WO2011023008A1

WO2011023008A1 - Method and system for switching international mobile subscriber identity number

Info

Publication number: WO2011023008A1
Application number: PCT/CN2010/073383
Authority: WO
Inventors: 何可为; 王寿林; 仝黎
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-08-27
Filing date: 2010-05-31
Publication date: 2011-03-03
Also published as: CN101998362A

Abstract

A method for switching International Mobile Subscriber Identity Number (IMSI) is provided, wherein the related mobile terminal has a built-in SIM card which stores multiple IMSIs, and the method includes that when the mobile terminal performs location update, a Home Location Register (HLR) determines whether the mobile terminal requires to switch an IMSI according to the prestored list preset, if so, a dedicated Over-The-Air (OTA) short message for instructing the mobile terminal to switch the IMSI is sent to the mobile terminal; and the mobile terminal receives the dedicated OTA short message and forwards it to the SIM card in the mobile terminal, and the SIM card switches the IMSI according to the instruction of the dedicated OTA short message. A system and an HLR for supporting the IMSI switch are also provided in the present invention. With the technical schemes of the present invention, the mobile terminal is enabled to select an IMSI with a lower rate in real time according to the country or operator's network in which the subscriber locates, without the participation of the subscriber.

Description

Method and system for switching international mobile subscriber identification code

TECHNICAL FIELD The present invention relates to the field of communications, and in particular, to a method and system for switching an international mobile subscriber identity.

BACKGROUND OF THE INVENTION Since the service network of each country or operator collects different tariff standards for operators to which each user belongs, the operator can purchase some International Mobile Subscriber Identification Number (IMSSI) numbers of other operators. Segments, at the same time, enable users to subscribe to multiple IMSIs belonging to different operators. In this way, when mobile phone users roam to other countries or operators' service networks, they can choose to use the IMSI of operators with lower local tariffs to enable operators to operate. The cost is reduced. For example, if the user of the operator A roams to the F country, the user subscribes to three IMSIs, which belong to the operator A, the operator B, and the operator C, respectively, and the operator F and the operator C in the F country. The operator's IMSI is set. In the F country, the carrier's IMSI tariff is relatively low. The easiest way is that the user can manually switch IMSI to select operator C's IMSI. Since switching IMSI mainly reduces the operating cost of the operator, and manual switching causes inconvenience to the user, in order to improve the user's perception, the IMSI process needs to be transparent to the user.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a method and system for switching an international mobile subscriber identity code, so that the mobile terminal can select an IMSI with a lower tariff in real time without user participation. In order to solve the above problem, the present invention discloses a method for switching an IMSI. The mobile terminal involved includes a customer identification module (SIM) card storing a plurality of IMSIs, and the method includes: when the mobile terminal performs location update, the home location register (HLR) determining, according to a pre-stored list set in advance, whether the mobile terminal needs to switch IMSI, and if yes, sending to the mobile terminal a dedicated air interface (OTA) short message, the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI; and the mobile terminal receives the dedicated OTA short message, and forwards the dedicated OTA short message to the SIM card inside the mobile terminal The SIM card switches the IMSI according to the indication of the dedicated OTA short message. In the above method, the dedicated OTA is further used to instruct the mobile terminal to return a return receipt message; after the step of the SIM card in the mobile terminal indicating the handover of the IMSI, the method further includes: the SIM card generating a return receipt message according to the handover result. And instructing the mobile terminal to send the receipt message to the HLR; and the HLR receives the receipt message, and when the receipt message indicates that the handover is successful, the HLR records that the mobile terminal successfully switches the IMSI. The pre-stored list includes at least a preferred IMSI of a different roaming country or an operator. The step of the HLR determining that the mobile terminal needs to switch the IMSI includes: if the mobile terminal located in a roaming country or an operator area performs location update, the IMSI used by the mobile terminal is not the roaming country in the pre-existing list Or the preferred IMSI of the operator, the HLR determines that the mobile terminal needs to handover the IMSI. After the step of determining, by the HLR, that the mobile terminal needs to switch the IMSI, the method further includes: when the HLR determines that at least one of the following conditions is met, performing, sending, to the mobile terminal, The step of the dedicated OTA short message is to instruct the mobile terminal to switch the IMSI: the time difference between the current time and the last successful handover of the IMSI of the mobile terminal is greater than the previously configured "disable IMSI time after the successful handover of the IMSI"; the visitor location register of the user location update The device number (VLRNUM) or the general wireless packet service support node device number (SGSNNUM) is inconsistent with the last registered VLRNUM or SGSNNUM. The invention also discloses a system for supporting switching IMSI, comprising an HLR and a mobile terminal, wherein the mobile terminal has a SIM card storing a plurality of IMSIs, wherein: the HLR is set to: when the mobile terminal performs location update Determining, according to the pre-stored list, whether the mobile terminal needs to handover the IMSI, and if yes, transmitting a dedicated air interface (OTA) short message to the mobile terminal, the dedicated OTA short message being used to instruct the mobile terminal to switch the IMSI; The terminal is configured to: receive the dedicated OTA short message, forward the dedicated OTA short message to a SIM card inside the mobile terminal, and the SIM card switches the IMSI according to the indication of the dedicated OTA short message. In the above system, the dedicated OTA short message is further used to instruct the mobile terminal to send a return receipt message; the HLR is further configured to: receive a return receipt message returned by the mobile terminal, and record the receipt message indicating that the handover is successful, The mobile terminal successfully switches the IMSI; and the mobile terminal is further configured to: after the SIM card of the mobile terminal switches the IMSI, generate a return receipt message according to the handover result, and send the receipt message to the HLR. The pre-stored list includes at least a preferred IMSI of a different roaming country or an operator. The HLR is configured to determine whether the mobile terminal needs to switch the IMSI as follows: if the mobile terminal located in a roaming country or an operator area performs location update, the IMSI used by the mobile terminal is not the pre-stored The preferred IMSI of the roaming country or the operator in the list, then the HLR determines that the mobile terminal needs to handover the IMSI. The HLR is further configured to: when determining, according to the pre-stored list, that the mobile terminal needs to switch the IMSI, and further determining that at least one of the following conditions is met, sending the dedicated OTA short message to the mobile terminal to indicate that the mobile terminal switches IMSI: The time difference between the current time and the last successful handover of the IMSI of the mobile terminal is greater than the previously configured "Forbidden to switch IMSI time after successful handover of IMSI"; the visitor location register device number (VLRNUM) of the user location update or the general wireless packet The service support node device number (SGSNNUM) does not match the last registered VLRNUM or SGSNNUM.

