CN113055980B

CN113055980B - Network selection method, device, terminal and storage medium

Info

Publication number: CN113055980B
Application number: CN202110274509.5A
Authority: CN
Inventors: 谢朝阳
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2022-11-04
Anticipated expiration: 2041-03-15
Also published as: CN113055980A

Abstract

The embodiment of the application discloses a network selection method, a network selection device, a terminal and a storage medium, and belongs to the technical field of communication. The method comprises the following steps: determining a reference PLMN and a calibration PLMN list corresponding to the reference PLMN, wherein the reference PLMN is a PLMN corresponding to a target frequency band needing to be searched in network searching, and the calibration PLMN in the calibration PLMN list is used for determining a sub-frequency band in the target frequency band; searching at least one sub-frequency band in a target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibration PLMN list; and responding to the searched HPLMN, and selecting the HPLMN to reside and register. The embodiment of the application can help reduce the redundant charge generated by the terminal residing history RPLMN.

Description

Network selection method, device, terminal and storage medium

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a network selection method, an apparatus, a terminal, and a storage medium.

Background

When the terminal is in the automatic Network selection mode, if the terminal is in a startup and loss coverage recovery scenario, the terminal may select a Network based on a Registered Public Land Mobile Network (RPLMN) priority mechanism.

In the RPLMN Priority mechanism, a terminal preferentially selects a historical RPLMN for residing, where the historical RPLMN is a PLMN registered before the terminal is in a power-on or coverage recovery scenario, and when the historical RPLMN is different from a Home Public Land Mobile Network (HPLMN), the terminal needs to reselect by using a Higher Priority Public Land Mobile Network (hppn) timer, and finally selects the HPLMN for residing, and the HPLMN provides a service.

In the RPLMN priority mechanism, if the historical RPLMN is different from the HPLMN, the terminal needs to preferentially select the historical RPLMN for residence and then reselect to the HPLMN for residence, and the residence time period of the terminal on the historical RPLMN results in generation of redundant charges.

Disclosure of Invention

The embodiment of the application provides a network selection method, a device, a terminal and a storage medium, which can help reduce redundant charges generated by a terminal resident history RPLMN. The technical scheme is as follows:

in one aspect, an embodiment of the present application provides a network selection method, which is applied to a terminal, and the method includes:

determining a reference PLMN and a calibration PLMN list corresponding to the reference PLMN, wherein the reference PLMN is a PLMN corresponding to a target frequency band needing to be searched in a network search, and the calibration PLMN in the calibration PLMN list is used for determining a sub-frequency band in the target frequency band;

searching at least one sub-frequency band in a target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibration PLMN list;

and responding to the searched HPLMN, and selecting the HPLMN to reside and register.

On the other hand, an embodiment of the present application provides a network selection apparatus, which is applied to a terminal, and the apparatus includes: the device comprises a determining module, a network searching module and a resident registering module;

the determining module is configured to determine a reference PLMN and a calibrated PLMN list corresponding to the reference PLMN, where the reference PLMN is a PLMN corresponding to a target frequency band that needs to be searched in a network search, and a calibrated PLMN in the calibrated PLMN list is used to determine a sub-frequency band in the target frequency band;

the network searching module is configured to search for a network for at least one sub-frequency band in a target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibrated PLMN list;

and the resident registration module is used for responding to the searched HPLMN and selecting the HPLMN to be resident and registered.

In another aspect, an embodiment of the present application provides a terminal, where the terminal includes a processor and a memory; the memory has stored therein at least one instruction, at least one program, set of codes, or set of instructions that is loaded and executed by the processor to implement the network selection method as described in the above aspect.

In another aspect, an embodiment of the present application provides a computer-readable storage medium, in which at least one computer program is stored, and the computer program is loaded and executed by a processor to implement the network selection method according to the above aspect.

In another aspect, a computer program product or computer program is provided, the computer program product or computer program comprising computer instructions stored in a computer readable storage medium. The processor of the terminal reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the terminal implements the network selection method provided in the various alternative implementations of the above aspects.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

in the embodiment, when the reference PLMN is determined as the historical RPLMN and the calibration PLMN list includes the HPLMN, if the HPLMN and the historical RPLMN exist in the current environment at the same time, the embodiment supports direct selection of the HPLMN for residence and registration, and compared with a scheme in the related art in which the terminal needs to preferentially select the historical RPLMN for residence and then reselect to the HPLMN for residence, the embodiment can help reduce the redundant charges generated by the terminal residence of the historical RPLMN.

Drawings

Fig. 1 is a schematic diagram of a communication system provided by an exemplary embodiment of the present application;

fig. 2 is a flowchart of a network searching process under the RPLMN prioritization mechanism according to an exemplary embodiment of the present application;

fig. 3 is a schematic diagram of time distribution of a network searching process in a scenario of starting up and coverage loss recovery under an RPLMN priority mechanism according to an exemplary embodiment of the present application;

FIG. 4 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 5 is a diagram illustrating overlapping of sub-bands provided by an exemplary embodiment of the present application;

FIG. 6 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 7 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 8 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 9 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 10 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

FIG. 11 is a flow chart of a network selection method provided by an exemplary embodiment of the present application;

fig. 12 is a block diagram of a network selection apparatus according to an exemplary embodiment of the present application;

fig. 13 is a block diagram of a computer device according to an exemplary embodiment of the present application.

Detailed Description

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

Reference herein to "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

First, the terms referred to in the embodiments of the present application will be briefly described:

public Land Mobile Network (PLMN): networks established and operated by governments or operators approved therefor for the purpose of providing land mobile services to the public.

Currently, PLMN = Mobile Country Code (MCC) + Mobile Network Code (MNC). For example: china is 460, manufacturer a is 00, manufacturer B is 01, PLMN of manufacturer a in china is 46000, PLMN of manufacturer B in china is 46001.

The PLMN may include the following types according to different attributes:

(1) Register Public Land Mobile Network (Registered Public Land Mobile Network, RPLMN): which is the PLMN that the terminal registered before the last power off or network disconnect.

(2) Home Public Land Mobile Network (HPLMN): which is the PLMN to which the user corresponding to the terminal belongs.

If the Universal subscriber identity card (Universal Sub)scriber Identity mobile, USIM) presence of EF _EHPLMN If not, the HPLMN is the PLMN in the file; if the file does not exist in the USIM card or exists, but the list in the file is empty, the HPLMN is the MCC and MNC obtained from the International Mobile Subscriber Identity (IMSI).

(3) User Controlled Public Land Mobile Network (UPLMN): which is a PLMN selection related parameter stored on a Subscriber Identity Module (SIM), UPLMN being a PLMN selected by the terminal when the user manually selects a network.

(4) Operator Controlled Public Land Mobile Network (OPLMN): the method is a parameter related to PLMN selection stored on the SIM, and mainly comprises the step that when an operator burns the SIM card, the operator PLMN signing a roaming agreement with the operator is written into a user identity identification card as an OPLMN so as to serve as a suggestion when a user roams and selects a network.

In the embodiment of the present application, the priority of the HPLMN is greater than the priority of the UPLMN, and the priority of the UPLMN is greater than the priority of the OPLMN.

Referring to fig. 1, a schematic diagram of a communication system according to an embodiment of the present application is shown. The communication system may include: access network 12 and terminal 14.

Several network devices 120 are included in access network 12. Network device 120 may be a base station, which is a device deployed in an access network to provide wireless communication functionality for terminals. The base stations may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In systems using different radio access technologies, the names of devices with base station functionality may differ, for example in LTE systems, called eNodeB or eNB; in a 5G NR-U system, it is called gNodeB or gNB. The description of "base station" may change as communication technology evolves. For convenience of this embodiment, the above-mentioned devices providing wireless communication function for the terminal 14 are collectively referred to as network devices.

The terminal 14 may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem with wireless communication capability, as well as various forms of user equipment, mobile Stations (MSs), terminals (terminal devices), and so forth. For convenience of description, the above-mentioned devices are collectively referred to as a terminal. The network device 120 and the terminal 14 communicate with each other via some air interface technology, such as a Uu interface.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: global System for Mobile communications (GSM) System, code Division Multiple Access (CDMA) System, wideband Code Division Multiple Access (WCDMA) System, general Packet Radio Service (GPRS), long Term Evolution (Long Term Evolution, LTE) System, LTE Frequency Division Duplex (FDD) System, LTE Time Division Duplex (TDD) System, advanced Long Term Evolution (Advanced Long Term Evolution), an LTE-a) System, a New Radio (NR) System, an Evolution System of the NR System, an LTE (LTE-based Access to Unlicensed spectrum) System on an Unlicensed Frequency band, an NR-U System, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) Communication System, a Wireless Local Area Network (WLAN), a Wireless Fidelity (WiFi), a next-generation Communication System, or other Communication systems.

Generally, the conventional Communication system supports a limited number of connections and is easy to implement, however, with the development of Communication technology, the mobile Communication system will support not only conventional Communication but also, for example, device-to-Device (D2D) Communication, machine-to-Machine (M2M) Communication, machine Type Communication (MTC), vehicle-to-Vehicle (V2V) Communication, and Vehicle networking (V2X) system, etc. The embodiments of the present application can also be applied to these communication systems.

According to the current third generation partnership project (the 3) ^rd Generation Partnership Project,3 GPP) TS22.122 and TS31.102, when in automatic network selection mode, the terminal selects network under the scene of starting and losing coverage recovery according to the file EF in the SIM card _LRPLMNSI To determine the network selection sequence:

the first condition is as follows: EF _LRPLMNSI The value is '00', and the terminal is required to always preferentially select the historical RPLMN to reside and attempt registration. After the historical RPLMN is successfully registered as the current RPLMN, a timer mechanism (HPPLMN timer) is utilized to periodically attempt back to the HPLMN or HPPLMN if the current RPLMN is not the HPLMN.

And a second condition: EF _LRPLMNSI Taking the value '01', the terminal is required to always preferentially select one of the historical RPLMN or HPLMN for camping and attempting registration.

Considering that the historical RPLMN is the most likely network in most cases, the terminal generally selects the RPLMN priority mechanism, that is, preferentially selects the historical RPLMN to camp and attempt to register, and the network searching process under the RPLMN priority mechanism is combined with the process shown in fig. 2, which includes the following steps:

step 201, starting up or losing the coverage recovery scene.

The initial state of the terminal is a startup or loss coverage recovery scene, and an RPLMN priority mechanism is adopted for residence and attempted registration.

Step 202, the terminal selects a historical RPLMN to search the network.

In step 203, the terminal searches for a network on the selected Radio Access Technology (RAT).

