JP2024099351A - Electronic information storage medium, IC chip, program, and connection switching request method - Google Patents

Abstract

[Problem] To provide an electronic information storage medium, an IC chip, a program, and a connection switching request method that can realize a connection switching to a wireless communication network desired by a user when a terminal is connected to one of a plurality of wireless communication networks. [Solution] A SIM acquires location information of a currently connected public wireless communication network NWn from a terminal T, compares the acquired location information with location information of the wireless communication network NWn in an NVM 14, and requests a connection switching from the currently connected public wireless communication network NW2 to a private wireless communication network NW1 based on the result of the comparison of the location information. [Selected Figure] Figure 4

Description

The present invention relates to the technical field of SIMs (Subscriber Identity Modules) that are installed in mobile devices that can connect to any one of multiple different wireless communication networks.

Conventionally, communication services such as LTE/5G have been realized by connecting terminals such as mobile devices to a core network. Among such wireless communication networks, so-called public wireless communication networks (carrier networks) have an extremely wide coverage area and can be connected anywhere. On the other hand, private wireless communication networks are known that can be used only within a certain area by providing LTE/5G networks only in specific areas. Generally, the cost of public wireless communication networks is proportional to the amount of communication, so private wireless communication networks are expensive to introduce but inexpensive to operate.

However, there are cases where the coverage areas of multiple wireless communication networks overlap. In such cases, a method is known in which a terminal uses a REFRESH command of the SIM installed in the terminal to connect to the desired wireless communication network. In this method, for example, a Secured Packet format SMS (Short Message Service) message defined by 3GPP (Third Generation Partnership Project) (registered trademark) shown in Patent Document 1 is used, and appropriate authentication processing is performed to prevent pranks and service disruptions.

JP 2017-76930 A

However, when a terminal is connected to one of multiple wireless communication networks in the case where their coverage areas overlap, the terminal maintains a connection to the same wireless communication network until it leaves the area and the connection is lost in order to maintain service. Therefore, if a terminal is connected to a public wireless communication network and enters the range of a private wireless communication network with overlapping coverage areas, the terminal does not switch wireless communication networks. This poses the problem that the private wireless communication network cannot be used effectively.

The present invention has been made in consideration of the above problems, and aims to provide an electronic information storage medium, an IC chip, a program, and a connection switching request method that can realize a connection switch to a wireless communication network desired by a user when a terminal is connected to one of multiple wireless communication networks.

In order to solve the above problem, the invention described in claim 1 is an electronic information storage medium mounted on a terminal that can connect to any one of a plurality of different wireless communication networks, and is characterized by comprising: a storage means for storing in advance first position information of at least a specific wireless communication network of the plurality of wireless communication networks; an acquisition means for acquiring second position information of a wireless communication network to which the terminal is currently connected; a comparison means for comparing the first position information with the second position information; and a request means for requesting a connection switch from the currently connected wireless communication network to another wireless communication network based on the result of the comparison by the comparison means.

The invention described in claim 2 is characterized in that in the electronic information storage medium described in claim 1, the coverage area of the other wireless communication network overlaps with a portion of the coverage area of the specific wireless communication network.

The invention described in claim 3 is characterized in that, in the electronic information storage medium described in claim 1, the other wireless communication network is a private wireless communication network other than a public wireless communication network provided by a mobile communication carrier.

The invention described in claim 4 is an electronic information storage medium described in any one of claims 1 to 3, characterized in that the request means requests the connection switching when the first location information and the second location information match as a result of the comparison by the comparison means.

The invention described in claim 5 is characterized in that, in the electronic information storage medium described in any one of claims 1 to 3, if the result of the comparison by the comparison means is that the first location information and the second location information do not match, the acquisition means reacquires the second location information from the terminal after a first set time has elapsed, and the comparison means recompares the first location information with the reacquired second location information.

The invention described in claim 6 is the electronic information storage medium described in claim 5, characterized in that, when the result of the re-comparison by the comparison means is that the first location information and the reacquired second location information match, the request means requests the connection switching.

The invention described in claim 7 is characterized in that, in the electronic information storage medium described in claim 5, when the result of the re-comparison by the comparison means is that the first location information does not match the reacquired second location information and the reacquired second location information matches the second location information previously acquired, the acquisition means reacquires the second location information from the terminal after a second set time longer than the first set time has elapsed, and the comparison means re-compares the first location information with the re-acquired second location information.

