Communication method and communication device

Abstract

The invention provides a communication method and a communication device. In the method, when a terminal device is configured to use a connection service of a first communication system in a VPLMN (Virtual Public Land Mobile Network), if the terminal device cannot use the connection service of the first communication system, the terminal device can be triggered to be switched to obtain a connection service of a second communication system through first indication information; and the normal communication of the terminal equipment is prevented from being influenced because the terminal equipment cannot acquire the connection service.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a communication method and a communication device. Background Art

[0002] A public land mobile network (PLMN) is a network established and operated by the government or operators to provide land mobile communication services to the public. The network can be interconnected with the public switched telephone network (PSTN) to form a communication network on a regional or national scale. PLMN is used to distinguish different mobile communication operators in a country or region, and a service area can be composed of one or several PLMNs. PLMN consists of a 3-digit mobile country code (MCC) and a 2-digit mobile network code (MNC). PLMN is an important part of the international mobile subscriber identity (IMSI). IMSI does not exceed 15 digits, the first 5 digits are PLMN, and the following digits are allocated by the network operator as needed. IMSI is stored in the user's subscriber identity module (SIM) card or universal subscriber identity module (USIM). The PLMN in the IMSI is called the home public land mobile network (HPLMN). The HPLMN is the PLMN where the user opens an account. User information and the services available to the user are stored in the HPLMN. When the user leaves the coverage of the HPLMN and registers with another PLMN, the user enters the roaming state. The PLMN corresponding to the user when roaming is called the visited public land mobile network (VPLMN). A cell corresponds to one or more PLMNs. The system information broadcast by the cell may include the identification information (identity) of the PLMN corresponding to the cell. The PLMNs corresponding to different cells may be the same or different. When the terminal device accesses the network, it first searches for the PLMN. After determining the PLMN, it performs the cell selection process on the PLMN and selects a suitable cell on the PLMN to reside.

[0003] Since mobile networks may not be able to provide services when disasters occur (such as fire, natural disasters, network equipment failure, core network equipment failure, etc.), the current 3GPP Release 17 proposes the feature of minimization of service interruption (MINT). MINT requires that the communication system has the ability to reduce service interruptions. Specifically, it allows users to disaster roam from a PLMN in a disaster condition to other PLMNs to obtain services (such as voice calls, mobile data services). The other PLMN here refers to the PLMN that is willing to receive users in disaster conditions. Among them, the disaster condition can be a condition that the government decides whether to allow terminal equipment to perform disaster roaming based on natural disasters or man-made disasters. Disaster roaming is a special roaming strategy applicable during disaster conditions.

[0004] However, the current communication standards propose that MINT only uses disaster roaming with the fifth generation (5G) network. That is, when a user roams to a VPLMN, it is possible that the user will be set to only access the VPLMN's 5G network. If the VPLMN's 5G network fails, the user will have no available network, resulting in communication anomalies. Summary of the invention

[0005] The embodiments of the present application provide a communication method and a communication device to ensure normal communication of a terminal device.

[0006] In a first aspect, an embodiment of the present application provides a communication method, which can be performed by a terminal device or a module (such as a chip) applied to the terminal device. The method includes: the terminal device is registered in a VPLMN, and the terminal device is configured to use a connection service of a first communication standard; receiving first indication information; and obtaining a connection service of a second communication standard according to the first indication information.

[0007] In the above scheme, when the terminal device is configured to use the connection service of the first communication standard in the VPLMN, if the terminal device cannot use the connection service of the first communication standard, the terminal device can be triggered to switch to obtain the connection service of the second communication standard through the first indication information, which helps to avoid the terminal device being unable to obtain the connection service and affecting the normal communication of the terminal device.

[0008] In a possible implementation method, the first indication information instructs the terminal device to obtain a connection service of the second communication standard.

[0009] In the above scheme, when the terminal device receives the first indication information, it skips obtaining the connection service of the first communication standard of other available PLMNs, and directly obtains the connection service of the second communication standard, which helps the terminal device to quickly obtain the connection service of the second communication standard.

[0010] In a possible implementation method, the first indication information indicates that the terminal device is allowed to obtain the connection service of the second communication standard; obtaining the connection service of the second communication standard according to the first indication information includes: obtaining the connection service of the first communication standard according to the first indication information; and obtaining the connection service of the second communication standard in the event that the connection service of the first communication standard fails.

[0011] In the above scheme, when the terminal device receives the first indication information, it first tries to obtain the connection service of the first communication standard of other available PLMNs. In the case of success in obtaining the connection service of the first communication standard of other available PLMNs, the connection service of the first communication standard is used. In the case of failure to obtain the connection service of the first communication standard, it tries to obtain the connection service of the second communication standard and finally obtains the connection service of the second communication standard. This scheme ensures that the connection service of the first communication standard is preferentially selected, which helps to improve the communication quality of the terminal device.

[0012] In a possible implementation method, the first indication information indicates a frequency list of the second communication standard; and obtaining the connection service of the first communication standard according to the first indication information includes: obtaining the connection service of the second communication standard according to the frequency list of the second communication standard.

[0013] In the above scheme, the terminal device attempts to obtain the connection service of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtains the connection service of the second communication standard. This scheme helps the terminal device to quickly obtain the connection service of the second communication standard.

[0014] In a possible implementation method, obtaining the connection service of the second communication standard according to the frequency list of the second communication standard includes: obtaining the connection service of the first communication standard; and in case the connection service of the first communication standard fails to be obtained, obtaining the connection service of the second communication standard according to the frequency list of the second communication standard.

[0015] In the above scheme, the terminal device may first try to obtain the connection service of the first communication standard of other available PLMNs according to the first indication information. In the case of success in obtaining the connection service of the first communication standard of other available PLMNs, the connection service of the first communication standard is used. In the case of failure to obtain the connection service of the first communication standard, the terminal device may try to obtain the connection service of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtain the connection service of the second communication standard. This scheme ensures that the connection service of the first communication standard is preferentially selected, which helps to improve the communication quality of the terminal device and helps the terminal device quickly obtain the connection service of the second communication standard.

[0016] In a possible implementation method, the method also includes: receiving second indication information, wherein the second indication information indicates that a network failure occurs in at least one PLMN under the first communication standard; and obtaining the connection service of the first communication standard includes: obtaining the connection service of the first communication standard on a PLMN other than the at least one PLMN.

