CN110177392B

CN110177392B - Cell selection method and device

Info

Publication number: CN110177392B
Application number: CN201910371073.4A
Authority: CN
Inventors: 党淑君
Original assignee: Huawei Device Co Ltd
Current assignee: Huawei Device Co Ltd
Priority date: 2014-11-20
Filing date: 2014-11-20
Publication date: 2021-08-03
Anticipated expiration: 2034-11-20
Also published as: CN110177392A; CN105611603B; CN105611603A

Abstract

The invention discloses a cell selection method and a device, wherein the method comprises the following steps: acquiring the state and operator of the RPLMN before the last shutdown or offline of the mobile terminal; acquiring the information of the country where the mobile terminal is currently located; if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the previous shutdown or the network disconnection, acquiring first frequency scanning information, scanning frequency according to the information, sequencing a frequency point set obtained by frequency scanning according to the signal intensity of frequency points, and starting cell selection from the foremost frequency point according to a sequenced result, wherein the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the previous shutdown or the network disconnection of the mobile terminal, or frequency band information supported by the country of the RPLMN before the previous shutdown or the network disconnection of the mobile terminal. By the mode, the network searching time can be shortened, and the power consumption of network searching is reduced.

Description

Cell selection method and device

Technical Field

The present invention relates to the field of mobile communications technologies, and in particular, to a cell selection method and apparatus.

Background

Cell search or cell selection is one of the most basic processes of a mobile communication system, and a mobile terminal needs to search again when initially accessing and dropping a network, and the cell search or cell selection is carried out when the mobile terminal searches again.

For a specific standard, such as Global System for Mobile Communication (GSM), a typical cell search procedure in the prior art is as follows:

firstly, frequency bands supported by a mobile terminal are swept, and the frequency points obtained by sweeping are sequenced according to the magnitude of frequency point receiving power; trying to receive broadcast channels one by one according to the sequence of the frequency points; acquiring Public Land Mobile Network (PLMN) information carried in a broadcast channel, and judging whether the acquired PLMN is consistent with a local Public Land Mobile Network (Home Public Land Mobile Network, HPLMN) of a Mobile terminal or a Registered Public Land Mobile Network (Registered Public Land Mobile Network, RPLMN), if so, attempting to register at the frequency point, and if not, continuing to search a next frequency point until the registration is successful or the attempt is completed.

However, the inventors of the present application have found in long-term research and development that, in the prior art, when there are many frequency bands supported by a mobile terminal and there are frequency points of multiple operators in one frequency band, cell search takes a long time and consumes much power.

Disclosure of Invention

The invention mainly solves the technical problem of providing a cell selection method and a cell selection device, which can reduce the network search time and reduce the power consumption of network search.

In a first aspect, the present invention provides a cell selection method, including: acquiring country information and operator information of a Registered Public Land Mobile Network (RPLMN) before the last shutdown or offline of the mobile terminal; acquiring the information of the country where the mobile terminal is currently located; if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring first frequency scanning information, carrying out frequency scanning according to the first frequency scanning information, sequencing a frequency point set obtained by the frequency scanning according to the signal intensity of frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by the operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by a country of the RPLMN before the last shutdown or offline of the mobile terminal.

In a first possible implementation manner of the first aspect, after the step of obtaining the information of the country where the mobile terminal is currently located, the method further includes: if the country where the mobile terminal is located is different from the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring second frequency sweep information, carrying out frequency sweep according to the second frequency sweep information, sequencing a frequency point set obtained by the frequency sweep according to the signal intensity of the frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result; the second frequency sweep information includes frequency point information supported by an operator preset in the country where the mobile terminal is currently located, or frequency band information supported by the country where the mobile terminal is currently located.

In a second possible implementation manner of the first aspect, an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency point information supported by the operator to which the smart card belongs; the frequency sweeping is carried out according to the first frequency sweeping information, the frequency point set obtained by the frequency sweeping is sequenced according to the signal intensity of the frequency points, and then the cell selection is carried out from the foremost frequency point according to the sequenced result, which comprises the following steps: and performing frequency sweeping according to the frequency point information supported by the operator to which the smart card belongs, sequencing the frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and then performing cell selection from the foremost frequency point according to the sequenced result.

In a third possible implementation manner of the first aspect, an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency band information supported by the operator to which the smart card belongs; the frequency sweeping is carried out according to the first frequency sweeping information, the frequency point set obtained by the frequency sweeping is sequenced according to the signal intensity of the frequency points, and then the cell selection is carried out from the foremost frequency point according to the sequenced result, which comprises the following steps: and performing frequency sweeping according to frequency band information supported by an operator to which the smart card belongs, sequencing a frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and selecting a cell from the foremost frequency point according to the sequenced result.

In a fourth possible implementation manner of the first aspect, a country of the RPLMN before the mobile terminal is powered off or disconnected is a home country of the smart card, and the first frequency scanning information includes frequency band information supported by the home country of the smart card; the frequency sweeping is carried out according to the first frequency sweeping information, the frequency point set obtained by the frequency sweeping is sequenced according to the signal intensity of the frequency points, and then the cell selection is carried out from the foremost frequency point according to the sequenced result, which comprises the following steps: and performing frequency sweeping according to the frequency band supported by the country of the smart card, sequencing the frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and further performing cell selection from the foremost frequency point according to the sequenced result.

In a fifth possible implementation manner of the first aspect, the step of obtaining information of a country where the mobile terminal is currently located includes: if the mobile terminal has the state of emergency service in the preset time and the country of the operator of the emergency service cell is the same as the country of the RPLMN before the power-off or the network disconnection of the mobile terminal at the last time in the state of the emergency service, the country where the mobile terminal is currently located is the same as the country of the RPLMN before the power-off or the network disconnection of the mobile terminal at the last time; if the mobile terminal has the state of emergency service in the preset time and the country of the operator of the emergency service cell is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal in the state of the emergency service, the country of the current mobile terminal is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal.

