WO2024051546A1

WO2024051546A1 - Network selection method and apparatus, and terminal

Info

Publication number: WO2024051546A1
Application number: PCT/CN2023/115668
Authority: WO
Inventors: 张鹏飞; 王慧; 康艳超
Original assignee: 维沃移动通信有限公司
Priority date: 2022-09-06
Filing date: 2023-08-30
Publication date: 2024-03-14
Also published as: CN117715154A

Abstract

The present application relates to the technical field of communications, and discloses a network selection method and apparatus, and a terminal. The network selection method in embodiments of the present application comprises: a terminal selects a target underlay network according to stored first indication information and one or more target overlay networks, the target overlay network providing a target service for the terminal, and the target underlay network being a network for accessing the target overlay network to establish data connection, wherein the first indication information comprises at least one of the following: first information indicating an underlay network list corresponding to each overlay network; second information indicating an overlay network list corresponding to each underlay network; third information indicating a mapping relationship between the underlay network list and the overlay network list, the underlay network list comprising at least one underlay network, and the overlay network list comprising at least one overlay network; and fourth information indicating a network selection mode of the terminal.

Description

Network selection method, device and terminal

Cross-references to related applications

This application claims priority to Chinese Patent Application No. 202211086061.5 filed in China on September 6, 2022, the entire content of which is incorporated herein by reference.

Technical field

This application belongs to the field of communication technology, and specifically relates to a network selection method, device, and terminal.

Background technique

For reasons such as security, business cooperation between operators, and network deployment, when the terminal passes through the underlay network (which can be a Public Land Mobile Network (PLMN)) or an independent non-public network (Stand- alone Non-Public Network (SNPN))) when accessing the upper layer (overlay) network (which can be PLMN or SNPN), there are restrictions on the underlay network, that is, the terminal can only access the overlay network through certain underlay networks. Then, how to select a network in this scenario is a problem that needs to be solved.

Contents of the invention

Embodiments of the present application provide a network selection method, device, and terminal, which enable the terminal to select and access the target underlay network, and then access the target overlay network.

The first aspect provides a network selection method, including:

The terminal selects a target underlay network based on the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network establishes a data connection for accessing the target overlay network. network of;

Wherein, the first indication information includes at least one of the following:

The first information indicates the underlay network list corresponding to each overlay network;

The second information indicates the overlay network list corresponding to each underlay network;

The third information indicates the mapping relationship between the underlay network list and the overlay network list. The underlay network list includes at least one underlay network, and the overlay network list includes at least one overlay network;

The fourth information indicates the network selection mode of the terminal.

In the second aspect, a network selection device is provided, including:

A processing module configured to select a target underlay network based on the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network is for accessing the target overlay. Network A network for establishing data connections;

The fourth information indicates the network selection mode of the terminal.

In a third aspect, a terminal is provided. The terminal includes a processor and a memory. The memory stores programs or instructions that can be run on the processor. When the program or instructions are executed by the processor, the following implementations are implemented: The steps of the method described in one aspect.

In a fourth aspect, a terminal is provided, including a processor and a communication interface, wherein the processor is configured to select a target underlay network according to the stored first indication information and one or more target overlay networks, and the target overlay network is The terminal provides a target service, and the target underlay network is a network that accesses the target overlay network to establish a data connection; wherein the first indication information includes at least one of the following: first information, indicating a connection with each overlay network The corresponding underlay network list; the second information indicates the overlay network list corresponding to each underlay network; the third information indicates the mapping relationship between the underlay network list and the overlay network list, and the underlay network list includes at least one underlay network, so The overlay network list includes at least one overlay network; fourth information indicates the network selection mode of the terminal.

In a fifth aspect, a readable storage medium is provided. Programs or instructions are stored on the readable storage medium. When the programs or instructions are executed by a processor, the steps of the method described in the first aspect are implemented.

In a sixth aspect, a chip is provided. The chip includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the method described in the first aspect. .

In a seventh aspect, a computer program/program product is provided, the computer program/program product is stored in a storage medium, and the computer program/program product is executed by at least one processor to implement the method described in the first aspect. Steps for choosing a network method.

In this embodiment of the present application, the terminal stores first indication information. The first indication information indicates the correspondence between the overlay network and the underlay network or the network selection mode of the terminal. The terminal can select an access target based on the first indication information. The target underlay network of the overlay network, or the terminal's network reselection process is triggered based on the first instruction information to select a target underlay network that can access the target overlay network, thereby achieving access to the target overlay network through the target underlay network.

Description of the drawings

Figure 1 is a block diagram of a wireless communication system applicable to the embodiment of the present application;

Figure 2 is a schematic diagram of a terminal accessing the overlay network through the underlay network;

Figures 3-5 are schematic flow charts of the network selection method according to the embodiment of the present application;

Figure 6 is a schematic structural diagram of a network selection device according to an embodiment of the present application;

Figure 7 is a schematic structural diagram of a communication device according to an embodiment of the present application;

Figure 8 is a schematic structural diagram of a terminal according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of this application.

The terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances so that the embodiments of the present application can be practiced in sequences other than those illustrated or described herein, and that "first" and "second" are distinguished objects It is usually one type, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and/or" in the description and claims indicates at least one of the connected objects, and the character "/" generally indicates that the related objects are in an "or" relationship.

It is worth pointing out that the technology described in the embodiments of this application is not limited to Long Term Evolution (Long Term Evolution, LTE)/LTE Evolution (LTE-Advanced, LTE-A) systems, and can also be used in other wireless communication systems, such as code Code Division Multiple Access (CDMA), Time Division Multiple Access (Time Division Multiple Access, TDMA), Frequency Division Multiple Access (Frequency Division Multiple Access, FDMA), Orthogonal Frequency Division Multiple Access (Orthogonal Frequency Division Multiple Access, OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA) and other systems. The terms "system" and "network" in the embodiments of this application are often used interchangeably, and the described technology can be used not only for the above-mentioned systems and radio technologies, but also for other systems and radio technologies. The following description describes a New Radio (NR) system for example purposes, and uses NR terminology in much of the following description, but these techniques can also be applied to applications other than NR system applications, such as 6th Generation , 6G) communication system.