[0017] In the above scheme, when the terminal device obtains the connection service of the first communication standard of other available PLMNs, it can skip the search or acquisition of the connection service under the first communication standard of at least one PLMN, thereby helping the terminal device to quickly obtain the available connection service and improve the communication quality.

[0018] In a possible implementation method, the method also includes: receiving second indication information, the second indication information indicating that a network failure occurs in a first communication standard of at least one PLMN; and obtaining a connection service of the second communication standard based on the first indication information, including: obtaining a connection service of the second communication standard when all PLMNs available to the terminal device are included in the at least one PLMN.

[0019] In the above scheme, the terminal device determines, based on the second indication information, that all PLMNs available to the terminal device have failed, and further determines that the first communication standards of the PLMNs available to the terminal device have all suffered disasters or failures. Therefore, the terminal device obtains the connection service of the second communication standard to ensure the normal communication of the terminal device, thereby improving the communication quality.

[0020] In a possible implementation method, the first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of the second communication standard under each PLMN.

[0021] In a possible implementation method, the method further includes: receiving third indication information, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

[0022] In the above scheme, the terminal device determines which PLMNs allow the terminal device to obtain the connection service of the second communication standard according to the third indication information, and then tries to obtain the connection service of the second communication standard, which helps the terminal device to quickly obtain the connection service of the second communication standard.

[0023] In a possible implementation method, the method also includes: receiving fourth indication information, the fourth indication information instructing the terminal device to prohibit the use of the connection service of the second communication standard, or instructing the terminal device to obtain the connection service of the first communication standard; and obtaining the connection service of the first communication standard according to the fourth indication information.

[0024] The above solution can trigger the terminal device to resume the connection service of the first communication standard, thereby ensuring the communication quality of the terminal device.

[0025] In a possible implementation method, the receiving of the fourth indication information includes: receiving an RRC release message sent by a network device, the RRC release message including the fourth indication information; or, receiving a detachment request message sent by a core network device, the detachment request message including the fourth indication information, and the fourth indication information is a cause value.

[0026] In a possible implementation method, the first indication information is carried in a system message or an RRC message, wherein the system message can be used in a connected state or a non-connected state, and the RRC message can be used in a connected state.

[0027] In a second aspect, an embodiment of the present application provides a communication method, which can be performed by a network device or a module (such as a chip) applied to a network device. The method includes: sending a first indication message to a terminal device, the terminal device is registered in a VPLMN, the terminal device is configured to use a connection service of a first communication standard, and the first indication message is used to trigger the terminal device to obtain a connection service of a second communication standard.

[0028] In a possible implementation method, the first indication information instructs the terminal device to obtain a connection service of the second communication standard.

[0029] In a possible implementation method, the first indication information indicates that the terminal device is allowed to obtain a connection service of the second communication standard.

[0030] In a possible implementation method, the first indication information indicates a frequency list of the second communication standard.

[0031] In a possible implementation method, the method further includes: sending second indication information, where the second indication information indicates that a network failure occurs in at least one PLMN under the first communication standard.

[0032] In a possible implementation method, the first indication information indicates that a failure occurs in at least one PLMN, and whether each PLMN of the at least one PLMN supports the terminal device to obtain the connection service of the second communication standard under each PLMN.

[0033] In a possible implementation method, the method further includes: sending third indication information, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

[0034] In a possible implementation method, the method further includes: sending fourth indication information, wherein the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard.

[0035] In a possible implementation method, the fourth indication information is carried in an RRC release message.

[0036] In a possible implementation method, the first indication information is carried in a system message or an RRC message, wherein the system message can be used in a connected state or a non-connected state, and the RRC message can be used in a connected state.

[0037] In a third aspect, an embodiment of the present application provides a communication device, which may be a terminal device or a module (such as a chip) for a terminal device. The device has the function of implementing any implementation method of the first aspect above. The function may be implemented by hardware or by executing corresponding software implementation by hardware. The hardware or software includes one or more modules corresponding to the above functions.

[0038] In a fourth aspect, an embodiment of the present application provides a communication device, which may be a network device or a module (such as a chip) for a network device. The device has the function of implementing any implementation method of the second aspect above. The function may be implemented by hardware or by executing corresponding software implementation by hardware. The hardware or software includes one or more modules corresponding to the above functions.

[0039] In a fifth aspect, an embodiment of the present application provides a communication device, comprising a unit or means for executing each step of any implementation method in the first to second aspects above.

[0040] In a sixth aspect, an embodiment of the present application provides a communication device, including a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute any implementation method in the first to second aspects above. The processor includes one or more.

[0041] In a seventh aspect, an embodiment of the present application provides a communication device, comprising a processor coupled to a memory, the processor being used to call a program stored in the memory to execute any implementation method in the first to second aspects above. The memory may be located inside the device or outside the device. And the processor may be one or more.

[0042] In an eighth aspect, an embodiment of the present application provides a communication device, comprising a memory; the memory is used to store computer instructions, and when the computer instructions are executed, the device executes any implementation method in the above-mentioned first to second aspects.

[0043] In a possible implementation method, the communication device further includes a processor configured to execute computer instructions stored in the memory.

[0044] In the ninth aspect, an embodiment of the present application further provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a communication device, any implementation method in the above-mentioned first to second aspects is executed.

[0045] In the tenth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, and when the computer-readable storage medium is run on a communication device, any implementation method in the above-mentioned first to second aspects is executed.

[0046] In the eleventh aspect, an embodiment of the present application further provides a chip system, comprising: a processor, configured to execute any implementation method in the above-mentioned first aspect to the second aspect.

[0047] In the twelfth aspect, an embodiment of the present application further provides a communication system, comprising a terminal device for implementing any implementation method of the above-mentioned first aspect and a network device for implementing any implementation method of the above-mentioned second aspect.