The present invention also discloses a Home Location Register (HLR) supporting a mobile terminal to switch an International Mobile Subscriber Identity (IMSI), the mobile terminal having a Subscriber Identity Module (SIM) card storing a plurality of IMSIs, the HLR including a judging module and a message sending module; wherein the judging module is configured to: when the mobile terminal performs location update, determine, according to the pre-stored list, whether the mobile terminal needs to switch the IMSI, and if yes, notify the message sending module; The message sending module is configured to: send a dedicated air interface (OTA) short message to the mobile terminal, where the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI, so that the mobile terminal is receiving the dedicated OTA short message. Thereafter, the dedicated OTA short message is forwarded to a SIM card inside the mobile terminal, and the SIM card switches the IMSI according to the indication of the dedicated OTA short message. The dedicated OTA short message is further used to indicate that the mobile terminal sends a return receipt message, and the HLR further includes a message receiving module, where: the message receiving module is configured to: receive the mobile terminal after the internal SIM card switches the IMSI The receipt message generated and transmitted according to the handover result, and when receiving the receipt message indicating that the handover is successful, records that the mobile terminal successfully switches the IMSI. The pre-existing list includes at least preferred IMSIs of different roaming countries or operators. The determining module is configured to determine whether the mobile terminal needs to switch according to the following manner

IMSI: If the mobile terminal used in a roaming country or an operator area performs location update, the IMSI used by the mobile terminal is not the preferred IMSI of the roaming country or the operator in the pre-stored list, then the determining module It is determined that the mobile terminal needs to switch the IMSI. The determining module is further configured to: determine, according to the pre-stored list, that the mobile terminal needs to switch

After the IMSI, when it is determined that at least one of the following conditions is met, the dedicated OTA short message is sent to the mobile terminal to instruct the mobile terminal to switch the IMSI: The time difference between the current time and the last successful handover of the IMSI by the mobile terminal is greater than the previously configured "disable IMSI time after successful handover of the IMSI"; the location location register device number (VLRNUM) of the user location update or the general wireless packet service support node device number ( SGSNNUM ) is inconsistent with the last registered VLRNUM or SGSNNUM.

The technical solution of the present invention enables the mobile terminal to select the IMSI with lower tariff in real time according to the country or operator network where the user is located without the user's participation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a main idea of the present invention; FIG. 2 is a flow chart of the HLR notifying a mobile terminal to switch an IMSI through a dedicated OTA short message in the embodiment; FIG. 3 is an IMSI implemented between the HLR and the mobile terminal in this embodiment. Switching flow chart.

