CN116250288A

CN116250288A - Public land mobile network selection method and device

Info

Publication number: CN116250288A
Application number: CN202080104566.2A
Authority: CN
Inventors: 吴烨丹; 耿婷婷
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-08-03
Filing date: 2020-08-03
Publication date: 2023-06-09
Also published as: WO2022027187A1; CN116250288A8

Abstract

The application discloses a public land mobile network selection method and a public land mobile network selection device, which are used for solving the problem that in a non-terrestrial communication network, a public land mobile network selected by terminal equipment is likely not to be the public land mobile network of the country where the terminal equipment is located, so that normal communication is difficult. The method comprises the following steps: the terminal equipment determines candidate public land mobile network identifiers, the candidate public land mobile networks corresponding to the candidate public land mobile network identifiers have access requirements, and the access requirements are access allowed for the terminal equipment located in the country corresponding to the candidate public land mobile networks; the terminal equipment determines the country where the terminal equipment is currently located, and determines to select the candidate public land mobile network access when the country where the terminal equipment is currently located is consistent with the country corresponding to the candidate public land mobile network.

Description

Public land mobile network selection method and device

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a method and an apparatus for selecting a public land mobile network.

Background

Public land mobile networks (public land mobile network, PLMNs) are networks established and operated by governments or operators approved by them for the purpose of providing land mobile services to the public. When selecting a PLMN, a User Equipment (UE) needs to meet the national security and regulatory requirements, that is, the UE can only access the PLMN of the country where the UE is located, for example, the UE can only access the PLMN of the country a when the UE is in the country a, and can only access the PLMN of the country B when the UE is in the country B.

But in a non-terrestrial network (non-terrestrial network, NTN), the higher the orbit of a satellite, the larger its coverage area, and one satellite may cover an area of multiple countries, since one satellite may be shared by the core networks of multiple countries, one satellite may broadcast PLMN identities (PLMN identification, PLMN IDs) of multiple countries, resulting in that the UE is likely to select PLMNs other than the country where it is located in the course of PLMN selection and cell selection/reselection, and thus it is difficult to communicate normally.

Disclosure of Invention

The application provides a PLMN selection method and device, which are used for solving the problem that in NTN, a PLMN selected by terminal equipment is possibly not the PLMN of the country where the terminal equipment is located, so that normal communication is difficult.

In a first aspect, the present application provides a PLMN selection method, where the method may be applied to a terminal device, or a chip, or a chipset, or a functional module in a chip that performs the method, etc. Taking a terminal device as an example, the method includes: the terminal equipment determines a candidate PLMN identifier, and the candidate PLMN corresponding to the candidate PLMN identifier has an access requirement which is to allow the terminal equipment located in the country corresponding to the candidate PLMN to access; the terminal equipment determines the country in which the terminal equipment is currently located; and the terminal equipment determines to select the candidate PLMN to be accessed when the country in which the terminal equipment is currently located is consistent with the country corresponding to the candidate PLMN.

In the embodiment of the application, through cell system message broadcasting or protocol provision, the UE judges whether the selected PLMN is the PLMN of the current country when selecting the PLMN, so that the UE can normally communicate under the supervision of the current country, the safety and the reliability of satellite communication can be ensured, and the breeding of criminal activities is prevented.

In one possible design, it may be determined that the candidate PLMN corresponds to an access requirement if the candidate PLMN satisfies the following condition: the candidate PLMN identities are associated with an indication that indicates the PLMN identities of the country in which the terminal device needs to select. In the design, the indication information indicates the terminal equipment to judge whether the selected PLMN is the PLMN of the current country when the PLMN is selected.

In one possible design, the indication information may be associated with a PLMN identity that is a candidate PLMN identity. In the design, the granularity of the indication information is smaller, so that the flexibility is higher.

In yet another possible design, the indication information may also be associated with a PLMN identification group including at least one PLMN identification, and the at least one PLMN identification includes candidate PLMN identifications. In the design, the granularity of the indication information is smaller, so that the signaling overhead is saved when the flexibility is improved.

In yet another possible design, the indication information may also be associated with a cell, where the PLMN identity of the cell includes candidate PLMN identities. In the design, the granularity of the indication information is smaller, so that the signaling overhead is saved when the flexibility is improved.

In yet another possible design, the indication information may also be associated with a cell group including at least one cell, and the PLMN identity of the at least one cell including the candidate PLMN identity. In the design, the granularity of the indication information is larger, so that the signaling overhead can be saved.

In one possible design, the indication information is associated with a frequency point, one frequency point includes at least one cell for which a signal is transmitted, and the PLMN identity of the at least one cell includes candidate PLMN identities. In the design, the granularity of the indication information is larger, so that the signaling overhead can be saved.

In one possible design, the terminal device may receive a candidate PLMN identity sent by the access network, where the candidate PLMN identity carries the indication information. In the design, the indication information is carried by the candidate PLMN identifier, so that the terminal equipment can judge whether the country where the terminal equipment is currently located is consistent with the country corresponding to the candidate PLMN identifier when the candidate PLMN identifier is selected, and the terminal equipment can normally communicate under the supervision of the country where the terminal equipment is currently located.

In one possible design, when the terminal device determines the country in which the terminal device is currently located, country information sent by the access network device may be received, where the country information indicates a geographical location range of the corresponding country, or the country information indicates a country boundary of the corresponding country. The terminal equipment acquires the current position of the terminal equipment, and determines the current country of the terminal equipment according to the country information and the position. Through the design, the terminal equipment with the positioning function can judge the country according to the country information broadcast by the access network equipment and the positioning result.

In one possible design, when the terminal device determines the country in which the terminal device is currently located according to the country information and the location, if the location is within the geographical location range of the corresponding country indicated by the country information, it may be determined that the country in which the terminal device is currently located is the corresponding country.

In still another possible design, when the terminal device determines the country in which the terminal device is currently located according to the country information and the location, if the location is not within the geographical location range of the corresponding country indicated by the country information and the distance between the location and the country boundary line of the corresponding country indicated by the country information is less than the distance threshold, it may be determined that the country in which the terminal device is currently located is the corresponding country. In the mode, the terminal equipment in a certain range near the national boundary is allowed to be accessed, so that the situation that the terminal equipment cannot be accessed due to positioning errors can be avoided, the access efficiency of the terminal equipment can be ensured, and the user experience is improved.