[0048] In the thirteenth aspect, an embodiment of the present application also provides a communication method, including: a network device sends a first indication message to a terminal device, the terminal device is registered in a visited public land mobile network VPLMN, and the terminal device is configured to use a connection service of a first communication standard; the terminal device obtains a connection service of a second communication standard according to the first indication message. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG1( a ) is a schematic diagram of the architecture of a communication system used in an embodiment of the present application;

[0050] FIG1( b ) shows a schematic diagram of a network device;

[0051] Figure 2 A flow chart of a communication method provided in an embodiment of the present application;

[0052] Figure 3 A flow chart of a communication method provided in an embodiment of the present application;

[0053] Figure 4 A flow chart of a communication method provided in an embodiment of the present application;

[0054] Figure 5 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0055] Figure 6 A schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] FIG1(a) is a schematic diagram of the architecture of a communication system used in an embodiment of the present application. The communication system 1000 shown in FIG1(a) includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 also includes the Internet 300. Among them, the wireless access network 100 may include at least one network device (such as 110a and 110b in FIG1(a)), and may also include at least one terminal device (such as 120a-120j in FIG1(a)). The terminal device is connected to the network device by wireless means, and the network device is connected to the core network by wireless or wired means. The core network device and the network device may be independent and different physical devices, or the functions of the core network device and the logical functions of the network device may be integrated on the same physical device, or the functions of some core network devices and some network devices may be integrated on one physical device. Terminal devices and terminal devices and network devices and network devices may be connected to each other by wire or wireless means. FIG1(a) is only a schematic diagram, and the communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in FIG1(a).

[0057] Network equipment is an access device that terminal equipment uses to access the communication system through wired or wireless means. Network equipment can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in the fifth generation (5G) mobile communication system, a next generation base station in the sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a wireless fidelity (WiFi) system, etc.; it can also be a module or unit that completes part of the functions of a base station, for example, a centralized unit (CU) or a distributed unit (DU). The CU here completes the functions of the radio resource control protocol and the packet data convergence layer protocol (PDCP) of the base station, and can also complete the function of the service data adaptation protocol (SDAP); the DU completes the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and can also complete the functions of part of the physical layer or all of the physical layer. For the specific description of the above-mentioned various protocol layers, please refer to the relevant technical specifications of the third generation partnership project (3GPP). The network device can be a macro base station (such as 110a in Figure 1 (a)), a micro base station or an indoor station (such as 110b in Figure 1 (a)), or a relay node or a donor node, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device.

[0058] The terminal device is a device with wireless transceiver function, which can send signals to the network device or receive signals sent by the network device. The terminal device includes but is not limited to terminal devices, terminals, user equipment (UE), mobile stations, mobile terminals, etc. The terminal device can be widely used in various scenarios, for example, device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal device can specifically be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0059] The network equipment and terminal equipment can be fixed or movable. The network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on airplanes, balloons, and artificial satellites. The embodiments of the present application do not limit the application scenarios of the network equipment and terminal equipment.

[0060] The roles of network devices and terminal devices can be relative. For example, the helicopter or drone 120i in FIG. 1(a) can be configured as a mobile network device. For the terminal devices 120j that access the wireless access network 100 through 120i, the terminal device 120i is a network device; but for the network device 110a, 120i is a terminal device, that is, 110a and 120i communicate through the wireless air interface protocol. Of course, 110a and 120i can also communicate through the interface protocol between network devices. In this case, relative to 110a, 120i is also a network device. Therefore, network devices and terminal devices can be collectively referred to as communication devices. 110a and 110b in FIG. 1(a) can be referred to as communication devices with network device functions, and 120a-120j in FIG. 1(a) can be referred to as communication devices with terminal device functions.

[0061] Network devices and terminal devices, network devices and network devices, and terminal devices and terminal devices can communicate through authorized spectrum, unauthorized spectrum, or both; can communicate through spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or spectrum below 6 GHz and spectrum above 6 GHz. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0062] In the embodiments of the present application, the functions of the network device may also be performed by a module (such as a chip) in the network device, or by a control subsystem including the network device function. The control subsystem including the network device function here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal device may also be performed by a module (such as a chip or a modem) in the terminal device, or by a device including the terminal device function.

[0063] In this application, the network device sends a downlink signal or downlink information to the terminal device, and the downlink information is carried on the downlink channel; the terminal device sends an uplink signal or uplink information to the network device, and the uplink information is carried on the uplink channel. In order to communicate with the network device, the terminal device needs to establish a wireless connection with the cell controlled by the network device. The cell that has established a wireless connection with the terminal device is called the service cell of the terminal device.

[0064] FIG1(b) shows a schematic diagram of a network device. As shown in FIG1(b), the network device includes one or more CUs, one or more DUs, and one or more radio units (RUs). For clarity, FIG1(b) shows only one CU, DU, and RU. The CU is used to connect to the core network and one or more DUs. Optionally, the CU may have some functions of the core network. The CU may include a CU-control plane (CP) and a CU-user plane (UP).

[0065] CU and DU can be configured according to the protocol layer functions of the wireless network they implement: for example, CU is configured to implement the functions of the PDCP layer and the protocol layers above (such as the radio resource control (RRC) layer and / or the SDAP layer, etc.); DU is configured to implement the functions of the protocol layers below the PDCP layer (such as the radio link control (RLC) layer, the MAC layer, and / or the physical (PHY) layer, etc.). For another example, CU is configured to implement the functions of the protocol layers above the PDCP layer (such as the RRC layer and / or the SDAP layer), and DU is configured to implement the functions of the protocol layers below the PDCP layer (such as the RLC layer, the MAC layer, and / or the PHY layer, etc.).

[0066] The above configuration of CU and DU is only an example, and the functions of CU and DU can also be configured as needed. For example, CU or DU can be configured to have functions of more protocol layers, or CU or DU can be configured to have partial processing functions of protocol layers. For example, some functions of the RLC layer and the functions of the protocol layers above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are set in the DU. For another example, the functions of CU or DU can be divided according to service type or other system requirements, such as by delay, and the functions whose processing time needs to meet the smaller delay requirement are set in the DU, and the functions that do not need to meet the delay requirement are set in the CU.

[0067] DU and RU can cooperate to jointly implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in a variety of ways according to the design. For example, DU is configured to implement baseband functions, and RU is configured to implement mid-RF functions. For another example, DU is configured to implement high-level functions in the PHY layer, and RU is configured to implement low-level functions in the PHY layer or to implement the low-level functions and RF functions. The high-level functions in the physical layer may include a part of the functions of the physical layer, which is closer to the MAC layer, and the low-level functions in the physical layer may include another part of the functions of the physical layer, which is closer to the mid-RF side.