In a sixth possible implementation manner of the first aspect, the step of obtaining the first sweep information includes: and acquiring first frequency scanning information from a first association list in an unerasable storage area of the mobile terminal, wherein the first association list comprises a first operator existing in the country of the RPLMN before the mobile terminal is powered off or disconnected from the network last time and a frequency point or a frequency band supported by the first operator, or the frequency band supported by the country of the RPLMN before the mobile terminal is powered off or disconnected from the network last time.

With reference to the first possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the step of obtaining the second frequency sweep information includes: and acquiring second frequency sweeping information from a second association list in the non-erasable storage area of the mobile terminal, wherein the second association list comprises different countries, a second operator preset in each country, frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

In a second aspect, the present invention provides a cell selection apparatus, including: the system comprises a first acquisition module, a second acquisition module, a third acquisition module, a first frequency scanning module, a first sequencing module and a first cell selection module; the first acquisition module is used for acquiring the country information and operator information of a public land mobile network (RPLMN) registered before the mobile terminal is powered off or disconnected last time; the second acquisition module is used for acquiring the information of the country where the mobile terminal is currently located; the third acquisition module is used for acquiring first frequency scanning information when the country where the mobile terminal is located is the same as the country of the RPLMN before the mobile terminal is shut down or disconnected last time, the first frequency scanning module is used for scanning frequency according to the first frequency scanning information, the first sequencing module is used for sequencing the frequency point set obtained by the frequency scanning according to the signal intensity of the frequency points, and the first cell selection module is used for carrying out cell selection from the foremost frequency point according to the sequenced result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by the operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by a country of the RPLMN before the last shutdown or offline of the mobile terminal.

In a first possible implementation manner of the second aspect, the apparatus further includes: the device comprises a fourth acquisition module, a second frequency sweeping module, a second sequencing module and a second cell selection module; the fourth acquisition module is used for acquiring second frequency sweep information when the country where the mobile terminal is located is different from the country of the RPLMN before the mobile terminal is shut down or disconnected last time, the second frequency sweep module is used for carrying out frequency sweep according to the second frequency sweep information, the second sorting module is used for sorting the frequency point set obtained by the frequency sweep according to the signal intensity of the frequency point, and the second cell selection module is used for carrying out cell selection from the foremost frequency point according to the sorted result; the second frequency sweep information includes frequency point information supported by an operator preset in the country where the mobile terminal is currently located, or frequency band information supported by the country where the mobile terminal is currently located.

In a second possible implementation manner of the second aspect, an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency point information supported by the operator to which the smart card belongs; the first frequency scanning module is specifically configured to scan frequencies according to frequency point information supported by an operator to which the smart card belongs.

In a third possible implementation manner of the second aspect, an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency band information supported by the operator to which the smart card belongs; the first frequency scanning module is specifically configured to perform frequency scanning according to frequency band information supported by an operator to which the smart card belongs.

In a fourth possible implementation manner of the second aspect, a country of the RPLMN before the mobile terminal is powered off or disconnected is a home country of the smart card, and the first frequency scanning information includes frequency band information supported by the home country of the smart card; the first frequency scanning module is specifically configured to perform frequency scanning according to a frequency band supported by a country of the smart card.

In a fifth possible implementation manner of the second aspect, the second obtaining module is specifically configured to, when the mobile terminal has a state of emergency service within a predetermined time, and when the state of emergency service is the same, the country of an operator of an emergency service cell is the same as the country of the RPLMN before the mobile terminal was last powered off or disconnected from the network, and the country of the mobile terminal where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal was last powered off or disconnected from the network; and when the mobile terminal has the state of emergency service in the preset time and the country of the operator of the emergency service cell is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal in the state of the emergency service, the country where the mobile terminal is located currently is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal.

In a sixth possible implementation manner of the second aspect, the third obtaining module is specifically configured to obtain first frequency scanning information from a first association list in an unerasable storage area of the mobile terminal, where the first association list includes a first operator existing in a country of the RPLMN before the mobile terminal is powered off or disconnected last time and a frequency point or a frequency band supported by the first operator, or a frequency band supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

With reference to the first possible implementation manner of the second aspect, in a seventh possible implementation manner of the second aspect, the fourth obtaining module is specifically configured to obtain second frequency sweep information from a second association list in an erasable storage area of the mobile terminal, where the second association list includes different countries, a second operator preset in each country, and frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

The invention has the beneficial effects that: different from the situation of the prior art, the invention acquires the country information of the registered public land mobile network RPLMN before the last shutdown or offline of the mobile terminal and the operator information of the country; acquiring the information of the country where the mobile terminal is currently located; and if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring first frequency scanning information, carrying out frequency scanning according to the first frequency scanning information, sequencing the frequency point set obtained by frequency scanning according to the signal intensity of the frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result. Because the first frequency scanning information comprises frequency point information supported by an operator, or frequency band information supported by the operator, or frequency band information supported by a country, the time of network search can be reduced, and the power consumption of network search is reduced.

Drawings

Fig. 1 is a flow chart of an embodiment of a cell selection method of the present invention;

fig. 2 is a flow chart of another embodiment of a cell selection method of the present invention;

fig. 3 is a flowchart of a cell selection method according to another embodiment of the present invention;

fig. 4 is a flowchart of a cell selection method according to another embodiment of the present invention;

fig. 5 is a flowchart of a cell selection method according to another embodiment of the present invention;

fig. 6 is a flowchart of a cell selection method according to another embodiment of the present invention;

fig. 7 is a schematic structural diagram of a cell selection apparatus according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another embodiment of the cell selection apparatus of the present invention;

fig. 9 is a schematic structural diagram of a cell selection apparatus according to another embodiment of the present invention;

fig. 10 is a schematic physical structure diagram of a cell selection apparatus according to an embodiment of the present invention.