In another possible design, when the terminal device determines the country in which the terminal device is currently located, the terminal device may receive N PLMN identities sent by the access network device, where one PLMN identity corresponds to one country; the terminal equipment determines the country in which the terminal equipment is currently located as a first country, wherein the number of PLMN identifications corresponding to the first country in the N PLMN identifications is the largest. According to the design, aiming at the terminal equipment without positioning capability, the searched ground network can be used for judging the country and selecting the PLMN, so that the terminal equipment without positioning capability can normally communicate under the supervision of the current country in the processes of PLMN selection, cell selection, reselection and the like, the safety and the reliability of satellite communication can be ensured, and the breeding of criminal activities can be prevented.

In one possible design, the terminal device may further select the first cell to camp on, where a country corresponding to at least one PLMN identity of the plurality of PLMN identities corresponding to the first cell is the same as a country corresponding to the candidate PLMN identity.

In a second aspect, an embodiment of the present application provides a communication apparatus, where the apparatus may be a terminal device, or may be a chip or a module in the terminal device. The apparatus may include a processing unit, a transceiving unit, and a receiving unit. It should be understood that the transmitting unit and the receiving unit may also be referred to herein as a combination as transceiving unit. When the apparatus is a terminal device, the processing unit may be a processor, and the transmitting unit and the receiving unit may be transceivers; the communication device may further comprise a storage unit, which may be a memory; the storage unit is configured to store instructions, and the processing unit executes the instructions stored in the storage unit, so that the terminal device performs the method in the first aspect or any one of the possible designs of the first aspect. When the apparatus is a chip in a terminal device, the processing unit may be a processor, and the transmitting unit and the receiving unit may be input/output interfaces, pins, circuits, or the like; the processing unit executes instructions stored by the storage unit to cause the chip to perform the method of the first aspect or any one of the possible designs of the first aspect. The storage unit is used for storing instructions, and the storage unit may be a storage unit (for example, a register, a cache, etc.) in the chip, or may be a storage unit (for example, a read-only memory, a random access memory, etc.) located outside the chip in the terminal device.

In a third aspect, embodiments of the present application also provide a computer readable storage medium storing a computer program which, when run on a computer, causes the computer to perform the method of the first aspect described above.

In a fourth aspect, embodiments of the present application also provide a computer program product comprising a computer program which, when run on a computer, causes the computer to perform the method of the first aspect described above.

In a fifth aspect, there is provided a communication apparatus comprising: a processor, a communication interface, and a memory. The communication interface is used to transfer information, and/or messages, and/or data between the device and other devices. The memory is configured to store computer-executable instructions that, when executed by the apparatus, cause the apparatus to perform the method of the first aspect and any possible designs thereof described above.

In a sixth aspect, embodiments of the present application provide a chip, where the chip is coupled to a memory, and performs the method described in the first aspect and any possible designs thereof. It should be noted that "coupled" in the embodiments of the present application means that two components are directly or indirectly combined with each other.

In a seventh aspect, embodiments of the present application provide a chip comprising a communication interface and at least one processor, the processor obtaining computer program instructions via the communication interface and running to perform the method of the first aspect and any of its possible designs described above.

The technical effects that any one of the second to seventh aspects may be designed to achieve are described with reference to any one of the first aspects, and the description thereof is not repeated here.

Drawings

Fig. 1 is a schematic diagram of a protocol stack according to an embodiment of the present application;

FIG. 2A is a schematic diagram of a satellite according to an embodiment of the present disclosure;

FIG. 2B is a schematic diagram of another satellite according to an embodiment of the present disclosure;

fig. 2C is a schematic diagram of RRC state transition provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of an access network device according to an embodiment of the present application;

fig. 4 is a schematic diagram of an NTN application scenario provided in an embodiment of the present application;

fig. 5 is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 6 is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 7 is a schematic diagram of an interface provided in an embodiment of the present application;

Fig. 8 is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 9A is a schematic diagram of another NTN application scenario provided in an embodiment of the present application;

fig. 9B is a schematic diagram of a satellite sharing scenario provided in an embodiment of the present application;

fig. 10 is a flowchart of a PLMN selection method according to an embodiment of the present application;

fig. 11 is a schematic diagram of a PLMN selecting process of a terminal device provided in an embodiment of the present application;

fig. 12 is a schematic diagram of another PLMN selection procedure of a terminal device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of a communication device according to an embodiment of the present application.

Detailed Description

In the following, some terms in the present application are explained for easy understanding by those skilled in the art.

1. Non-access stratum (NAS) and Access Stratum (AS)

In long term evolution (long term evolution, LTE) and New Radio (NR), the UE and base station/access and mobility management function (access and mobility management function, AMF) entities communicate over the air. For better processing of data, the network protocol defines several protocol stacks, each stack having a different function, for example as shown in fig. 1. The NAS is a signaling channel between the UE and the AMF, and the specific process may be that the UE sends a NAS message to the base station, the base station transparently transmits the NAS message to the AMF, and the base station does not parse the NAS message in the transparent transmission process. The NAS is mainly responsible for some management functions, such AS PLMN selection, manual selection, access control, registration, subscription information, etc., and specific procedures can be performed in cooperation with other protocol layers (e.g. AS).

The AS refers to a protocol layer other than the NAS layer, and may include radio resource control (radio resource control, RRC), packet data convergence protocol (packet data convergence protocol, PDCP), radio link control (radio link control, RLC), medium access control (medium access control, MAC), physical layer (PHY), and the AS is mainly responsible for functions of handover, ciphering, data retransmission, sequencing, transmission, and the like.

2、PLMN

A common PLMN for providing network services to terminal devices in daily life. The PLMN is a network established and operated by the government or its approved operators for the purpose of providing land mobile services to the public. Different PLMN networks may be distinguished by different PLMN Identities (IDs). The PLMN identity consists of a mobile country number (mobile contrary code, MCC) and a mobile network number (MNC). Where MCC uniquely indicates the country to which the mobile subscriber belongs, e.g. chinese MCC 460.MNC uniquely represents a network in that country, e.g. MNC for chinese movement is 00 and MNC for chinese communication is 01.

When the UE accesses the base station, a network needs to be selected, and the network selecting process is PLMN selection. PLMN selection may be as follows:

A1, the AS of the UE scans Radio Frequency (RF) channels (channels) of all NR bands (bands) according to its own capability to find available PLMNs. The UE will find the cell with the best RSRP in each frequency point and then read the system message block 1 (system information block, sib1) of that cell to obtain the PLMN ID.

A2, the AS of the UE reports a PLMN list (list) to the NAS of the UE, wherein the PLMN list comprises PLMN IDs acquired by the AS of the UE.

A3, after receiving PLMN list reported by the AS of the UE, the NAS of the UE selects one of the PLMN IDs AS the PLMN used by the UE.