Optionally, in the current environment, multiple RATs exist, and the terminal selects one RAT and searches for a network on the selected RAT.

In step 204, the terminal determines whether a historical RPLMN exists in the current RAT.

Optionally, the terminal searches all frequency bands under the current RAT to determine whether there is a historical RPLMN under the current RAT.

If yes, go to step 205; if not, go to step 206.

In step 205, the terminal selects a historical RPLMN to camp on and attempts to register.

In step 206, the terminal determines whether all RATs have been searched.

If yes, go to step 207; if not, go to step 208.

Step 207, the terminal selects the next PLMN for network searching.

And the terminal selects the next PLMN for searching the network after the current round of PLMN searching of the historical RPLMN is finished. Optionally, the PLMN selection order is HPLMN, UPLMN, OPLMN. That is, after the current round of PLMN search for the historical RPLMN is finished, the terminal selects the HPLMN to search the network; after the PLMN search of the HPLMN in the current round is finished, the terminal selects the UPLMN to search the network; and after the current round of PLMN search for the UPLMN is finished, the terminal selects the OPLMN to search the network.

In step 208, the terminal selects the next RAT on the same PLMN and jumps to step 203.

And the terminal takes the next RAT as the selected RAT, and searches the network for the same PLMN on the RAT.

In step 209, the terminal selects the searched PLMN to camp on and attempts registration, and jumps to step 210.

And step 210, the terminal is successfully registered and obtains service on the current RPLMN.

In step 211, the terminal determines whether the current RPLMN is the HPLMN.

If yes, go to step 212; if not, go to step 213.

In step 212, the terminal obtains service on the HPLMN and network selection is finished.

In step 213, the terminal starts the HPPLMN timer.

Optionally, the duration of the HPPLMN timer is T: t = T1 is turned on for the first time; non-first turn on T = T2.

In step 214, in response to the expiration of the HPPLMN timer, the terminal determines whether a current Radio Resource Control (RRC) state is an IDLE (IDLE) state or an INACTIVE (INACTIVE) state.

If yes, go to step 215; if not, go to step 216.

Step 215, the terminal searches for the network.

Optionally, the network searching method of the terminal includes: and each access layer searches all frequency bands supported by the terminal, and reports the search results to the non-access layer together after all the frequency bands are searched by all the access layers.

In step 216, the terminal waits for the RRC state to return to the IDLE state or INACTIVE state, and jumps to step 215.

Step 217, the terminal determines whether a higher priority PLMN exists in the environment.

If yes, go to step 218; if not, go to step 213.

Step 218: the terminal selects the PLMN with the highest priority in the current environment to camp on and tries to register.

Step 219: and after the terminal registration is successful, jumping to step 211.

In FIG. 2 above, the durations T1 and T2 of the HPPLMN timer are defined as follows:

t1: starting up a scene, wherein the time length can be any value between [2min and T2 ]; in other scenarios, if the SIM card configuration enables a Fast First high Priority PLMN search (Fast First high Priority PLMN search) item, the time length may be any value between [2min, T2], otherwise, T2.

T2: if SIM card file EF _HPPLMN When the file exists, the duration is min (EF) _HPPLMN Value, EF _NASCONFIG A Minimum Periodic Search Timer); if SIM card file EF _HPPLMN None, with duration min (default, EF) _NASCONFIG Minimum period search timer).

Wherein the default value may be 60 minutes or 72 hours, selected according to the access technology currently supported and used by the terminal. Such as: the terminal does not support Extended Coverage Global System for Mobile Communications Internet of Things (EC-GSM-IoT), category M1, and category NB1, or the terminal supports the above-mentioned technique but does not use the above-mentioned technique when the HPPLMN timer is started, the default value is 60 minutes.

As shown in fig. 2, based on the current protocol framework, in the case of RPLMN priority mechanism, the terminal can only select the historical RPLMN first at each power-on or loss of coverage recovery, and when the historical RPLMN is different from the HPLMN, that is, the historical RPLMN is not the highest priority PLMN, the HPLMN needs to be reselected by using the HPLMN timer, and finally the HPLMN is returned.

In an extreme case, when the HPLMN and the historical RPLMN exist at the same time, the terminal still selects the historical RPLMN first. Then the scenario shown in fig. 3 may occur:

terminal searching network in initial state using T _Search The time of the duration. Terminal performs resident registration and uses T _Registration For a long period of time, at which time the terminal may register with the HPLMN but choose to register with the historical RPLMN. The terminal waits for the time of T duration for the HPPLMN timer to time out. The terminal uses T for waiting the RRC state to return to the network searching state _Wait The time of the duration. Terminal searches for network again and uses T _Search The time of the duration. Terminal performs resident registration and uses T _Registration And (5) the time of duration, at the moment, the terminal is registered in the HPLMN, and the network selection is finished.

It can be seen that the RPLMN priority mechanism in the related art enables the user to keep more T on the historical RPLMN _Waste ＝T+T _Wait +T _Search +T _Registration Time of day, wasting unnecessary charges to the user, wherein, T _Wait May be 0 or longer (e.g., 10 minutes, 20 minutes, etc.), depending on the service status and duration of the terminal.

In the embodiment of the application, concepts of a reference PLMN and a calibration PLMN list are introduced, the reference PLMN is a PLMN corresponding to a target frequency band needing to be searched in a network search, the calibration PLMN in the calibration PLMN list is used for determining a sub-frequency band in the target frequency band, and at least one sub-frequency band in the target frequency band corresponding to the reference PLMN is searched, so that a frequency band search sequence when the target frequency band is searched is optimized.

In the case that the reference PLMN is determined as the historical RPLMN and the calibration PLMN list includes the HPLMN, if the HPLMN and the historical RPLMN exist in the current environment at the same time, this embodiment supports direct selection of the HPLMN for camping and registering, without selecting the historical RPLMN for camping, and reselecting to the HPLMN for camping,

next, a network selection method provided in the embodiment of the present application is exemplarily described.

Fig. 4 is a flowchart illustrating a network selection method provided in an exemplary embodiment of the present application, which may be applied to a terminal, and the method may include the following steps:

step 401, determining a reference PLMN and a calibration PLMN list corresponding to the reference PLMN, where the reference PLMN is a PLMN corresponding to a target frequency band to be searched in the network search, and the calibration PLMN in the calibration PLMN list is used to determine a sub-frequency band in the target frequency band.

Optionally, before performing a search, the terminal selects a reference PLMN and an alignment PLMN list corresponding to the reference PLMN.

The calibration PLMN list comprises at least one calibration PLMN, and the calibration PLMN is used for determining a sub-frequency band in a target frequency band. The sub-bands are all or part of the target bands. In the embodiment of the present application, the sub-bands in the target band may or may not overlap with each other.

For example, in the embodiment of the present application, the initialized reference PLMN is the historical RPLMN, and the initialized calibration PLMN list is the HPPLMN. And the historical RPLMN is a PLMN registered by the terminal before the terminal is in the starting-up or coverage recovery scene, and the HPPLMN comprises at least one PLMN with higher priority than the historical RPLMN.

Illustratively, if the historical RPLMN is a high quality PLMN, then the HPPLMN includes HPLMN, UPLMN, OPLMN; RPLMN is OPLMN, then HPPLMN includes HPLMN, UPLMN.

Step 402, searching at least one sub-frequency band in the target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibration PLMN list.

Optionally, the terminal determines a searched target frequency band based on the reference PLMN, determines multiple sub-frequency bands in the target frequency band in combination with the calibration PLMN list, and performs network searching on at least one sub-frequency band in the target frequency band corresponding to the reference PLMN according to the granularity of the sub-frequency bands.

Optionally, in order to avoid a problem of repeated searching caused by mutual overlapping of sub-bands in the target frequency band, the terminal supports marking the searched frequency band. For example, referring to fig. 5 in combination, the terminal first searches for the sub-band 510, marks the band corresponding to the sub-band 510 after the search is completed, and when the sub-band 520 needs to be searched next time, because the band 521 in the sub-band 520 is overlapped with the sub-band 510, and the band 522 in the sub-band 520 is not overlapped with the sub-band 510, the terminal does not need to search the band 521 repeatedly, but only needs to search for the band 522.

It can be understood that, in the embodiment of the present application, the reference PLMN and the calibrated PLMN list support updating, so that the terminal can perform network search on different target frequency bands corresponding to different reference PLMNs, thereby implementing network search as comprehensive as possible and improving the probability of searching a network.

And 403, responding to the searched HPLMN, selecting the HPLMN to reside and register.

In a possible implementation manner, the terminal acquires the search result, confirms the search result, and directly selects the HPLMN to reside and register in the HPLMN under the condition that the HPLMN is searched, so that the HPLMN becomes the current RPLMN.

For example, in the case that the terminal currently searches only the HPLMN, the terminal selects the HPLMN to camp on and registers in the HPLMN.

Illustratively, in the case where the terminal currently searches for the HPLMN and other types of PLMNs (e.g., historical RPLMNs), the terminal selects the HPLMN for camping and registers with the HPLMN.

In summary, in the method provided in this embodiment, concepts of a reference PLMN and a calibration PLMN list are introduced, where the reference PLMN is a PLMN corresponding to a target frequency band that needs to be searched in a network search, and the calibration PLMN in the calibration PLMN list is used to determine a sub-frequency band in the target frequency band, when the terminal searches for the target frequency band, the terminal may search for at least one sub-frequency band in the target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibration PLMN list, and compared with a scheme in which all target frequency bands corresponding to one PLMN are searched at one time in the related art, and then a search result is checked.

Meanwhile, under the condition that the reference PLMN in this embodiment is determined to be the historical RPLMN, if the HPLMN and the historical RPLMN exist in the current environment at the same time, this embodiment supports direct selection of the HPLMN for residence and registration, and compared with a scheme in which a terminal needs to preferentially select the historical RPLMN for residence and then reselect to the HPLMN for residence in the related art, this embodiment can help reduce the redundant charges generated by the terminal residence of the historical RPLMN.

In an exemplary embodiment, the sub-bands include a common sub-band, where the common sub-band refers to a frequency band common to the reference PLMN and the calibration PLMN in the target frequency band, and since there is a possibility that at least one of the reference PLMN and the calibration PLMN is searched in the common sub-band, performing a preferential search on the common sub-band may improve network searching efficiency.

In an alternative embodiment based on fig. 4, fig. 6 shows a flowchart of a network selection method provided in an exemplary embodiment of the present application, and the method may be applied to a terminal, where the terminal is in a power-on or coverage recovery scenario. In this embodiment, step 402 may alternatively be implemented as the following steps:

step 601, obtaining a frequency band checking result, where the frequency band checking result is used to indicate a mapping PLMN list, and the mapping PLMN list includes a calibration PLMN having a common sub-frequency band with a reference PLMN in the calibration PLMN list.