Figure 1 shows a block diagram of a wireless communication system to which embodiments of the present application are applicable. The wireless communication system includes a terminal 11 and a network side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), or a notebook computer, a personal digital assistant (Personal Digital Assistant, PDA), a palmtop computer, a netbook, or a super mobile personal computer. (ultra-mobile personal computer, UMPC), mobile Internet device (Mobile Internet Device, MID), augmented reality (AR)/virtual reality (VR) equipment, robots, wearable devices (Wearable Device) , Vehicle User Equipment (VUE), Pedestrian User Equipment (PUE), smart home (home equipment with wireless communication functions, such as refrigerators, TVs, washing machines or furniture, etc.), game consoles, personal computers (personal computer, PC), teller machine or self-service machine and other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets) bracelets, smart anklets, etc.), smart wristbands, smart clothing, etc. It should be noted that the embodiment of the present application does not limit the specific type of the terminal 11. The network side device 12 may include access network equipment or core network equipment, where the access network The device may also be called a radio access network device, a radio access network (Radio Access Network, RAN), a radio access network function or a radio access network unit. Access network equipment may include a base station, a Wireless Local Area Network (WLAN) access point or a Wireless Fidelity (WiFi) node, etc. The base station may be called a Node B or an Evolved Node B. eNB), access point, Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home B Node, home evolved B node, transmitting receiving point (Transmitting Receiving Point, TRP) or some other suitable term in the field. As long as the same technical effect is achieved, the base station is not limited to specific technical terms. It needs to be explained that , in the embodiment of this application, only the base station in the NR system is taken as an example for introduction, and the specific type of the base station is not limited.

The terminal accesses the overlay network through the underlay network, as shown in Figure 2, including the following steps:

1. The UE registers with the PLMN through the Uu port of the PLMN (using the PLMN contract);

2. When the UE wants to obtain services from the SNPN, the UE establishes a data connection to the non-3GPP Interworking Function (N3IWF) corresponding to the SNPN;

3. The UE sends a registration message to the SNPN core network (Core Network, CN) through the above data connection (using PLMN contract);

4. After the UE registers with the SNPN CN, it obtains services from the SNPN;

5. For available PLMNs, the terminal selects a network based on the PLMN priority list.

The network selection method provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings through some embodiments and application scenarios.

The embodiment of the present application provides a network selection method, as shown in Figure 3, including:

Step 101: The terminal selects a target underlay network based on the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network is for accessing the target overlay network. Establish a network for data connections;

The fourth information indicates the network selection mode of the terminal.

The target service is the service that the terminal wants to obtain, and the overlay network is the service that the terminal wants to obtain. Standard network, it can be understood that the overlay network is a network that provides target services. The underlay network is a network that the terminal accesses through the Uu port and establishes a data connection for accessing the overlay network. The overlay network can be PLMN or SNPN, and the underlay network can be PLMN or SNPN.

When the UE uses the user plane established on the PLMN to access the SNPN service through NWu, the PLMN is an underlay network and SNPN is an overlay network. When the UE uses the user plane established on the SNPN to access the PLMN service through NWu, the PLMN is an underlay network and the SNPN is an overlay network.

The terminal can obtain the first indication information from the overlay network or the underlay network and store it, and can also pre-configure the first indication information in the terminal. The first indication information can be located in at least one of the following of the terminal: Global User Identification Card (Universal Subscriber Identity Module, USIM); internal memory ME of the terminal; entry (entry) of SNPN subscription information.

The first indication information may include one or more first information. For example, the first indication information may include one or more underlay network lists. In a specific example, taking the overlay network and the underlay network as both PLMNs as an example, the overlay network includes PLMN1 and PLMN2, the underlay network includes PLMN a, PLMN b, PLMN c, PLMN d,..., PLMN h. The first indication information includes underlay network list 1 and underlay network list 2. Underlay network list 1 indicates the underlay network list corresponding to PLMN1, The underlay networks in the underlay network list 1 can access PLMN1. The underlay networks in the underlay network list 1 are: PLMN a, PLMN b, PLMN c, PLMN d. Among them, the ordering of the underlay networks in the underlay network list 1 can reflect the underlay The priority of the network, the underlay networks in underlay network list 1 can be arranged from high to low priority, or can be arranged from low to high priority; underlay network list 2 indicates the underlay network list corresponding to PLMN2, The underlay networks in the underlay network list 2 can access PLMN2. The underlay networks in the underlay network list 2 are: PLMN e, PLMN f, PLMN g, PLMN h. Among them, the ordering of the underlay networks in the underlay network list 2 can reflect the underlay network. The priority of the network. The underlay networks in underlay network list 2 can be arranged from high to low priority, or they can be arranged from low to high priority.

The first indication information may include one or more second information. For example, the first indication information may include one or more overlay network lists. In a specific example, taking the overlay network and the underlay network as both PLMNs as an example, the underlay network includes PLMN3 and PLMN4, the overlay network includes PLMN i, PLMN j, PLMN k, PLMN l,..., PLMN p, the first indication information includes overlay network list 1 and overlay network list 2, overlay network list 1 is the overlay network list corresponding to PLMN3, PLMN3 can access the overlay networks in the overlay network list. The overlay networks in the overlay network list 1 are: PLMN i, PLMN j, PLMN k, PLMN l. Among them, the ordering of the overlay networks in the overlay network list 1 can reflect the access of PLMN3. The priority of accessing the overlay network. The overlay networks in the overlay network list 1 can be arranged from high to low priority, or they can be arranged from low to high priority. PLMN3 preferentially accesses the overlay network with the highest priority. ; Overlay network list 2 is the overlay network list corresponding to PLMN4. PLMN4 can access the overlay network in the overlay network list. The overlay networks in overlay network list 2 are: PLMN m, PLMN n, PLMN o, PLMN p, where, The ordering of overlay networks in overlay network list 2 can reflect the priority of PLMN4 access to overlay networks. level, the overlay networks in overlay network list 2 can be arranged from high to low priority, or from low to high priority. PLMN4 preferentially accesses the overlay network with the highest priority.