The invention described in claim 8 is an IC chip mounted on a terminal that can connect to any one of a plurality of different wireless communication networks, and is characterized in that it comprises: a storage means for storing in advance first position information of at least a specific wireless communication network of the plurality of wireless communication networks; an acquisition means for acquiring second position information of a wireless communication network to which the terminal is currently connected; a comparison means for comparing the first position information with the second position information; and a request means for requesting a connection switch from the currently connected wireless communication network to another wireless communication network based on the result of the comparison by the comparison means.

The invention described in claim 9 is characterized in that a computer included in an electronic information storage medium mounted on a terminal that can connect to any one of a plurality of different wireless communication networks is made to function as a storage means for storing in advance first position information of at least a specific wireless communication network of the plurality of wireless communication networks, an acquisition means for acquiring second position information of a wireless communication network to which the terminal is currently connected, a comparison means for comparing the first position information with the second position information, and a request means for requesting a connection switch from the currently connected wireless communication network to another wireless communication network based on the result of the comparison by the comparison means.

The invention described in claim 10 is an electronic information storage medium mounted on a terminal that can connect to any one of a plurality of different wireless communication networks, and is provided with a storage means for storing in advance first position information of at least a specific wireless communication network among the plurality of wireless communication networks, and is characterized in that the connection switching request method executed by the electronic information storage medium includes the steps of acquiring second position information of the currently connected wireless communication network from the terminal, comparing the first position information with the second position information, and requesting a connection switch from the currently connected wireless communication network to another wireless communication network based on the result of the comparison.

According to the present invention, when a terminal is connected to one of multiple wireless communication networks, it is possible to switch the connection to a wireless communication network desired by the user.

2 is a diagram showing an example of a schematic configuration of a terminal T. 1 is a conceptual diagram showing an example of the positional relationship of wireless communication networks NWn. FIG. 13 is a diagram showing an example of setting information stored in an EF record. 10 is a flowchart showing an example of a connection control process of a CPU 15 in the SIM. 5 is a diagram showing a specific example of an initial sequence performed between the SIM and the terminal T (control unit 5) in step S1 shown in FIG. 4. 11 is a diagram illustrating an example of a temporary storage area prepared in the RAM 12 or the NVM 14 before the connection control process.

The following describes in detail an embodiment of the present invention with reference to the drawings. The embodiment described below is an embodiment in which the present invention is applied to a SIM installed in a terminal that can connect to any one of multiple different wireless communication networks.

[1. General configuration of terminal T]
First, the general configuration of the terminal T will be described with reference to FIG. 1. FIG. 1 is a diagram showing an example of the general configuration of the terminal T. As shown in FIG. 1, the terminal T is configured to include an I/F unit 1, a wireless communication unit 2, a storage unit 3, an operation/display unit 4, and a control unit 5. The terminal T is, for example, a mobile device (portable terminal) such as a smartphone. The terminal T is equipped with a SIM. The SIM is an example of the electronic information storage medium and IC chip of the present invention, and may be detachably mounted on the terminal T as an IC (Integrated Circuit) card, or may be an eUICC (Embedded Universal Integrated Circuit Card) mounted (for example, soldered) on a board so that it cannot be easily removed or replaced from the terminal T. The I/F unit 1 serves as an interface with the SIM. It is preferable that such an interface is an ISO7816 interface. However, the I/F unit 1 may be applied with an SPI (Serial Peripheral Interface) or an I ² C (Inter-Integrated Circuit). The control unit 5 and the SIM communicate with each other via the I/F unit 1 in accordance with, for example, the APDU (Application Protocol Data Unit) protocol.

The wireless communication unit 2 has a modem that detects the base stations of a number of different wireless communication networks NWn (n indicates all or part of 1, 2, 3, 4), and is capable of connecting to any one of these wireless communication networks NWn to perform wireless communication. Here, NW1 indicates a private wireless communication network (a private network, an example of another wireless communication network), and NW2 to NW4 each indicate a public wireless communication network (public network). The public wireless communication networks NW2 to NW4 are mobile communication networks built by different mobile communication carriers, and provide voice communication, SMS communication, and data communication. On the other hand, the private wireless communication network NW1 is a mobile communication network other than the public wireless communication networks NW2 to NW4 provided by a mobile communication carrier, and is, for example, a mobile communication network built in a specific area (for example, a facility such as a factory) by a company or organization other than the mobile communication carrier. The wireless communication network NWn is composed of a wireless network including a base station and a core network including a core, and authentication processing for connection to the wireless communication network NWn is performed using a SIM prepared by the network builder (i.e., a mobile communication operator, or a company or organization other than a mobile communication operator).