BEST MODE FOR CARRYING OUT THE INVENTION The main idea of the present invention is: for a mobile terminal having a Subscriber Identity Module (SIM) card in which a plurality of IMSIs are stored and each IMSI can perform normal service processing, When the location update is performed, the home location register (HLR) of the network side can notify the mobile terminal to switch the IMSI by using a dedicated over-the-air (OTA) short message to select the appropriate (for example, the tariff is low) ) IMSI. For example, as shown in FIG. 1 , when the user of the operator A roams in the F country, the IMSI of the operator B preset by the user is used for location registration, and the registration request is forwarded to the HLR of the operator A through the network; The rule (that is, the pre-stored list set in advance), the HLR judges that the IMSI service of the operator C is preferably used in the country F, and then sends a dedicated OTA short message to the user to instruct the user to switch the IMSI, that is, the user is required to re-select the operator C. The IMSI performs location registration; after receiving the dedicated OTA short message, the mobile terminal re-selects the IMSI of the operator C for location registration. After the success, the service can be used by the operator C. In order to ensure the critical data, the key data can be checked and verified according to the 3GPP TS 03.48 protocol, and the key data is encrypted.

The technical solutions of the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments. A system for switching IMSI, comprising a mobile terminal and an HLR, wherein the mobile terminal involved in the system has a built-in SIM card for storing a plurality of IMSIs. The functions of each part are described below.

The HLR is set to: when the mobile terminal performs the location update, whether the mobile terminal needs to switch the IMSI according to the preset pre-stored list, and if yes, sends a dedicated OTA short message to the mobile terminal to instruct the mobile terminal to switch the IMSI, otherwise There is a process operation; wherein, the preset pre-stored list includes at least the preferred IMSI of each roaming country or operator, and when the mobile terminal located in a roaming country or the operator area performs location update, the used IMSI is not in the pre-stored list. In the preferred IMSI of the roaming country or the operator, the HLR determines that the mobile terminal needs to switch the IMSI. In some embodiments, when the HLR determines that the mobile terminal needs to handover the IMSI, it may further determine whether any of the following conditions are met:

The time difference between the current time and the last successful handover of the IMSI by the mobile terminal is greater than the previously configured "disable IMSI time after successful handover of the IMSI"; the Visitor Location Register (VLR) device number (VLRNUM) of the user location update (or general purpose) The Serving GPRS Support Node (SGSN SGSNNUM) is inconsistent with the last registered VLRNUM (or SGSNNUM); when at least one of the above conditions is met, the HLR sends a dedicated OTA short message to the mobile terminal to indicate The mobile terminal switches the IMSI. The mobile terminal is configured to: receive the dedicated OTA short message sent by the HLR, and the mobile terminal forwards the dedicated OTA short message to the SIM card, because the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI. The SIM card parses the dedicated OTA short message and switches according to the instructions therein. IMSI. In other embodiments, the HLR may configure the handover IMSI to require a return receipt message, that is, the dedicated OTA short message sent by the HLR to the mobile terminal further indicates that the mobile terminal returns a receipt message, and at this time, the SIM card in the mobile terminal switches according to the dedicated OTA short message. After the IMSI, the receipt message is further generated according to the handover structure, and the mobile terminal is instructed to send the receipt message to the HLR. After receiving the receipt message, the HLR records the successful IMSI handover of the mobile terminal if the handover message indicates that the handover is successful. A home location register (HLR) supporting a mobile terminal to switch an International Mobile Subscriber Identity (IMSI), the mobile terminal having a subscriber identity module (SIM) card storing a plurality of IMSIs, the HLR comprising a judging module and a message sending module; The determining module is configured to: when the mobile terminal performs location update, determine, according to the pre-stored list, whether the mobile terminal needs to switch the IMSI, and if yes, notify the message sending module; the message sending module is configured to: send a dedicated air interface (OTA) to the mobile terminal. a short message, the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI, so that after receiving the dedicated OTA short message, the mobile terminal forwards the dedicated OTA short message to the SIM card inside the mobile terminal, where the SIM card is The indication of the dedicated OTA short message switches the IMSI. The dedicated OTA short message is further used to instruct the mobile terminal to send a return receipt message, and the HLR further includes a message receiving module, where: the message receiving module is configured to: receive a return receipt message generated and sent by the mobile terminal according to the handover result after the internal SIM card switches the IMSI, And when receiving the receipt message indicating that the handover is successful, the mobile terminal is recorded to successfully switch the IMSI. The pre-existing list includes at least the preferred IMSIs of different roaming countries or operators. The judging module is configured to determine whether the mobile terminal needs to switch the IMSI as follows: if the mobile terminal located in a roaming country or the operator area performs location update, the IMSI used by the mobile terminal is not the roaming country in the pre-existing list. Or the preferred IMSI of the operator, the judging module determines that the mobile terminal needs to switch the IMSI. The determining module is further configured to: after determining, according to the pre-stored list, that the mobile terminal needs to switch the IMSI, and further determining that the following one condition is met, sending the dedicated OTA short message to the mobile terminal to instruct the mobile terminal to switch the IMSI: the current time and the mobile The time difference between the last successful handover of the IMSI by the terminal is greater than the previously configured "Forbidden to switch IMSI time after successful handover of IMSI"; the location location register device number (VLRNUM) of the user location update or the general wireless packet service support node device number (SGSNNUM) and the last time The registered VLRNUM or SGSNNUM is inconsistent.