Detailed Description

Referring to fig. 1 to 4, fig. 1 to 4 are flowcharts of four embodiments of the cell selection method of the present invention, including:

step S101: acquiring the country information and operator information of the registered public land mobile network RPLMN before the last power-off or offline of the mobile terminal.

Step S101 is to obtain the country information of the public land mobile network RPLMN registered before the power-off or the off-line of the mobile terminal and the operator information of the country.

The RPLMN, if stored on a smart Card, may be obtained via the smart Card, which is typically one of Integrated Circuit cards (IC cards), and may be a Subscriber Identity Module (SIM), Universal Subscriber Identity Module (USIM), User Identity Module (UIM), or the like. If the RPLMN is stored in the memory of the mobile terminal, the RPLMN can be obtained through the memory of the mobile terminal. And obtaining the RPLMN, namely obtaining the national information and the operator information of the RPLMN.

A public land Mobile network PLMN is a network established and operated by a government or an operator approved by the government for the purpose of providing land Mobile communication services to the public, and is MCC + MNC, wherein MCC (Mobile Country Code, abbreviated as MCC) is a Country Code to which a Mobile subscriber belongs, and occupies 3 digits, and MCC of china is specified as 460; MNC (Mobile Network Code, abbreviated as MNC) is a Mobile Network Code, and is composed of two or three digits, and the Mobile Network Code of china Mobile is 00, for example, the PLMN of china Mobile is 46000, and the PLMN of china unicom is 46001.

The smart card further stores an International Mobile Subscriber Identity (IMSI) which is a mark for distinguishing Mobile subscribers, and the total length of the IMSI does not exceed 15 digits and uses 0-9 digits. The MCC takes 3 digits, the MNC is a Mobile network code and is composed of two or three digits, and the MSIN (Mobile Subscriber identity Number, abbreviated as MSIN) is a Mobile Subscriber identity for identifying a Mobile Subscriber in a certain Mobile communication network. The MCC in the IMSI is called the country of the smart card, and the MNC in the IMSI is called the operator to which the smart card belongs. Currently, for china, there are three operators of wireless mobile communication, and the names are: china mobile communication group company (china mobile), china union network communication group limited company (china unicom), and china telecom group company (china telecom).

The HPLMN (Home PLMN, abbreviated HPLMN) is a Home PLMN, which is a PLMN to which the mobile terminal user belongs. That is, the MCC and MNC contained in the IMSI number on the mobile terminal smart card are identical to the MCC and MNC on the HPLMN, which is only one for a certain subscriber.

The RPLMN (Registered PLMN, abbreviated RPLMN) is a Registered PLMN, which is a PLMN Registered by the mobile terminal before the last power-off or the last network disconnection. Typically stored in a smart card or in the memory of the mobile terminal.

When the HPLMN is the same as the RPLMN, the smart card is more in a non-roaming state, and when the HPLMN is not the same as the RPLMN, the smart card is more in a roaming state.

When the smart card is used in the country of the smart card or the smart card roams to other countries, the country of the RPLMN is the country of the smart card when the smart card is started for the first time in the country of the roaming place or the smart card is not registered in the country of the roaming place, and the HPLMN is the same as the RPLMN; when the smart card roams to another country where it is not first powered on or where it is registered, the country of the RPLMN is the roaming country, and the HPLMN is not the same as the RPLMN.

Step S102: and acquiring the information of the country where the mobile terminal is currently located.

The country information of the mobile terminal is the country in which the mobile terminal is currently used. For example, in China; if it is abroad (e.g., UK, USA, etc.). There are many ways to obtain the information of the country where the mobile terminal is currently located, for example: the country information where the mobile terminal is currently located is obtained through MCC information in a PLMN to which an emergency service cell where the mobile terminal resides, and the country information where the mobile terminal is currently located can also be obtained through the MCC information of a country code in the PLMN information contained in a cell broadcast channel covering the area and received by a mobile phone.

Step S103: if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is last powered off or disconnected from the network, acquiring first frequency scanning information, carrying out frequency scanning according to the first frequency scanning information, sequencing a frequency point set obtained by frequency scanning according to the signal intensity of frequency points, and then carrying out cell selection from the foremost frequency point according to a sequenced result, wherein the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is last powered off or disconnected from the network, or frequency band information supported by the country of the RPLMN before the mobile terminal is last powered off or disconnected from the network.

If the country where the mobile terminal is currently located is the same as the country of the RPLMN, there are two situations:

in the first case, the smart card is not roaming, i.e. the country in which the mobile terminal is currently located is the same as the country of the smart card, at this time, the country in which the mobile terminal is currently located is the same as the country of the RPLMN, which is the same as the HPLMN. In this case, the country of the RPLMN before the mobile terminal is powered off or disconnected from the network is the home country of the smart card, and the operator of the RPLMN before the mobile terminal is powered off or disconnected from the network is the operator to which the smart card belongs, so the first frequency scanning information may specifically include frequency point information supported by the operator to which the smart card belongs, frequency band information supported by the operator to which the smart card belongs, or frequency band information supported by the country of the smart card.

In the second case, the smart card roams to another country where it is not first powered on or where it is registered, i.e. the country in which the mobile terminal is currently located is not the same as the country in which the smart card belongs, and at this point the country in which the mobile terminal is currently located is the same as the country of the RPLMN, but the RPLMN is not the same as the HPLMN. In this case, the country of the RPLMN before the mobile terminal is powered off or disconnected is the country of the roaming destination, and the operator of the RPLMN before the mobile terminal is powered off or disconnected is the registered operator of the country of the roaming destination, so the first frequency scanning information may specifically include frequency point information supported by the registered operator of the country of the roaming destination, frequency band information supported by the registered operator of the country of the roaming destination, or frequency band information supported by the country of the roaming destination.