Figure 2 is a conceptual diagram showing an example of the positional relationship of the wireless communication network NWn. In the example of Figure 2, the cover areas AR1 to AR4 are shown in a rectangular shape for convenience of explanation, but are not limited to this. In the example of Figure 2, the cover areas AR2 to AR4 (communication areas to which terminal T can be connected) of the public wireless communication networks NW2 to NW4 are different from each other (do not overlap). However, the cover areas AR2 to AR4 may overlap. In addition, the cover area AR2 of the public wireless communication network NW2 (an example of a specific wireless communication network) includes the cover area AR1 of the private wireless communication network NW1. In other words, the cover area AR1 of the private wireless communication network NW1 overlaps with a part of the cover area AR2 of the public wireless communication network NW2. In addition, the cover area AR3 of the public wireless communication network NW3 is farther away from the cover area AR1 of the private wireless communication network NW1 than the cover area AR2 of the public wireless communication network NW2. In addition, the coverage area AR4 of the public wireless communication network NW4 is farther away from the coverage area AR1 of the private wireless communication network NW1 than the coverage area AR3 of the public wireless communication network NW3.

When the wireless communication unit 2 is currently connected to the public wireless communication network NW2 in the coverage area AR1 of the private wireless communication network NW1, the wireless communication unit 2 maintains the connection. In this case, the connection is switched from the currently connected public wireless communication network NW2 to the private wireless communication network NW1 by a REFRESH command from the SIM. The storage unit 3 is composed of, for example, a non-volatile memory, and stores an operating system and applications. The operation and display unit 4 has an input function for accepting input from the user and a display function for displaying various information on a display (for example, a touch panel). The operation and display unit 4 outputs the PIN (an example of an input value) entered by the user to the control unit 5.

The control unit 5 corresponds to a UE defined by 3GPP (registered trademark) and is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory). The control unit 5 performs control to connect to one of the wireless communication networks NWn by the wireless communication unit 2. The control unit 5 also performs contact communication with the SIM via the I/F unit 1. When the control unit 5 receives a REFRESH command from the SIM via the I/F unit 1, it reloads the communication network data in the SIM via the I/F unit 1 and performs a re-search process for the wireless communication network NWn, thereby performing control to connect to one of the wireless communication networks NWn. The communication network data includes authentication information used to connect to the wireless communication network NWn, IMSI (International Mobile Subscription Identity), information on the wireless communication network NWn to be preferentially connected, and the FPLM of the connection prohibition list. If the communication network data includes information about the private wireless communication network NW1 as the wireless communication network NWn to be preferentially connected, the control unit 5 can switch the connection from the currently connected public wireless communication network NW2 to the private wireless communication network NW1 in the coverage area AR1 of the private wireless communication network NW1.

The SIM is compatible with UICC defined by 3GPP (registered trademark), and as shown in FIG. 1, is configured to include an I/F unit 11, a RAM 12, a ROM 13, a NVM (Nonvolatile Memory) 14, and a CPU 15. The I/F unit 11 serves as an interface with the terminal T (control unit 5). The SIM complies with, for example, ISO/IEC 7816, and is basically configured to receive a command APDU from the terminal T and return a response APDU, but while maintaining this configuration, a proactive command is provided as a function for pseudo-sending a command APDU from the SIM to the terminal T. In this embodiment, the above-mentioned REFRESH command, PROVIDE LOCAL INFORMATION command, and TIMER MANAGEMENT command are used as such proactive commands.

The PROVIDE LOCAL INFORMATION command is used when the SIM obtains location information (second location information) of the currently connected wireless communication network NWn from the terminal T (control unit 5). Such location information includes MCC (Mobile Country Code)/MNC (Mobile Network Code)/LAC (Location Area Code) information indicating which wireless communication network NWn it is. Note that LAC can represent a small area such as a city, ward, town, village, or facility. The TIMER MANAGEMENT command is used when the terminal T notifies the SIM that a set time has elapsed. Since the SIM does not measure time, it cannot detect how much time has elapsed, but the SIM can determine the elapsed time by using the TIMER MANAGEMENT command. Note that the TIMER MANAGEMENT command includes the set time.