[0068] Figure 2 A flow chart of a communication method provided in an embodiment of the present application, the method comprising the following steps:

[0069] Step 201: The network device sends first indication information. Correspondingly, the terminal device receives the first indication information.

[0070] The terminal device is registered in the VPLMN, and the terminal device is configured to use a connection service of a first communication standard.

[0071] Taking the first communication standard as 5G as an example, the terminal device is registered in the VPLMN and is configured as 5G only, that is, the terminal device can only use the 5G connection service of the VPLMN, and cannot use the connection services of other communication standards of the VPLMN, such as the fourth generation (4G) connection service, the sixth generation (6G) connection service, etc.

[0072] The first indication information is used to trigger the terminal device to obtain a connection service of the second communication standard.

[0073] The first indication information may be carried in a system message. In an optional manner, the system message is broadcast by a network device. The system message may be SIB1 or SIB15, or may be a newly defined system information block (SIB). The system message may be used in any RRC state.

[0074] In another optional manner, when the terminal device is in an RRC connected state, the first indication information may also be carried in a radio resource control (RRC) message, such as an RRC release message or an RRC reestablishment message.

[0075] Step 202: The terminal device obtains a connection service of the second communication standard according to the first indication information.

[0076] The first communication standard is different from the second communication standard.

[0077] In the above scheme, when the terminal device is configured to use the connection service of the first communication standard in the VPLMN, if the terminal device cannot use the connection service of the first communication standard, the terminal device can be triggered to switch to obtain the connection service of the second communication standard through the first indication information, which helps to avoid the terminal device being unable to obtain the connection service and affecting the normal communication of the terminal device.

[0078] In one possible manner, the terminal device is configured to use the connection service of the first communication standard, which is understood to be that the terminal device is configured to use only the connection service of the first communication standard and cannot use the connection service of other communication standards (such as the second communication standard). When the terminal device roams to the VPLMN and is configured to use the connection service of the first communication standard of the VPLMN, when a disaster (or failure) occurs in the core network or network equipment of the VPLMN, the terminal device is unable to obtain the connection service of the first communication standard of the VPLMN. At this time, since the terminal device is configured to use only the connection service of the first communication standard of the VPLMN, the terminal device cannot obtain the connection service of other communication standards (such as the second communication standard) of the VPLMN, thereby affecting the normal communication of the terminal device. In an embodiment of the present application, when the terminal device cannot use the connection service of the first communication standard of the VPLMN, the network device sends a first indication message to the terminal device, triggering the terminal device to obtain the connection service of the second communication standard according to the first indication message. For example, the first communication standard is 5G and the second communication standard is 4G. Therefore, even if the terminal device is configured as 5G only in the VPLMN, the first indication information can be used to trigger the terminal device to obtain 4G connection services, which helps to improve the communication quality of the terminal device.

[0079] Different implementation methods of the first indication information are described below in different scenarios.

[0080] Scenario 1: The terminal device roams and registers to a VPLMN, and a disaster or failure occurs in the core network of the first communication standard of the VPLMN.

[0081] In the first scenario, when the network device of the first communication standard of the VPLMN finds that a disaster or failure occurs in the core network of the first communication standard of the VPLMN, the first indication information is sent.

[0082] Based on the first scenario, the implementation method of the first indication information may be any one or more combinations of the following:

[0083] Method 1: The first indication information instructs the terminal device to obtain a connection service of the second communication standard.

[0084] Based on method 1, when the terminal device receives the first indication information, it skips obtaining the connection service of the first communication standard of other available PLMNs and directly obtains the connection service of the second communication standard. Among them, other available PLMNs refer to one or more PLMNs other than the VPLMN registered by the terminal device, which are uniformly explained here and will not be repeated later.

[0085] The second communication standard connection service acquired by the terminal device may be the second communication standard connection service of the VPLMN registered by the terminal device, or the second communication standard connection service of other PLMNs, which is not limited in this application.

[0086] Method 2: The first indication information indicates that the terminal device is allowed to obtain a connection service of the second communication standard.

[0087] Based on method 2, when the terminal device receives the first indication information, it first attempts to obtain the connection service of the first communication standard of other available PLMNs. If the connection service of the first communication standard of other available PLMNs is successfully obtained, the connection service of the first communication standard is used. If the connection service of the first communication standard fails to be obtained, it attempts to obtain the connection service of the second communication standard and finally obtains the connection service of the second communication standard.

[0088] Method 3: The first indication information indicates a frequency list of the second communication standard.

[0089] Based on method 3, the terminal device attempts to obtain connection services of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtains the connection services of the second communication standard.

[0090] In one implementation method, the terminal device may first try to obtain the connection service of the first communication standard of other available PLMNs according to the first indication information. If the connection service of the first communication standard of other available PLMNs is successfully obtained, the connection service of the first communication standard is used. If the connection service of the first communication standard fails to be obtained, the terminal device may then try to obtain the connection service of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtain the connection service of the second communication standard.

[0091] The above methods 1 to 3 can be implemented independently or in combination. For example, when method 1 is combined with method 3, the terminal device skips obtaining the connection service of the first communication standard of other available PLMNs, and directly obtains the connection service of the second communication standard according to the frequency list of the second communication standard indicated by the first indication information.

[0092] In one implementation method, the network device may also send a second indication information, where the second indication information indicates that a disaster or failure has occurred in the network under the first communication standard of at least one PLMN. If the first indication information is implemented by the above method 2 or method 3, the terminal device may skip the search or acquisition of the connection service under the first communication standard of the at least one PLMN when acquiring the connection service of the first communication standard of other available PLMNs, thereby helping the terminal device to quickly acquire the available connection service and improve the communication quality. For example, the second indication information indicates that a disaster or failure has occurred in the network under the first communication standard of PLMN1, PLMN2 and PLMN3, and the terminal device first attempts to acquire the connection service of the first communication standard according to the first indication information, and the terminal device will not attempt to acquire the connection service of the first communication standard on PLMN1, PLMN2 and PLMN3, but will attempt to acquire the connection service of the first communication standard on other PLMNs except PLMN1, PLMN2 and PLMN3.