Referring to fig. 2, if the operator of the RPLMN before the mobile terminal is powered off or disconnected from the network last time is the operator to which the smart card belongs, the obtained first frequency sweeping information is frequency point information supported by the operator to which the smart card belongs, frequency sweeping is performed according to frequency points supported by the operator to which the smart card belongs, and at this time, the frequency sweeping range is very small, so that network search time can be greatly reduced, and at this time, step S103 is:

step S103 a: acquiring frequency point information supported by an operator to which the smart card belongs, sweeping frequency according to the frequency points supported by the operator to which the smart card belongs, sequencing a frequency point set obtained by sweeping frequency according to the signal intensity of the frequency points, and then selecting a cell from the foremost frequency point according to a sequenced result.

Referring to fig. 3, if the operator of the RPLMN before the mobile terminal is powered off or disconnected last time is the operator to which the smart card belongs, the obtained first frequency scanning information is frequency band information supported by the operator to which the smart card belongs, and scanning is performed according to the frequency band supported by the operator to which the smart card belongs, at this time, the frequency scanning range is slightly larger than the previous frequency point range, but is still much smaller than the full frequency band range, so that the network search time can be greatly reduced; in this case, step S103 is:

step S103 b: acquiring frequency band information supported by an operator to which the smart card belongs, sweeping frequency according to the frequency band supported by the operator to which the smart card belongs, sequencing a frequency point set obtained by sweeping frequency according to the signal intensity of the frequency point, and then performing cell selection from the foremost frequency point according to the sequenced result.

Referring to fig. 4, if the country of the RPLMN before the mobile terminal is turned off or off-line last time is the country of the smart card, the obtained first frequency scanning information is frequency band information supported by the country of the smart card, and frequency scanning is performed according to the frequency band supported by the country of the smart card, although frequency scanning is performed in full frequency band, since the frequency point set obtained by frequency scanning is sorted according to the signal intensity of the frequency points, and then cell selection is performed from the foremost frequency point, that is, the frequency point with the largest signal intensity according to the sorted result, and cell selection is performed from the foremost frequency point, the time for network search can also be reduced. In this case, step S103 is:

step S103 c: the method comprises the steps of obtaining frequency band information supported by the country of the smart card, sweeping frequency according to the frequency band supported by the country of the smart card, sequencing a frequency point set obtained by sweeping frequency according to the signal intensity of frequency points, and then selecting a cell from the foremost frequency point according to the sequenced result.

In the frequency sweeping mode, the time of network searching time can be reduced, and the power consumption of network searching can be correspondingly reduced.

The method comprises the steps that the country information of a registered public land mobile network RPLMN and the operator information of the country before the mobile terminal is powered off or disconnected are obtained; acquiring the information of the country where the mobile terminal is currently located; and if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring first frequency scanning information, carrying out frequency scanning according to the first frequency scanning information, sequencing the frequency point set obtained by frequency scanning according to the signal intensity of the frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result. Because the first frequency scanning information comprises frequency point information supported by an operator, or frequency band information supported by the operator, or frequency band information supported by a country, the time of network search can be reduced, and the power consumption of network search is reduced.

Referring to fig. 5 and 6, fig. 5 and 6 are flowcharts of two other embodiments of the cell selection method of the present invention, which are substantially the same as the embodiments of fig. 1 to 4, and please refer to fig. 1 to 4 and the corresponding text for description. The method comprises the following steps:

step S201: the method comprises the steps of obtaining the country information of a registered public land mobile network RPLMN before the last power-off or network disconnection of the mobile terminal and the operator information of the country.

Step S202: and acquiring the information of the country where the mobile terminal is currently located.

Wherein, step S202 specifically includes:

step S202 a: and judging whether the mobile terminal has the state of emergency service within the preset time.

The predetermined time is that the country in which the mobile terminal is currently located is not changed from one country to another, for example, the user of the mobile terminal wants to go to the uk, 3 hours are required for the china to sit on an airplane, the mobile terminal has an emergency service state before 3 hours, and the user of the mobile terminal does not arrive in the uk within 1 hour, so the predetermined time can be set to be 1 hour, or shorter, or longer. The setting of the predetermined time is determined according to the actual application.

Step S202 b: if the mobile terminal has the state of emergency service in the preset time, judging whether the country of the operator of the emergency service cell is the same as the country of the RPLMN before the last power-off or network disconnection of the mobile terminal in the state of the emergency service. If the two are the same, the process proceeds to step S202c, and if they are not the same, the process proceeds to step S202 d.

Step S202 c: if the state of the mobile terminal is the same as the state of the RPLMN before the last shutdown or offline of the mobile terminal, the current state of the mobile terminal is the same as the state of the RPLMN before the last shutdown or offline of the mobile terminal. Step S203 is entered as shown in fig. 5.

If the country of the operator of the emergency service cell is the same as the country of the RPLMN before the last shutdown or offline of the mobile terminal in the state of emergency service, the country where the mobile terminal is currently located is the country of the RPLMN before the last shutdown or offline of the mobile terminal, and the method comprises two conditions: in the first case, the smart card is not roaming, i.e. the country in which the mobile terminal is currently located is the same as the country in which the smart card belongs; in the second case, the smart card roams to another country where it is not first powered on or where it is registered.

Step S202 d: if not, the country where the mobile terminal is currently located is different from the country of the RPLMN before the last shutdown or offline of the mobile terminal. Step S205 is entered as shown in fig. 6.

If the country of the operator of the emergency service cell is different from the country of the smart card in the emergency service state, it indicates that the country in which the mobile terminal is currently located is not the country of the smart card, and this corresponds to: when the smart card roams to another country, is powered on for the first time in the country of the roaming site or is not registered in the country of the roaming site, the RPLMN on the memory of the smart card or mobile terminal is also the RPLMN in the country of the smart card since the smart card is powered on for the first time or is not registered in the country of the roaming site.

Step S203: the method comprises the steps of obtaining first frequency scanning information from a first association list in an unerasable storage area of a mobile terminal, wherein the first association list comprises a first operator in the state of the RPLMN before the mobile terminal is powered off or disconnected last time and a frequency point or a frequency band supported by the first operator, or the frequency band supported by the state of the RPLMN before the mobile terminal is powered off or disconnected last time.