The third information indicates the mapping relationship between the underlay network list and the overlay network list. The underlay network list includes at least one underlay network. The overlay network list includes at least one overlay network. In a specific example, the overlay network and the underlay network are Taking PLMN as an example, the overlay network in the third information includes PLMN5, PLMN6 and PLMN7, and the underlay network includes PLMN q, PLMN r, PLMN s and PLMN t, then the third information indicates PLMN q, PLMN r, PLMN s, PLMN PLMN t can all access PLMN5, PLMN q, PLMN r, PLMN s, and PLMN t can all access PLMN6, and PLMN q, PLMN r, PLMN s, and PLMN t can all access PLMN7.

In some embodiments, the network selection mode includes at least one of the following:

SNPN access mode, indicating priority or only selecting SNPN as the target underlay network;

Non-SNPN access mode, indicating priority or only selecting PLMN as the target underlay network;

The first access mode indicates selecting SNPN as the target underlay network or indicating selecting PLMN as the target underlay network.

If the network selection mode of the terminal is SNPN access mode, SNPN is preferred or only selected as the target underlay network; if the network selection mode of the terminal is non-SNPN access mode, PLMN is preferred or only selected as the target underlay network; if The network selection mode of the terminal is the first access mode, and SNPN or PLMN is selected as the target underlay network. The configuration granularity of the network selection mode can be for each network or each terminal. For example, the same network selection mode can be configured for terminals in each network, or the network selection mode can be configured individually for each terminal.

In some embodiments, selecting the target underlay network includes:

If the network currently registered by the terminal meets the preset network selection conditions, access the one or more target overlay networks through the currently registered network;

If the network currently registered by the terminal does not meet the preset network selection conditions, reselect the target underlay network according to the first instruction information;

Wherein, the network selection conditions include at least one of the following:

The network currently registered by the terminal is in the underlay network list corresponding to the one or more target overlay networks;

The one or more target overlay networks are in the overlay network list corresponding to the network currently registered by the terminal;

There is a mapping relationship between the network currently registered by the terminal and the one or more target overlay networks;

The network currently registered by the terminal conforms to the network selection mode of the terminal.

Through the technical solution of this embodiment, it can be clarified how the terminal accesses the overlay network through the underlay network.

In the case where the first indication information includes the first information, if the network currently registered by the terminal is in the underlay network list corresponding to the one or more target overlay networks, the network currently registered by the terminal can be used as the target. The underlay network accesses the target overlay network through the currently registered network and obtains services; If the network currently registered by the terminal is not in the underlay network list corresponding to the target overlay network, the network currently registered by the terminal cannot be used as the target underlay network, and network reselection is performed. When there is one target overlay network, if the network currently registered by the terminal is in the underlay network list corresponding to the target overlay network, it can access the target overlay network through the current underlay network; when there are multiple target overlay networks If the network currently registered by the terminal is included in the underlay network list corresponding to multiple target overlay networks, it can access the target overlay network through the current underlay network. Otherwise, it cannot access the target overlay network through the current underlay network.

In the case where the first indication information includes the second information, if the one or more target overlay networks are in the overlay network list corresponding to the network currently registered by the terminal, the network currently registered by the terminal can be used as the target. The underlay network accesses the target overlay network through the currently registered network and obtains services; if the target overlay network is not in the overlay network list corresponding to the network currently registered by the terminal, the network currently registered by the terminal cannot be used as the target. Underlay network, perform network reselection.

In the case where the first indication information includes the third information, if there is a mapping relationship between the network currently registered by the terminal and the one or more target overlay networks, the network currently registered by the terminal can be used as the target underlay network, Access the target overlay network through the currently registered network and obtain services; if there is no mapping relationship between the network currently registered by the terminal and the target overlay network, the network currently registered by the terminal cannot be used as the target underlay network, and network Reselect.

In the case where the first indication information includes the fourth information, if the network currently registered by the terminal complies with the network selection mode of the terminal, the network currently registered by the terminal can be used as the target underlay network, through the currently registered network Access the target overlay network; if the network currently registered by the terminal does not comply with the terminal's network selection mode, the network currently registered by the terminal cannot be used as the target underlay network, and network reselection is performed. For example, the network selection mode of the terminal is SNPN access mode, and the network currently registered by the terminal is SNPN, then the network currently registered by the terminal can be used as the target underlay network, and the target overlay network can be accessed through the currently registered network; if The network selection mode is non-SNPN access mode, and the network currently registered by the terminal is SNPN. The network currently registered by the terminal cannot be used as the target underlay network, and network reselection is required.

Wherein, the opportunity to reselect the target underlay network according to the first instruction information includes any of the following:

Trigger network reselection immediately and select the target underlay network. Network reselection can be performed immediately after judging that the network currently registered by the terminal cannot be used as the target underlay network. This allows the terminal to access the target underlay network as soon as possible and then access the target overlay network. ;

After the preset first timer times out, network reselection is triggered to select the target underlay network. The first timer can be protocol-defined or pre-configured or network-side device configuration, so that terminal access can be controlled as needed. The timing of the target underlay network;

After the preset high-priority service ends, network reselection is triggered and the target underlay network is selected. That is, when there is no high-priority service, the network reselection process is immediately initiated; if there is high-priority service, wait until the high-priority service is available. After the end of high-priority services, a network reselection process is initiated to ensure the normal operation of high-priority services and avoid interruption of high-priority services.

Wherein, the high-priority services include at least one of the following:

Internet Protocol (IP) multimedia subsystem registration signaling;

Multimedia telephony (MMTEL) voice call;

MMTEL video call;

Transmitting short message service (SMS) through the non-access stratum (Non-access stratum, NAS) (i.e. SMS over NAS);

Short messages are transmitted through the IP multimedia subsystem (i.e. SMS over IP).