When the UE selects a PLMN, the searched PLMN may be: registered PLMN (RPLMN), which is the PLMN registered before the UE is shut down or off network; equivalent PLMN (EPLMN), which is the PLMN with the same priority as the PLMN currently selected by the UE; home PLMN (HPLMN), the identity of which is stored in a mobile subscriber identity module (subscriber identity module, SIM) card, only one HPLMN per SIM card, burned in at the factory; equivalent HPLMN (EHPLMN) and PLMNs with the same priority as the HPLMN.

A4, after selecting the PLMN ID, the NAS of the UE can provide EPLMN list and forbidden tracking area (forbidden tracking area, forbidden TA) for the AS of the UE according to the selected PLMN ID, and the AS of the UE can perform cell selection and reselection according to the EPLMN list and forbidden TA.

3. Cell selection

When the UE is powered on or radio link failure occurs, after PLMN selection is completed, the UE will perform a cell search procedure and select a suitable cell for camping as soon as possible, which is called "cell selection".

The cell in which the UE may reside is called a suitable cell (subscriber), which needs to have the following conditions:

condition one: the PLMN ID of the cell belongs to one of the selected PLMN, RPLMN, EPLMN.

Condition II: the cell needs to meet the S criterion, i.e. if the S value of the cell is greater than 0, it is indicated that the cell is a suitable cell (a cell suitable for camping on), and S is the level value calculated in the cell selection/reselection process.

And (3) a third condition: the cell does not prohibit UE access.

Condition four: on the premise that the PLMN ID of the cell satisfies the condition one, at least one TA is not within the forbidden TA.

4. Cell reselection

After a UE in IDLE (IDLE) state camps on one cell, the UE may need to change to another higher priority or better signaled cell camping, which is a cell reselection procedure, as the UE moves. Cell selection is the process of finding a suitable cell as soon as possible, and cell reselection is the process of selecting a more suitable cell. In the reselection process, the UE measures the neighbor cells according to the RRC release message and the frequency point and the priority in the broadcast message of the resident cell, and reselects the cells according to the measurement result.

5. NTN communication

NTN communication may also be referred to as satellite communication. The architecture of satellite communication is divided into two major types, namely a transparent forwarding (transparent) architecture, and at the moment, the satellite only serves as a relay or an amplifier, and can perform radio frequency filtering, amplifying and the like to regenerate signals; and secondly, a regenerated architecture, in which the satellite can be used as a new generation node B (gNB), a Distributed Unit (DU), a relay, where the relay is different from the relay in the first class, and the satellite is not a pure relay and has a signal processing function, and is similar to an access backhaul integrated (integrated access and backhaul, IAB) node or other relay nodes. Wherein when the satellite is a gNB, DU, IAB or other relay node, it functions similarly to a normal gNB, DU, IAB or other relay node.

The NTN communication provides seamless coverage for the terminal equipment by deploying the functions of the access network equipment or part of the access network equipment on non-ground equipment (such as a high-altitude platform or a satellite and the like), and the reliability of the communication system can be improved because the non-ground equipment is less affected by natural disasters. For convenience in description and understanding of the embodiments of the present application, the present application will be described hereinafter with reference to an NTN communication system in which access network devices are deployed on a satellite. For convenience of description, the "access network device on satellite" will be replaced by "satellite" and the "NTN communication" will be replaced by "satellite communication" in the following description. I.e. communication between a terminal device and a satellite, to which the present application refers subsequently, actually refers to communication between a terminal device and an access network device on the satellite. The details are unified and will not be described in detail later.

Satellite systems can be classified into high elliptical orbit (highly elliptical orbiting, HEO) satellites, geosynchronous (geostationary earth orbit, GEO) satellites, medium orbit (medium earth orbit, MEO) satellites, and low-earth orbit (LEO) satellites according to satellite heights, i.e., satellite orbital heights, as shown in fig. 2A or fig. 2B. In addition, the NTN system may further include an air network device such as a high altitude platform (high altitude platform station, HAPS) communication system, and the network device according to the present invention is not limited to the above example.

6. RRC state

In NR, the RRC state of the UE includes rrc_connected (CONNECTED state), rrc_inactive (deactivated state or tri-state), rrc_idle (IDLE state), where when the UE is in rrc_connected state, the UE has established a link with the base station and the core network, and when data arrives at the network, the data can be directly transmitted to the UE; when the UE is in RRC_INACTIVE state, it means that the UE has established a link with the base station and the core network before, but the link from the UE to the base station is released, and the base station stores the context of the UE although the link is released, and when data needs to be transmitted, the base station can quickly recover the link; when the UE is in rrc_idle state, there is no link between the UE and the base station and between the UE and the network, and when there is data to be transmitted, a link between the UE and the base station and between the UE and the core network needs to be established. The transition between the three states is shown in fig. 2C.

It should be noted that, as the technology is continuously developed, the terms of the embodiments of the present application may be changed, but all the terms are within the protection scope of the present application.

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

The network element related in the embodiment of the application comprises network equipment and terminal equipment.

The network device may be an access network device. An access network device is an entity in the network side for transmitting or receiving signals, such as a new generation base station (generation Node B, gNodeB). The access network device may be a device for communicating with a mobile device. The access network device may be an Access Point (AP) in a wireless local area network (wireless local area networks, WLAN), an evolved base station (evolutional Node B, eNB or eNodeB) in long term evolution (long term evolution, LTE), or a relay station or access point or access backhaul integration (integrated access and backhaul, IAB), or an in-vehicle device, a wearable device, and an access network device in a future 5G network or an access network device in a future evolved public land mobile network (public land mobile network, PLMN) network, or a gNB in an NR system, etc. In addition, in the embodiment of the present application, the access network device provides services for the cell, and the terminal device communicates with the access network device through transmission resources (for example, frequency domain resources, or spectrum resources) used by the cell. The access network device in the embodiment of the present application may refer to a Central Unit (CU) or a DU. Alternatively, the access network device may be composed of CUs and DUs, as shown in fig. 3, for example. The CU and the DU may be physically separated or may be disposed together, which is not specifically limited in the embodiment of the present application. One CU may be connected to one DU, or one CU may be shared by a plurality of DUs, which may save costs and facilitate network expansion. The segmentation of CUs and DUs may be in terms of protocol stack segmentation, with one possible way being to deploy radio resource control (radio resource control, RRC), traffic data adaptation protocol stack (service data adaptation protocol, SDAP) and packet data convergence protocol (packet data convergence protocol, PDCP) layers at the CUs and the remaining radio link control (radio link control, RLC), medium access control (media access control, MAC) and physical layers at the DUs. The present invention is not limited to the above protocol stack splitting method, and other splitting methods are also possible. The CU and the DU are connected through an F1 interface. CU stands for gNB connected to the core network via Ng interface. The access network device in the embodiments of the present application may refer to a centralized unit control plane (CU-CP) node or a centralized unit user plane (CU-UP) node, or the network device may also be a CU-CP and a CU-UP. Wherein the CU-CP is responsible for control plane functions, mainly including RRC and PDCP-C. The PDCP-C is mainly responsible for encryption and decryption of control plane data, integrity protection, data transmission and the like. CU-UP is responsible for user plane functions, mainly including SDAP and PDCP-U. Where the SDAP is mainly responsible for handling data of the core network and mapping flows (flows) to bearers. The PDCP-U is mainly responsible for encryption and decryption of a data surface, integrity protection, header compression, sequence number maintenance, data transmission and the like. Wherein CU-CP and CU-UP are connected through E1 interface. CU-CP stands for gNB connected to the core network via Ng interface. Connected through F1-C (control plane) and DU. CU-UP is connected to DU through F1-U (user plane). Of course, a further possible implementation is that the PDCP-C is also in the CU-UP. The access network device mentioned in the embodiments of the present application may be a device including a CU, or a DU, or a device including a CU and a DU, or a device including a control plane CU node (CU-CP node) and a user plane CU node (CU-UP node), and a DU node. Furthermore, the access network device may be other means of providing wireless communication functionality for the terminal device, as other possibilities. The specific technology and specific device configuration adopted by the access network device in the embodiments of the present application are not limited. For convenience of description, in the embodiments of the present application, an apparatus for providing a wireless communication function for a terminal device is referred to as an access network device.