[0093] Optionally, if all PLMNs available to the terminal device are included in at least one of the above PLMNs, indicating that a disaster or failure has occurred in the first communication standard of all PLMNs available to the terminal device, the terminal device can skip obtaining the connection service of the first communication standard and directly obtain the connection service of the second communication standard. The PLMN available to the terminal device refers to the connection service of the first communication standard that the terminal device can use for the available PLMN.

[0094] In one implementation method, the first indication information may be of PLMN granularity, and each PLMN is associated with one first indication information, that is, each PLMN may be configured with the first indication information separately. For example, the first indication information associated with PLMN a indicates that the terminal device obtains the connection service of the second communication standard. After receiving the first indication information, the terminal device registered to the PLMN a skips obtaining the connection service of the first communication standard of other available PLMNs and directly obtains the connection service of the second communication standard according to the first indication information. For another example, the first indication information associated with PLMN b indicates that the terminal device is allowed to obtain the connection service of the second communication standard. After receiving the first indication information, the terminal device registered to the PLMN b first attempts to obtain the connection service of the first communication standard of other available PLMNs according to the first indication information. If the connection service of the first communication standard of other available PLMNs is successfully obtained, the connection service of the first communication standard is used. If the connection service of the first communication standard fails to be obtained, the terminal device attempts to obtain the connection service of the second communication standard and finally obtains the connection service of the second communication standard.

[0095] Optionally, for scenario one, after sending the first indication information, the network device can shut down the network device to save energy consumption, and trigger the terminal devices connected to or residing in the network device to reselect to other available PLMNs. This is because: a disaster or failure occurs in the core network of the first communication standard, so the terminal devices under the core network cannot obtain normal communication services. After the network device under the core network is shut down, the terminal devices connected to or residing in the network device cannot obtain network services, thereby triggering a reselection mechanism to reselect to other available PLMNs. On the one hand, it saves energy consumption of the network device, and on the other hand, it allows the terminal device to reselect the PLMN to obtain normal communication services.

[0096] Scenario 2: The terminal device roams and registers to a VPLMN, and a network device of the first communication standard of the VPLMN encounters a disaster or fails.

[0097] In scenario two, when a disaster or failure occurs in the network device of the first communication standard of the VPLMN of the terminal device (hereinafter referred to as network device 1), the network device of other PLMNs (hereinafter referred to as network device 2) can sense that the network device 1 has failed, and then the network device 2 sends a first indication message.

[0098] Based on the second scenario, the implementation method of the first indication information may be any one or more combinations of the following:

[0099] Method 1: The first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of a second communication standard under each PLMN.

[0100] Alternatively, it can be understood that the first indication information indicates that a failure occurs in the at least one PLMN, and the terminal device registered to the at least one PLMN switches from obtaining a connection service of the first communication standard to obtaining a connection service of the second communication standard without changing the PLMN.

[0101] The indication information may be based on PLMN granularity. It should be noted that the at least one PLMN may include not only the PLMN corresponding to the cell of network device 1, but also the PLMN corresponding to the cell of other network devices (such as network device 3) where disaster or failure occurs.

[0102] For example, the first indication information indicates that PLMN4, PLMN5 and PLMN6 have failed, and the terminal device receives the first indication information from other PLMNs (such as PLMN2 and PLMN3). For example, the VPLMN currently registered by the terminal device is PLMN4. On the one hand, the terminal device determines that PLMN4 has failed according to the first indication information, and on the other hand, the terminal device obtains the connection service of the second communication standard of the PLMN4. That is, the terminal device switches from obtaining the connection service of the first communication standard of the VPLMN to obtaining the connection service of the second communication standard of the VPLMN.

[0103] Of course, if the terminal device cannot obtain the connection service of the second communication standard under the VPLMN due to some reasons (such as poor signal quality), the terminal device can also search for and obtain the connection service of the second communication standard under other available PLMNs.

[0104] Optionally, the first indication information further indicates that a failure occurs in at least one other PLMN, and each PLMN of the at least one other PLMN does not support the terminal device to obtain a connection service of the second communication standard.

[0105] Method 2: The first indication information indicates a frequency list of the second communication standard.

[0106] Based on method 2, the terminal device attempts to obtain connection services of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtains the connection services of the second communication standard.

[0107] In one implementation method, the terminal device may first try to obtain the connection service of the first communication standard of other available PLMNs according to the first indication information. If the connection service of the first communication standard of other available PLMNs is successfully obtained, the connection service of the first communication standard is used. If the connection service of the first communication standard fails to be obtained, the terminal device may then try to obtain the connection service of the second communication standard of other PLMNs on the frequency list of the second communication standard indicated by the first indication information, and finally obtain the connection service of the second communication standard.

[0108] In one implementation method, for the above scenario 1 or scenario 2, the network device of the second communication mode under the VPLMN registered by the terminal device (hereinafter referred to as network device 4) can also broadcast third indication information, and the third indication information indicates that the terminal device of at least one PLMN is allowed to inbound roam, and the at least one PLMN includes the VPLMN registered by the terminal device. The third indication information can be based on the granularity of PLMN. Among them, inbound roaming can be understood as allowing the use of connection services. Exemplarily, there are cell 1 and cell 2 under network device 4, cell 1 corresponds to PLMN7 and PLMN8, cell 2 corresponds to PLMN9 and PLMN10, and the third indication information may indicate: PLMN7 allows terminal devices registered to PLMN1 to use the connection service of the second communication standard of PLMN7, PLMN8 allows terminal devices registered to PLMN1 and PLMN2 to use the connection service of the second communication standard of PLMN8, PLMN9 allows terminal devices registered to PLMN3 and PLMN4 to use the connection service of the second communication standard of PLMN9, and PLMN10 allows terminal devices registered to PLMN3 and PLMN5 to use the connection service of the second communication standard of PLMN10. When the terminal device receives the above-mentioned first indication information and the third indication information, if the terminal device needs to search for the connection service of the second communication standard, the terminal device may be implemented in the following manner: the terminal device determines which PLMNs allow the terminal device to obtain the connection service of the second communication standard, and then tries to obtain the connection service of the second communication standard. For example, if the VPLMN registered by the terminal device is PLMN1, the terminal device determines, based on the third indication information, that PLMN8 allows the terminal device to use the connection service of the second communication standard, and the terminal device can obtain the connection service of the second communication standard in PLMN8.