The process of implementing the IMSI handover by the above system is described below. This embodiment introduces the process in which the HLR in the above system notifies the mobile terminal to switch the IMSI through the dedicated OTA short message. As shown in FIG. 2, the method includes the following steps: Step 201: The mobile terminal performs circuit switching (Circuit Switch, CS) on the visited network or Packet switching (PS) location update; Step 202: The HLR to which the mobile terminal belongs determines whether the roaming area number changes (ie, determines whether the roaming country or region has changed), and if yes, proceeds to step 207, if not Go to step 203; Step 203: The HLR determines, according to the pre-stored list, whether the IMSI used by the mobile terminal currently performing the location update is the most preferred IMSI configured by the location update location, and if yes, proceeds to step 208, if not, proceeds to step 204. Step 204: The HLR determines whether the time difference between the current time of the system and the last successful handover IMSI is within the configuration of “prohibiting the handover IMSI time after successfully switching the IMSI”. If yes, go to step 208, if no, go to step 205; 205: The HLR determines whether the VLRNUM (or SGSNNUM) of the user location update is the same as the last registered VLRNUM (or SG). SNNUM) is consistent, if yes, go to step 208, if not, go to step 206; Step 206: Start dedicated OTA switch to optimize the IMSI service flow, that is, send to the mobile terminal a dedicated OTA short message, the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI, and the process ends. In this step, the dedicated OTA short message of the IMSI is sent by the HLR to the mobile terminal, and thus may be a short message termination call. (MAP-MT Forward Short Message) message. Step 207: The user roaming area changes, and the HLR determines whether the IMSI of the current location update is the most preferred IMSI configured by the location update location. If yes, go to step 208, otherwise go to step 206; Step 208: Do not start the dedicated OTA handover preference. The IMSI business process, using the IMSI in the location update, the entire process ends. In other embodiments, the order of step 204 and step 205 may be interchanged, or the operations of step 204 and step 205 may not be performed, that is, whether the IMSI used by the mobile terminal currently performing location update is only based on the pre-stored list. The preferred IMSI of the local configuration is updated, and if it is the most preferred IMSI, the dedicated OTA short message is not delivered, and if it is not the preferred IMSI, the dedicated OTA short message is delivered. Alternatively, one of step 204 and step 205 may also be performed.