The terminal device may be a wireless terminal device capable of receiving access network device scheduling and indication information, and the wireless terminal device may be a device providing voice and/or data connectivity to a user, or a handheld device having wireless connectivity functionality, or other processing device connected to a wireless modem. The wireless terminal device may communicate with one or more core networks or the internet via a radio access network (e.g., radio access network, RAN), which may be a mobile terminal device such as a mobile phone (or "cellular" phone), a computer, and a data card, e.g., a portable, pocket, hand-held, computer-built-in, or vehicle-mounted mobile device that exchanges voice and/or data with the radio access network. Such as personal communication services (personal communications service, PCS) phones, cordless phones, session Initiation Protocol (SIP) phones, wireless local loop (wireless local loop, WLL) stations, personal digital assistants (personal digital assistant, PDAs), tablet computers (Pad), computers with wireless transceiver capabilities, and the like. The wireless terminal device may also be referred to as a system, subscriber unit (subscriber unit), subscriber station (subscriber station), mobile Station (MS), remote station (AP), access Point (AP), remote terminal device (remote), access terminal device (access terminal), user terminal device (user terminal), user agent (user agent), user station (subscriber station, SS), user equipment (customer premises equipment, CPE), terminal (terminal), user Equipment (UE), mobile Terminal (MT), etc. The wireless terminal device may also be a wearable device as well as a next generation communication system, e.g. a terminal device in a 5G network or a terminal device in a future evolved PLMN network, a terminal device in an NR communication system, etc.

In addition, the embodiment of the application can be also applied to other communication technologies facing the future. The network architecture and the service scenario described in the present application are for more clearly describing the technical solution of the present application, and do not constitute a limitation on the technical solution provided in the present application, and as a person of ordinary skill in the art can know, with evolution of the network architecture and appearance of a new service scenario, the technical solution provided in the present application is also applicable to similar technical problems.

It should be noted that, the embodiments of the present application are not limited to the type and the format of the above communication system. For example: the communication system may be: the fifth generation (The 5th Generation,5G) communication system, LTE communication system, and The like.

The embodiments of the present application may be applied to fourth generation mobile communication systems (the fourth generation, 4G) systems, 5G systems, NTN systems, car-to-anything (vehicle to everything, V2X), long term evolution-car networking (LTE-V), car-to-car (vehicle to vehicle, V2V), car networking, machine-like communication (Machine Type Communications, MTC), internet of things (internet of things, ioT), long term evolution-machine-to-machine (LTE-machine to machine, LTE-M), machine-to-machine (machine to machine, M2M), internet of things, or future mobile communication systems.

Each application scenario is specifically described below with reference to the accompanying drawings.

For example, in the application scenario shown in fig. 4, the satellite may be used as a base station to establish an N2 or Ng connection with an AMF entity in the core network, so as to provide a radio access service for the terminal device.

For example, in a communication system, an X2 or Xn connection may be established between two base stations in the RAN to transmit data such as cell information, so as to implement cell reselection and handover of the terminal device. For example, two base stations in the RAN that establish a connection may be: the satellite as a base station and the satellite as a base station, the satellite as a base station and a conventional base station, between a base station composed of a plurality of partial functions and a conventional base station, or between a base station composed of a plurality of partial functions and the satellite as a base station, or the like. In the application scenario shown in fig. 5, a connection may be established between two satellites as base stations for interaction of data and signaling.

For example, in a communication system supporting carrier aggregation, dual-connectivity (DC) technology may be cited to provide users with higher rates and improved spectrum efficiency, in which a terminal device supporting dual connectivity may connect two base stations at the same time to increase throughput of a single user. Connection is also required to be established between two base stations connected simultaneously by the terminal device through corresponding interfaces to perform interaction of data and signaling, as shown in fig. 6. When the terminal equipment needs to be described, one of the two base stations connected with the terminal equipment simultaneously serves as a main base station, and the other one serves as an auxiliary base station. When the core networks to which the base stations are connected are different and the types of the two base stations are different, the interfaces between the AMF entity and the base stations and the interfaces between the two base stations also change correspondingly, as shown in the schematic diagrams of the interfaces in fig. 7.

For example, in the application scenario shown in fig. 8, the satellite may also be used as a relay device between the terminal device and the base station or as a remote radio unit (remote radio unit, RRU) of the base station. In this scenario, the satellite is mainly responsible for L1 relay for physical layer forwarding and is not visible to higher layers.

Illustratively, in the application scenario shown in fig. 9A, the base station in the RAN is split into two functional parts, DU and CU, where the satellite can act as a DU. In this application scenario, the interface between the DU and CU is the F1 interface.

It should be further noted that the application scenario shown in fig. 4 to fig. 9A is only an example of an application scenario applicable to the present application, and satellites are taken as an example in the above examples.

At present, when the UE selects PLMN, the selected PLMN ID mainly meets the following conditions: the PLMN corresponding to the PLMN ID is RPLMN or EPLMN or HPLMN or EHPLMN. When the UE performs cell selection and reselection, the selected cell mainly meets the following conditions: at least one PLMN ID of the cell corresponds to an RPLMN or EPLMN or HPLMN or EHPLMN.