The NVM 14 (an example of a storage means) is a non-volatile memory such as a flash memory. The NVM 14 stores an operating system, a connection control application (including the program of the present invention) including a USAT (User Subscriber Identity Module Application Toolkit) application, an ICCID (IC Card IDentifier), and the above-mentioned communication network data. In addition, setting information corresponding to the wireless communication network NWn is stored in advance in the records of the EF (Elementary File) of the NVM 14. FIG. 3 is a diagram showing an example of setting information stored in the records of the EF. In FIG. 3, record No. 1 corresponds to the private wireless communication network NW1, record No. 2 corresponds to the public wireless communication network NW2, record No. 3 corresponds to the public wireless communication network NW3, and record No. 4 corresponds to the public wireless communication network NW4. Each piece of setting information is configured by associating the location information of the wireless communication network NWn, whether or not a REFRESH command can be transmitted, and a reference time that is the basis for the setting time set in the TIMER MANAGEMENT command. Note that record No. 5 is unused.

For example, the setting information stored in record No. 1 is composed of location information "123456FF(h)" (4 bytes), whether or not to send a REFRESH command "00(h)" (1 byte), and reference time "000000(h)" (3 bytes) that are associated with each other. Here, the location information "123456FF(h)" indicates the MCC/MNC/LAC information of the private wireless communication network NW1. Whether or not to send a REFRESH command "00(h)" indicates that a REFRESH command will not be sent to terminal T. The reference time "000000(h)" indicates that record No. 1 corresponds to the private wireless communication network NW1. Any time other than the reference time "000000(h)" corresponds to one of the public wireless communication networks NW2 to 4, or is unused (i.e., "FFFFFF(h)"). The setting information stored in record No. 2 is configured by associating location information "98765401(h)" (4 bytes), REFRESH command transmission availability "01(h)" (1 byte), and reference time "001000(h)" (3 bytes). Here, location information "98765401(h)" indicates MCC/MNC/LAC information (e.g., LAC=01) of the public wireless communication network NW2. REFRESH command transmission availability "01(h)" indicates that a REFRESH command is to be sent to terminal T. In the reference time "001000(h)", the first 2 bytes indicate the hour, the next 2 bytes indicate the minute, and the next 2 bytes indicate the second. Therefore, the reference time "001000(h)" corresponds to 16 minutes (decimal number).

The setting information stored in record No. 3 is configured by associating location information "98765402(h)" (4 bytes), whether or not a REFRESH command can be sent "00(h)" (1 byte), and reference time "002000(h)" (3 bytes). Here, the location information "98765402(h)" indicates the MCC/MNC/LAC information of the public wireless communication network NW3 (for example, LAC=02). The reference time "002000(h)" corresponds to 32 minutes (decimal number). The setting information stored in record No. 4 is configured by associating location information "98765403(h)" (4 bytes), whether or not a REFRESH command can be sent "00(h)" (1 byte), and reference time "003000(h)" (3 bytes). Here, the location information "98765403(h)" indicates the MCC/MNC/LAC information of the public wireless communication network NW4 (e.g., LAC=03). The reference time "003000(h)" corresponds to 48 minutes (decimal). In this way, the public wireless communication network NWn corresponding to a cover area farther away from the cover area AR1 of the private wireless communication network NW1 is associated with a longer reference time.

The CPU 15 functions as an acquisition means, a comparison means, and a request means in the present invention. For example, the CPU 15 acquires the location information (second location information) of the currently connected public wireless communication network NWn from the terminal T by transmitting a PROVIDE LOCAL INFORMATION command to the terminal T (control unit 5) in accordance with the connection control application. The CPU 15 then compares the acquired location information with the location information (first location information) of the wireless communication network NWn in the NVM 14. Based on the result of the comparison of the location information, the CPU 15 transmits a REFRESH command to the terminal T to request a connection switch from the currently connected public wireless communication network NW2 to the private wireless communication network NW1. For example, if the result of the comparison of the location information indicates that the acquired location information matches the location information of the public wireless communication network NW2 in the NVM 14, the REFRESH command is transmitted to the terminal T.