The existence of a common sub-band for the reference PLMN and the calibration PLMN means that there is a possibility that at least one of the reference PLMN and the calibration PLMN is searched for on the common sub-band.

In one possible embodiment, the terminal includes: the system comprises a non-access layer and n access layers, wherein the n access layers correspond to n different wireless access technologies one by one, the n access layers are sorted from high to low according to priority, and n is a positive integer; the non-access layer obtains n frequency band checking results from the n access layers, wherein the ith frequency band checking result in the n frequency band checking results is used for indicating an ith mapping PLMN list corresponding to the ith access layer, and i is a positive integer not greater than n. It will be appreciated that the priority of the n access stratum layers can be customized as desired.

Illustratively, the terminal includes: a non-access layer and 2 access layers (5G access layer and 4G access layer), the non-access layer obtains a 1 st frequency band check result from the 5G access layer, and the 1 st frequency band check result is used for indicating a 1 st mapping PLMN list corresponding to the 5G access layer; the non-access layer obtains a 2 nd frequency band checking result from the 4G access layer, and the 2 nd frequency band checking result is used for indicating a 2 nd mapping PLMN list corresponding to the 4G access layer.

In a possible implementation, the manner in which the non-access stratum obtains n frequency band check results from n access stratum refers to the following steps:

s11, the non-access stratum sends an ith frequency band checking request to an ith access stratum in the n access stratums, the ith frequency band checking request carries a reference PLMN and an ith calibration PLMN sublist, and the ith calibration PLMN sublist comprises a calibration PLMN supporting a wireless access technology corresponding to the ith access stratum in the calibration PLMN list.

Illustratively, the list of calibrated PLMNs includes: PLMN a, PLMN B and PLMN C. Wherein, PLMN a does not support the radio access technology corresponding to the ith access layer, PLMN B and PLMN C support the radio access technology corresponding to the ith access layer, and the ith calibration PLMN sublist carried in the ith frequency band check request includes: PLMN B and PLMN C.

S12, the ith access layer determines an ith mapping PLMN list based on the received ith frequency band check request.

Optionally, after receiving the ith frequency band check request, the ith access layer checks whether a common frequency sub-band exists between the reference PLMN and the calibration PLMN in the ith calibration PLMN sub-list according to the correspondence between the PLMN and the frequency band stored in the ith access layer, and adds the calibration PLMN in which the common frequency sub-band exists to the ith mapping PLMN list.

Optionally, the ith access layer obtains and stores the corresponding relationship between the PLMN and the frequency band through predefining or self-learning.

S13, the ith access layer sends an ith frequency band checking result to the non-access layer, and the ith frequency band checking result carries an ith mapping PLMN list.

S14, the non-access layer obtains n frequency band checking results from the 1 st access layer to the nth access layer.

Wherein, the ith frequency band checking result in the n frequency band checking results is used for indicating the ith mapping PLMN list corresponding to the ith access stratum, and i is a positive integer not greater than n.

Step 602, based on the mapped PLMN list, a network search is performed on the common sub-frequency band in the target frequency band corresponding to the reference PLMN.

Optionally, after acquiring the mapping PLMN list, the terminal performs, based on the indication of the mapping PLMN list, a preferential search on the common sub-bands in the target frequency band.

In one possible embodiment, the terminal includes: the access layer comprises a non-access layer and n access layers, wherein the n access layers correspond to n different wireless access technologies one by one, the n access layers are sorted from high to low according to priority, and n is a positive integer; in response to n of n frequency band checking results _k The mapping PLMN list corresponding to the frequency band checking result comprises the kth calibration PLMN, the execution is carried out between the non access layer and the jth access layer, and the kth calibration PLMN list and the jth calibration PLMN list are contained in the mapping PLMN list corresponding to the frequency band checking result _j Common sub-band dependent kth _j And (5) searching the network. It will be appreciated that the priority of the n access stratum layers can be customized as desired.

Wherein the kth calibration PLMN is a calibration PLMN corresponding to the kth priority in the calibration PLMN list, and the jth access stratum is n _k N corresponding to frequency band checking result _k J access stratum of the access stratum, k is a positive integer which is increased from 1 and is not larger than x, x is the number of the calibration PLMNs in the calibration PLMN list, n _k Is a positive integer not greater than n, j is an increasing integer starting from 1 and not greater than n _k Positive integer of (b), k _j Is a positive integer, k _j The common sub-band is a sub-band shared between the reference PLMN and the kth calibration PLMN in the radio access technology corresponding to the jth access stratum.

In the embodiment of the present application, x calibration PLMNs in the calibration PLMN list are arranged from high to low according to priority, and the kth calibration PLMN is a calibration PLMN in the calibration PLMN list corresponding to the kth priority.

In one possible embodiment, the kth _j The network searching process comprises the following steps:

s21, non-access stratum to n _k J access stratum of access stratum transmitting k _j Network search request, kth _j The network searching request carries a reference PLMN and a kth calibration PLMN.

S22, the jth access stratum receives the kth _j And (5) searching the network.

Optionally, kth _j The reference PLMN and the kth calibrated PLMN in the network search request may inform the jth access stratum that the PLMN to be searched by the jth access stratum is the reference PLMN, but the frequency band information of the kth calibrated PLMN is to be combined.

S23, the jth access layer is based on the kth _j Network searching request, determining kth _j A common frequency sub-band.

Kth of _j The common sub-band is a sub-band shared between the reference PLMN and the kth calibration PLMN in the radio access technology corresponding to the jth access stratum. At the k-th _j On the common sub-band, there is a possibility that the jth access stratum searches for at least one of the reference PLMN and the kth calibration PLMN.

Optionally, the jth access stratum receives the kth access stratum _j After the network searching request is carried out, whether the kth calibration PLMN is arranged between the reference PLMN and the kth calibration PLMN or not is checked according to the corresponding relation between the PLMN stored by the user and the frequency band _j A common frequency sub-band.

Optionally, the jth access layer obtains and stores the corresponding relationship between the PLMN and the frequency band through predefining or self-learning.

S24, the jth access stratum pair _j Searching the frequency bands which are not searched in the common frequency sub-bands to generate the kth frequency band _j And (6) searching results.

Optionally, the jth access stratum pair kth _j After searching the frequency bands which are not searched in the common sub-frequency bands, marking the frequency bands which execute the searching operation. Because each frequency band search of the access layer needs to mark the frequency band which has already executed the network search in the current network search, the aim at the frequency band search can be avoidedThe problem of repeatedly executing search operation in the process of searching the network in one round in the same frequency band is solved, and therefore the efficiency of frequency band search is improved.

S25, the j access stratum sends the k layer to the non access stratum _j And (6) searching results.

S26, in response to the k _j If the search result does not satisfy the network searching end condition, j is added with 1, and then the non-access layer is added to n again _k J access stratum in the access stratum sends k _j And the step of searching the network begins to be executed.

Wherein, searching the net and finishing the condition includes: the search result comprises at least one of HPPLMN and historical RPLMN, the historical RPLMN is a PLMN registered before the terminal is in a starting or coverage recovery scene, the HPPLMN comprises at least one PLMN with higher priority than the historical RPLMN, and the HPPLMN comprises the HPLMN.

For the k calibration PLMN, n of the n frequency band check results _k The mapping PLMN list corresponding to the frequency band checking result comprises the k calibration PLMN, and for n _k N corresponding to frequency band checking result _k An access stratum, n _k The access layers are arranged according to the priority from high to low, and the terminal is arranged according to the following steps: non-access stratum and n _k Performing with the kth access layer 1 of the access layers ₁ Common sub-band dependent kth ₁ Network searching process, non-access stratum and n _k Performing a and operation between 2 nd access layers of the access layers ₂ Common sub-band dependent kth ₂ Searching network process, … …, non-access layer and n _k N in one access stratum _k Performing between access stratum with kn _k Common sub-band dependent kn _k And (3) executing jump searching among different wireless access technologies according to the searching sequence of the network searching process until the searching result reported by any network searching process meets the network searching ending condition.

For example, for the 1 st calibration PLMN, the mapping PLMN list corresponding to 2 frequency band check results in the n frequency band check results includes the 1 st calibration PLMN, and the 2 access layers corresponding to the 2 frequency band check results include: access stratum a corresponding to priority 1 (i.e., access stratum 1); access stratum B corresponding to priority 2 (i.e., access stratum 2), then notFirst execution between access stratum and access stratum A and 1 st ₁ Common sub-band related 1 st ₁ Searching for a network, if k ₁ Kth obtained in the process of searching network ₁ If the search result does not satisfy the network searching end condition, executing the 1 st operation between the non-access layer and the access layer B ₂ Common sub-band related 1 st ₂ And (5) searching the network.

S27, responding to j reaching n _k And k is a _j If the search result does not meet the network searching end condition, adding 1 to k and resetting j to 1, and then, starting the non-access layer to n again _k J access stratum of access stratum transmitting k _j And the step of the network searching request is started to be executed.

Wherein, searching the net and finishing the condition includes: the search result comprises at least one of m HPPLMNs and historical RPLMNs.

For k calibration of PLMN, if the terminal has finished non access stratum and n _k N in one access stratum _k Performed between access layers and kn _k Common sub-band dependent kn _k Network searching process, and kth _k If the search result still does not meet the network searching end condition, adding 1 to k and resetting j to 1, and then, starting the non-access layer to n again _k J access stratum of access stratum transmitting k _j And the step of the network searching request is started to be executed.

Illustratively, the list of calibration PLMNs includes 3 calibration PLMNs: PLMN a corresponding to priority 1 (i.e., calibration PLMN 1); PLMN B corresponding to priority 2 (i.e., 2 nd calibration PLMN); PLMN C corresponding to 3 rd priority (i.e. 3 rd calibration PLMN), the terminal will follow: 1 st of calibration PLMNs with PLMN A as 1 st ₁ Network searching process to No. 1n ₁ Searching a network; 2 nd of using PLMN B as 2 nd calibration PLMN ₁ Network searching process to 2n ₂ Searching a network; 3 rd of 3 rd calibration PLMN with PLMN C as 3 rd calibration PLMN ₁ Network searching process to No. 3n ₃ And the searching sequence of the network searching process executes searching until the searching result reported by any network searching process meets the network searching ending condition.

Optionally, at k _j In the process of searching the network, if the k-th network is obtained _j If the search result meets the network searching end condition, the non-access layerStopping the subsequent network searching process at the k _j And selecting the PLMN carried in the search result, selecting one PLMN for residing, registering in the PLMN, and deleting the marks of all the access layers on the searched frequency bands after the registration is successful. Specifically, the following three cases are included:

case one, in response to the kth _j The search result comprises HPLMN, and the non-access layer selects HPLMN to reside and register.