In the terrestrial communication, during the RRC establishment or RRC recovery procedure, the UE may carry the PLMN ID selected by the UE in the RRC establishment completion message or the RRC recovery completion message, so long as the PLMN ID selected by the UE satisfies the above conditions, the network allows the UE to access.

However, in satellite communications, the coverage of a satellite is very large, such as GEO satellites, and the area of a beam may reach hundreds of kilometers. Also, since one satellite can be shared by core networks of a plurality of countries, for example, as shown in fig. 9B, one satellite cell may broadcast core network PLMN IDs of a plurality of countries, resulting in that a UE is likely to select a PLMN other than the country in which it is located in the process of making PLMN selection and cell selection/reselection, thereby making it difficult to normally communicate.

Based on this, the embodiments of the present application provide a PLMN selecting method and apparatus, so as to solve the problem that in NTN, a PLMN selected by a terminal device may not be a PLMN of a country where the terminal device is located, and thus it is difficult to normally communicate. The method and the device are based on the same inventive concept, and because the principles of solving the problems by the method and the device are similar, the implementation of the device and the method can be referred to each other, and the repetition is not repeated.

It should be understood that in embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein A, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one (item) below" or the like, refers to any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, a and b, a and c, b and c, or a, b and c, wherein a, b and c can be single or multiple.

It should be appreciated that in the description herein, the words "first," "second," and the like are used solely for distinguishing between the descriptions and not necessarily for indicating or implying a relative importance or order.

The method for controlling access of terminal equipment provided by the application is specifically described below with reference to the accompanying drawings.

As shown in fig. 10, a PLMN selection method is provided in an embodiment of the present application. The method may be applied to a terminal device, or a chip, or a chipset, or a functional module in a chip that performs the method, etc. Taking a terminal device as an example, PLMN selection specifically may include:

s1001, the terminal equipment determines the candidate PLMN identification, and the candidate PLMN corresponding to the candidate PLMN identification has an access requirement, wherein the access requirement is to allow the terminal equipment located in the country corresponding to the candidate PLMN to access.

For example, if the candidate PLMN satisfies the following conditions, it may be determined that the candidate PLMN corresponds to an access requirement: the candidate PLMN identities are associated with an indication that indicates the PLMN identities of the country in which the terminal device needs to select. In some embodiments, the terminal device may determine whether the candidate PLMN corresponds to an access requirement based on whether the candidate PLMN identity is associated with the indication information.

Alternatively, the granularity of the indication information may be valid for a single PLMN ID, i.e. one indication information is associated with one PLMN ID. Each PLMN ID may carry indication information, i.e. the maximum number of occurrences of indication information is the same as the number of PLMN IDs. For example, the PLMN ID of the cell 1 includes PLMN 1, PLMN 2 (carrying indication information), and PLMN 3, where PLMN 2 is associated with the indication information, so that the terminal device determines that PLMN 2 corresponds to an access requirement, and if PLMN 2 is to be selected, it needs to determine whether the country in which the terminal device is currently located is consistent with the country corresponding to PLMN 2.

Alternatively, the granularity of the indication information may be valid for a plurality of PLMN IDs, i.e. one indication information associates a plurality of PLMN IDs. For example, the PLMN ID of the cell 1 includes PLMN 1, PLMN 2, and PLMN 3, wherein the indication information is valid for PLMN 1 and PLMN 2, and then PLMN 1 and PLMN 2 are associated with the indication information.

Alternatively, the granularity of the indication information may be valid for one cell, i.e. one indication information is associated with one cell, the PLMN IDs of which are each associated with an indication. Each cell may carry indication information, i.e. the maximum number of occurrences of indication information is the same as the number of cells. For example, the indication information is valid for cell 1, and the PLMN ID of cell 1 includes PLMN 1, PLMN 2, and PLMN 3, wherein PLMN 1, PLMN 2, and PLMN 3 are associated with the indication information.

Alternatively, the granularity of the indication information may be valid for a plurality of cells, i.e. one indication information associates a plurality of cells, the PLMN IDs of which are each associated with an indication.

Alternatively, the granularity of the indication information may be valid for all PLMN IDs. For example, the access network device carries an indication in the system message, where the indication is valid for all PLMN IDs broadcasted by the access network device, i.e. all PLMN IDs broadcasted by the access network device are associated with the indication.

Alternatively, the granularity of the indication information may be valid for one frequency point, i.e. the indication information is associated with one frequency point, one frequency point includes at least one cell transmitting a signal with the frequency point, and thus the indication information is valid for the PLMN ID of the cell transmitting the signal using the frequency point, and it may be understood that the PLMN ID of the cell transmitting the signal using the frequency point is associated with the indication information.

When selecting the PLMN ID associated with the indication information, the terminal equipment needs to judge whether the country in which the terminal equipment is located is consistent with the country corresponding to the PLMN ID.

In some embodiments, the terminal device may determine whether the candidate PLMN identity is associated with the indication information by: when receiving the candidate PLMN identification sent by the access network, the terminal device may associate the candidate PLMN identification with the indication information if the candidate PLMN identification carries the indication information. If the candidate PLMN identification does not carry the indication information, the candidate PLMN identification is not associated with the indication information.

Or, when receiving the candidate PLMN identifier sent by the access network, if the indication bit carried by the candidate PLMN identifier takes a value of a first value (for example, 1), the candidate PLMN identifier is associated with the indication information. If the indication bit carried by the candidate PLMN identity is a second value (e.g. 0), the candidate PLMN identity is not associated with the indication information.

The access network device may be a satellite, for example, as a stand-alone access network device, connected to a core network. Alternatively, the access network device may be a satellite connected to a ground base station as a relay device. Alternatively, the access network device may be a satellite connected to the ground CU as a DU, or the like.

In other embodiments, the protocol may also specify that some candidate PLMN identities are associated with the indication information, so that when the terminal device selects these candidate PLMN identities, it needs to determine whether the country in which the terminal device is located is consistent with the country corresponding to the PLMN ID.

S1002, the terminal device determines the country in which the terminal device is currently located.

In one implementation, the terminal device may determine the location of the terminal device via a global positioning system (global positioning system, GPS), and then may determine the country in which the terminal device is located based on the country information sent by the access network device and the location of the terminal device. The country information indicates a geographical location range, such as a latitude and longitude range, or the like, of the corresponding country. Alternatively, the country information indicates a country boundary of the corresponding country. For example, the country information sent by the access network device is the latitude and longitude range of the a country, and if the latitude and longitude of the terminal device is within the latitude and longitude range of the a country, the country where the terminal device is currently located is the a country. If the longitude and latitude of the terminal equipment are out of the longitude and latitude range of the A country, the country where the terminal equipment is currently located is other countries.