The first association list comprises a first operator and frequency points supported by the first operator in the country of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency bands supported by the first operator and the first operator in the country of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency bands supported by the country of the RPLMN before the mobile terminal is powered off or disconnected last time.

For example, the country of the RPLMN before the mobile terminal is turned off or disconnected last time is the country of the smart card and is continental china, the first association list of the frequency points supported by the first operator and the first operator GSM may be shown in table 1, the first association list of the frequency bands supported by the first operator and the first operator GSM may be shown in table 2, and the first association list of the frequency bands supported by the continental china may be shown in table 3.

TABLE 1

TABLE 2

TABLE 3

If the server has the updated first association table, the updated first association table may be downloaded and obtained from the server and then saved in the non-erasable storage area.

Step S204: frequency sweeping is carried out according to the first frequency sweeping information, the frequency point set obtained by frequency sweeping is sequenced according to the signal intensity of the frequency points, and then cell selection is carried out from the foremost frequency point according to the sequenced result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is powered off or disconnected last time, frequency band information supported by the operator of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency band information supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

The first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by the operator of the RPLMN before the last shutdown or offline of the mobile terminal, or frequency band information supported by a country of the RPLMN before the last shutdown or offline of the mobile terminal; if the operator of the RPLMN before the last shutdown or offline of the mobile terminal is the operator to which the smart card belongs, and the country of the RPLMN before the last shutdown or offline of the mobile terminal is the country to which the smart card belongs, then: if the first association table comprises a first operator existing in the country of the smart card and the frequency points supported by the first operator, the frequency points supported by the operator can be found in the first association table according to the operator to which the smart card belongs, and frequency sweeping is carried out according to the frequency points supported by the operator; if the first association table comprises a first operator existing in the country of the smart card and the frequency bands supported by the first operator, the frequency bands supported by the operator can be found in the first association table according to the operator to which the smart card belongs, and frequency sweeping is carried out according to the frequency bands supported by the operator; if the first association table comprises the frequency bands supported by the country of the smart card, the frequency bands supported by the country can be found in the first association table according to the country of the smart card, and frequency sweeping can be performed according to the frequency bands supported by the country.

If the operator of the RPLMN before the last power-off or network-off of the mobile terminal is the operator registered in the country of the roaming place, and the country of the RPLMN before the last power-off or network-off of the mobile terminal is the country of the roaming place, the method is also performed. Step S205: and acquiring second frequency sweeping information from a second association list in the non-erasable storage area of the mobile terminal, wherein the second association list comprises different countries, a second operator preset in each country, frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

If the country of the operator of the emergency service cell is different from the RPLMN before the last shutdown or offline of the mobile terminal in the emergency service state, the current country of the mobile terminal is not the country of the smart card, and the situation corresponds to the following conditions: when the smart card roams to another country, is powered on for the first time in the country of the roaming site or is not registered in the country of the roaming site, the RPLMN on the memory of the smart card or mobile terminal is also the RPLMN in the country of the smart card since the smart card is powered on for the first time or is not registered in the country of the roaming site.

The second association list includes different countries, a second operator preset in each country, and frequency points supported by the second operator, as shown in table 4; or different countries, a second operator preset in each country, and a frequency band supported by the second operator, as shown in table 5; or the frequency bands supported by different countries, each as shown in table 6.

TABLE 4

TABLE 5

TABLE 6

When the country where the mobile terminal is currently located is another country and is not the country of the smart card, a second operator providing services may be preset, and the second operator may be a second operator having an agreement with the operator to which the smart card belongs, or a second operator with a high quality network status. The setting of the second operator is determined according to practical situations, and is not limited herein.

If the server updates the second association table, the updated second association table is downloaded and obtained from the server and then stored in the non-erasable storage area.

Step S206: frequency sweeping is carried out according to the second frequency sweeping information, the frequency point set obtained by frequency sweeping is sequenced according to the signal intensity of the frequency points, and then cell selection is carried out from the foremost frequency point according to the sequenced result; the second frequency sweeping information comprises frequency point information supported by an operator preset in the country where the mobile terminal is located currently, or frequency band information supported by the country where the mobile terminal is located currently.

The second frequency sweep information comprises frequency point information supported by an operator preset in the country where the mobile terminal is currently located, or frequency band information supported by the country where the mobile terminal is currently located; if the second association table comprises different countries, a second operator preset by each country and frequency points supported by the second operator, finding the frequency points supported by the operator in the second association table according to the operator preset by the country where the mobile terminal is currently located, and sweeping frequency according to the frequency points supported by the operator; if the second association table comprises different countries, a second operator preset by each country and frequency bands supported by the second operator, finding the frequency bands supported by the operators in the second association table according to the operators preset by the country where the mobile terminal is currently located, and sweeping the frequency according to the frequency bands supported by the operators; if the second association table comprises the frequency band supported by the country where the mobile terminal is currently located, the frequency band supported by the country can be found in the second association table according to the country where the mobile terminal is currently located, and frequency sweeping can be performed according to the frequency band supported by the country.

Referring to fig. 7, fig. 7 is a schematic diagram illustrating a cell selection apparatus according to an embodiment of the present invention, which can perform the steps shown in fig. 1 to 6. The device includes: a first obtaining module 101, a second obtaining module 102, a third obtaining module 103, a first frequency scanning module 104, a first sequencing module 105, and a first cell selecting module 106.

The first obtaining module 101 is configured to obtain country information and operator information of a public land mobile network RPLMN registered before the mobile terminal is powered off or disconnected last time.

If the RPLMN is stored on a smart card, it can be obtained by the smart card, which is typically one of integrated circuit cards, and can be a SIM, USIM, UIM, or the like. If the RPLMN is stored in the memory of the mobile terminal, the RPLMN can be obtained through the memory of the mobile terminal. And obtaining the RPLMN, namely obtaining the national information and the operator information of the RPLMN.

The second obtaining module 102 is configured to obtain information of a country where the mobile terminal is currently located.