At the k-th _j In the case that the HPLMN is included in the search result, such as: kth _j Only the HPLMN is included in the search results; or, k < th > _j The search result comprises the HPLMN and other PLMNs, and the non-access layer selects the HPLMN to reside and register.

Case two, in response to the kth _j HPLMN is not included in the search results, and kth _j The search result comprises at least one residual HPPLMN, and the non-access layer selects the target residual HPPLMN for residence and registration.

The residual HPPLMNNs comprise other HPPLMNNs except the HPLMN, and the target residual HPPLMNN is the HPPLMNN with the highest priority in the residual HPPLMNNs.

At the k-th _j If the search result does not include the HPLMN and includes at least one remaining HPLMN, such as: kth _j Only at least one remaining HPPLMN is included in the search results; or, k < th > _j The search result comprises at least one residual HPPLMN and PLMN (such as historical RPLMN) belonging to non-HPPLMN type, and the non-access layer selects target residual HPPLMN from at least one residual HPPLMN to reside and register.

Case three, in response to the kth _j HPPLMN is not included in the search results, and kth _j The search result comprises historical RPLMN, and the non-access stratum selects the historical RPLMN to reside and register.

At the k-th _j If the search result does not include the HPPLMN and includes the historical RPLMN, such as: kth _j Only historical RPLMN is included in the search result; or, k < th > _j The search result comprises historical RPLMN and PLMN belonging to non-HPPLMN type and non-historical RPLMN type, and the non-access layer selects the historical RPLMN typeLine resident and register.

It can be understood that, as shown in the above 3 cases, the terminal performs the camping selection, the HPPLMN (including the HPLMN) is prioritized when the terminal selects the network, so as to maximally ensure that the terminal can obtain the service on the HPPLMN more quickly.

Optionally, if x calibrated PLMNs in the calibrated PLMN list are detected, the terminal has completed the xth calibrated PLMN related to the xth calibrated PLMN _nx Network searching process, and x _nx And if the search result still does not meet the network searching end condition, the terminal searches the sub-frequency bands which are not searched in the target frequency bands corresponding to the reference PLMN under each wireless access technology. Specific reference is made to: in response to the x _nx The search result does not satisfy the condition of network searching end, and the (x + 1) th related to the p remaining sub-frequency band is executed between the non-access layer and the p access layer in the n access layers _p The network searching process generates the (x + 1) th _p Searching results;

the pth remaining sub-band is a sub-band which is not searched in a target frequency band corresponding to the reference PLMN in the radio access technology corresponding to the pth access stratum, and p is a positive integer which is increased from 1 and is not greater than n.

In one possible embodiment, the (x + 1) th _p The network searching process comprises the following steps:

s31, the non access layer sends the (x + 1) th to the p access layer _p Network search request, number (x + 1) _p The network searching request carries a reference PLMN.

S32, the p access layer receives the (x + 1) th _p And (5) network searching request.

Optional, no. (x + 1) _p The reference PLMN in the network searching request may inform the p-th access layer that the PLMN to be searched is the reference PLMN, without combining the frequency band information of the calibration PLMN.

S33, the p access layer is based on the (x + 1) th _p Searching the network request, searching the pth residual frequency sub-band to generate the (x + 1) th _p And (6) searching results.

Optionally, each frequency band search of the access layer needs to mark a frequency band in which the search has been performed in the current round of network search, and the p-th access layer receives the (x + 1) -th frequency band _p After the network searching request, the unmarked frequency band in the target frequency band corresponding to the reference PLMN is taken as the pth surplus sub-frequency band, the pth surplus sub-frequency band is searched, and the (x + 1) th is generated _p And (6) searching results.

S34, the p access stratum sends the (x + 1) th to the non access stratum _p And (6) searching results.

S35, responding to the (x + 1) th _p The searching result does not satisfy the network searching end condition, adds 1 to p and then sends the (x + 1) th message from the non-access layer to the p-access layer _p And the step of the network searching request is started to be executed.

Wherein, searching the net and finishing the condition includes: the search result comprises at least one of HPPLMN and historical RPLMN.

The terminal will follow: performing (x + 1) th correlation with the 1 st remaining sub-band between the non-access stratum and the 1 st access stratum ₁ Network searching process, executing (x + 1) th related to 2 nd residual frequency sub-band between non-access layer and 2 nd access layer ₂ Searching the network, … …, executing the (x + 1) th related to the nth residual sub-band between the non-access layer and the nth access layer _n And (3) executing jump searching among different wireless access technologies according to the searching sequence of the network searching process until the searching result reported by any network searching process meets the network searching ending condition.

Illustratively, the n access stratum layers include: access stratum a corresponding to priority 1 (i.e., access stratum 1); corresponding to the access stratum B with the 2 nd priority (i.e. the 2 nd access stratum), the (x + 1) th sub-band related to the 1 st remaining sub-band is executed between the non-access stratum and the access stratum A ₁ Network searching process, if the (x + 1) th ₁ (x + 1) th obtained in the process of searching network ₁ If the search result does not satisfy the network searching end condition, executing the (x + 1) th related to the 2 nd residual sub-frequency band between the non-access layer and the access layer B ₂ And (5) searching the network.

Alternatively, in the (x + 1) th _p In the process of searching the network, if the obtained (x + 1) th network is obtained _p If the search result meets the network searching end condition, the non-access layer will stop the subsequent network searching process, at the (x + 1) th _p Selecting PLMN carried in search results, selecting a PLMN to reside, registering in the PLMN, deleting after successful registrationExcept for all access stratum labels on the searched frequency bands. Specifically, the following three cases are included:

case one, in response to the (x + 1) th _p The search result comprises the HPLMN, and the non-access layer selects the HPLMN to reside and register.

In the (x + 1) _p In the case that the HPLMN is included in the search result, such as: (x + 1) _p Only the HPLMN is included in the search results; or, the (x + 1) th _p The search result comprises the HPLMN and other PLMNs, and the non-access layer selects the HPLMN to reside and register.

Case two, in response to the (x + 1) th _p The search result does not include HPLMN, and the (x + 1) th _p The search result comprises at least one residual HPPLMN, and the non-access layer selects the target residual HPPLMN for residence and registration.

In the (x + 1) _p If the search result does not include the HPLMN and includes at least one remaining HPLMN, such as: (x + 1) _p Only at least one remaining HPPLMN is included in the search results; or, the (x + 1) _p The search result comprises at least one residual HPPLMN and PLMN (such as historical RPLMN) belonging to non-HPPLMN type, and the non-access layer selects target residual HPPLMN from at least one residual HPPLMN to reside and register.

Case three, in response to the (x + 1) th _p HPPLMN is not included in the search results, and the (x + 1) th _p The search result comprises historical RPLMN, and the non-access stratum selects the historical RPLMN to reside and register.

In the (x + 1) _p If the search result does not include the HPPLMN and includes the historical RPLMN, such as: (x + 1) _p Only historical RPLMN is included in the search result; or, the (x + 1) _p The search result comprises historical RPLMN and PLMN which belongs to non-HPPLMN type and non-historical RPLMN type, and the non-access stratum selects the historical RPLMN type to reside and register.

It can be understood that, as shown in the above 3 cases, the terminal performs the camping selection, the HPPLMN (including the HPLMN) is prioritized when the terminal selects the network, so as to maximally ensure that the terminal can acquire the service at the HPPLMN more quickly.

In summary, in the method provided in this embodiment, the reference PLMN and the calibrated PLMN list may be used for the terminal to determine the mapped PLMN list, and the calibrated PLMN in the mapped PLMN list and the reference PLMN have a common sub-band, and the terminal may perform a preferential network search on the common sub-band in the target frequency band corresponding to the reference PLMN based on the mapped PLMN list.

Meanwhile, in the method provided by this embodiment, when the search result includes at least one of the HPPLMN and the historical RPLMN, the terminal stops the network searching process, so that resource consumption caused by a long-term network searching process can be avoided. And when the residing selection is carried out subsequently, the HPPLMN (including the HPLMN) is considered preferentially when the terminal selects the network, so that the terminal can be ensured to acquire the service in the HPPLMN more quickly to the maximum extent.

In an exemplary embodiment, in order to conform to a basic idea of an RPLMN priority mechanism proposed in a current protocol, in the embodiment of the present application, when initializing a reference PLMN and a calibration PLMN list, the initialized reference PLMN is a historical RPLMN, and the initialized calibration PLMN list is an hplmn, so as to ensure that a terminal searches for a relevant frequency band of the historical RPLMN first.

In an alternative embodiment based on fig. 4, fig. 7 is a flowchart illustrating a network selection method provided in an exemplary embodiment of the present application, where the method may be applied to a terminal, and the terminal is in a power-on or coverage recovery scenario. In this embodiment, step 401 may alternatively be implemented as the following steps:

in step 701, a reference PLMN is determined.

In one possible implementation, corresponding to the initialization and update scenarios of the reference PLMN, the step 701 has two determination manners as follows:

1) Prior to searching for a network, the historical RPLMN is determined as an initialized reference PLMN.

2) And in response to that all search results obtained by searching at least one sub-frequency band in the target frequency band corresponding to the reference PLMN do not meet the network searching ending condition, updating the reference PLMN to the HPPLMN with the highest priority in the last calibration PLMN list.

Step 702 determines a calibrated PLMN list corresponding to the reference PLMN based on the HPPLMN information.

The HPPLMN information is used for indicating the HPPLMNN, the HPPLMNN comprises at least one PLMN with higher priority than a historical RPLMN, and the historical RPLMN is a PLMN which is registered before the terminal is in a starting or coverage recovery scene.

Optionally, the HPPLMN information is known from the SIM card.

In one possible implementation, corresponding to the initialization and update scenarios of the calibration PLMN list, step 702 has two determination manners as follows:

1) The HPPLMN in the HPPLMN information is determined to be an initialized calibrated PLMN list prior to a network search.

2) And in response to that all search results obtained by searching at least one sub-frequency band in the target frequency band corresponding to the reference PLMN do not meet the network searching ending condition, updating the calibration PLMN list to other HPPLMNs except the HPPLMN with the highest priority in the last calibration PLMN list.

That is, for the initialized reference PLMN and the initialized calibration PLMN list, the initialized reference PLMN is the historical RPLMN, and the initialized calibration PLMN is the HPPLMN with a higher priority than the historical RPLMN. Aiming at the non-initial reference PLMN and the non-initial calibration PLMN list, the terminal screens the HPPLMNs which are not subjected to reference in the HPPLMNs, carries out priority sequencing on the HPPLMNs, then selects the HPPLMNs with the highest priority as the next reference PLMN, and selects the rest HPPLMNs as the next calibration PLMN.

