents: identification information of the HPLMN, and information of an area where the terminal device is not allowed to access the VPLMN. For details, refer to the description of 504.

[0170] 508. The UE sends a deregistration request message to AMF2.

[0171] In a possible implementation, after the UE receives the broadcast message, if the HPLMN in the broadcast message is the same as the HPLMN of the UE, the UE learns, according to the second indication information, that the dynamic roaming agreement between the HPLMN and the VPLMN is deactivated. Therefore, the UE sends a deregistration request message to AMF2, triggering the UE to log off from the VPLMN.

[0172] 509. The UE selects the HPLMN.

[0173] In a possible implementation, after receiving the broadcast message, the UE learns that the dynamic roaming agreement between the HPLMN and the VPLMN is deactivated according to the second indication information. The UE may select to access the HPLMN according to the PLMN selection list stored in the UE.

[0174] 510. The UE sends a registration request message to AMF1 in the HPLMN.

[0175] Through the operations of 504 to 510 above, when the HPLMN failure is recovered, the UE can return from the VPLMN to the HPLMN.

[0176] When the HPLMN failure is restored, Figure 6 The embodiment shown provides another method for UE to return from VPLMN to HPLMN. Specifically, the method includes:

[0177] For details of 605~605, please refer to the description of 501~505.

[0178] 606. AMF2 network element sends a deregistration request message to RAN2.

[0179] In a possible implementation, after the AMF2 network element receives the second notification message from the NEF network element or the OAM network element, the AMF2 network element determines whether the HPLMN corresponding to the UE currently registered with the AMF2 is the same as the HPLMN included in the second notification message; if they are the same, the AMF2 network element further determines whether the current location of the UE belongs to the area according to the area information included in the second notification message that does not allow the terminal device to access the VPLMN; if it does, AMF2 initiates a deregistration process for the UE. Specifically, the AMF2 network element sends a deregistration request message to RAN2. The deregistration request message includes the second indication information.

[0180] In a possible implementation, the registration request message may further include at least one of the following contents: area information that does not allow the terminal device to access the VPLMN. See the description of 504 for details.

[0181] 607. The RAN2 network element sends a deregistration request message to the UE.

[0182] In a possible implementation manner, after receiving the deregistration request message, RAN2 sends a deregistration request message to the UE. The deregistration request message includes the second indication information.

[0183] After receiving the deregistration request message, the UE learns that the dynamic roaming agreement between the HPLMN and the VPLMN is deactivated according to the second indication information. Therefore, the UE deactivates from the VPLMN.

[0184] For details of 608-609, please refer to the description of 509-510.

[0185] Through the operations 604 to 609 above, when the HPLMN failure is recovered, the UE can also return from the VPLMN to the HPLMN.

[0186] In a possible implementation manner, the PLMN selection list stored in the UE may include information of dynamic roaming PLMNs, as shown in Table 1.

[0187] Table 1

[0188]

[0189]

[0190] In Table 1, the network selection priority of PLMN is expressed in the order from 1 to 6 from high to low. The network selection priority corresponding to the PLMN in the order "1" is the highest, and the network selection priority corresponding to the PLMN in the order "6" is the lowest. For example: HPLMN or EHPLMN has the highest priority. The user-controlled PLMN has the second level of priority. Further, Table 1 may also include the access technology type corresponding to the user-controlled PLMN. The operator-controlled PLMN has the third level of priority. Further, Table 1 may also include the access technology type corresponding to the operator-controlled PLMN. The dynamic roaming PLMN refers to the second PLMN mentioned above. The dynamic roaming PLMN has the fourth level of priority. When the terminal device obtains the information of the second PLMN, the information of the second PLMN is stored in the dynamic roaming PLMN. The PLMN selected according to the service quality requirement has the fifth level of priority. The PLMN selected according to the service quality requirement means that the terminal device selects the PLMN that meets the quality requirement according to the signal quality and / or access technology type of each PLMN.

[0191] It should be noted that the information of the second PLMN (i.e., the dynamic roaming PLMN in Table 1) is added to Table 1 only after the UE obtains the information of the second PLMN. It can be understood that the dynamic roaming PLMN in Table 1 is dynamically generated by the terminal device according to the received dynamic roaming PLMN information. Before the UE obtains the information of the second PLMN, the PLMN selection list of the terminal device does not include the information of the second PLMN, that is, Table 1 does not include the information of the second PLMN, and the terminal device will not consider the information of the second PLMN during the network selection process.