In some embodiments, when the number of the target overlay network is one, reselecting the target underlay network according to the first indication information includes:

Determine the target underlay network set, and select the target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the target underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

The target overlay network is in the overlay network list corresponding to the candidate underlay network;

There is a mapping relationship between the target underlay network and the target overlay network;

Comply with the network selection mode of the terminal.

If the target underlay network set includes multiple candidate underlay networks, selecting the target underlay network from the target underlay network set includes at least one of the following:

According to the priority order of candidate underlay networks in the target underlay network set, select the candidate underlay network with the highest priority as the target underlay network;

Randomly select a candidate underlay network from the set of target underlay networks.

Specifically, as shown in Figure 4, when the number of target overlay networks is one, the network selection method includes the following steps:

Step 0: The terminal stores the first indication information;

Step 1: UE registers in underlay network 1;

Step 2: UE wants to register to overlay network 1;

Step 3: UE checks the first indication information;

If the first indication information includes the first information and underlay network 1 is in the underlay network list corresponding to overlay network 1, access overlay network 1 through underlay network 1 to register and obtain services, skipping steps 4 and 5; underlay network 1 is not in the list. In the underlay network list corresponding to overlay network 1, trigger the network reselection process and turn to step 4;

If the first indication information includes the second information and overlay network 1 is in the overlay network list corresponding to underlay network 1, access overlay network 1 through underlay network 1 to register and obtain services, skipping steps 4 and 5; overlay network 1 is not in the list. In the overlay network list corresponding to underlay network 1, trigger the network reselection process and turn to step 4;

If the first indication information includes the third information, there is a mapping relationship between overlay network 1 and underlay network 1, Then access overlay network 1 through underlay network 1 to register and obtain services, skip steps 4 and 5; there is no mapping relationship between overlay network 1 and underlay network 1, trigger the network reselection process, and go to step 4;

If the first indication information includes the fourth information and the underlay network 1 conforms to the terminal's network selection mode, access the overlay network 1 through the underlay network 1 to register and obtain the service, skipping steps 4 and 5; the underlay network 1 does not conform to the terminal's selection mode. Network mode, trigger the network reselection process, and go to step 4;

Step 4: The terminal triggers the network reselection process;

The terminal can trigger the network reselection process immediately; or trigger the network reselection process after the preset first timer expires; or determine whether to initiate the network reselection process based on whether there are high-priority services, that is, there is no high-priority service If there is a service, the network reselection process will be initiated immediately. If there is a high-priority service, the network reselection process will be initiated after the high-priority service ends.

If the first indication information includes the first information and only underlay network 2 is in the underlay network list corresponding to overlay network 1, then underlay network 2 is selected as the target underlay network; if there are multiple underlay networks such as underlay network 2, underlay network 3, Underlay networks 4 are all in the underlay network list corresponding to overlay network 1. Then the underlay network 2 with the highest priority can be selected as the target underlay network according to the priority order of the underlay networks in the underlay network list, or an underlay network can be randomly selected. network as the target underlay network.

If the first indication information includes the second information and overlay network 1 is only in the overlay network list corresponding to underlay network 2, then underlay network 2 is selected as the target underlay network; if overlay network 1 is included in multiple underlay networks at the same time, such as underlay network 2 , underlay network 3, and underlay network 4. In the overlay network list corresponding to underlay network 3 and underlay network 4, the underlay network 2 with the highest priority can be selected as the target underlay network according to the priority order of multiple underlay networks, or an underlay network can be randomly selected as the target underlay network. The target underlay network. The priority order of the underlay network can be preconfigured or configured by the network side device or defined by the protocol.

If the first indication information includes the third information, and only underlay network 2 and overlay network 1 have a mapping relationship, then underlay network 2 is selected as the target underlay network; if there are multiple underlay networks such as underlay network 2, underlay network 3, and underlay network 4 all have a mapping relationship with overlay network 1, then the underlay network 2 with the highest priority can be selected as the target underlay network according to the priority order of multiple underlay networks, or an underlay network can be randomly selected as the target underlay network. . The priority order of the underlay network can be preconfigured or configured by the network side device or defined by the protocol.

If the first indication information includes the fourth information and only underlay network 2 matches the network selection mode of the terminal, then underlay network 2 is selected as the target underlay network. If there are multiple underlay networks, such as underlay network 2, underlay network 3, and underlay network 4, all of which conform to the network selection mode of the terminal, the underlay network 2 with the highest priority can be selected as the target according to the priority order of the multiple underlay networks. underlay network, you can also randomly select an underlay network as the target underlay network. The priority order of the underlay network can be preconfigured or configured by the network side device or defined by the protocol.

Step 5: UE registers in underlay network 2;

Step 6: UE registers in overlay network 1.

In some embodiments, when the number of target overlay networks is multiple, reselecting the target underlay network according to the first indication information includes:

For each target overlay network, determine a set of candidate underlay networks corresponding to the target overlay network according to the first indication information;

Determine the target underlay network set according to the candidate underlay network set of multiple target overlay networks, where the target underlay network set is the intersection of multiple candidate underlay network sets;

Select a target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the candidate underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

There is a mapping relationship with the target overlay network;

Comply with the network selection mode of the terminal.

Specifically, as shown in Figure 5, when the number of target overlay networks is multiple, the network selection method includes the following steps:

Step 0: The terminal stores the first indication information;

Step 1: UE registers in underlay network 1;

Step 2: The UE wants to register to overlay network 1 and overlay network 2;

Step 3: UE checks the first indication information;

First, for overlay network 1, the candidate underlay network set corresponding to overlay network 1 is determined according to the first indication information. If the first indication information includes the first information, the candidate underlay network in the candidate underlay network set is located in the underlay network list corresponding to overlay network 1. in; if the first indication information includes the second information, overlay network 1 is located in the overlay network list corresponding to the candidate underlay network in the candidate underlay network set; if the first indication information includes the third information, overlay network 1 and the candidate underlay network set There is a mapping relationship among the candidate underlay networks in the set; if the first indication information includes the fourth information, the candidate underlay networks in the candidate underlay network set conform to the network selection mode of the terminal.