In the implementation, if the longitude and latitude of the terminal device are outside the longitude and latitude range of the country a, but the distance between the location of the terminal device and the country boundary line of the country a is smaller than the distance threshold, the country where the terminal device is currently located may be considered as the country a. In the mode, the terminal equipment in a certain range near the national line is allowed to be accessed, so that the situation that the terminal equipment cannot be accessed due to positioning errors can be avoided, the access efficiency of the terminal equipment can be ensured, and the user experience is improved.

In another implementation manner, the terminal device may also determine the country in which the terminal device is currently located according to the PLMN identifier broadcasted by the access network device. For example, the terminal device receives N PLMN identities sent by the access network device, where one PLMN identity corresponds to one country, and the number of PLMN identities corresponding to a first country in the N PLMN identities is the largest, and the terminal device may determine that the country in which the terminal device is currently located is the first country.

S1002 and S1001 have no strict sequence relationship, and the terminal device may determine, according to other information, the country in which the terminal device is currently located. For example, the terminal device may determine the current country based on the previously stored location information and its own movement speed.

S1003, when the country where the terminal equipment is currently located is consistent with the country corresponding to the candidate PLMN, the terminal equipment determines to select the candidate PLMN for access.

Optionally, after selecting the PLMN, the terminal device may select the first cell to reside, where a country corresponding to at least one PLMN identifier in the plurality of PLMN identifiers corresponding to the first cell is the same as a country corresponding to the candidate PLMN identifier.

For a better understanding of the method provided by the embodiments of the present application, PLMN selection is described in detail below in conjunction with specific scenarios. The terminal device selection PLMN procedure may be as shown in fig. 11:

s1101, the AS of the UE reads the cell system message of each frequency band.

Illustratively, the PLMN ID list for the cell may be carried in a cell system message.

The cell system message may also carry country information. In one implementation, the cell system message may carry a geographic location range or country boundary for the country. In another implementation, the PLMN ID may carry country information to which the PLMN ID belongs.

In some embodiments, the cell system message may also carry indication information, where the indication information is used to indicate that the UE needs to select the PLMN ID of the country in which the UE is currently located. The indication information may be valid for one PLMN ID, may be valid for a plurality of PLMN IDs, may be valid for one cell, may be valid for a plurality of cells, or may be valid for all PLMN IDs list.

In other embodiments, the indication information may also be protocol-specified.

S1102, the AS of the UE reports the PLMN ID list, country information and indication information to the NAS of the UE.

For example, the AS layer of the UE scans for the following cells:

cell 1: the mobile terminal comprises PLMN1, PLMN2 and PLMN3, wherein the PLMN2 carries indication information.

Cell 2: the cell system message containing PLMN4, PLMN5, PLMN6, cell 2 carries indication information which is valid for all three PLMN IDs.

Cell 3: the cell system message of cell 3 contains PLMN7, PLMN8, PLMN9, and does not carry indication information.

After the AS of the UE reads the cell system message of the cell, PLMN1-9 and the indication information can be reported to the NAS of the UE.

S1103, after receiving the PLMN list reported by the AS of the UE, the NAS of the UE selects a PLMN corresponding to one of the PLMN IDs AS a PLMN used by the UE.

Alternatively, PLMN selection may be NAS automatic selection, i.e. UE automatically completes PLMN selection, without involving man-machine interaction. Alternatively, the PLMN selection may be manually selected by the user, e.g., the NAS of the UE uploads the PLMN ID to a higher layer, such as an application layer, which the user manually selects. For example, after the UE is powered on, the display interface of the UE may display words such as chinese UNICOM, chinese mobile, etc. for the user to select.

In a specific implementation, the UE has positioning capability, and the country in which the UE is currently located can be determined in combination with country information in the cell system message. In the scenario that the UE automatically completes PLMN selection, if the NAS of the UE selects a PLMN ID associated with the indication information, the NAS of the UE may determine whether the country in which the UE is currently located is consistent with the country corresponding to the PLMN ID, and if not, the PLMN ID cannot be selected. In the scenario that the user manually selects the PLMN, if the PLMN ID selected by the user is associated with the indication information, the NAS of the UE may determine whether the country in which the UE is currently located is consistent with the country corresponding to the PLMN ID, and if not, may prompt the user to reselect, for example, display a prompt such as "non-home PLMN, please reselect" on the display interface of the UE, so that the user performs another selection until the user selects the PLMN in the country in which the UE is currently located.

S1104, after selecting the PLMN, the NAS of the UE may provide the EPLMN list and the forbidden TA for cell selection and reselection to the AS of the UE according to the selected PLMN.

The UE performs cell selection and reselection while in an RRC IDLE or INACTIVE state (INACTIVE). Since the UE has positioning capability, the UE can also learn which country the UE is in according to the current positioning during the moving process. In the embodiment of the present application, when the UE selects and reselects a cell, the cell may select to camp, where at least one PLMN corresponding to a PLMN ID in PLMN ID list of the cell is to be satisfied, and if not, the UE cannot camp in the cell.

The terminal device selection PLMN procedure may also be as shown in fig. 12:

s1201, the AS of the UE reads the cell system message of each frequency band.

S1202, the AS of the UE reports the PLMN ID list and the indication information to the NAS of the UE.

In step S1202, the manner of reporting the PLMN ID list and the indication information to the NAS of the UE in step S1102 may be specifically referred to, and the detailed description is not repeated here.

S1203, after receiving the PLMN list reported by the AS of the UE, the NAS of the UE selects a PLMN corresponding to one of the PLMN IDs AS a PLMN used by the UE.

In an implementation, the UE may not have positioning capability, and the NAS of the UE receives a PLMN ID list reported by the AS of the UE, and determines the country in which the UE is currently located according to the country corresponding to the PLMN ID in the PLMN ID list, for example, if the PLMN ID of the country a in the PLMN ID list is the largest, it may be determined that the country in which the UE is currently located is the country a. For example, since the first MCC of the PLMN ID is the country code, if a PLMN ID corresponding to a certain MCC in the PLMN ID list is the largest, it can be determined that the country in which the UE is currently located is the country corresponding to the MCC.

For example, the NAS of the UE receives the following PLMN ID list from the AS of the UE:

PLMN1(MCC＝460)；

PLMN2(MCC＝460)；

PLMN3(MCC＝440)；

PLMN4(MCC＝460)；

the country in which the UE is currently located may be determined to be the country corresponding to mcc=460.