[0192] In one possible manner, the content in Table 1 above may be stored in a subscriber identity module (SIM) of a terminal device. In one possible implementation, if the terminal device accesses a PLMN by automatically selecting a network, the terminal device may select the corresponding PLMN to access in sequence according to the priority of the PLMN in Table 1.

[0193] exist Figures 4 to 6 For the same or similar contents, please refer to Figure 3 Description of embodiments.

[0194] Figure 7 701, a receiving unit 702, a sending unit 703, and a storage unit 704. The processing unit 701, the receiving unit 702, the sending unit 703, and the storage unit 704 may be physically separated units, or may be integrated into one or more physical units, which is not limited here.

[0195] The receiving unit 702 and the sending unit 703 are used to realize the content interaction between the processing unit 701 and other units or network elements. Specifically, the sending unit 703 can be a sending circuit or a transmitter. The receiving unit 702 can be a receiving circuit or a receiver. The sending unit 703 and the receiving unit 702 can also be the transceiver of the communication device. The sending unit 703 and the receiving unit 702 can also be the communication interface or the transceiver circuit of the processing unit 701. Optionally, the sending unit 703 and the receiving unit 702 can be a transceiver chip.

[0196] Although Figure 7 Only one sending unit 703 and one receiving unit 702 are shown in the figure, and the communication device may also include multiple sending units 703 and multiple receiving units 702. The sending unit 703 and the receiving unit 702 may also be subunits of one or more sending and receiving units.

[0197] The processing unit 701 is used to implement the processing of data by the communication device. The processing unit 701 can be a processing circuit or a processor. Among them, the processor can be a central processing unit (CPU), a network processor (NP) or a combination of a CPU and a NP. The processor can further include a hardware chip. The above-mentioned hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof.

[0198] Although Figure 7 Only one processing unit 701 is shown in the figure, and the communication device may also include multiple processing units or the processing unit 701 may include multiple sub-data processing units. Specifically, the processor may be a single-CPU processor or a multi-CPU processor.

[0199] The storage unit 704 is used to store computer instructions executed by the processing unit 701. The storage unit 704 can be a storage circuit or a memory. The memory 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.

[0200] The storage unit 704 may be a unit independent of the processing unit 701, or may be a storage unit in the processing unit 701, which is not limited here. Figure 7 Only one storage unit is shown in the figure, and the communication device may also include multiple storage units or the storage unit may include multiple sub-storage units.

[0201] In various embodiments of the present application, the processing unit 701 may perform content interaction with other network elements through the sending unit 703 and the receiving unit 702 , for example, the processing unit 701 obtains or receives content from other network elements.

[0202] In a possible implementation, the processing unit 701, the sending unit 703, the receiving unit 702, and the storage unit 704 may be interconnected via a bus. The bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc.

[0203] The communication device may be Figure 3-Figure 6 Terminal device in the embodiment. Specifically, the communication device includes: a processing unit, used for connecting the communication device to a second PLMN when the communication device cannot access a first PLMN, and activating a dynamic roaming agreement between the second PLMN and the first PLMN; a receiving unit, used for receiving indication information from the second PLMN, the indication information being used for indicating deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; and a sending unit, used for sending an access request message to the first PLMN according to the indication information.

[0204] In a possible implementation manner, the receiving unit is configured to receive a broadcast message from the second PLMN, where the broadcast message includes the indication information.

[0205] In a possible implementation manner, the broadcast message further includes identification information of the first PLMN and / or area information that does not allow the communication device to access the second PLMN.

[0206] In a possible implementation manner, the processing unit is further configured to deregister the communication device in the second PLMN.

[0207] In a possible implementation manner, the receiving unit is configured to receive a deregistration request message from the second PLMN, where the deregistration request message includes the indication information.

[0208] In a possible implementation manner, the deregistration request message further includes area information that does not allow the communication device to access the second PLMN.

[0209] In a possible implementation manner, the receiving unit is further configured to receive indication information from the second PLMN indicating that a dynamic roaming agreement between the second PLMN and the first PLMN is activated before the communication device accesses the second PLMN.

[0210] In a possible implementation manner, the receiving unit is further configured to obtain information of the second PLMN before the communication device accesses the second PLMN.

[0211] In a possible implementation, the information of the second PLMN further includes at least one of the following information: an access technology type allowing the communication device to access the second PLMN, area information allowing the communication device to access the second PLMN, and priority information of the second PLMN.

[0212] In a possible implementation manner, the second PLMN and the first PLMN have the same mobile country code, and a mobile network code of the second PLMN is different from a mobile network code of the first PLMN.