The country information of the mobile terminal is the country in which the mobile terminal is currently used. For example, in China; if it is abroad (e.g., UK, USA, etc.). There are many ways to obtain the information of the country where the mobile terminal is currently located, for example: the country information where the mobile terminal is currently located is obtained through MCC information in a PLMN to which an emergency service cell where the mobile phone resides, and the country information where the mobile terminal is currently located can also be obtained through the MCC information of a country code in the PLMN information contained in a cell broadcast channel covering the area and received by the mobile phone.

The third obtaining module 103 is configured to obtain the first frequency scanning information when the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is last powered off or disconnected.

The first frequency sweeping module 104 is configured to sweep frequency according to the first frequency sweeping information.

The first sequencing module 105 is configured to sequence the frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point.

The first cell selection module 106 is configured to perform cell selection from the foremost frequency point according to the sorted result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is powered off or disconnected last time, frequency band information supported by the operator of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency band information supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

If the frequency point information supported by the operator to which the smart card belongs is acquired, the first frequency sweeping module 104 sweeps the frequency according to the frequency point supported by the operator to which the smart card belongs, and the frequency sweeping range is very small, so that the network searching time can be greatly reduced. If the frequency band information supported by the operator to which the smart card belongs is acquired, the first frequency scanning module 104 scans according to the frequency band supported by the operator to which the smart card belongs, and at this time, the frequency scanning range is slightly larger than the previous frequency point range, but is still much smaller than the full frequency band range, so that the network search time can be greatly reduced. If the frequency band information supported by the country of the smart card is acquired, the first frequency scanning module 104 performs frequency scanning according to the frequency band supported by the country of the smart card, and although the frequency scanning is performed in full frequency band, since the frequency point set obtained by frequency scanning is sorted according to the signal intensity of the frequency points, and then cell selection is performed from the foremost frequency point according to the sorted result, the foremost frequency point is also the frequency point with the largest signal intensity, and the cell selection is performed from the foremost frequency point, so that the time for network search can also be reduced.

Referring to fig. 8 to 9, fig. 8 to 9 are schematic structural diagrams of two other embodiments of the cell selection apparatus according to the present invention, which can perform the steps shown in fig. 5 to 6. The device includes: a first obtaining module 201, a second obtaining module 202, a third obtaining module 203, a first scanning module 204, a first ordering module 205, and a first cell selecting module 206.

The first obtaining module 201 is configured to obtain country information of a public land mobile network RPLMN registered before the mobile terminal is powered off or disconnected last time and operator information of the country.

The second obtaining module 202 is configured to obtain information of a country where the mobile terminal is currently located.

Wherein, the second obtaining module 202 includes: a first judgment unit 2021, a second judgment unit 2022, and a confirmation unit 2023.

The first judging unit 2021 is configured to judge whether the mobile terminal has a state of emergency service within a predetermined time.

The second determining unit 2022 is configured to determine, when the mobile terminal has a state of emergency service within a predetermined time, whether a country of an operator of the emergency service cell is the same as a country of the RPLMN before the mobile terminal was powered off or disconnected last time in the state of emergency service.

The determining unit 2023 is configured to, in the emergency service state, determine that the country where the operator of the emergency service cell belongs is the same as the country of the RPLMN before the previous shutdown or offline of the mobile terminal, and determine that the country where the mobile terminal is currently located is the same as the country of the RPLMN before the previous shutdown or offline of the mobile terminal; and when the country of the operator of the emergency service cell is different from the country of the RPLMN before the last shutdown or offline of the mobile terminal in the emergency service state, confirming that the country of the current mobile terminal is different from the country of the RPLMN before the last shutdown or offline of the mobile terminal.

The third obtaining module 203 is configured to obtain the first frequency scanning information when the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is last powered off or disconnected.

The third obtaining module 203 is specifically configured to obtain the first frequency scanning information from a first association list in an unerasable storage area of the mobile terminal, where the first association list includes a first operator existing in a country of the RPLMN before the mobile terminal is powered off or disconnected last time and a frequency point or a frequency band supported by the first operator, or a frequency band supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

If the server updates the first association table, the updated first association table is downloaded and obtained from the server and then stored in the non-erasable storage area.

The first sweep module 204 is configured to sweep according to the first sweep information.

The first sequencing module 205 is configured to sequence the frequency point set obtained by frequency sweeping according to the signal strength of the frequency points.

The first cell selection module 206 is configured to perform cell selection from the foremost frequency point according to the sorted result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is powered off or disconnected last time, frequency band information supported by the operator of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency band information supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

If the operator of the RPLMN before the last power-off or network-off of the mobile terminal is the operator registered in the country of the roaming place, and the country of the RPLMN before the last power-off or network-off of the mobile terminal is the country of the roaming place, the method is also performed.

Referring to fig. 9, the apparatus further comprises: a fourth acquisition module 207, a second sweep module 208, a second ranking module 209, and a second cell selection module 210.

The fourth obtaining module 207 is configured to obtain the second frequency sweep information when the country where the mobile terminal is currently located is different from the country of the RPLMN before the mobile terminal is last powered off or disconnected from the network. The fourth obtaining module 207 is specifically configured to obtain second frequency sweep information from a second association list in the non-erasable storage area of the mobile terminal, where the second association list includes different countries, a second operator preset in each country, frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

The second association list includes different countries, a second operator preset in each country and frequency points supported by the second operator, or frequency bands supported by the second operator and frequency bands supported by the second operator preset in each country and frequency bands supported by the second operator in each country, or frequency bands supported by different countries and each country.

The second frequency sweep module 208 is configured to perform frequency sweeping according to the second frequency sweep information.

The second sorting module 209 is configured to sort the frequency point sets obtained by frequency sweeping according to the signal intensity of the frequency points.

The second cell selection module 210 is configured to perform cell selection from the foremost frequency point according to the sorted result; the second frequency sweeping information comprises frequency point information supported by an operator preset in the country where the mobile terminal is located currently, or frequency band information supported by the country where the mobile terminal is located currently.