On the other hand, if the result of the comparison of the position information shows that the acquired position information does not match the position information of the public wireless communication network NW2 in NVM14, but matches the position information of the public wireless communication network NW3 or NW4, the CPU 15 transmits a TIMER MANAGEMENT command to the terminal T to reacquire the position information of the currently connected wireless communication network NWn from the terminal T after the set time (first set time) set in the TIMER MANAGEMENT command has elapsed. The CPU 15 then recompares the reacquired position information with the position information of the wireless communication network NWn in NVM14. If the result of the recomparison of the position information shows that the reacquired position information matches the position information of the public wireless communication network NW2 in NVM14, a REFRESH command is transmitted to the terminal T.

On the other hand, if the re-comparison of the position information shows that the re-acquired position information does not match the position information of the public wireless communication network NW2 in NVM14 and matches the previously acquired position information (i.e., the terminal T has not moved across the coverage area), the CPU 15 transmits a TIMER MANAGEMENT command to the terminal T with a set time (second set time) longer than the set time (first set time) set in the previous TIMER MANAGEMENT command, thereby re-acquiring the position information of the currently connected wireless communication network NWn from the terminal T after the set time (second set time) has elapsed. Then, the CPU 15 re-compares the re-acquired position information with the position information of the wireless communication network NWn in NVM14. If the re-comparison of the position information shows that the acquired position information matches the position information of the public wireless communication network NW2 in NVM14, a REFRESH command is transmitted to the terminal T. Thereafter, the same process is repeated.

2. Operation at Terminal T
Next, the operation of the terminal T will be described with reference to Figs. 4 to 6. Fig. 4 is a flow chart showing an example of the connection control process of the CPU 15 in the SIM. Fig. 5 is a diagram showing a specific example of the initial sequence performed between the SIM and the terminal T (control unit 5) in step S1 shown in Fig. 4. Fig. 6 is a diagram showing an example of a temporary storage area prepared in the RAM 12 or NVM 14 before the connection control process. In the example of Fig. 6, a location information area M1, a measurement time counter M2, and a REFRESH transmission status area M3 are shown as the temporary storage areas. The location information area M1 stores location information (MCC/MNC/LAC information) acquired from the terminal T. The measurement time counter M2 stores the number of consecutive acquisitions of the same location information. The REFRESH transmission status area M3 stores information indicating whether or not a REFRESH command has been transmitted (for example, not yet transmitted or already transmitted).

The process shown in FIG. 4 is started, for example, when terminal T is started and power is supplied from terminal T, and an initial sequence is executed (step S1). At this time, the SIM initializes all temporary storage areas prepared in RAM 12 or NVM 14 (location information area M1=FFFFFFFF, measurement time counter M2=0, REFRESH transmission status area M3=not transmitted). In the initial sequence, as shown in FIG. 5, terminal T (control unit 5) transmits a RESET to the SIM (step S101). When the SIM receives a RESET from terminal T, it transmits an ATR (Answer To Reset) to terminal T (step S102).

Next, when terminal T receives the ATR from the SIM, it sends a SELECT command to the SIM to select an application (step S103). When the SIM receives the SELECT command from terminal T, it selects the application specified in the SELECT command and sends a response including FCI (File Control Information) and SW:9000 (successful completion) to terminal T (step S104).

Next, upon receiving the response from the SIM, terminal T transmits a READ BINARY/READ RECORD command to the SIM (step S105). Upon receiving the READ BINARY/READ RECORD command from terminal T, the SIM transmits a response including the ICCID, IMSI, FPLM from the connection prohibition list, and SW:9000 (successful completion) to terminal T (step S106). Note that the processes of steps S105 and S106 are repeated for the amount of data required by terminal T.

Next, upon receiving the response from the SIM, terminal T transmits an AUTHENTICATE command to the SIM (step S107). Upon receiving the AUTHENTICATE command from terminal T, the SIM generates a session key for terminal T to connect to the wireless communication network NWn, and transmits a response including the generated session key and SW:9000 (successful completion) to terminal T (step S108).