It can be understood that, when all HPPLMNs have been marked with the reference PLMN, the search result obtained by the terminal still does not satisfy the network search end condition, that is, the terminal still does not find a suitable PLMN for residing and registering, and in the n access layers, there is at least one access layer in which the frequency band is not searched, and the terminal may instruct the access layer to complete one search of all the unsearched frequency bands and report the search result. At this time, the reference PLMN and the calibration PLMN may be understood as both being set to null.

If all the frequency bands are searched, the terminal does not search at least one of the HPPLMN and the historical RPLMN, but searches other types of PLMNs which are available and allowed for the terminal, the terminal selects one PLMN to perform a resident registration attempt, and simultaneously deletes the mark of the searched access stratum frequency band.

If all the frequency bands are searched, the terminal does not search at least one of the HPPLMN and the historical RPLMN, and does not search other types of PLMNs which are available and allowed for the terminal, the terminal means that the terminal currently limits service or is offline, the terminal network selection fails, and meanwhile, the mark of the searched access layer frequency band is deleted.

In summary, in the method provided in this embodiment, when initializing the reference PLMN and calibrating the PLMN list, the initialized reference PLMN is the historical RPLMN, and the initialized calibrating PLMN list is the HPPLMN, so as to ensure that the terminal searches the relevant frequency bands of the historical RPLMN first, and meet the basic idea of the RPLMN priority mechanism proposed in the current protocol.

Meanwhile, in the method provided by the embodiment, the reference PLMN and the calibrated PLMN list support updating, so that the terminal can search for different target frequency bands corresponding to different reference PLMNs, thereby realizing network search as comprehensive as possible and improving the probability of searching for a network.

In an exemplary embodiment, if the current RPLMN is not the HPLMN, and the terminal needs to return to the HPLMN using the HPLMN timer mechanism, the terminal may search the frequency band corresponding to the HPLMN ahead on different RATs in the network searching process after the HPLMN timer expires.

In an alternative embodiment based on fig. 4, fig. 8 is a flowchart illustrating a network selection method provided in an exemplary embodiment of the present application, where the method may be applied to a terminal, and the terminal is in a power-on or coverage recovery scenario. In this embodiment, step 403 may be followed by the following steps:

step 801, in response to that the current RPLMN is not the HPLMN, in the network searching process after the HPLMN timer is overtime, searching is performed according to the searching sequence that the frequency band corresponding to the HPLMN is searched first, and then the remaining frequency bands are searched.

And the rest frequency bands are other frequency bands except the frequency band corresponding to the HPLMN in the frequency bands supported by the terminal.

Optionally, in the network searching process after the HPPLMN timer is overtime, the terminal uses the frequency band corresponding to the HPLMN as the first priority frequency band on each RAT to perform search in advance, and then uses the remaining frequency bands as the second priority frequency bands on each RAT to perform search in a delayed manner. At this time, the reference PLMN may be understood as being set to the HPLMN, and the calibration PLMN may be understood as being set to null.

And step 802, responding to the searched HPLMN, reporting the search result carrying the HPLMN, and stopping the network searching process after the HPLMN timer is overtime.

In summary, in the method provided in this embodiment, in the network searching process after the HPPLMN timer expires, the terminal may perform advanced search on the frequency band corresponding to the HPLMN in different RATs, and if the HPLMN exists in the environment, the HPLMN may be searched faster.

Meanwhile, according to the method provided by the embodiment, once the HPLMN is searched, the access layer can report the search result in advance without waiting for reporting together after all the frequency bands to be searched are searched, so that the non-access layer processes the search result, the network searching process after the HPLMN timer is overtime is stopped, and the resident registration on the HPLMN is directly executed, thereby shortening the time for returning to the HPLMN as a whole.

Next, the network selection method proposed in the above embodiment is exemplarily described with reference to fig. 9 to fig. 11 as follows.

Fig. 9 is a flowchart illustrating a network selection method according to an exemplary embodiment of the present application, where the method may be applied to a terminal, and the terminal is in a power-on or coverage recovery scenario. In this embodiment, the method includes the following steps:

step 901, start up or lose coverage recovery scenario.

The initial state of the terminal is a boot-up or lost coverage recovery scenario.

Step 902, synchronizing the HPLMN or EHPLMN with the non-access stratum in the terminal.

Before searching for the network for the first time, the access stratum needs to acquire the EHPLMN or HPLMN of the current SIM card (when the EHPLMN does not exist).

Optionally, when the terminal is powered on, the non-access layer notifies the access layer of the HPLMN or the EHPLMN, or the access layer directly obtains the HPLMN or the EHPLMN through the SIM card.

Step 903, the terminal detects whether the network is searched for the first time in the current round.

If yes, go to step 904; if not, go to step 905.

And step 904, the terminal acquires HPPL MN information.

Wherein the HPPLMN information is used to indicate an HPPLMN comprising at least one PLMN having a higher priority than the historical RPLMN.

Step 905, the terminal determines a reference PLMN and a calibration PLMN.

The reference PLMN is a PLMN to be searched in the network searching, namely, a target frequency band corresponding to the PLMN is searched in the network searching; the calibration PLMN is a PLMN used for sequencing target frequency bands corresponding to the reference PLMN, and a calibration PLMN list is formed by a plurality of calibration PLMNs.

Step 906, the terminal uses the PLMN + frequency band + RAT to perform comprehensive network searching, and searches for HPLMN or HPLMN as much as possible.

The specific implementation of step 906 is shown in fig. 10 below, and is not described herein again.

Step 907, the non-access stratum determines whether the reported search result has the HPLMN.

If yes, go to step 908; if not, step 909 is executed.

Step 908, the non-access stratum selects the HPLMN for camping registration and jumps to step 919.

Optionally, once the HPLMN reported by the access layer is received, the current round of PLMN search is stopped no matter whether the historical RPLMNs are found at the same time, the non-access layer directly selects the HPLMN for residence and registration, and the mark of the access layer after frequency band search is deleted.

One special case of this scenario is a shared network (shared network) scenario: a certain cell belongs to both historical RPLMN and HPLMN, an access layer under the RAT needs to be explicitly informed that the terminal is registered in the HPLMN, and the terminal is registered in the HPLMN in the subsequent registration process, so that the waste of the time for continuous searching is avoided.

In step 909, the non-access stratum determines whether there are other hppmmns in the search result reported this time.

If yes, go to step 910; if not, go to step 911.

In step 910, the non-access stratum selects the highest priority HPPLMN for camping registration, and jumps to step 919.

The access layer does not report the HPLMN, but reports other HPPLMNNs (such as UPLMN, OPLMN and the like), no matter whether the RPLMN is found at the same time, the subsequent network searching operation is not carried out any more, and the non-access layer is directly registered to the HPPLMNN. And if a plurality of HPPLMNs are found, selecting the HPPLMNs with the highest priority as the current RPLMN, and deleting the mark of the searched access layer frequency band.

One special case of this scenario is a shared network (shared network) scenario: a cell belongs to both the RPLMN and the highest priority HPPLMN, and an access stratum under the RAT needs to be explicitly notified that the terminal is registered at the highest priority HPPLMN, and then the terminal is registered with the highest priority HPPLMN in a subsequent registration process, thereby avoiding wasting time for continuing searching.

And step 911, the non-access stratum judges whether the reported search result has historical RPLMN.

If yes, go to step 912; if not, step 913 is performed.

In step 912, the non-access stratum selects the historical RPLMN for camping registration, and jumps to step 919.

The access layer reports the historical RPLMN, but no other HPPLMNs (including HPLMN) exist, the non-access layer selects the historical RPLMN to reside and register according to the current mechanism, and then returns to the HPLMN through an HPPLMN timer mechanism.

Step 913, the non-access stratum determines whether the search of the reference PLMN is finished.

If yes, go to step 914; if not, go to step 906.

In step 914, the non-access stratum determines whether all the frequency bands supported by the terminal have been searched.

If yes, go to step 915; if not, go to step 916.

In step 915, the non-access stratum determines whether there are any available and allowed PLMNs in the search result of the round.

If yes, go to step 917; if not, go to step 918.

In step 916, the terminal performs a search for a next reference PLMN.

After the searching of the reference PLMN is finished, neither history RPLMN nor HPPLMN exists: and if no frequency band is searched currently, entering a searching process of the next reference PLMN.

Step 917, the terminal selects PLMN for camping according to the existing implementation, and jumps to step 919.

If all frequency bands are searched and neither historical RPLMN nor HPPLMN exists, selecting an available and allowed PLMN to perform a camping registration attempt according to the current mechanism.

Step 918, the terminal ends the network searching process of the round; deleting the frequency band search mark of the access layer; the terminal is either limited service or off-line.

Step 919, the terminal ends the network searching process of the round; the terminal executes PLMN residing registration; and deleting the access layer related frequency band searching marks.

Specifically, as shown in fig. 10, only two RATs, i.e., 5G and 4G, are taken as an example in fig. 10, and the priority of the 5G RAT is higher than that of the 4G RAT, so that the terminal can directly extend when supporting more RATs. In this embodiment, the method comprises the following steps:

the following steps 1001 to 1006 correspond to a network searching information checking procedure.

And step 1001, the terminal takes the historical RPLMN as a reference PLMN and the HPPLMN as a calibration PLMN.

Optionally, the HPPLMN includes, but is not limited to: HPLMN, UPLMN, OPLMN.

Step 1002, the non-access stratum sends a frequency band check request to the 5G access stratum.

Optionally, the frequency band check request includes parameters: the reference PLMN is a historical RPLMN, and the list of calibrated PLMNs includes the following calibrated PLMNs: HPLMN, UPLMN (if UPLMN supports 5G), OPLMN (if OPLMN supports 5G).

Step 1003,5G, after receiving the frequency band check request from the non-access stratum, the access stratum acquires a calibration PLMN in the calibration PLMN list, which has a common frequency band with the reference PLMN.

Optionally, the 5G access layer checks whether a common frequency band exists between the reference PLMN and the calibrated PLMN according to the pre-defined or self-learned correspondence between PLMNs and frequency bands, and adds the calibrated PLMN in which the common frequency band exists to the mapped PLMN list.

Illustratively, the 5G access layer checks whether a common frequency band exists between historical RPLMN and HPLMN, and if yes, the HPLMN is added into a mapping PLMN list; the 5G access layer checks whether a common frequency band exists between the historical RPLMN and the UPLMN, and if so, the UPLMN is added into a mapping PLMN list; and the 5G access layer checks whether a common frequency band exists between the historical RPLMN and the OPLMN, and if so, the OPLMN is added into the mapping PLMN list.