Referring to fig. 10, fig. 10 is a schematic physical structure diagram of an embodiment of the apparatus for selecting a cell according to the present invention, and the apparatus of the embodiment is a physical apparatus of the apparatus. The device includes: a processor 11, a memory 12 coupled to the processor 11, a frequency scanner 13, a receiver 14, and a data line 15 connecting the processor 11, the memory 12, the frequency scanner 13, and the receiver 14.

The memory 12 is used for storing the first sweep information.

The processor 11 is configured to obtain country information and operator information of a public land mobile network RPLMN registered before the mobile terminal is powered off or disconnected last time; acquiring the information of the country where the mobile terminal is currently located; if the country where the mobile terminal is currently located is the same as the country of the RPLMN before the mobile terminal is turned off or disconnected last time, calling the memory 12 and acquiring first frequency scanning information, controlling the frequency scanner 13 to perform frequency scanning according to the first frequency scanning information, sequencing a frequency point set obtained by frequency scanning according to the signal intensity of frequency points, and further controlling the receiver 14 to perform cell selection from the foremost frequency point according to the sequenced result; the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is powered off or disconnected last time, frequency band information supported by the operator of the RPLMN before the mobile terminal is powered off or disconnected last time, or frequency band information supported by a country of the RPLMN before the mobile terminal is powered off or disconnected last time.

Wherein the memory 12 is further configured to store second frequency sweep information.

The processor 11 is further configured to, when the country where the mobile terminal is currently located is different from the country of the RPLMN before the mobile terminal was last turned off or disconnected from the network, invoke the memory 12 and obtain second frequency sweep information, control the frequency sweep device 13 to sweep frequency according to the second frequency sweep information, and sequence a frequency point set obtained by the frequency sweep according to the signal intensity of the frequency point, and further control the receiver 14 to perform cell selection from the foremost frequency point according to the sequenced result; the second frequency sweep information includes frequency point information supported by an operator preset in the country where the mobile terminal is currently located, or frequency band information supported by the country where the mobile terminal is currently located.

The RPLMN operator before the mobile terminal is powered off or disconnected is the operator to which the intelligent card belongs, and the first frequency scanning information comprises frequency point information supported by the operator to which the intelligent card belongs; the processor 11 is configured to control the frequency scanner 13 to perform frequency scanning according to the frequency point information supported by the operator to which the smart card belongs.

The RPLMN operator before the mobile terminal is powered off or disconnected is the operator to which the smart card belongs, and the first frequency scanning information comprises frequency band information supported by the operator to which the smart card belongs; the processor 11 is configured to control the frequency scanner 13 to perform frequency scanning according to the frequency band information supported by the operator to which the smart card belongs.

The RPLMN country before the mobile terminal is powered off or disconnected is the country of the smart card, and the first frequency scanning information comprises frequency range information supported by the country of the smart card; the processor 11 is configured to control the frequency scanner 13 to perform frequency scanning according to the frequency band supported by the country of the smart card.

The processor 11 is further configured to determine that a country where the mobile terminal is currently located is the same as a country of an RPLMN before the mobile terminal was powered off or disconnected last time when the mobile terminal has a state of emergency service within a predetermined time and when the country of an operator of an emergency service cell is the same as the country of the RPLMN before the mobile terminal was powered off or disconnected last time in the state of emergency service; when the mobile terminal has an emergency service state in a preset time and the country of an operator of an emergency service cell is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal in the emergency service state, determining that the country of the current mobile terminal is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal.

Wherein the memory 12 is further configured to store a first association list, the first association list being stored in an unerasable storage area of the memory 12.

The processor 11 is further configured to obtain first frequency scanning information from a first association list in an unerasable storage area of the memory 12, where the first association list includes a first operator existing in a country of the RPLMN before the mobile terminal is powered off or disconnected from the network last time and a frequency point or a frequency band supported by the first operator, or a frequency band supported by a country of the RPLMN before the mobile terminal is powered off or disconnected from the network last time.

Wherein the memory 12 is further configured to store a second association list, the second association list being stored in an unerasable storage area of the memory 12.

The processor 11 is further configured to obtain second frequency sweep information from a second association list in the non-erasable storage area of the memory 12, where the second association list includes different countries, a second operator preset in each country, frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

In the several embodiments provided in the present invention, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A method of cell selection, the method comprising:

acquiring country information and operator information of a Registered Public Land Mobile Network (RPLMN) before the last shutdown or offline of the mobile terminal;

acquiring the information of the country where the mobile terminal is currently located;

when the country where the mobile terminal is located is the same as the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring first frequency scanning information, carrying out frequency scanning according to the first frequency scanning information, wherein the frequency scanning range is smaller than the full frequency band range, sequencing a frequency point set obtained by frequency scanning according to the signal intensity of frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result;

the first frequency scanning information comprises frequency point information supported by an operator of the RPLMN before the mobile terminal is powered off or disconnected from the network last time, or frequency band information supported by the operator of the RPLMN before the mobile terminal is powered off or disconnected from the network last time.

2. The method according to claim 1, wherein after the step of obtaining the information of the country where the mobile terminal is currently located, the method further comprises:

when the country where the mobile terminal is located is different from the country of the RPLMN before the mobile terminal is turned off or disconnected last time, acquiring second frequency sweep information, carrying out frequency sweep according to the second frequency sweep information, sequencing a frequency point set obtained by the frequency sweep according to the signal intensity of the frequency points, and further carrying out cell selection from the foremost frequency point according to the sequenced result;

the second frequency sweep information includes frequency point information supported by an operator preset in the country where the mobile terminal is currently located, or frequency band information supported by the country where the mobile terminal is currently located.