[0109] In one implementation method, for the above scenario 1 or scenario 2, after the disaster of the core network or network device of the first communication standard ends (or the failure ends), the network device or core network device of the second communication standard can send a fourth indication information, and the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard, so that the terminal device initiates a registration request to the network device of the first communication standard according to the fourth indication information, completes the registration process of the first communication standard, and obtains the connection service of the first communication standard. That is, the terminal device recovers from obtaining the connection service of the second communication standard to obtaining the connection service of the first communication standard. For example, the network device of the second communication standard can send an RRC release message, and the RRC release message includes the fourth indication information. For another example, the core network device of the second communication standard can send a detach request message, and the detach request message includes the fourth indication information, and the fourth indication information can be a cause value (cause).

[0110] The above solution is described in detail below with reference to two specific examples.

[0111] the following Figure 3 , Figure 4 In the embodiment of the present invention, the first communication standard is 5G communication standard and the second communication standard is 4G communication standard. In practical applications, the first communication standard and the second communication standard may also be other two different communication standards. For example, the first communication standard is 6G communication standard and the second communication standard is 5G communication standard.

[0112] Figure 3 A flow chart of a communication method provided for an embodiment of the present application is provided for the above-mentioned scenario 1, that is, a core network of the first communication standard of the VPLMN registered by the terminal device fails. In this embodiment, the terminal device is registered in the VPLMN and uses the 5G connection service of the VPLMN. When a disaster occurs in the 5G core network, the terminal device switches to use the 4G connection service. This embodiment takes the network device of the first communication standard as a 5G base station and the network device of the second communication standard as a 4G base station as an example.

[0113] The method comprises the following steps:

[0114] Step 301: When a disaster occurs in the 5G core network, the 5G base station sends a first indication message. Correspondingly, the terminal device receives the first indication message.

[0115] The specific meaning of the first indication information can refer to the aforementioned Figure 2 Description of scenario 1 in the embodiment.

[0116] Optionally, the 5G base station shuts down the 5G base station after sending the first indication information.

[0117] Step 302: The terminal device obtains the 4G connection service according to the first indication information.

[0118] The 4G connection service obtained by the terminal device may be a connection service of the 4G network of the VPLMN to which the terminal device is registered, or a connection service of the 4G network of another PLMN.

[0119] Step 303: The 4G base station broadcasts the third indication information. Accordingly, the terminal device receives the third indication information.

[0120] The third indication information indicates that inbound roaming of the terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN registered by the terminal device. For a specific example of the third indication information, please refer to Figure 2 Description of embodiments.

[0121] Step 304: The terminal device selects a 4G cell for registration.

[0122] The terminal device selects a 4G cell for registration according to the first indication information; or selects a 4G cell for registration according to the first indication information and the third indication information. For a specific description, refer to Figure 2 Example.

[0123] The 4G cell may be a 4G cell of the VPLMN to which the terminal device is registered, or a 4G cell of another VPLMN. The figure takes a 4G cell registered to the VPLMN as an example.

[0124] Step 305a: The 4G core network sends fourth indication information to the terminal device. Correspondingly, the terminal device receives the fourth indication information.

[0125] Step 305b: The 4G base station sends fourth indication information to the terminal device. Correspondingly, the terminal device receives the fourth indication information.

[0126] After the 5G core network disaster ends, the above step 305a or step 305b is performed. The fourth indication information instructs the terminal device to prohibit the use of 4G connection services, or instructs the terminal device to obtain 5G connection services, so that the terminal device initiates a registration request to the 5G base station according to the fourth indication information, completes the 5G registration process, and restores to the 5G connection service.

[0127] Step 306: The terminal device selects a 5G cell for registration.

[0128] The terminal device initiates a registration request to the 5G base station according to the fourth indication information, completes the 5G registration process and obtains the 5G connection service.

[0129] Figure 4 A flow chart of a communication method provided for an embodiment of the present application, this embodiment is for the above-mentioned scenario 2, that is, the network device of the first communication standard of the VPLMN registered by the terminal device fails. In this embodiment, the terminal device is registered in the VPLMN and uses the 5G connection service of the VPLMN. When a disaster occurs in the 5G base station, the terminal device switches to use the 4G connection service. This embodiment takes the network device of the first communication standard as a 5G base station and the network device of the second communication standard as a 4G base station as an example.

[0130] The method comprises the following steps:

[0131] Step 401: When a disaster occurs in the 5G base station 1 of the VPLMN, the 5G base station 2 of the other PLMN sends a first indication message. Accordingly, the terminal device receives the first indication message.

[0132] The specific meaning of the first indication information can refer to the aforementioned Figure 2 Description of scenario 2 in the embodiment.

[0133] Step 402: The terminal device obtains a 4G connection service according to the first indication information.

[0134] The 4G connection service obtained by the terminal device may be a connection service of the 4G network of the VPLMN to which the terminal device is registered, or a connection service of the 4G network of other PLMNs.

[0135] Step 403: The 4G base station of the VPLMN broadcasts the third indication information. Accordingly, the terminal device receives the third indication information.

[0136] The third indication information indicates that inbound roaming of the terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN registered by the terminal device. For a specific example of the third indication information, please refer to Figure 2 Description of embodiments.

[0137] Step 404: The terminal device selects a 4G cell for registration.

[0138] The terminal device selects a 4G cell for registration according to the first indication information; or selects a 4G cell for registration according to the first indication information and the third indication information. For a specific description, refer to Figure 2 Example.

[0139] The 4G cell may be a 4G cell of the VPLMN to which the terminal device is registered, or a 4G cell of another VPLMN. The figure takes a 4G cell registered to the VPLMN as an example.

[0140] Step 405a: The 4G core network sends fourth indication information to the terminal device. Correspondingly, the terminal device receives the fourth indication information.

[0141] Step 405b: The 4G base station sends fourth indication information to the terminal device. Correspondingly, the terminal device receives the fourth indication information.