In the scenario that the UE automatically completes PLMN selection, if the NAS of the UE selects a PLMN ID associated with the indication information, the NAS of the UE may determine whether the country in which the UE is currently located is consistent with the country corresponding to the PLMN ID, and if not, the PLMN ID cannot be selected. In the scenario that the user manually selects the PLMN, if the PLMN ID selected by the user is associated with the indication information, the NAS of the UE may determine whether the country in which the UE is currently located is consistent with the country corresponding to the PLMN ID, and if not, may prompt the user to reselect, for example, display a prompt such as "non-home PLMN, please reselect" on the display interface of the UE, so that the user performs another selection until the user selects the PLMN in the country in which the UE is currently located.

S1204 may refer to step S1104, and the detailed description is not repeated here.

It should be noted that, the method provided in the embodiment of the present application may be used not only for PLMN selection, but also for independent private network (snp) selection, non-independent private network (public network integrated-non-public network, PNI-NPN) selection, closed access group (closed access group, CAG) selection, and the like in the private network. The method of SNPN selection, PNI-NPN selection and CAG selection is similar to the method of PLMN selection, except that UE searches PLMN ID in PLMN selection, SNPN ID can be composed of PLMN ID and network identification code (network identification, NID), PNI-NPN ID can be composed of PLMN ID+CAG ID in PNI-NPN selection, and UE searches CAG ID in CAG selection, other processes are similar and repeated without redundant description.

In addition, aiming at the UE without positioning capability, the searched ground network can be used for judging the country and selecting PLMN, so that the UE without positioning capability can normally communicate under the supervision of the current country in the processes of PLMN selection, cell selection, reselection and the like, the safety and the reliability of satellite communication can be ensured, and the breeding of criminal activities can be prevented.

Based on the same inventive concept as the method embodiment, the present embodiment provides a communication device, which may have a structure as shown in fig. 13, including a storage unit 1301, and a processing unit 1302 and a transceiving unit 1303. The communication means may be used in particular for implementing the method performed by the terminal device in the embodiments of fig. 10 to 12, and the means may be the terminal device itself, or may be a chip or a chip set in the terminal device or a part of a chip for performing the functions of the related method. The transceiver 1303 is configured to transmit and receive information; a storage unit 1301 for storing program codes; a processing unit 1302, configured to call the program code stored in the storage unit 1301 to execute: determining a candidate PLMN identifier, wherein the candidate PLMN corresponding to the candidate PLMN identifier has an access requirement which is to allow terminal equipment located in a country corresponding to the candidate PLMN to access; determining the country in which the terminal equipment is currently located; when the country in which the terminal device is currently located is consistent with the country corresponding to the candidate PLMN, it is determined that the candidate PLMN is selected for access through the transceiver unit 1303.

For example, if the candidate PLMN satisfies the following conditions, the candidate PLMN corresponds to an access requirement: the candidate PLMN identities are associated with indication information indicating that the terminal device needs to select a PLMN identity of the country in which it is located.

Optionally, the indication information is associated with a PLMN identity, which is a candidate PLMN identity.

Alternatively, the indication information is associated with a PLMN identification group, the PLMN identification group comprising at least one PLMN identification, and the at least one PLMN identification comprising a candidate PLMN identification.

Alternatively, the indication information is associated with a cell, and the PLMN identities of the cell include candidate PLMN identities.

Alternatively, the indication information is associated with a cell group, the cell group comprising at least one cell, and the PLMN identities of the at least one cell comprising candidate PLMN identities.

In one implementation manner, the transceiver unit 1303 is configured to receive a candidate PLMN identifier sent by the access network, where the candidate PLMN identifier carries indication information.

Optionally, the transceiver unit 1303 is further configured to receive country information sent by the access network device, where the country information indicates a geographical location range of a corresponding country, or the country information indicates a country boundary line of the corresponding country; the processing unit 1302 is specifically configured to, when determining the country in which the terminal device is currently located: acquiring the current position of the terminal equipment; and determining the current country of the terminal equipment according to the country information and the position.

The processing unit 1302 is specifically configured to, when determining, according to country information and a location, a country in which the terminal device is currently located: if the position is within the geographical position range of the corresponding country indicated by the country information, the terminal equipment determines that the country where the terminal equipment is currently located is the corresponding country; or if the location is not within the geographical location range of the corresponding country indicated by the country information and the distance between the location and the country boundary line of the corresponding country indicated by the country information is less than the distance threshold, determining that the country in which the terminal device is currently located is the corresponding country.

The transceiver 1303 may be further configured to receive N PLMN identities sent by the access network device, where one PLMN identity corresponds to one country.

The processing unit 1302, when determining the country in which the terminal device is currently located, may be specifically configured to: and determining the country in which the terminal equipment is currently located as a first country, wherein the number of PLMN identifications corresponding to the first country in the N PLMN identifications is the largest.

Optionally, the processing unit 1302 may be further configured to: selecting a first cell to reside in, wherein a country corresponding to at least one PLMN identifier in a plurality of PLMN identifiers corresponding to the first cell is the same as a country corresponding to the candidate PLMN identifier.

The division of the modules in the embodiments of the present application is schematically only one logic function division, and there may be another division manner in actual implementation, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, or may exist separately and physically, or two or more modules may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. It will be appreciated that the function or implementation of each module in the embodiments of the present application may further refer to the relevant description of the method embodiments.

In a possible manner, the communication apparatus may be a communication device or a chip in a communication device, where the communication device may be a terminal device or a network device, as shown in fig. 14. The apparatus may include a processor 1401, a communication interface 1402, and a memory 1403. Wherein the processing unit 1302 may be the processor 1401. The transceiver unit 1303 may be a communication interface 1402.

The processor 1401 may be a central processing module (central processing unit, CPU), or a digital processing module, or the like. The communication interface 1402 may be a transceiver, or may be an interface circuit such as a transceiver circuit, or may be a transceiver chip, or the like. The apparatus further comprises: a memory 1403 for storing programs executed by the processor 1401. The memory 1403 may be a nonvolatile memory such as a Hard Disk Drive (HDD) or a Solid State Drive (SSD), or may be a volatile memory (RAM). Memory 1403 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 1401 is configured to execute the program code stored in the memory 1403, and specifically is configured to execute the actions of the processing unit 1302, which are not described herein. The communication interface 1402 is specifically configured to perform the actions of the transceiver unit 1303 described above, which is not described herein.

The specific connection medium between the communication interface 1402, the processor 1401, and the memory 1403 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 1403, the processor 1401 and the communication interface 1402 are connected through the bus 1404 in fig. 14, and the bus is shown by a thick line in fig. 14, and the connection manner between other components is merely illustrative and not limited to the above. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 14, but not only one bus or one type of bus.