Next, when terminal T receives a response from the SIM, it sends an UPDATE BINARY/UPDATE RECORD command including authentication data derived from the session key to the SIM (step S109). When the SIM receives the UPDATE BINARY/UPDATE RECORD command from terminal T, it writes the authentication data derived from the session key to NVM14 and sends a response including SW:9000 (successful completion) to terminal T (step S110). The process up to this point is the initial sequence. After that, terminal T sends a STATUS command to the SIM to check whether the SIM is alive (i.e., whether it has not been removed and is in a state where it can respond to commands), and the process of receiving a response including SW:9000 (successful completion) from the SIM is repeated, for example, once every 15 seconds.

In the above initial sequence, in this embodiment, the SIM sends a response to the AUTHENTICATE command that includes the session key and SW:91XX to terminal T. Here, SW:91XX indicates that the SIM contains a PROVIDE LOCAL INFORMATION command with a data length of "XX". Alternatively, the SIM may send a response to the first STATUS command that includes SW:91XX to terminal T. When terminal T receives a response from the SIM that includes SW:91XX, it sends a FETCH command to the SIM.

When the SIM receives the FETCH command from terminal T, as shown in FIG. 4, it transmits a PROVIDE LOCAL INFORMATION command to terminal T to obtain location information (MCC/MNC/LAC information) of the currently connected wireless communication network NWn as a response to the command (terminal response) (step S2). Next, the SIM compares the location information obtained in step S2 with the location information (MCC/MNC/LAC information) stored in the record of the EF of NVM14 (step S3). Next, the SIM identifies a record that stores location information that matches the location information obtained in step S2 as a result of the comparison in step S3 (step S4).

The SIM then determines whether the record identified in step S4 corresponds (or is relevant) to the public wireless communication network NWn (step S5). If it is determined that the record identified in step S4 is not a record that corresponds to the public wireless communication network NWn (i.e., it is record No. 1 that corresponds to the private wireless communication network NW1) (step S5: NO), all temporary storage areas are initialized and the process shown in FIG. 4 ends. On the other hand, if it is determined that the record identified in step S4 corresponds to the public wireless communication network NWn (step S5: YES), the process proceeds to step S6.

In step S6, the SIM determines whether the record identified in step S4 is a record for which a REFRESH command should not be sent. For example, if the REFRESH command sending permission stored in the record identified in step S4 is "00(h)", it is determined that the record is a record for which a REFRESH command should not be sent (i.e., record No. 3 or No. 4) (step S6: YES), and the process proceeds to step S10. On the other hand, if the REFRESH command sending permission stored in the record identified in step S4 is "01(h)", it is determined that the record is not a record for which a REFRESH command should not be sent (step S6: NO), and the process proceeds to step S7.

In step S7, the SIM refers to the REFRESH transmission status area M3 and determines whether or not a REFRESH command should be sent to the terminal T. In other words, it determines whether to switch the wireless communication network NWn immediately or after a certain period of time. For example, if the REFRESH transmission status area M3 = not yet transmitted, it is determined that a REFRESH command should be sent to the terminal T (step S7: YES), and the process proceeds to step S8. On the other hand, if the REFRESH transmission status area M3 = transmitted, it is determined that a REFRESH command should not be sent to the terminal T (step S7: NO), and the process proceeds to step S10.

In step S8, the SIM updates the temporary storage area. For example, if location information has already been temporarily stored in the location information area M1 and the temporarily stored location information does not match the location information acquired in step S2, the temporarily stored location information is changed (overwritten) to the acquired location information. When the temporarily stored location information is changed in this way, the measurement time counter M2 is set to 0. Furthermore, the REFRESH transmission status area M3 is set to transmitted.

Then, the SIM requests a connection switch from the currently connected public wireless communication network NW2 to the private wireless communication network NW1 by sending a REFRESH command to the terminal T (step S9). After that, the SIM returns to step S2 to check whether the coverage area has changed due to the movement of the terminal T or whether the wireless communication network NWn has been switched, and by resending the PROVIDE LOCAL INFORMATION command to the terminal T, the SIM obtains the location information (MCC/MNC/LAC information) of the currently connected wireless communication network NWn and performs the same process as above.