[0213] In a possible implementation, the dynamic roaming agreement between the second PLMN and the first PLMN includes: if the communication device can access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is deactivated; if the communication device cannot access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is activated.

[0214] In a possible implementation manner, the first PLMN is a home public land mobile network HPLMN, and the second PLMN is a visited public land mobile network VPLMN.

[0215] In the embodiment of the present application, the receiving unit 702 is used to execute Figure 3-Figure 6 The signal receiving operation of the terminal device in the embodiment. The sending unit 703 is used to perform Figure 3-Figure 6 The signal sending operation of the terminal device in the embodiment. The processing unit 701 is used to execute Figure 3-Figure 6 The signal processing operation of the terminal device in the embodiment. Figure 3-Figure 6 Description in the examples.

[0216] In a possible implementation, the processing unit 71 causes the communication device to execute according to the computer instructions stored in the storage unit 704. Figure 3-Figure 6 Operation of the terminal device in the embodiment.

[0217] In another possible implementation, the communication device may also be an access management network element. The communication device may include: a receiving unit, configured to obtain first indication information when the terminal device cannot access the first PLMN, the first indication information being used to indicate activation of a dynamic roaming agreement between a second PLMN and the first PLMN, the communication device being a device in the second PLMN; and a sending unit, configured to send the first indication information to the terminal device.

[0218] In a possible implementation manner, the receiving unit is used to obtain a first notification message, where the first notification message includes the first indication information.

[0219] In a possible implementation manner, the first notification message further includes information about the first PLMN, and the information about the first PLMN includes identification information of the first PLMN.

[0220] In a possible implementation, the first notification message further includes at least one of the following information: an access technology type allowing the terminal device to access the second PLMN, area information allowing the terminal device to access the second PLMN, and priority information of the second PLMN.

[0221] In a possible implementation, the communication device further includes a processing unit, configured to determine the access network device according to the area information allowing the terminal device to access the second PLMN, wherein the access network device is located within the area allowing the terminal device to access the second PLMN.

[0222] In a possible implementation manner, the receiving unit is configured to obtain the first notification message from a network management network element through a network open function network element in the second PLMN.

[0223] In a possible implementation, the receiving unit is further used to obtain second indication information, where the second indication information is used to indicate deactivation of the dynamic roaming agreement between the second PLMN and the first PLMN; the sending unit is further used to send the second indication information to the terminal device through the access network device.

[0224] The communication device may also be Figures 4 to 6 The access management network element in the network, such as AM1 or AMF2. Correspondingly, the receiving unit 702 is used to execute Figures 4 to 6 The signal receiving operation of the AMF network element in the embodiment. The sending unit 703 is used to perform Figures 4 to 6 The signal sending operation of the AMF network element in the embodiment. The processing unit 701 is used to execute Figures 4 to 6 The signal processing operation of the AMF network element in the embodiment. Figures 4 to 6Description in the examples.

[0225] In a possible implementation, the processing unit 701 causes the communication device to execute according to the computer instructions stored in the storage unit 704. Figures 4 to 6 Operation of the AMF network element in the embodiment.

[0226] Figure 8 80 is a schematic diagram of another communication device in an embodiment of the present application. Specifically, the communication device includes at least one processor 801, a transceiver 802, and a memory 803. At least one processor 801, a transceiver 802, and a memory 803 are connected via a communication line 804.

[0227] The processor 801 may be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the present application.

[0228] The memory 803 is used to store computer-executable instructions for executing the solution of the present application, and the processor 801 controls the execution. The processor 801 is used to execute the computer-executable instructions stored in the memory 803, thereby realizing the above-mentioned solution of the present application. Figure 3-Figure 6 The operation of the terminal device or AMF network element in the embodiment.

[0229] The computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which is not specifically limited in the embodiments of the present application.

[0230] In a specific implementation, as an embodiment, the processor 801 may include one or more CPUs, such as Figure 8 CPU0 and CPU1 in.

[0231] In a specific implementation, as an embodiment, the processor 801 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor.

[0232] Fig. 9 901 and 902 are schematic diagrams of the structure of a chip or a chip system provided in an embodiment of the present application. The chip includes one or more (including two) processors 901 and a communication interface 902.

[0233] The chip or chip system may further include a memory 903 , which may include a read-only memory and a random access memory, and provide operation instructions and data to the processor 901 .

[0234] In some implementations, the memory 903 stores the following elements, execution modules or data structures, or a subset thereof, or an extended set thereof.

[0235] In the embodiment of the present application, the above-mentioned Figure 3-Figure 6 In the embodiment, the terminal device or AMF network element performs corresponding operations.