Step 1004,5G the access stratum returns the frequency band check result to the non-access stratum.

And carrying a mapping PLMN list in the frequency band checking result, wherein the mapping PLMN list comprises a calibration PLMN having a common frequency band with the historical RPLMN.

Step 1005, the non-access stratum sends a frequency band check request to the 4G access stratum.

Optionally, the frequency band checking request includes parameters: the reference PLMN is the historical RPLMN and the calibration PLMNs are HPLMN, UPLMN (if UPLMN supports 4G), OPLMN (if OPLMN supports 4G).

Step 1006,4G, after receiving the frequency band check request of the non-access layer, the access layer adopts the same processing mode as the 5G access layer and returns the frequency band check result of the 4G access layer to the non-access layer.

Step 1007, the non-access stratum saves the frequency band checking result obtained from each RAT access stratum.

Optionally, the subsequent non-access stratum executes a network searching process according to the obtained frequency band check result.

In an exemplary embodiment, in the search network information inspection of this round, the collected frequency band inspection results are as follows:

common sub-band under RAT of 5G: historical RPLMN + HPLMN; historical RPLMN + OPLMN.

Common sub-band under RAT of 4G: historical RPLMN + HPLMN; historical RPLMN + UPLMN.

The present embodiment will take this as an example to describe the network searching execution process described below.

The following steps 1008 to 1019 correspond to the PLMN + band + RAT network search execution procedure.

And the non-access stratum executes the segmented network searching of the target frequency band corresponding to the reference PLMN for each RAT according to the common sub-frequency band indicated in the collected frequency band checking results by taking the PLMN priority as the standard. Wherein, the PLMN priority is from high to low: HPLMN, UPLMN, OPLMN. The details are as follows:

step 1008, the non-access stratum sends a network searching request to the 5G access stratum.

Optionally, the network searching request carries a history RPLMN as a selected PLMN, and the HPLMN is used as a preferred PLMN, and the 5G access layer is informed that the PLMN to be searched is the history RPLMN, but frequency band information of the HPLMN is combined.

Step 1009,5G, after receiving the network searching request, the access layer searches the shared sub-band which is shared by the history RPLMN and HPLMN and is not searched, and locally marks the searched frequency band.

Optionally, the 5G access layer may check locally stored PLMN and frequency band correspondence information, select a frequency band shared by the HPLMN from historical RPLMN-related frequency bands, search for these frequency bands if there are frequency bands that have not been searched yet in these frequency bands, and mark these frequency bands that have been subjected to the search operation.

Step 1010,5G the access stratum returns the search results to the non-access stratum.

In step 1011, the non-access stratum sends a network searching request to the 4G access stratum.

Optionally, the non-access stratum continues to perform the HPLMN related search, the network search request carries the historical RPLMN as the selected PLMN, the HPLMN is used as the preferred PLMN, and the 4G access stratum is informed that the PLMN to be searched is the historical RPLMN, but the frequency band information of the HPLMN is combined.

Step 1012,4G, after receiving the network searching request, the access layer searches the shared sub-band which is shared by the history RPLMN and HPLMN and is not searched, and locally marks the searched frequency band.

Optionally, the 4G access layer and the 5G access layer perform the same processing, select a frequency band shared by the HPLMN from the historical RPLMN related frequency bands, and perform network searching operation on the frequency band not yet searched.

Step 1013,4G the access stratum returns the search results to the non-access stratum.

Step 1014, the non-access stratum sends a network searching request to the 4G access stratum.

Optionally, after the HPLMN related search is finished, the non-access layer may continue to perform the UPLMN related search, and according to the frequency band check result obtained in step 1007, the UPLMN and the RPLMN only have a common sub-frequency band in 4G, the non-access layer directly sends a network search request to the 4G access layer, and the PLMN to be searched is notified that the PLMN to be searched is the historical RPLMN, but the frequency band information of the UPLMN is to be combined, with the historical RPLMN as the selected PLMN and the UPLMN as the preferred PLMN.

Step 1015,4G, after receiving the network searching request, the access layer searches the shared sub-band which is shared by the history RPLMN and UPLMN and is not searched, and locally marks the searched frequency band.

Optionally, the 4G access layer may check locally stored PLMN and frequency band correspondence information, select a frequency band shared with the UPLMN from historical RPLMN-related frequency bands, search for these frequency bands if there are frequency bands that have not been searched yet in these frequency bands, and mark these frequency bands that have been subjected to the search operation.

Step 1016,4G the access stratum returns the search results to the non-access stratum.

Step 1017, the non-access layer sends a network searching request to the 5G access layer.

Optionally, after the relevant search of the UPLMN is finished, the non-access layer continues to perform the relevant search on the OPLMN, and the non-access layer sends a network search request to the 5G access layer, where the network search request carries the historical RPLMN as the selected PLMN and the OPLMN as the preferred PLMN, and informs the 5G access layer that the PLMN to be searched is the historical RPLMN but the frequency band information of the OPLMN is to be combined.

Step 1018,5G, after receiving the network searching request, the access layer searches the shared sub-frequency bands which are shared by the historical RPLMN and the historical OPLMN and are not searched, and locally marks the searched frequency band.

Optionally, the 5G access layer may check locally stored PLMN and frequency band correspondence information, select a frequency band shared with the OPLMN from historical RPLMN-related frequency bands, search for these frequency bands if there are frequency bands that have not been searched yet in these frequency bands, and mark these frequency bands that have been subjected to the search operation.

Step 1019,5G the access stratum returns the search results to the non-access stratum.

The following steps 1020 to 1025 correspond to the remaining sub-band search process.

And when the search of all the common sub-bands is finished, the non-access layer finally executes the search of the remaining sub-bands in the target frequency band corresponding to the historical RPLMN to the access layer of each RAT. The method comprises the following specific steps:

step 1020, the non-access stratum sends a network searching request to the 5G access stratum.

Optionally, the network searching request includes parameters: the PLMN is selected as the historical RPLMN and the preferred PLMN is NULL (NULL). And informing the 5G access layer that the PLMN to be searched by the access layer is the historical RPLMN.

Step 1021,5G, after receiving the network searching request, the access layer searches the historical RPLMN residual sub-band.

Optionally, the 5G access layer directly searches for a frequency band in the history RPLMN for which network search has not been performed yet without considering a common sub-frequency band, and directly performs subsequent network search operations.

Step 1022,5G the access stratum returns the search results to the non-access stratum.

In step 1023, the non-access layer sends a network searching request to the 4G access layer.

Optionally, the network searching request includes parameters: the PLMN is selected as the historical RPLMN and the preferred PLMN is NULL (NULL). The 4G access stratum is informed that the PLMN it is searching for is a historical RPLMN.

And step 1024,4G, after the access layer receives the network searching request, searching the historical RPLMN residual sub-frequency band.

Optionally, the 4G access layer directly searches for a frequency band in the history RPLMN for which network search has not been performed yet without considering a common frequency band, and directly performs subsequent network search operations.

Step 1025,4G the access stratum returns the search results to the non-access stratum.

In order to simply and clearly explain the comprehensive network searching scheme provided in the embodiment of the present application, the whole execution process is described in fig. 10 by taking the historical RPLMN as the reference PLMN as an example, and the reference PLMN and the calibration PLMN in the subsequent network searching may be directly replaced each time.

If the current RPLMN is not the HPLMN, the scheme performed by the terminal after step 919 of fig. 9 to return to the HPLMN using the HPLMN timer mechanism is shown in fig. 11.

In this embodiment, steps 1110 to 1114 are as shown in steps 210 to 214 in fig. 2, and steps 1116 to 1119 are as shown in steps 216 to 219 in fig. 2, which are not described herein again.

In this embodiment, step 115 includes the following steps:

and 1115, taking the HPLMN as a reference PLMN without calibrating the PLMN, searching the PLMN + frequency band + RAT network, and reporting the HPLMN to the non-access stratum in advance once the HPLMN is searched.

Optionally, in the network searching process after the HPPLMN timer is overtime, the terminal may perform advanced search on a frequency band corresponding to the HPLMN in different RATs, and if the HPLMN exists in the environment, the HPLMN may be searched faster. Once the HPLMN is searched, the access layer can report the search result in advance without waiting for the search of all the frequency bands to be searched and reporting the search result together, so that the non-access layer processes the search result, stops the network searching process after the HPLMN timer is overtime and directly executes the resident registration on the HPLMN, thereby shortening the time for returning to the HPLMN as a whole.

As shown in fig. 9 to 11, the above-mentioned search scheme can ensure to the greatest extent that when the HPPLMN and the historical RPLMN coexist on a certain frequency band, or when the historical RPLMN does not exist but the HPPLMN exists, the HPPLMN is found and reported to the non-access stratum, and the search of the HPPLMN itself is also performed according to the priority order; once finding the HPLMN, the access layer can directly report the intermediate result to the non-access layer without waiting for the completion of searching all the frequency bands.

Next, based on the above-mentioned scheme shown in the embodiment of the present application, in different situations, the results of the terminal executed by using the related technology or the scheme in the embodiment of the present application are compared.

In case 1, in a scenario of startup or coverage loss recovery, an RPLMN priority mechanism is adopted, and a historical RPLMN and hppmmn that exist simultaneously in the current RAT may perform network selection, including the shared network form related to the above embodiment.

In the related technology, the terminal selects to reside and register to the historical RPLMN, and searches for the resident HPPLMN again after waiting for the HPPLMN timer to time out and the RRC state to return to the IDLE state or the INACTIVE state.

In the embodiment of the application, the terminal directly selects to camp on the HPPLMN.

In this case, the embodiment of the present application can avoid the time of staying on the historical RPLMN.

And 2, under the condition of starting or losing coverage recovery, an RPLMN priority mechanism is adopted, and the HPPLMN exists in the current RAT but the historical RPLMN does not exist.

In the related technology, the terminal continuously tries to search on other RATs and continuously searches for historical RPLMNs until all the RATs are searched, and selects to reside on the historical RPLMNs when the historical RPLMNs are found, and selects to reside on the HPPLMNs when the historical RPLMNs are not found.

In the embodiment of the application, the terminal directly selects to camp on the HPPLMN without camping on the HPPLMN or the historical RPLMN after searching multiple RATs.

In this case, the embodiment of the present application may avoid the time for searching on multiple RATs and the time for multiple dwells on the historical RPLMN.

And 3, under the starting or coverage loss recovery scene, adopting an RPLMN priority mechanism to search each access layer in the initial network search mode.