[0142] After the disaster of 5G base station 1 ends, the above step 405a or step 405b is performed. The fourth indication information instructs the terminal device to prohibit the use of 4G connection services, or instructs the terminal device to obtain 5G connection services, so that the terminal device initiates a registration request to the 5G base station according to the fourth indication information, completes the 5G registration process, and restores to the 5G connection service.

[0143] Step 406: The terminal device selects a 5G cell for registration.

[0144] The terminal device initiates a registration request to the 5G base station according to the fourth indication information, completes the 5G registration process and obtains the 5G connection service.

[0145] It is understandable that, in order to implement the functions in the above embodiments, the terminal device or network device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0146] Figure 5 and Figure 6 A schematic diagram of the structure of possible communication devices provided for embodiments of the present application. These communication devices can be used to implement the functions of the terminal device or network device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In the embodiments of the present application, the communication device can be a terminal device or a network device, and can also be a module (such as a chip) applied to a terminal device or a network device.

[0147] Figure 5 The communication device 500 shown includes a processing unit 510 and a transceiver unit 520. The communication device 500 is used to implement the functions of the terminal device or the network device in the above method embodiment.

[0148] When the communication device 500 is used to implement the functions of the terminal device in the above method embodiment, the terminal device is registered in the VPLMN, and the terminal device is configured to use the connection service of the first communication standard; the transceiver unit 520 is used to receive the first indication information; the processing unit 510 is used to obtain the connection service of the second communication standard according to the first indication information.

[0149] In a possible implementation method, the first indication information instructs the terminal device to obtain a connection service of the second communication standard.

[0150] In one possible implementation method, the first indication information indicates that the terminal device is allowed to obtain the connection service of the second communication standard; the processing unit 510 is used to obtain the connection service of the second communication standard according to the first indication information, specifically including: obtaining the connection service of the first communication standard according to the first indication information; if the connection service of the first communication standard fails to be obtained, obtaining the connection service of the second communication standard.

[0151] In one possible implementation method, the first indication information indicates a frequency list of the second communication standard; the processing unit 510 is used to obtain the connection service of the first communication standard according to the first indication information, specifically including: obtaining the connection service of the second communication standard according to the frequency list of the second communication standard.

[0152] In a possible implementation method, the processing unit 510 is used to obtain the connection service of the second communication standard according to the frequency list of the second communication standard, specifically including: obtaining the connection service of the first communication standard; in case of failure to obtain the connection service of the first communication standard, obtaining the connection service of the second communication standard according to the frequency list of the second communication standard.

[0153] In a possible implementation method, the transceiver unit 520 is also used to receive second indication information, wherein the second indication information indicates that a network failure occurs in at least one PLMN under the first communication standard; the processing unit 510 is used to obtain a connection service of the first communication standard, specifically including: obtaining a connection service of the first communication standard on a PLMN other than the at least one PLMN.

[0154] In a possible implementation method, the transceiver unit 520 is also used to receive second indication information, wherein the second indication information indicates that a network failure has occurred in a first communication standard of at least one PLMN; the processing unit 510 is used to obtain a connection service of the second communication standard based on the first indication information, specifically including: obtaining a connection service of the second communication standard when all PLMNs available to the terminal device are included in the at least one PLMN.

[0155] In a possible implementation method, the first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of the second communication standard under each PLMN.

[0156] In a possible implementation method, the transceiver unit 520 is further configured to receive third indication information, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

[0157] In a possible implementation method, the transceiver unit 520 is also used to receive a fourth indication information, wherein the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard; the processing unit 510 is also used to obtain the connection service of the first communication standard according to the fourth indication information.

[0158] In a possible implementation method, the transceiver unit 520 is used to receive the fourth indication information, specifically including: receiving an RRC release message sent by a network device, the RRC release message including the fourth indication information; or receiving a detachment request message sent by a core network device, the detachment request message including the fourth indication information, and the fourth indication information is a cause value.

[0159] In a possible implementation method, the first indication information is carried in a system message or an RRC message.

[0160] When the communication device 500 is used to implement the function of the network device in the above method embodiment, the processing unit 510 is used to control the transceiver unit 520: send a first indication information to the terminal device, the terminal device is registered in the VPLMN, the terminal device is configured to use the connection service of the first communication standard, and the first indication information is used to trigger the terminal device to obtain the connection service of the second communication standard.

[0161] In a possible implementation method, the first indication information instructs the terminal device to obtain a connection service of the second communication standard.

[0162] In a possible implementation method, the first indication information indicates that the terminal device is allowed to obtain a connection service of the second communication standard.

[0163] In a possible implementation method, the first indication information indicates a frequency list of the second communication standard.

[0164] In a possible implementation method, the processing unit 510 is further configured to control the transceiver unit 520 to send second indication information, where the second indication information indicates that a network failure occurs in the first communication standard of at least one PLMN.

[0165] In a possible implementation method, the first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of the second communication standard under each PLMN.

[0166] In a possible implementation method, the processing unit 510 is further used to control the transceiver unit 520 to send third indication information, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

[0167] In a possible implementation method, the processing unit 510 is also used to control the transceiver unit 520 to send a fourth indication information, wherein the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard.

[0168] In a possible implementation method, the fourth indication information is carried in an RRC release message.

[0169] In a possible implementation method, the first indication information is carried in a system message or an RRC message.

[0170] For a more detailed description of the processing unit 510 and the transceiver unit 520, reference may be made to the relevant description in the above method embodiment, which will not be repeated here.

[0171] Figure 6 The communication device 600 shown includes a processor 610 and an interface circuit 620. The processor 610 and the interface circuit 620 are coupled to each other. It is understood that the interface circuit 620 can be a transceiver or an input-output interface. Optionally, the communication device 600 may also include a memory 630 for storing instructions executed by the processor 610 or storing input data required by the processor 610 to execute instructions or storing data generated after the processor 610 executes instructions.

[0172] When the communication device 600 is used to implement the above method embodiment, the processor 610 is used to implement the function of the above processing unit 510 , and the interface circuit 620 is used to implement the function of the above transceiver unit 520 .

[0173] It is understandable that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0174] The method steps in the embodiments of the present application can be implemented by hardware, or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, register, hard disk, mobile hard disk, compact disc read-only memory (compact disc read-only memory, CD-ROM) or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a terminal device or a network device. Of course, the processor and the storage medium can also be present in an access network device or a terminal as discrete components.