For overlay network 2, determine the candidate underlay network set corresponding to overlay network 2 according to the first indication information. If the first indication information includes the first information, the candidate underlay network in the candidate underlay network set is located in the underlay network list corresponding to overlay network 2. ; If the first indication information includes the second information, overlay network 2 is located in the overlay network list corresponding to the candidate underlay network in the candidate underlay network set; such as If the first indication information includes the third information, there is a mapping relationship between the overlay network 2 and the candidate underlay network in the candidate underlay network set; if the first indication information includes the fourth information, the candidate underlay network in the candidate underlay network set conforms to the selection of the terminal. network mode.

Determine the intersection of the candidate underlay network set corresponding to overlay network 1 and the candidate underlay network set corresponding to overlay network 2 as the target underlay network set;

If the currently registered network, namely underlay network 1, is in the target underlay network set, access overlay network 1 and overlay network 2 through underlay network 1 to register and obtain services, skip steps 4 and 5. If the currently registered network is the underlay network, 1 is not in the target underlay network set, triggers the network reselection process, and goes to step 4;

Step 4: The terminal triggers the network reselection process;

If there is only underlay network 2 in the target underlay network set, select underlay network 2 as the target underlay network; if there are multiple underlay networks in the target underlay network set, such as underlay network 2, underlay network 3, and underlay network 4, you can select According to the priority order of the underlay networks, the underlay network 2 with the highest priority is selected as the target underlay network, or an underlay network can be randomly selected as the target underlay network. The priority order of the underlay network can be preconfigured or configured by the network side device or defined by the protocol.

Step 5: UE registers in underlay network 2;

Step 6a & Step 6b: The UE registers in overlay network 1 and overlay network 2 respectively.

For the network selection method provided by the embodiment of the present application, the execution subject may be a network selection device. In the embodiment of the present application, the network selection device performing the network selection method is taken as an example to illustrate the network selection device provided by the embodiment of the present application.

An embodiment of the present application provides a network selection device 200, as shown in Figure 6, including:

The processing module 210 is configured to select a target underlay network according to the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network is for accessing the target. Overlay network establishes a data connection network;

The fourth information indicates the network selection mode of the terminal.

Among them, the target service is the service that the terminal wants to obtain, the overlay network is the target network that the terminal wants to obtain the service, and the underlay network is the network that the terminal accesses through the Uu port and establishes a data connection for accessing the overlay network. It can be PLMN or SNPN, and the underlay network can be PLMN or SNPN.

The terminal can obtain the first indication information from the overlay network or the underlay network and store it, and can also pre-configure the first indication information in the terminal. The first indication information can be located in at least one of the following of the terminal: Global User Identification Card USIM; internal memory ME of the terminal; entry of SNPN subscription information.

The first indication information may include one or more second information. For example, the first indication information may include one or more overlay network lists. In a specific example, taking the overlay network and the underlay network as both PLMNs as an example, the underlay network includes PLMN3 and PLMN4, the overlay network includes PLMN i, PLMN j, PLMN k, PLMN l,..., PLMN p. The first indication information includes overlay network list 1 and overlay network list 2. Overlay network list 1 is the overlay network list corresponding to PLMN3. PLMN3 can access the overlay networks in the overlay network list. The overlay networks in the overlay network list 1 are: PLMN i, PLMN j, PLMN k, PLMN l. Among them, the ordering of the overlay networks in the overlay network list 1 can reflect the access of PLMN3. The priority of accessing the overlay network. The overlay networks in the overlay network list 1 can be arranged from high to low priority, or they can be arranged from low to high priority. PLMN3 preferentially accesses the overlay network with the highest priority. ; Overlay network list 2 is the overlay network list corresponding to PLMN4. PLMN4 can access the overlay network in the overlay network list. The overlay networks in overlay network list 2 are: PLMN m, PLMN n, PLMN o, PLMN p, where, The ordering of overlay networks in overlay network list 2 can reflect the priority of PLMN4 access to the overlay network. The overlay networks in overlay network list 2 can be arranged from high to low priority, or from low to high priority. Arrange, PLMN4 preferentially accesses the overlay network with the highest priority.

The third information indicates the mapping relationship between the underlay network list and the overlay network list, the underlay network list includes at least one underlay network, and the overlay network list includes at least one overlay network, In a specific example, assuming that both the overlay network and the underlay network are PLMN, the overlay network in the third information includes PLMN5, PLMN6 and PLMN7, and the underlay network includes PLMN q, PLMN r, PLMN s and PLMN t, then the third information Indicates that PLMN q, PLMN r, PLMN s, and PLMN t can all access PLMN5, PLMN q, PLMN r, PLMN s, and PLMN t can all access PLMN6, and PLMN q, PLMN r, PLMN s, and PLMN t can all access. PLMN7.

Independent non-public network SNPN access mode, indicating priority or only selecting SNPN as the target underlay network;

Non-SNPN access mode, indicating priority or only selecting the public land mobile network PLMN as the target underlay network;

In some embodiments, the processing module 210 is specifically configured to access the one or more target overlay networks through the currently registered network if the network to which the terminal is currently registered meets preset network selection conditions; if the network to which the terminal is currently registered meets preset network selection conditions; The network currently registered by the terminal does not meet the preset network selection conditions, and the target underlay network is re-selected according to the first instruction information;

In the case where the first indication information includes the first information, if the network currently registered by the terminal is in the underlay network list corresponding to the one or more target overlay networks, the network currently registered by the terminal can be used as the target. The underlay network accesses the target overlay network through the currently registered network and obtains services; if the network currently registered by the terminal is not in the underlay network list corresponding to the target overlay network, the network currently registered by the terminal cannot be used as the target. Underlay network, perform network reselection. When there is one target overlay network, if the network currently registered by the terminal is in the underlay network list corresponding to the target overlay network, Then the target overlay network can be accessed through the current underlay network; in the case of multiple target overlay networks, if the network currently registered by the terminal is included in the underlay network list corresponding to multiple target overlay networks at the same time, it can be accessed through the current underlay network. The underlay network is connected to the target overlay network, otherwise it cannot be connected to the target overlay network through the current underlay network.