In the related technology, a terminal selects a historical RPLMN for searching, and after all frequency bands are searched under one RAT, the terminal enters the next RAT for searching.

In the embodiment of the application, the terminal selects the historical RPLMN for searching, considers the frequency band sharing condition of the historical RPLMN and the HPPLMN, defines the shared frequency band between the historical RPLMN and the HPPLMN, preferentially searches the shared frequency band, optimizes the frequency band searching sequence, and simultaneously jumps for searching among different RATs.

In this case, the embodiment of the present application can search for the HPPLMN more quickly, and does not affect the search efficiency of the historical RPLMNs themselves.

And 4, network search is performed after the HPPL MN timer is overtime in the starting or coverage loss recovery scene.

In the related art, searching is performed according to a frequency band sequence supported by a terminal, and after all network searching is performed on the frequency bands supported by the terminal in the current environment, the searching results are reported together.

In the embodiment of the application, the frequency bands supported and/or existing by the HPLMN are searched in advance on different RATs, and once the HPLMN is searched and reported in advance, the time length for returning to the HPLMN is shortened on the whole.

In comparison, in this case, the embodiment of the present application can return to the HPLMN more quickly.

Optionally, for the above-mentioned scheme shown in this embodiment of the present application, the terminal may be checked in any one of the following manners, and whether the terminal performs network selection using the above-mentioned scheme is detected:

the method I comprises the following steps of aiming at the examination of a network searching stage: and connecting the terminal with a detection instrument, and checking whether the terminal performs jump search on the common sub-frequency band between the reference PLMN and the calibration PLMN among different wireless access technologies when network search is performed.

And in the second mode, aiming at the examination in the network selection stage: in a specific environment, for example, before the terminal is powered off, only the historical RPLMN exists in the current environment, the terminal is powered off, the HPLMN with the same frequency band as the historical RPLMN is added in the current environment, the terminal is powered on, and whether the terminal resides in the HPLMN or not after being powered on is checked.

Optionally, for the above-mentioned scheme shown in the embodiment of the present application, any one of the following extensions may be performed:

according to the first expansion scheme, when network searching is executed, under the starting-up and coverage loss recovery scenes, the terminal respectively uses two different priority mechanisms.

When the terminal is powered on, the HPLMN priority mechanism is used by the terminal. Such as: the non-access layer sends a HPLMN search request to the access layer, and the access layer carries out preferential search on the frequency bands supported and/or existing by the HPLMN based on the HPLMN search request.

When losing the coverage and recovering, the terminal uses RPLMN priority mechanism. Such as: the non-access layer sends an RPLMN search request to the access layer, and the access layer carries out preferential search on frequency bands supported and/or existing by the historical RPLMN based on the RPLMN search request.

And according to the second expansion scheme, the scheme is integrally executed, and the reference PLMN and/or the calibration PLMN list adopted in part of the network searching process is set to be null.

Such as: and setting the calibration PLMN list to be null when the initialized reference PLMN and the calibration PLMN list are used for carrying out initial network searching.

Such as: and only when the initialized reference PLMN and calibration PLMN lists are used for carrying out initial network searching, the reference PLMN and calibration PLMN lists are not empty, namely the historical RPLMN is the reference PLMN, the m HPPLMNs are the calibration PLMNs, and when the initial network searching is not carried out, the reference PLMN and calibration PLMN lists are both set to be empty.

And thirdly, the scheme is integrally executed, but in the initial network searching, in response to the target occurrence situation, the higher-priority wireless access technology information is recorded, and the resident registration is carried out again on the basis of the higher-priority wireless access technology information, wherein the higher-priority wireless access technology information is used for indicating that the current RPLMN of the terminal has the possibility of existing in the higher-priority wireless access technology.

The target condition comprises that the terminal selects a target PLMN for resident registration, but the current RAT is not the highest priority RAT supported by the target PLMN, and a higher priority RAT is not searched yet. Such as: the preferred RAT is a successful RAT registered last time, and the target PLMN is successfully searched.

Optionally, the recording the higher priority radio access technology information includes: and the terminal selects a target PLMN on the current RAT for resident registration, and records the information of the higher priority wireless access technology by marking priorratExist = TRUE.

Optionally, the updating the current RPLMN based on the higher priority radio access technology information includes: after the registration is successful, when the RRC state of the terminal returns to the IDLE state or the INACTIVE state, even if the HPPLMN timer is not overtime, the terminal executes the operation of stopping the timer, searches the target PLMN on all unsearched higher priority RATs, and selects the target PLMN on the higher priority RAT for residence registration if the target PLMN is found on the higher priority RAT, so that the terminal obtains service on the highest priority RAT and restarts the HPPLMN timer according to the requirement.

It should be noted that the above method embodiments may be implemented individually or in combination, and the present application is not limited thereto.

The following are embodiments of the apparatus of the present application, and for details that are not described in detail in the embodiments of the apparatus, reference may be made to corresponding descriptions in the above method embodiments, and details are not described herein again.

Fig. 12 is a block diagram of a network selection apparatus provided in an exemplary embodiment of the present application, which may be implemented by software, hardware, or a combination of the two, and is a part of or all of a terminal, where the apparatus includes: a determining module 1201, a network searching module 1202 and a resident registering module 1203;

the determining module 1201 is configured to determine a reference PLMN and a calibration PLMN list corresponding to the reference PLMN, where the reference PLMN is a PLMN corresponding to a target frequency band that needs to be searched in a network search, and a calibration PLMN in the calibration PLMN list is used to determine a sub-frequency band in the target frequency band;

the network searching module 1202 is configured to search for a network for at least one sub-frequency band in a target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibrated PLMN list;

the residence registration module 1203 is configured to select the HPLMN for residence and registration in response to the HPLMN being searched.

In an alternative embodiment, the web searching module 1202 is configured to,

obtaining a frequency band checking result, wherein the frequency band checking result is used for indicating a mapping PLMN list, and the mapping PLMN list comprises a calibration PLMN which has a common sub-frequency band with the reference PLMN in the calibration PLMN list;

and searching the common sub-frequency band in the target frequency band corresponding to the reference PLMN based on the mapping PLMN list.

In an optional embodiment, the terminal includes: the access device comprises a non-access layer and n access layers, wherein the n access layers correspond to n different wireless access technologies one by one, the n access layers are sorted from high to low according to priority, and n is a positive integer; the network searching module 1202 is configured to,

the non-access stratum acquires n frequency band checking results from the n access stratums, wherein the ith frequency band checking result in the n frequency band checking results is used for indicating an ith mapping PLMN list corresponding to the ith access stratum, and i is a positive integer not greater than n;

in response to n of the n frequency band checking results _k The mapping PLMN list corresponding to the frequency band checking result comprises the kth calibration PLMN, and the kth calibration PLMN is executed between the non-access layer and the jth access layer _j Common sub-band dependent kth _j Searching a network;

wherein the k calibration PLMN is a calibration PLMN in the calibration PLMN list corresponding to a k priority, and the j access stratum is the n _k N corresponding to frequency band checking result _k A j access stratum of the access stratum, the k being a positive integer increasing from 1 and not greater than x, the x being the calibration PLMN number of calibrated PLMNs in the list, said N _k Is a positive integer not greater than n, j is increasing from 1 and not greater than n _k A positive integer of (a), said k _j Is a positive integer, the k-th _j The common sub-band is a sub-band that is common between the reference PLMN and the kth calibration PLMN in the radio access technology corresponding to the jth access stratum.

In an alternative embodiment, the kth _j The network searching process comprises the following steps:

the non-access stratum layer to the n _k The jth access stratum in each access stratum transmits a kth signal _j Network searching request, the kth _j The network searching request carries the reference PLMN and the kth calibration PLMN;

the jth access layer receiving the kth access layer _j A network searching request is made;

the jth access stratum is based on the kth _j Network searching request is determined, and the kth network searching request is determined _j A common sub-band;

the j access stratum pair the k _j Searching the frequency bands which are not searched in the common frequency sub-bands to generate the kth frequency band _j Searching results;

the jth access stratum sends the kth access stratum to the non-access stratum _j Searching results;

in response to the k-th _j The searching result does not satisfy the network searching end condition, j is added with 1, and then the non access layer is added to n again _k The jth access stratum in each access stratum transmits a kth signal _j Starting to execute the step of the network searching request;

in response to the j reaching the n _k And said k is _j And after the search result does not meet the network searching end condition, adding 1 to k and resetting the j to 1, and then, starting the non-access layer to the n again _k The jth access stratum in each access stratum transmits a kth signal _j Starting to execute the step of the network searching request;

wherein, the net searching ending condition comprises: the search result comprises at least one of a HPPLMN and a historical RPLMN, the historical RPLMN is a PLMN registered by the terminal before the terminal is in the boot-up or coverage recovery scene, the HPPLMN comprises at least one PLMN with higher priority than the historical RPLMN, and the HPPLMN comprises the HPLMN.

In an alternative embodiment, the resident registration module 1203 is configured to respond to the kth _j The search result comprises the HPLMN, and the non-access layer selects the HPLMN to reside and register.

In an alternative embodiment, the resident registration module 1203 is configured to respond to the kth _j The HPLMN is not included in the search results, and the kth _j The search result comprises at least one residual HPPLMN, and the non-access layer selects a target residual HPPLMN to reside and register; the resident registration module 1203, configured to respond to the kth _j The HPPLMN is not included in the search result, and the k-th _j The search result comprises the historical RPLMN, and the non-access layer selects the historical RPLMN to reside and register;

wherein the remaining HPPLMNNs include HPPLMNNs other than the HPLMN, and the target remaining HPPLMN is the highest priority HPPLMN of the remaining HPPLMNNs.

In an alternative embodiment, the web searching module 1202 is configured to respond to the xth _nx The search result does not satisfy the network searching end condition, and the (x + 1) th related to the p remaining sub-frequency band is executed between the non-access layer and the p access layer in the n access layers _p Searching network to generate the (x + 1) th _p Searching results;

the pth remaining sub-band is a sub-band that has not been searched in a target frequency band corresponding to the reference PLMN in the radio access technology corresponding to the pth access stratum, and p is a positive integer that is incremented from 1 and is not greater than n.

In an alternative embodiment, the (x + 1) th _p The network searching process comprises the following steps:

the non-access stratum sends the (x + 1) th access stratum to the pth access stratum _p Request for searching network, the (x + 1) th _p In the network searching requestCarrying the reference PLMN;

the p access stratum receives the (x + 1) th _p A network searching request is made;

the p access stratum is based on the (x + 1) th _p A network searching request is made to search the pth residual sub-frequency band to generate the (x + 1) th _p Searching results;

the p access stratum transmits the (x + 1) th to the non-access stratum _p Searching results;

in response to the (x + 1) th _p The searching result does not satisfy the network searching end condition, adds 1 to the p, and then sends the (x + 1) th message from the non-access layer to the p-access layer _p And the step of searching the network begins to be executed.