[0175] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using 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. A computer program (English: Computer Program) refers to a set of instructions that indicate each step of an electronic computer or other device with message processing capability, usually written in a certain programming language, and runs on a certain target architecture. 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 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, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both volatile and non-volatile types of storage media.

[0176] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0177] In this application, "at least one" means one or more, and "more than one" 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. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of this application, the character " / " indicates that the previous and next associated objects are in a "division" relationship.

[0178] It is understood that the various numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that: Applied to terminal equipment, including: The terminal device is registered in a visited public land mobile network VPLMN, and the terminal device is configured to use a connection service of a first communication standard; receiving first indication information; According to the first indication information, a connection service of the second communication standard is obtained.

2. The method according to claim 1, characterized in that The first indication information instructs the terminal device to obtain a connection service of the second communication standard.

3. The method according to claim 1, characterized in that The first indication information indicates that the terminal device is allowed to obtain the connection service of the second communication standard; The acquiring, according to the first indication information, a connection service of the second communication standard includes: Acquire a connection service of the first communication standard according to the first indication information; In case that the connection service of the first communication standard fails to be obtained, the connection service of the second communication standard is obtained.

4. The method according to claim 1, characterized in that The first indication information indicates a frequency list of the second communication standard; The acquiring, according to the first indication information, a connection service of the first communication standard includes: According to the frequency list of the second communication standard, a connection service of the second communication standard is acquired.

5. The method according to claim 4, characterized in that The acquiring the connection service of the second communication standard according to the frequency list of the second communication standard includes: Acquire a connection service of the first communication standard; In the case where the connection service of the first communication standard fails to be acquired, the connection service of the second communication standard is acquired according to the frequency list of the second communication standard.

6. The method according to claim 3 or 5, characterized in that The method further comprises: receiving second indication information, where the second indication information indicates that a network failure occurs in the first communication mode of at least one public land mobile network PLMN; The obtaining of the connection service of the first communication standard includes: On a PLMN other than the at least one PLMN, a connection service of the first communication standard is obtained.

7. The method according to claim 1, characterized in that The method further comprises: receiving second indication information, where the second indication information indicates that a network failure occurs in a first communication standard of at least one PLMN; The acquiring, according to the first indication information, a connection service of the second communication standard includes: In a case where all PLMNs available to the terminal device are included in the at least one PLMN, a connection service of the second communication standard is obtained.

8. The method according to claim 1, characterized in that The first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of the second communication standard under each PLMN.

9. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Third indication information is received, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

10. The method according to any one of claims 1 to 9, characterized in that The method further comprises: receiving fourth indication information, wherein the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard; According to the fourth indication information, a connection service of the first communication standard is obtained.

11. The method according to claim 10, characterized in that The receiving fourth indication information includes: receiving a radio resource control (RRC) release message sent by a network device, wherein the RRC release message includes the fourth indication information; or, A detach request message sent by a core network device is received, where the detach request message includes the fourth indication information, and the fourth indication information is a cause value.

12. The method according to any one of claims 1 to 11, characterized in that The first indication information is carried in a system message or an RRC message.

13. A communication method, characterized in that: Applied to network equipment, including: A first indication message is sent to a terminal device, the terminal device is registered in a visited public land mobile network VPLMN, the terminal device is configured to use a connection service of a first communication standard, and the first indication message is used to trigger the terminal device to obtain a connection service of a second communication standard.

14. The method according to claim 13, characterized in that The first indication information instructs the terminal device to obtain a connection service of the second communication standard.

15. The method according to claim 13, characterized in that The first indication information indicates that the terminal device is allowed to obtain the connection service of the second communication standard.

16. The method according to claim 13, characterized in that The first indication information indicates a frequency list of the second communication standard.

17. The method according to claim 15 or 16, characterized in that The method further comprises: Sending second indication information, where the second indication information indicates that a network failure occurs in the first communication standard of at least one PLMN.

18. The method according to claim 13, characterized in that The first indication information indicates that a failure occurs in at least one PLMN, and each PLMN of the at least one PLMN supports a terminal device to obtain a connection service of the second communication standard under each PLMN.

19. The method according to any one of claims 13 to 15, characterized in that The method further comprises: Send third indication information, where the third indication information indicates that inbound roaming of a terminal device of at least one PLMN is allowed, and the at least one PLMN includes the VPLMN.

20. The method according to any one of claims 13 to 19, characterized in that The method further comprises: Sending fourth indication information, wherein the fourth indication information instructs the terminal device to prohibit the use of the connection service of the second communication standard, or instructs the terminal device to obtain the connection service of the first communication standard.

21. The method of claim 20, wherein: The fourth indication information is carried in a radio resource control RRC release message.

22. The method according to any one of claims 13 to 21, characterized in that The first indication information is carried in a system message or an RRC message.

23. A communication device, characterized in that: The invention comprises a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the method described in any one of claims 1 to 12, or execute the method described in any one of claims 13 to 22.

24. A communication device, characterized in that: Comprising a module for executing the method of any one of claims 1 to 12, or the method of any one of claims 13 to 22.

25. A communication device, characterized in that: The method comprises a processor configured to execute the method according to any one of claims 1 to 12, or to execute the method according to any one of claims 13 to 22.

26. A communication device, characterized in that: The invention comprises a memory; the memory is used to store computer instructions, and when the computer instructions are executed, the method as claimed in any one of claims 1 to 12 is implemented, or the method as claimed in any one of claims 13 to 22 is implemented.

27. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or instruction. When the computer program or instruction is executed by the communication device, the method as claimed in any one of claims 1 to 12 is implemented, or the method as claimed in any one of claims 13 to 22 is implemented.

28. A computer program product, characterized in that The computer program product includes a computer program or instructions, and when the computer program or instructions are executed by a communication device, the method according to any one of claims 1 to 12 or the method according to any one of claims 13 to 22 is executed.

29. A communication method, characterized in that: include: The network device sends first indication information to the terminal device, the terminal device is registered in a visited public land mobile network VPLMN, and the terminal device is configured to use a connection service of a first communication standard; The terminal device obtains a connection service of the second communication standard according to the first indication information.

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