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

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

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

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

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

Claims

A public land mobile network, PLMN, selection method, comprising:

the terminal equipment determines a candidate PLMN identifier, wherein the candidate PLMN corresponding to the candidate PLMN identifier corresponds to an access requirement, and the access requirement is to allow the terminal equipment located in the country corresponding to the candidate PLMN to access;

the terminal equipment determines the country in which the terminal equipment is currently located;

and the terminal equipment determines to select the candidate PLMN to be accessed when the country in which the terminal equipment is currently located is consistent with the country corresponding to the candidate PLMN.
The method of claim 1, wherein the candidate PLMN corresponds to an access requirement if the candidate PLMN satisfies the following condition:

the candidate PLMN identities are associated with indication information, where the indication information is used to indicate that the terminal device needs to select a PLMN identity of the country.
The method of claim 2, wherein the indication information is associated with a PLMN identity, the PLMN identity being the candidate PLMN identity;

alternatively, the indication information is associated with a PLMN identification group, the PLMN identification group including at least one PLMN identification, and the at least one PLMN identification including the candidate PLMN identification;

or the indication information is associated with a cell, and the PLMN identification of the cell comprises the candidate PLMN identification;

alternatively, the indication information is associated with a cell group, the cell group comprising at least one cell, and the candidate PLMN identity is included in the PLMN identities of the at least one cell.
A method according to claim 2 or 3, wherein the method further comprises:

and the terminal equipment receives the candidate PLMN identification sent by the access network, wherein the candidate PLMN identification carries the indication information.
The method according to any of claims 1-4, wherein the determining by the terminal device the country in which the terminal device is currently located comprises:

the terminal equipment receives country information sent by the access network equipment, wherein the country information indicates the geographical position range of the corresponding country, or the country information indicates the country boundary line of the corresponding country;

the terminal equipment acquires the current position of the terminal equipment;

and the terminal equipment determines the current country of the terminal equipment according to the country information and the position.
The method of claim 5, wherein the determining, by the terminal device, the country in which the terminal device is currently located based on the country information and the location comprises:

if the position is within the geographical position range of the corresponding country indicated by the country information, the terminal equipment determines that the country where the terminal equipment is currently located is the corresponding country; or,

and if the position is not in the geographical position range of the corresponding country indicated by the country information and the distance between the position and the national boundary of the corresponding country indicated by the country information is smaller than a distance threshold value, the terminal equipment determines that the country where the terminal equipment is currently located is the corresponding country.
The method according to any of claims 1-4, wherein the determining by the terminal device the country in which the terminal device is currently located comprises:

the terminal equipment receives N PLMN identifications sent by the access network equipment, wherein one PLMN identification corresponds to one country;

the terminal equipment determines the country in which the terminal equipment is currently located as a first country, wherein the number of PLMN identifications corresponding to the first country in the N PLMN identifications is the largest.
The method of any one of claims 1-7, wherein the method further comprises:

the terminal equipment selects a first cell to reside in, and a country corresponding to at least one PLMN identifier in a plurality of PLMN identifiers corresponding to the first cell is the same as a country corresponding to the candidate PLMN identifier.
A public land mobile network, PLMN, selection apparatus, comprising:

the receiving and transmitting unit is used for receiving and transmitting information;

a storage unit for storing the program code;

a processing unit for calling the program code stored in the storage unit to execute:

determining a candidate PLMN identifier, wherein the candidate PLMN corresponding to the candidate PLMN identifier corresponds to an access requirement, and the access requirement is to allow terminal equipment located in a country corresponding to the candidate PLMN to access;

Determining the country in which the terminal equipment is currently located;

and when the country where the terminal equipment is currently located is consistent with the country corresponding to the candidate PLMN, determining to select the candidate PLMN to access through the receiving-transmitting unit.
The apparatus of claim 9, wherein the candidate PLMN corresponds to an access requirement if the candidate PLMN satisfies the following condition:

the candidate PLMN identities are associated with indication information, where the indication information is used to indicate that the terminal device needs to select a PLMN identity of the country.
The apparatus of claim 10, wherein the indication information is associated with a PLMN identity, the PLMN identity being the candidate PLMN identity;

alternatively, the indication information is associated with a PLMN identification group, the PLMN identification group including at least one PLMN identification, and the at least one PLMN identification including the candidate PLMN identification;

or the indication information is associated with a cell, and the PLMN identification of the cell comprises the candidate PLMN identification;

alternatively, the indication information is associated with a cell group, the cell group comprising at least one cell, and the candidate PLMN identity is included in the PLMN identities of the at least one cell.
The apparatus according to claim 10 or 11, wherein the transceiver unit is configured to receive the candidate PLMN identifier sent by the access network, where the candidate PLMN identifier carries the indication information.
The apparatus according to any one of claims 9-12, wherein the transceiver unit is further configured to receive country information sent by an access network device, where the country information indicates a geographical location range of a corresponding country, or where the country information indicates a country boundary of the corresponding country;

the processing unit is specifically configured to, when determining the country in which the terminal device is currently located:

acquiring the current position of the terminal equipment;

and determining the current country of the terminal equipment according to the country information and the position.
The apparatus of claim 13, wherein the processing unit, when determining the country in which the terminal device is currently located based on the country information and the location, is specifically configured to:

if the position is within the geographical position range of the corresponding country indicated by the country information, determining the country where the terminal equipment is currently located as the corresponding country; or,

And if the position is not in the geographical position range of the corresponding country indicated by the country information and the distance between the position and the country boundary line of the corresponding country indicated by the country information is smaller than a distance threshold value, determining that the country where the terminal equipment is currently located is the corresponding country.
The apparatus according to any one of claims 9-12, wherein the transceiver unit is configured to receive N PLMN identities sent by an access network device, where one PLMN identity corresponds to one country;

the processing unit is specifically configured to, when determining the country in which the terminal device is currently located:

and determining the country in which the terminal equipment is currently located as a first country, wherein the number of PLMN identifications corresponding to the first country in the N PLMN identifications is the largest.
The apparatus of any of claims 9-15, wherein the processing unit is further configured to: and selecting a first cell to reside, wherein the country corresponding to at least one PLMN identifier in a plurality of PLMN identifiers corresponding to the first cell is the same as the country corresponding to the candidate PLMN identifier.
A communication device comprising a transceiver, a processor, and a memory; program instructions are stored in the memory; the program instructions, when executed by the processor, cause the communication device to perform the method of any of claims 1 to 8 through the transceiver.
A chip, characterized in that the chip is coupled to a memory in an electronic device such that the chip, when run, invokes program instructions stored in the memory, implementing the method according to any of claims 1 to 8.
A computer readable storage medium, characterized in that the computer readable storage medium comprises program instructions which, when run on a device, cause the device to perform the method of any of claims 1 to 8.