Meanwhile, in response to a request (REFRESH command) from the SIM, terminal T (control unit 5) transmits a READ BINARY/READ RECORD command to the SIM to reacquire communication network data from the SIM and performs a re-search process for the wireless communication network NWn. Then, if terminal T is within the coverage area AR1 of the private wireless communication network NW1, it switches its connection from the currently connected public wireless communication network NW2 to the private wireless communication network NW1. Note that if terminal T is within the coverage area AR2 of the public wireless communication network NW2 but not within the coverage area AR1 of the private wireless communication network NW1, it cannot switch its connection to the private wireless communication network NW1.

In step S10, the SIM updates the temporary storage area. For example, if location information has already been temporarily stored in the location information area M1 and the temporarily stored location information does not match the location information acquired in step S2, the temporarily stored location information is changed (overwritten) to the acquired location information. When the temporarily stored location information is changed in this way, the measurement time counter M2 is set to 1. On the other hand, when the temporarily stored location information is not changed, 1 is added to the value of the measurement time counter M2. Furthermore, the REFRESH transmission status area M3 is set to not transmitted.

The SIM then calculates the setting time to be set in the TIMER MANAGEMENT command by multiplying the reference time stored in the record identified in step S4 by the value of the measurement time counter M2 (step S11). The SIM then sends a TIMER MANAGEMENT command with the setting time calculated in step S11 set to terminal T (step S12), and when the SIM receives a response to the command (terminal response) from terminal T after the setting time has elapsed (i.e., the setting time is measured), it returns to step S2. As a result, the PROVIDE LOCAL INFORMATION command is resent to terminal T, and the location information of the currently connected wireless communication network NWn is obtained, and the same process as above is performed.

Here, we will explain an example of operation assuming that in step S2 in the loop of the connection control process shown in Figure 4, first the location information of the public wireless communication network NW4 is acquired, then the location information of the public wireless communication network NW4 is acquired again, then the location information of the public wireless communication network NW2 is acquired, and finally the location information of the private wireless communication network NW1 is acquired.

In the first step S2, MCC/MNC/LAC=98765403 is obtained, so record No. 4 is identified in step S4, and the process proceeds to step S10 via steps S5: YES and S6: YES. In step S10, the location information field M1=98765403, the measurement time counter M2=1, and the REFRESH transmission status field M3=not transmitted. Next, in step S11, the set time=003000 is calculated based on the reference time=003000 stored in record No. 4 and the measurement time counter M2=1, and in step S12, a TIMER MANAGEMENT command with the set time=003000 set is sent to terminal T.

In the next step S2, MCC/MNC/LAC=98765403 is reacquired, so record No. 4 is identified again in step S4, and the process proceeds to step S10 via steps S5: YES and S6: YES. In step S10, the location information field M1=98765403 (matches the previous time), the measurement time counter M2=2, and the REFRESH transmission status field M3=not transmitted. Next, in step S11, the set time=006000 (=003000*2) is calculated based on the reference time=003000 stored in record No. 4 and the measurement time counter M2=2, and in step S12, a TIMER MANAGEMENT command with the set time=006000 set is sent to terminal T.

In other words, since terminal T, which is within the coverage area AR4 of the public wireless communication network NW4, has not moved outside the coverage area AR4 since the last time location information was obtained by the SIM, a setting time longer than the previous setting time is set in the TIMER MANAGEMENT command and transmitted to terminal T. In this way, if terminal T continues to remain within the coverage area AR4, the setting time is extended each time location information is obtained, thereby reducing the processing load on the SIM.

In the next step S2, MCC/MNC/LAC=98765401 is obtained, so record No. 2 is identified in step S3, and the process proceeds to step S7 via step S5: YES and step S6: NO. In step S7, since the REFRESH transmission status field M3=not transmitted, it is determined that a REFRESH command should be transmitted to terminal T (step S7: YES), and the process proceeds to step S8. In step S8, the location information field M1=98765401 (not the same as last time), the measurement time counter M2=0, and the REFRESH transmission status field M3=transmitted. Next, in step S9, the REFRESH command is transmitted to terminal T.

In the final step S2, MCC/MNC/LAC=123456FF is obtained, so record No. 1 is identified in step S4, and via step S5: NO, the temporary storage area is initialized (location information area M1=FFFFFFFF, measurement time counter M2=0, REFRESH transmission status area M3=not transmitted), and the process ends.