In this embodiment, the process of implementing IMSI handover between the HLR and the mobile terminal is introduced. As shown in FIG. 3, the method includes the following steps: Step 301: After the mobile terminal performs CS or PS location update on the visited network, the HLR is configured according to a preset pre-stored list. Determining whether the IMSI needs to be switched. If the IMSI needs to be switched, the HLR sends a dedicated OTA short message through the visited Mobile Switching Center (MSC) (in this embodiment, the MAP-MT Forward Short Message conforms to the specification 3GPP TS 03.48) In the terminal mobile terminal, instructing the mobile terminal to update the GSM IMSI; wherein, the pre-stored list includes at least the preferred IMSI of each roaming country or operator (for example, each roaming country or an IMSI with a lower carrier fee, that is, a preferred IMSI) When the mobile terminal located in a roaming country or an operator area performs location update, the used IMSI is not the preferred IMSI of the roaming country or the operator in the pre-stored list, and the HLR determines that the mobile terminal needs to handover the IMSI. Step 302: The visited MSC (ie, the roaming service MSC) turns the dedicated OTA short message Sending to the mobile terminal; Step 303: The mobile terminal receives the dedicated OTA short message. Because it is a dedicated OTA short message (OTA handover GSM IMSI), the mobile terminal passes the dedicated OTA short message through Envelop (SMS-PP Data Download) The instruction is forwarded to the internal SIM card, and the SIM card decrypts the message and checks the correctness of the parameters in the message to perform the IMSI handover. Step 304: The mobile terminal returns a short message Short Message Transfer success response to the visited MSC to indicate successful reception. Go to the dedicated OTA short message; Step 305: The visited MSC receives a short message transfer (Short Message Transfer) success response, and returns a success response of the MAP-MT Forward Short Message to the HLR to indicate that the mobile terminal successfully receives the dedicated OTA short message. Step 306: When the SIM card parses the dedicated OTA short message, if the HLR requests to return the return receipt message, the remote management specification (3GPP TS 03.48) is followed to return a return receipt message indicating the handover result, that is, the SIM card sends the Send SMS to the mobile terminal. Active command, and requesting the mobile terminal to send the reply message to the HLR; Step 307: The mobile terminal calls The MSC sends an initial call (SMS MO) message; Step 308: The visited MSC receives the SMS MO call message and forwards the SMS MO message to the HLR; Step 309: After receiving the SMS MO call message, the HLR parses the The message, that is, the receipt message of the dedicated OTA short message, returns an SMS MO response to the visited MSC, and records a successful IMSI handover of the mobile terminal; Step 310: The visited MSC receives the SMS MO response and sends the response Mobile terminal; Step 311: The mobile terminal receives the SMS MO response and forwards it to the SIM card, and the SIM card sends a Refresh active command to the mobile terminal, and the instruction requests the mobile terminal to perform Card Reset.

It is a matter of course that the invention may be embodied in various other modifications, equivalents, modifications and improvements within the spirit and scope of the invention. It is intended to be within the scope of the appended claims.

Industrial Applicability The technical solution of the present invention enables a mobile terminal to select an IMSI with a lower tariff in real time according to a country or an operator network in which the user is located without user participation.

Claims

Claim

A method for switching an International Mobile Subscriber Identity (IMSI), wherein the mobile terminal includes a Subscriber Identity Module (SIM) card storing a plurality of IMSIs, the method comprising: a home location register when the mobile terminal performs location update (HLR) determining, according to a preset pre-stored list, whether the mobile terminal needs to switch IMSI, and if so, sending a dedicated air interface (OTA) short message to the mobile terminal, the dedicated OTA short message being used to instruct the mobile terminal to switch the IMSI; And the mobile terminal receives the dedicated OTA short message, and forwards the dedicated OTA short message to a SIM card inside the mobile terminal, and the SIM card switches the IMSI according to the indication of the dedicated OTA short message.

2. The method according to claim 1, wherein: the dedicated OTA is further configured to: instruct the mobile terminal to return a return receipt message; after the step of the SIM card in the mobile terminal indicating the handover of the IMSI, the method further includes: The SIM card generates a receipt message according to the handover result, and instructs the mobile terminal to send the receipt message to the HLR; and the HLR receives the receipt message, and when the receipt message indicates that the handover is successful, the HLR record The mobile terminal successfully switches the IMSI.

3. The method according to claim 1 or 2, wherein: the pre-existing list includes at least a preferred IMSI of a different roaming country or operator.

The method of claim 3, wherein the step of the HLR determining whether the mobile terminal needs to switch the IMSI comprises: if the mobile terminal located in a roaming country or an operator area performs location update, the moving The IMSI used by the terminal is not the preferred IMSI of the roaming country or the operator in the pre-stored list, and the HLR determines that the mobile terminal needs to handover the IMSI.

The method according to claim 1 or 2, wherein: the HLR determines, according to the pre-stored list, that the mobile terminal needs to switch the IMSI, and if yes, the method further includes: the HLR determining at least When the following condition is met, the step of sending the dedicated OTA short message to the mobile terminal is performed to instruct the mobile terminal to switch the IMSI: the time difference between the current time and the last successful handover of the IMSI by the mobile terminal is greater than the previously configured "successful handover" The IMSI time is prohibited after IMSI; the visitor location register device number (VLRNUM) of the user location update or the general wireless packet service support node device number (SGSNNUM) does not match the last registered VLRNUM or SGSNNUM.