In an alternative embodiment, the resident registration module 1203 is configured to respond to the (x + 1) th _p The search result comprises the HPLMN, and the non-access layer selects the HPLMN to reside and register.

In an alternative embodiment, the resident registration module 1203 is configured to respond to the (x + 1) th _p The HPLMN is not included in the search results, and the (x + 1) th _p The search result comprises at least one residual HPPLMN, and the non-access layer selects a target residual HPPLMN to reside and register; the resident register module 1203, for responding to the (x + 1) th _p The HPPLMN is not included in the search result, and the (x + 1) th _p The search result comprises the historical RPLMN, and the non-access layer selects the historical RPLMN to reside and register;

In an alternative embodiment, the web searching module 1202 is configured to,

the non-access stratum sends an ith frequency band checking request to an ith access stratum in the n access strata, wherein the ith frequency band checking request carries the reference PLMN and an ith calibration PLMN sublist, and the ith calibration PLMN sublist comprises a calibration PLMN supporting a radio access technology corresponding to the ith access stratum in the calibration PLMN sublist;

the ith access layer determines the ith mapping PLMN list based on the received ith frequency band check request;

the ith access layer sends an ith frequency band checking result to the non-access layer, wherein the ith frequency band checking result carries the ith mapping PLMN list;

and the non-access layer acquires the n frequency band checking results from the 1 st access layer to the nth access layer.

In an alternative embodiment, the determining module 1201 is configured to,

determining the reference PLMN;

determining the calibration PLMN list corresponding to the reference PLMN based on HPPLMN information;

wherein the HPPLMN information is used for indicating HPPLMNNs, the HPPLMNNs comprise at least one PLMN with higher priority than a historical RPLMN, and the historical RPLMN is a PLMN which the terminal is registered before the starting-up or coverage recovery scene.

In an alternative embodiment, the determining module 1201 is configured to,

before searching the network, determining the historical RPLMN as the initialized reference PLMN;

in response to that all search results obtained by searching at least one sub-frequency band in the target frequency band corresponding to the reference PLMN do not meet a network searching ending condition, updating the reference PLMN to the HPPLMN with the highest priority in the last calibration PLMN list;

wherein, the net searching ending condition comprises: the search result comprises at least one of the HPPLMN and the historical RPLMN.

In an alternative embodiment, the determining module 1201 is configured to,

determining the HPPLMN in the HPPLMN information as the initialized alignment PLMN list before searching for a network;

in response to that all search results obtained by searching at least one sub-frequency band in the target frequency band corresponding to the reference PLMN do not meet a network searching ending condition, updating the calibration PLMN list to other HPPLMNNs except the HPPLMN with the highest priority in the last calibration PLMN list;

In an alternative embodiment, the web searching module 1202 is configured to,

in response to that the current RPLMN is not the HPLMN, searching the network according to a searching sequence that the frequency band corresponding to the HPLMN is searched first and then the rest frequency bands are searched in the network searching process after the timer of the HPLMN is overtime;

responding to the HPLMN searched, reporting a search result carrying the HPLMN, and stopping a network searching process after the HPLMN timer is overtime;

and the remaining frequency bands are other frequency bands except the frequency band corresponding to the HPLMN in the frequency bands supported by the terminal.

Fig. 13 shows a schematic structural diagram of a computer device provided in an exemplary embodiment of the present application, where the computer device includes: a processor 1301, a receiver 1302, a transmitter 1303, a memory 1304, and a bus 1305.

The processor 1301 includes one or more processing cores, and the processor 101 executes various functional applications and information processing by running software programs and modules.

The receiver 1302 and the transmitter 1303 may be implemented as one communication component, which may be a communication chip.

The memory 1304 is coupled to the processor 101 via a bus 1305.

The memory 1304 may be used to store at least one instruction that the processor 1301 uses to execute in order to implement the various steps in the method embodiments described above.

Further, the memory 1304 may be implemented by any type or combination of volatile or non-volatile storage devices, including, but not limited to: magnetic or optical disks, electrically Erasable Programmable Read-Only memories (EEPROMs), erasable Programmable Read-Only memories (EPROMs), static Random Access Memories (SRAMs), read-Only memories (ROMs), magnetic memories, flash memories, programmable Read-Only memories (PROMs).

When the computer device is implemented as a terminal, the processor and the transceiver in the computer device according to the embodiment of the present application may execute the steps executed by the terminal in the method shown in any one of fig. 4 and fig. 6 to fig. 11, which is not described herein again.

Embodiments of the present application further provide a computer-readable storage medium, where at least one instruction is stored, and the at least one instruction is loaded and executed by a processor to implement the network selection method according to the above embodiments.

According to an aspect of the application, a computer program product or computer program is provided, comprising computer instructions, the computer instructions being stored in a computer readable storage medium. The processor of the terminal reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the terminal executes the network selection method provided in the various alternative implementations of the above aspects.

Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in the embodiments of the present application may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable storage medium. Computer-readable storage media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A network selection method is applied to a terminal, and the method comprises the following steps:

determining a reference Public Land Mobile Network (PLMN) and a calibration PLMN list corresponding to the reference PLMN, wherein the reference PLMN is a PLMN corresponding to a target frequency band needing to be searched in a network search, and the calibration PLMN in the calibration PLMN list is used for determining a sub-frequency band in the target frequency band; the reference PLMN comprises a history registered public land mobile network, RPLMN, the calibrated PLMN list comprises a home public land mobile network, HPLMN;

responding to the HPLMN searched, and selecting the HPLMN to reside and register;

wherein the historical RPLMN is a PLMN registered before the terminal is in a power-on or coverage recovery scenario.

2. The method of claim 1, wherein the searching at least one sub-band of the target frequency band corresponding to the reference PLMN based on the reference PLMN and the alignment PLMN list comprises:

acquiring a frequency band checking result, wherein the frequency band checking result is used for indicating a mapping PLMN list, and the mapping PLMN list comprises a calibration PLMN which has a common sub-frequency band with the reference PLMN in the calibration PLMN list;

3. The method of claim 2, wherein the terminal comprises: the access device comprises a non-access layer and n access layers, wherein the n access layers correspond to n different wireless access technologies one by one, the n access layers are sorted from high to low according to priority, and n is a positive integer;

the obtaining of the frequency band check result includes:

the searching the common sub-frequency band in the target frequency band corresponding to the reference PLMN based on the mapping PLMN list includes:

in response to n of the n frequency band checking results _k Mapping PLMN list corresponding to the frequency band checking result comprises kth calibration PLMN, and the execution between the non access stratum and the jth access stratum is equal to that between the non access stratum and the jth access stratum _j Common sub-band dependent kth _j Searching a network;

wherein the k calibration PLMN is a calibration PLMN in the calibration PLMN list corresponding to a k priority, and the j access stratum is the n _k N corresponding to frequency band checking result _k J access stratum of the access stratum, k being a positive integer increasing from 1 and not greater than x, x being the number of calibration PLMNs in the calibration PLMN list, n _k Is a positive integer not greater than n, j is an increasing integer starting from 1 and not greater than n _k A positive integer of (a), said k _j Is a positive integer, the k-th _j The common sub-band is a sub-band that is common between the reference PLMN and the kth calibration PLMN in the radio access technology corresponding to the jth access stratum.

4. The method of claim 3, wherein the kth point _j The network searching process comprises the following steps:

the non-access stratum layer to the n _k The jth access layer in a respective access layer transmitting a kth _j Searching netRequest, the k-th _j The network searching request carries the reference PLMN and the kth calibration PLMN;

the j access stratum pair to the k _j Searching the frequency bands which are not searched in the common frequency sub-bands to generate the kth frequency band _j Searching results;

in response to the k-th _j The searching result does not meet the network searching end condition, j is added with 1, and then the non-access layer is added to n again _k The jth access stratum in each access stratum transmits a kth signal _j Starting to execute the step of the network searching request;

in response to the j reaching the n _k And said k is _j And after the search result does not meet the network searching end condition, adding 1 to k and resetting the j to 1, and then, starting the non-access layer to the n again _k The jth access layer in a respective access layer transmitting a kth _j Starting to execute the step of the network searching request;

wherein, the net searching ending condition comprises: the search result includes at least one of a higher priority public land mobile network HPPLMN including at least one PLMN having a higher priority than the historical RPLMN, and the historical RPLMN, the HPPLMN including the HPLMN.

5. The method of claim 3, wherein the non-access stratum obtains n band check results from the n access stratum, and wherein the n band check results comprise:

the non-access stratum sends an ith frequency band checking request to an ith access stratum in the n access stratums, wherein the ith frequency band checking request carries the reference PLMN and an ith calibration PLMN sublist, and the ith calibration PLMN sublist comprises a calibration PLMN supporting a radio access technology corresponding to the ith access stratum in the calibration PLMN list;

6. The method of any of claims 1 to 5, wherein determining a reference PLMN and a list of calibration PLMNs corresponding to the reference PLMN comprises:

determining the reference PLMN;

wherein the HPPLMN information is to indicate an HPPLMN comprising at least one PLMN having a higher priority than the historical RPLMN.

7. The method of any of claims 1 to 5, further comprising:

8. A network selection apparatus, applied to a terminal, the apparatus comprising: the device comprises a determining module, a network searching module and a resident registering module;

the determining module is configured to determine a reference public land mobile network PLMN and a calibration PLMN list corresponding to the reference PLMN, where the reference PLMN is a PLMN corresponding to a target frequency band that needs to be searched in a network search, and a calibration PLMN in the calibration PLMN list is used to determine a sub-frequency band in the target frequency band; the reference PLMN comprises a history registered public land mobile network, RPLMN, the calibrated PLMN list comprises a home public land mobile network, HPLMN;

the network searching module is configured to search for a network for at least one sub-frequency band in a target frequency band corresponding to the reference PLMN based on the reference PLMN and the calibration PLMN list;

the resident registration module is used for responding to the searched HPLMN and selecting the HPLMN to be resident and registered;

9. A terminal, characterized in that the terminal comprises a processor and a memory; the memory has stored therein at least one instruction, at least one program, set of codes, or set of instructions that is loaded and executed by the processor to implement the network selection method of any of claims 1 to 7.

10. A computer-readable storage medium, in which at least one computer program is stored, which is loaded and executed by a processor to implement the network selection method according to any one of claims 1 to 7.