3. The method according to claim 1, wherein an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency point information supported by the operator to which the smart card belongs;

the frequency sweeping is carried out according to the first frequency sweeping information, the frequency point set obtained by the frequency sweeping is sequenced according to the signal intensity of the frequency points, and then the cell selection is carried out from the foremost frequency point according to the sequenced result, which comprises the following steps:

and performing frequency sweeping according to the frequency point information supported by the operator to which the smart card belongs, sequencing the frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and then performing cell selection from the foremost frequency point according to the sequenced result.

4. The method according to claim 1, wherein an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which a smart card belongs, and the first frequency scanning information includes frequency band information supported by the operator to which the smart card belongs;

and performing frequency sweeping according to frequency band information supported by an operator to which the smart card belongs, sequencing a frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and selecting a cell from the foremost frequency point according to the sequenced result.

5. The method according to claim 1, wherein the country of the RPLMN before the last power-off or network disconnection of the mobile terminal is the home country of the smart card, and the first frequency scanning information comprises frequency band information supported by the home country of the smart card;

and performing frequency sweeping according to the frequency band supported by the country of the smart card, sequencing the frequency point set obtained by the frequency sweeping according to the signal intensity of the frequency point, and further performing cell selection from the foremost frequency point according to the sequenced result.

6. The method according to claim 1, wherein the step of obtaining the information of the country where the mobile terminal is currently located comprises:

if the country of an operator of an emergency service cell is the same as the country of the RPLMN before the last shutdown or offline of the mobile terminal when the mobile terminal is in the state of emergency service, the country of the current mobile terminal is the same as the country of the RPLMN before the last shutdown or offline of the mobile terminal;

if the country of the operator of the emergency service cell is different from the country of the RPLMN before the last shutdown or offline of the mobile terminal when the mobile terminal is in the emergency service state, the country of the current mobile terminal is different from the country of the RPLMN before the last shutdown or offline of the mobile terminal.

7. The method of claim 1, wherein the step of obtaining the first sweep information comprises:

and acquiring first frequency scanning information from a first association list in an unerasable storage area of the mobile terminal, wherein the first association list comprises a first operator existing in the country of the RPLMN before the mobile terminal is powered off or disconnected last time and a frequency point or frequency band supported by the first operator.

8. The method of claim 2, wherein the step of acquiring the second sweep information comprises:

and acquiring second frequency sweeping information from a second association list in the non-erasable storage area of the mobile terminal, wherein the second association list comprises different countries, a second operator preset in each country, frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.

9. An apparatus for cell selection, the apparatus comprising: the system comprises a first acquisition module, a second acquisition module, a third acquisition module, a first frequency scanning module, a first sequencing module and a first cell selection module;

the first acquisition module is used for acquiring the country information and operator information of a public land mobile network (RPLMN) registered before the mobile terminal is powered off or disconnected last time;

the second acquisition module is used for acquiring the information of the country where the mobile terminal is currently located;

the third acquisition module is used for acquiring first frequency scanning information when the country where the mobile terminal is located is the same as the country of the RPLMN before the last shutdown or offline of the mobile terminal,

the first frequency scanning module is used for scanning frequency according to the first frequency scanning information, the frequency scanning range is smaller than the full frequency band range,

the first sequencing module is used for sequencing the frequency point set obtained by the frequency sweep according to the signal intensity of the frequency points,

the first cell selection module is used for selecting a cell from the foremost frequency point according to the sorted result;

10. The apparatus of claim 9, further comprising: the device comprises a fourth acquisition module, a second frequency sweeping module, a second sequencing module and a second cell selection module;

the fourth obtaining module is used for obtaining second frequency sweep information when the country where the mobile terminal is located is different from the country of the RPLMN before the mobile terminal is powered off or disconnected last time,

the second frequency sweep module is used for carrying out frequency sweep according to the second frequency sweep information,

the second sequencing module is used for sequencing the frequency point set obtained by the frequency sweep according to the signal intensity of the frequency points,

the second cell selection module is used for selecting a cell from the foremost frequency point according to the sorted result;

11. The apparatus according to claim 9, wherein an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency point information supported by the operator to which the smart card belongs;

the first frequency scanning module is specifically configured to scan frequencies according to frequency point information supported by an operator to which the smart card belongs.

12. The apparatus according to claim 9, wherein an operator of the RPLMN before the mobile terminal is powered off or disconnected last time is an operator to which the smart card belongs, and the first frequency scanning information includes frequency band information supported by the operator to which the smart card belongs;

the first frequency scanning module is specifically configured to perform frequency scanning according to frequency band information supported by an operator to which the smart card belongs.

13. The apparatus according to claim 9, wherein the country of the RPLMN before the mobile terminal was last powered off or disconnected from the network is a home country of the smart card, and the first frequency scanning information includes frequency band information supported by the home country of the smart card;

the first frequency scanning module is specifically configured to perform frequency scanning according to a frequency band supported by a country of the smart card.

14. The apparatus of claim 9,

the second obtaining module is specifically configured to, when the mobile terminal is in an emergency service state, when a country of an operator of an emergency service cell is the same as a country of the RPLMN before the mobile terminal is last powered off or disconnected from a network, determine that the country of the mobile terminal is the same as the country of the RPLMN before the mobile terminal is last powered off or disconnected from the network;

and when the mobile terminal is in the emergency service state and the country of the operator of the emergency service cell is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal last time, the country of the current mobile terminal is different from the country of the RPLMN before the power-off or the network disconnection of the mobile terminal last time.

15. The apparatus according to claim 9, wherein the third obtaining module is specifically configured to obtain first frequency scanning information from a first association list in an unerasable storage area of the mobile terminal, where the first association list includes a first operator existing in a country of the RPLMN before the mobile terminal is powered off or disconnected last time and a frequency point or a frequency band supported by the first operator.

16. The apparatus according to claim 10, wherein the fourth obtaining module is specifically configured to obtain second frequency sweep information from a second association list in the non-erasable storage area of the mobile terminal, where the second association list includes different countries, a second operator preset in each country, and frequency points or frequency bands supported by the second operator, or frequency bands supported by each country.