As described above, according to the above embodiment, the SIM is configured to acquire location information of the currently connected public wireless communication network NWn from the terminal T, compare the acquired location information with the location information of the wireless communication network NWn in the NVM14, and request a connection switch from the currently connected public wireless communication network NW2 to the private wireless communication network NW1 based on the result of the comparison of the location information. Therefore, when the terminal T is connected to the public wireless communication network NW2, the connection can be switched to the private wireless communication network NW1 as desired by the user. In other words, when the terminal T is connected to the public wireless communication network NW2 and the terminal T enters the coverage area AR1 of the private wireless communication network NW1, the SIM can switch the connection from the public wireless communication network NW2 to the private wireless communication network NW1.

In the above embodiment, the SIM is configured to request a connection switch from the currently connected public wireless communication network NW2 to the private wireless communication network NW1, but it may also be configured to request a connection switch from the public wireless communication network NW3 to the public wireless communication network NW2. Also, such a request may be made by a command other than the REFRESH command.

1 I/F section 2 Wireless communication section 3 Storage section 4 Operation and display section 5 Control section 11 I/F section 12 RAM
13 ROM
14 NVM
15 CPU
T Terminal NW1 Private wireless communication network NW2 to NW4 Public wireless communication network

Claims (10)

An electronic information storage medium mounted on a terminal connectable to any one of a plurality of different wireless communication networks,
a storage means for storing in advance first location information of at least a specific wireless communication network among the plurality of wireless communication networks;
an acquisition means for acquiring second location information of a currently connected wireless communication network from the terminal;
a comparison means for comparing the first location information with the second location information;
a request means for requesting switching of the currently connected wireless communication network to another wireless communication network based on a result of the comparison by the comparison means;
An electronic information storage medium comprising: The electronic information storage medium according to claim 1, characterized in that the coverage area of the other wireless communication network overlaps with a portion of the coverage area of the specific wireless communication network. The electronic information storage medium according to claim 1, characterized in that the other wireless communication network is a private wireless communication network other than a public wireless communication network provided by a mobile communication carrier. The electronic information storage medium according to any one of claims 1 to 3, characterized in that the request means requests the connection switching when the result of the comparison by the comparison means shows that the first location information and the second location information match. The electronic information storage medium according to any one of claims 1 to 3, characterized in that, if the first location information and the second location information do not match as a result of the comparison by the comparison means, the acquisition means reacquires the second location information from the terminal after a first set time has elapsed, and the comparison means recompares the first location information with the reacquired second location information. The electronic information storage medium according to claim 5, characterized in that, when the result of the re-comparison by the comparison means shows that the first location information and the reacquired second location information match, the request means requests the connection switching. The electronic information storage medium according to claim 5, characterized in that, if the result of the re-comparison by the comparison means is that the first location information does not match the reacquired second location information and the reacquired second location information matches the previously acquired second location information, the acquisition means reacquires the second location information from the terminal after a second set time longer than the first set time has elapsed, and the comparison means re-compares the first location information with the re-acquired second location information. An IC chip mounted on a terminal that can be connected to any one of a plurality of different wireless communication networks,
a storage means for storing in advance first location information of at least a specific wireless communication network among the plurality of wireless communication networks;
an acquisition means for acquiring second location information of a currently connected wireless communication network from the terminal;
a comparison means for comparing the first location information with the second location information;
a request means for requesting switching of the currently connected wireless communication network to another wireless communication network based on a result of the comparison by the comparison means;
An IC chip comprising: A computer included in an electronic information storage medium mounted on a terminal that is connectable to any one of a plurality of different wireless communication networks,
a storage means for storing in advance first location information of at least a specific wireless communication network among the plurality of wireless communication networks;
an acquisition means for acquiring second location information of a currently connected wireless communication network from the terminal;
a comparison means for comparing the first location information with the second location information;
a program causing the program to function as a request means for requesting switching of the connection from the currently connected wireless communication network to another wireless communication network based on a result of the comparison by the comparison means. A connection switching request method executed by an electronic information storage medium mounted on a terminal connectable to any one of a plurality of different wireless communication networks, the electronic information storage medium including a storage means for storing in advance first location information of at least a specific wireless communication network among the plurality of wireless communication networks, the method comprising:
acquiring second location information of a currently connected wireless communication network from the terminal;
comparing the first location information with the second location information;
requesting a switchover from the currently connected wireless communication network to another wireless communication network based on a result of the comparison;
A connection switching request method comprising:

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