Wherein, the high-priority services include at least one of the following:

IP multimedia subsystem registration signaling;

Multimedia telephone service MMTEL voice call;

MMTEL video call;

Transmitting short messages SMS over NAS through the non-access layer;

Transmit short messages SMS over IP through the IP multimedia subsystem.

In some embodiments, when the number of target overlay networks is one,

The processing module 210 is specifically configured to determine a target underlay network set, and select a target underlay network from the target underlay network set;

In the underlay network list corresponding to the target overlay network;

Comply with the network selection mode of the terminal.

In some embodiments, when the number of target overlay networks is multiple,

The processing module 210 is specifically configured to determine, for each target overlay network, a set of candidate underlay networks corresponding to the target overlay network according to the first indication information; and determine a target underlay based on a set of candidate underlay networks of multiple target overlay networks. Network set, the target underlay network set is the intersection of multiple candidate underlay network sets; select a target underlay network from the target underlay network set;

In the underlay network list corresponding to the target overlay network;

There is a mapping relationship with the target overlay network;

Comply with the network selection mode of the terminal.

In some embodiments, the processing module 210 is specifically configured to perform at least one of the following:

The network selection device in the embodiment of the present application may be an electronic device, such as an electronic device with an operating system, or may be a component in the electronic device, such as an integrated circuit or chip. The electronic device may be a terminal or other devices other than the terminal. For example, terminals may include but are not limited to the types of terminals 11 listed above, and other devices may be servers, network attached storage (Network Attached Storage, NAS), etc., which are not specifically limited in the embodiment of this application.

The network selection device provided by the embodiments of the present application can implement each process implemented by the method embodiments in Figures 3 to 5 and achieve the same technical effect. To avoid duplication, the details will not be described here.

Optionally, as shown in Figure 7, this embodiment of the present application also provides a communication device 600, which includes a processor 601 and a memory 602. The memory 602 stores programs or instructions that can be run on the processor 601, such as , when the communication device 600 is a terminal, when the program or instruction is executed by the processor 601, each step of the above network selection method embodiment is implemented. steps, and can achieve the same technical effect, to avoid repetition, they will not be repeated here.

An embodiment of the present application also provides a terminal, which includes a processor and a memory. The memory stores programs or instructions that can be run on the processor. When the program or instructions are executed by the processor, the above is implemented. The steps of the described network selection method.

An embodiment of the present application also provides a terminal, including a processor and a communication interface, wherein the processor is configured to select a target underlay network according to the stored first indication information and one or more target overlay networks, the target overlay network Provide target services for the terminal, and the target underlay network is a network that accesses the target overlay network to establish a data connection; wherein, the first indication information includes at least one of the following: first information, indicating that each overlay The underlay network list corresponding to the network; the second information indicates the overlay network list corresponding to each underlay network; the third information indicates the mapping relationship between the underlay network list and the overlay network list, and the underlay network list includes at least one underlay network, The overlay network list includes at least one overlay network; fourth information indicates the network selection mode of the terminal.

An embodiment of the present application also provides a terminal, including a processor and a communication interface. The terminal embodiment corresponds to the above-mentioned terminal-side method embodiment. Each implementation process and implementation manner of the above-mentioned method embodiment can be applied to this terminal embodiment. , and can achieve the same technical effect. Specifically, FIG. 8 is a schematic diagram of the hardware structure of a terminal that implements an embodiment of the present application.

The terminal 700 includes but is not limited to: a radio frequency unit 701, a network module 702, an audio output unit 703, an input unit 704, a sensor 705, a display unit 706, a user input unit 707, an interface unit 708, a memory 709, a processor 710, etc. At least some parts.

Those skilled in the art can understand that the terminal 700 may also include a power supply (such as a battery) that supplies power to various components. The power supply may be logically connected to the processor 710 through a power management system, thereby managing charging, discharging, and power consumption through the power management system. Management and other functions. The terminal structure shown in FIG. 8 does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown in the figure, or some components may be combined or arranged differently, which will not be described again here.

It should be understood that in the embodiment of the present application, the input unit 704 may include a graphics processing unit (Graphics Processing Unit, GPU) 7041 and a microphone 7042. The graphics processor 7041 is responsible for the image capture device (GPU) in the video capture mode or the image capture mode. Process the image data of still pictures or videos obtained by cameras (such as cameras). The display unit 706 may include a display panel 7061, which may be configured in the form of a liquid crystal display, an organic light emitting diode, or the like. The user input unit 707 includes a touch panel 7071 and at least one of other input devices 7072 . Touch panel 7071, also called touch screen. The touch panel 7071 may include two parts: a touch detection device and a touch controller. Other input devices 7072 may include but are not limited to physical keyboards, function keys (such as volume control keys, switch keys, etc.), trackballs, mice, and joysticks, which will not be described again here.

In this embodiment of the present application, after receiving downlink data from the network side device, the radio frequency unit 701 can transmit it to the processor 710 for processing; in addition, the radio frequency unit 701 can send uplink data to the network side device. Generally, the radio frequency unit 701 includes, but is not limited to, an antenna, amplifier, transceiver, coupler, low noise amplifier, duplexer, etc.

Memory 709 may be used to store software programs or instructions as well as various data. Memory 709 may primarily include stored programs A first storage area for programs or instructions and a second storage area for storing data, where the first storage area can store an operating system, an application program or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. . Additionally, memory 709 may include volatile memory or non-volatile memory, or memory 709 may include both volatile and non-volatile memory. Among them, the non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically removable memory. Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. Volatile memory can be random access memory (Random Access Memory, RAM), static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDRSDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synch link DRAM) , SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DRRAM). Memory 709 in embodiments of the present application includes, but is not limited to, these and any other suitable types of memory.