[0236] The chip or chip system may further include a communication line 904 , and the memory 901 , the communication interface 902 , and the processor 903 may be connected via the communication line 904 .

[0237] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device or other programmable device. The computer program or instruction may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer program or instruction may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, for example, a floppy disk, a hard disk, a tape; it may also be an optical medium, for example, a digital video disc (DVD); it may also be a semiconductor medium, for example, a solid state drive (SSD).

[0238] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

Claims

1. A roaming method, characterized in that: include: The terminal device receives a broadcast message from an access network device of a second PLMN, where the broadcast message includes first indication information, where the first indication information is used to indicate that a dynamic roaming agreement between the second PLMN and the first PLMN is activated; When the terminal device cannot access the first PLMN, the terminal device accesses the second PLMN according to the first indication information; The terminal device receives a deregistration request message from a core network element in the second PLMN, where the deregistration request message includes second indication information, where the second indication information is used to indicate deactivation of a dynamic roaming agreement between the second PLMN and the first PLMN; The terminal device sends an access request message to the first PLMN according to the second indication information.

2. The method according to claim 1, characterized in that The broadcast message also includes identification information of the first PLMN.

3. The method according to claim 1 or 2, characterized in that: The deregistration request message also includes area information that does not allow the terminal device to access the second PLMN.

4. The method according to claim 1 or 2, characterized in that: The method further comprises: Before the terminal device accesses the second PLMN, the terminal device obtains information about the second PLMN.

5. The method according to claim 4, characterized in that The information of the second PLMN also includes at least one of the following information: an access technology type allowing the terminal device to access the second PLMN, area information allowing the terminal device to access the second PLMN, and priority information of the second PLMN.

6. The method according to claim 1 or 2, characterized in that: The second PLMN has the same mobile country code as the first PLMN, and a mobile network code of the second PLMN is different from a mobile network code of the first PLMN.

7. The method according to claim 1 or 2, characterized in that: The dynamic roaming agreement between the second PLMN and the first PLMN includes: if the terminal device can access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is deactivated; if the terminal device cannot access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is activated.

8. The method according to claim 1 or 2, characterized in that: The first PLMN is a home public land mobile network HPLMN, and the second PLMN is a visited public land mobile network VPLMN.

9. A communication device, characterized in that: include: a receiving unit, configured to receive a broadcast message from an access network device of a second PLMN, wherein the broadcast message includes first indication information, and the first indication information is used to indicate that a dynamic roaming agreement between the second PLMN and the first PLMN is activated; a processing unit, configured to, when the communication device cannot access the first PLMN, enable the communication device to access the second PLMN according to the first indication information; The receiving unit is further configured to receive a deregistration request message from a core network element in the second PLMN, where the deregistration request message includes second indication information, where the second indication information is used to indicate deactivation of a dynamic roaming agreement between the second PLMN and the first PLMN; A sending unit is used to send an access request message to the first PLMN according to the second indication information.

10. The device according to claim 9, characterized in that The broadcast message also includes identification information of the first PLMN.

11. The device according to claim 9 or 10, characterized in that The deregistration request message further includes area information that does not allow the communication device to access the second PLMN.

12. The device according to claim 9 or 10, characterized in that The receiving unit is further configured to obtain information of the second PLMN before the communication device accesses the second PLMN.

13. The device according to claim 12, characterized in that The information of the second PLMN further includes at least one of the following information: an access technology type allowing the communication device to access the second PLMN, area information allowing the communication device to access the second PLMN, and priority information of the second PLMN.

14. The device according to claim 9 or 10, characterized in that The second PLMN has the same mobile country code as the first PLMN, and a mobile network code of the second PLMN is different from a mobile network code of the first PLMN.

15. The device according to claim 9 or 10, characterized in that The dynamic roaming agreement between the second PLMN and the first PLMN includes: if the communication device can access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is deactivated; if the communication device cannot access the first PLMN, the roaming agreement between the second PLMN and the first PLMN is activated.

16. The device according to claim 9 or 10, characterized in that The first PLMN is a home public land mobile network HPLMN, and the second PLMN is a visited public land mobile network VPLMN.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-readable instructions, and when the instructions are executed, the method according to any one of claims 1 to 8 is implemented.

18. A communication device, characterized in that: include: A processor, wherein the processor is used to run instructions stored in a memory to perform the method according to any one of claims 1 to 8.

19. A computer program product, characterized in that The computer program product comprises computer instructions, and when the computer instructions are executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 8.

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