6. A system for supporting handover of an International Mobile Subscriber Identity (IMSI), comprising a Home Location Register (HLR) and a mobile terminal, the mobile terminal having a Subscriber Identity Module (SIM) card storing a plurality of IMSIs, wherein: The HLR is set to: when the mobile terminal performs location update, determine, according to the pre-stored list, whether the mobile terminal needs to switch IMSI, and if yes, send a dedicated air interface (OTA) short message to the mobile terminal, the dedicated The OTA short message is used to instruct the mobile terminal to switch the IMSI; the mobile terminal is configured to: receive the dedicated OTA short message, and forward the dedicated OTA short message to the SIM card inside the mobile terminal, where the SIM card is short according to the dedicated OTA The indication of the message switches the IMSI.

7. The system according to claim 6, wherein: the dedicated OTA short message is further used to instruct the mobile terminal to send a return receipt message; the HLR is further configured to: receive a return receipt message returned by the mobile terminal, and receive the receipt message When the handover message indicating that the handover is successful, the mobile terminal is successfully switched to the IMSI; and the mobile terminal is further configured to: after the SIM card of the mobile terminal switches the IMSI, generate a receipt message according to the handover result, and send the receipt message to the HLR Send the receipt message.

8. The system of claim 6 or 7, wherein: The pre-existing list includes at least a preferred IMSI of a different roaming country or operator.

9. The system according to claim 8, wherein the HLR is configured to determine whether the mobile terminal needs to switch an IMSI as follows: if a mobile terminal located in a roaming country or an operator area performs location update, The IMSI used by the mobile terminal is not the preferred IMSI of the roaming country or the operator in the pre-stored list, and the HLR determines that the mobile terminal needs to handover the IMSI.

The system according to claim 6 or 7, wherein: the HLR is further configured to: when determining, according to the pre-stored list, that the mobile terminal needs to switch the IMSI, and further determining that at least one of the following conditions is met, The mobile terminal sends the dedicated OTA short message to instruct the mobile terminal to switch the IMSI: the time difference between the current time and the last successful handover of the IMSI of the mobile terminal is greater than the previously configured "disable IMSI time after the successful handover of the IMSI"; the visit of the user location update The location register device number (VLRNUM) or the general wireless packet service support node device number (SGSNNUM) does not match the last registered VLRNUM or SGSNNUM.

11. A home location register (HLR) supporting a mobile terminal to switch an International Mobile Subscriber Identity (IMSI), wherein the mobile terminal has a customer identification module (SIM) card storing a plurality of IMSIs, the HLR The determining module and the message sending module are configured to: when the mobile terminal performs location update, determine, according to the pre-stored list, whether the mobile terminal needs to switch IMSI, and if yes, notify the message sending module The message sending module is configured to: send a dedicated air interface (OTA) short message to the mobile terminal, where the dedicated OTA short message is used to instruct the mobile terminal to switch the IMSI, so that the mobile terminal is short in receiving the dedicated OTA After the message, the dedicated OTA short message is forwarded to the SIM card inside the mobile terminal, and the SIM card switches the IMSI according to the indication of the dedicated OTA short message.

The HLR of claim 11, wherein: the dedicated OTA short message is further used to indicate that the mobile terminal sends a return receipt message; the HLR further includes a message receiving module, where: the message receiving module is configured to: Receiving a receipt message generated and sent by the mobile terminal after the internal SIM card switches the IMSI according to the handover result, and when receiving the receipt message indicating that the handover is successful, recording the mobile terminal successfully switching the IMSI.

13. The HLR according to claim 11 or 12, wherein: the pre-existing list includes at least a preferred IMSI of a different roaming country or operator.

The HLR according to claim 3, wherein the determining module is configured to determine whether the mobile terminal needs to switch the IMSI as follows: if the mobile terminal located in a roaming country or an operator area performs location update The IMSI used by the mobile terminal is not the preferred IMSI of the roaming country or the operator in the pre-stored list, and the determining module determines that the mobile terminal needs to switch the IMSI.

The HLR according to claim 12 or 13, wherein: the determining module is further configured to: determine, according to the pre-stored list, that the mobile terminal needs to switch

After the IMSI, when it is determined that at least one of the following conditions is met, the dedicated OTA short message is sent to the mobile terminal to instruct the mobile terminal to switch the IMSI:

The time difference between the current time and the last successful handover of the IMSI by the mobile terminal is greater than the previously configured "disable IMSI time after successful handover of the IMSI"; the location location register device number (VLRNUM) of the user location update or the general wireless packet service support node device number ( SGSNNUM ) is inconsistent with the last registered VLRNUM or SGSNNUM.