The processor 710 may include one or more processing units; optionally, the processor 710 integrates an application processor and a modem processor, where the application processor mainly handles operations related to the operating system, user interface, application programs, etc., Modem processors mainly process wireless communication signals, such as baseband processors. It can be understood that the above-mentioned modem processor may not be integrated into the processor 710.

Processor 710, configured to select a target underlay network according to the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network is for accessing the target. Overlay network establishes a data connection network;

The fourth information indicates the network selection mode of the terminal.

In some embodiments, the processor 710 is specifically configured to access the one or more target overlay networks through the currently registered network if the network to which the terminal is currently registered meets preset network selection conditions; if the network to which the terminal is currently registered meets preset network selection conditions; terminal The currently registered network does not meet the preset network selection conditions, and the target underlay network is reselected according to the first instruction information;

In some embodiments, when the number of target overlay networks is one,

The processor 710 is specifically configured to determine a target underlay network set, and select a target underlay network from the target underlay network set;

In the underlay network list corresponding to the target overlay network;

Comply with the network selection mode of the terminal.

In some embodiments, when the number of target overlay networks is multiple,

The processor 710 is specifically configured to determine, for each target overlay network, a set of candidate underlay networks corresponding to the target overlay network according to the first indication information; and determine a target underlay based on a set of candidate underlay networks of multiple target overlay networks. Network set, the target underlay network set is the intersection of multiple candidate underlay network sets; select a target underlay network from the target underlay network set;

In the underlay network list corresponding to the target overlay network;

There is a mapping relationship with the target overlay network;

Comply with the network selection mode of the terminal.

In some embodiments, the processor 710 is specifically configured to perform at least one of the following:

In some embodiments, the opportunity to reselect the target underlay network according to the first indication information includes any of the following:

Immediately trigger network reselection and select the target underlay network;

After the preset first timer times out, network reselection is triggered and the target underlay network is selected;

After the preset high-priority service ends, network reselection is triggered and the target underlay network is selected.

In some embodiments, the high-priority services include at least one of the following:

IP multimedia subsystem registration signaling;

Multimedia telephone service MMTEL voice call;

MMTEL video call;

Transmitting short messages SMS over NAS through the non-access layer;

Transmit short messages SMS over IP through the IP multimedia subsystem.

In some embodiments, the first indication information is located in at least one of the following items of the terminal:

Global Subscriber Identity Card USIM;

The internal memory ME of the terminal;

Entry of SNPN contract information.

Embodiments of the present application also provide a readable storage medium. Programs or instructions are stored on the readable storage medium. When the program or instructions are executed by a processor, each process of the above network selection method embodiment is implemented, and the same can be achieved. The technical effects will not be repeated here to avoid repetition.

Wherein, the processor is the processor in the terminal described in the above embodiment. The readable storage medium includes computer readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disk or optical disk, etc.

An embodiment of the present application further provides a chip. The chip includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the above network selection method embodiment. Each process can achieve the same technical effect. To avoid duplication, it will not be described again here.

It should be understood that the chips mentioned in the embodiments of this application may also be called system-on-chip, system-on-a-chip, system-on-chip or system-on-chip, etc.

Embodiments of the present application further provide a computer program/program product. The computer program/program product is stored in a storage medium. The computer program/program product is executed by at least one processor to implement the above network selection method embodiment. Each process can achieve the same technical effect. To avoid repetition, we will not go into details here.

It should be noted that, in this document, the terms "comprising", "comprises" or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements, It also includes other elements not expressly listed or inherent in the process, method, article or apparatus. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article or apparatus that includes that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. Functions may be performed, for example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can It can be implemented with the help of software plus the necessary common hardware platform. Of course, it can also be implemented through hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application can be embodied in the form of a computer software product that is essentially or contributes to the existing technology. The computer software product is stored in a storage medium (such as ROM/RAM, disk , CD), including several instructions to cause a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in various embodiments of this application.

The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above-mentioned specific implementations. The above-mentioned specific implementations are only illustrative and not restrictive. Those of ordinary skill in the art will Inspired by this application, many forms can be made without departing from the purpose of this application and the scope protected by the claims, all of which fall within the protection of this application.

Claims

A method of selecting a network includes:

The terminal selects a target underlay network based on the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network establishes a data connection for accessing the target overlay network. network of;

Wherein, the first indication information includes at least one of the following:

The first information indicates the underlay network list corresponding to each overlay network;

The second information indicates the overlay network list corresponding to each underlay network;

The third information indicates the mapping relationship between the underlay network list and the overlay network list. The underlay network list includes at least one underlay network, and the overlay network list includes at least one overlay network;

The fourth information indicates the network selection mode of the terminal.
The method according to claim 1, wherein the network selection mode includes at least one of the following:

Independent non-public network SNPN access mode, indicating priority or only selecting SNPN as the target underlay network;

Non-SNPN access mode, indicating priority or only selecting the public land mobile network PLMN as the target underlay network;

The first access mode indicates selecting SNPN as the target underlay network or indicating selecting PLMN as the target underlay network.
The method according to claim 1, wherein selecting the target underlay network includes:

If the network currently registered by the terminal meets the preset network selection conditions, access the one or more target overlay networks through the currently registered network;

If the network currently registered by the terminal does not meet the preset network selection conditions, reselect the target underlay network according to the first instruction information;

Wherein, the network selection conditions include at least one of the following:

The network currently registered by the terminal is in the underlay network list corresponding to the one or more target overlay networks;

The one or more target overlay networks are in the overlay network list corresponding to the network currently registered by the terminal;

There is a mapping relationship between the network currently registered by the terminal and the one or more target overlay networks;

The network currently registered by the terminal conforms to the network selection mode of the terminal.
The method according to claim 3, wherein, when the number of the target overlay network is one, reselecting the target underlay network according to the first indication information includes:

Determine the target underlay network set, and select the target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the target underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

The target overlay network is in the overlay network list corresponding to the candidate underlay network;

There is a mapping relationship between the target underlay network and the target overlay network;

Comply with the network selection mode of the terminal.
The method according to claim 3, wherein when the number of the target overlay networks is multiple, reselecting the target underlay network according to the first indication information includes:

For each target overlay network, determine a set of candidate underlay networks corresponding to the target overlay network according to the first indication information;

Determine the target underlay network set according to the candidate underlay network set of multiple target overlay networks, where the target underlay network set is the intersection of multiple candidate underlay network sets;

Select a target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the candidate underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

The target overlay network is in the overlay network list corresponding to the candidate underlay network;

There is a mapping relationship with the target overlay network;

Comply with the network selection mode of the terminal.
The method according to claim 4 or 5, wherein selecting a target underlay network from the target underlay network set includes at least one of the following:

According to the priority order of candidate underlay networks in the target underlay network set, select the candidate underlay network with the highest priority as the target underlay network;

Randomly select a candidate underlay network from the set of target underlay networks.
The method according to claim 3, wherein the opportunity to reselect the target underlay network according to the first indication information includes any of the following:

Immediately trigger network reselection and select the target underlay network;

After the preset first timer times out, network reselection is triggered and the target underlay network is selected;

After the preset high-priority service ends, network reselection is triggered and the target underlay network is selected.
The method according to claim 7, wherein the high priority business includes at least one of the following:

IP multimedia subsystem registration signaling;

Multimedia telephone service MMTEL voice call;

MMTEL video call;

Transmitting short messages SMS over NAS through the non-access layer;

Transmit short messages SMS over IP through the IP multimedia subsystem.
The method according to claim 1, wherein the first indication information is located in at least one of the following of the terminal:

Global Subscriber Identity Card USIM;

The internal memory ME of the terminal;

Entry of SNPN contract information.
A network selection device includes:

A processing module configured to select a target underlay network based on the stored first indication information and one or more target overlay networks. The target overlay network provides target services for the terminal, and the target underlay network is established for access to the target overlay network. Data connection network;

Wherein, the first indication information includes at least one of the following:

The first information indicates the underlay network list corresponding to each overlay network;

The second information indicates the overlay network list corresponding to each underlay network;

The third information indicates the mapping relationship between the underlay network list and the overlay network list. The underlay network list includes at least one underlay network, and the overlay network list includes at least one overlay network;

The fourth information indicates the network selection mode of the terminal.
The device according to claim 10, wherein the network selection mode includes at least one of the following:

Independent non-public network SNPN access mode, indicating priority or only selecting SNPN as the target underlay network;

Non-SNPN access mode, indicating priority or only selecting the public land mobile network PLMN as the target underlay network;

The first access mode indicates selecting SNPN as the target underlay network or indicating selecting PLMN as the target underlay network.
The device of claim 10, wherein:

The processing module is specifically configured to access the one or more target overlay networks through the currently registered network if the network currently registered by the terminal meets the preset network selection conditions; if the network currently registered by the terminal If the preset network selection conditions are not met, reselect the target underlay network based on the first instruction information;

Wherein, the network selection conditions include at least one of the following:

The network currently registered by the terminal is in the underlay network list corresponding to the one or more target overlay networks;

The one or more target overlay networks are in the overlay network list corresponding to the network currently registered by the terminal;

There is a mapping relationship between the network currently registered by the terminal and the one or more target overlay networks;

The network currently registered by the terminal conforms to the network selection mode of the terminal.
The device according to claim 12, wherein when the number of the target overlay networks is one,

The processing module is specifically configured to determine a target underlay network set and select a target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the target underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

The target overlay network is in the overlay network list corresponding to the candidate underlay network;

There is a mapping relationship between the target underlay network and the target overlay network;

Comply with the network selection mode of the terminal.
The device according to claim 12, wherein when the number of target overlay networks is multiple,

The processing module is specifically configured to determine, for each target overlay network, a set of candidate underlay networks corresponding to the target overlay network according to the first indication information; and determine a target underlay network based on a set of candidate underlay networks of multiple target overlay networks. Set, the target underlay network set is the intersection of multiple candidate underlay network sets; select a target underlay network from the target underlay network set;

Wherein, the candidate underlay networks in the candidate underlay network set satisfy at least one of the following:

In the underlay network list corresponding to the target overlay network;

The target overlay network is in the overlay network list corresponding to the candidate underlay network;

There is a mapping relationship with the target overlay network;

Comply with the network selection mode of the terminal.
The device according to claim 13 or 14, wherein,

The processing module is specifically configured to perform at least one of the following:

According to the priority order of candidate underlay networks in the target underlay network set, select the candidate underlay network with the highest priority as the target underlay network;

Randomly select a candidate underlay network from the set of target underlay networks.
The device according to claim 12, wherein the opportunity to reselect the target underlay network according to the first indication information includes any of the following:

Immediately trigger network reselection and select the target underlay network;

After the preset first timer times out, network reselection is triggered and the target underlay network is selected;

After the preset high-priority service ends, network reselection is triggered and the target underlay network is selected.
The device according to claim 16, wherein the high priority service includes at least one of the following:

IP multimedia subsystem registration signaling;

Multimedia telephone service MMTEL voice call;

MMTEL video call;

Transmitting short messages SMS over NAS through the non-access layer;

Transmit short messages SMS over IP through the IP multimedia subsystem.
The device according to claim 10, wherein the first indication information is located in at least one of the following of the terminal:

Global Subscriber Identity Card USIM;

The internal memory ME of the terminal;

Entry of SNPN contract information.
A terminal includes a processor and a memory, the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the implementation of any one of claims 1 to 9 is achieved. The steps of the network selection method described above.
A readable storage medium on which programs or instructions are stored. When the programs or instructions are executed by a processor, the steps of the network selection method according to any one of claims 1 to 9 are implemented.