Method in mobile telephone systems in which a subscriber identity module (sim) is allocated at least two identities which are selectively activated by the user.

(54) NAME Procedure for telephone systems (56) PUBLICATIONS Cited: --- (57) SUMMARY:

Method in mobile telephone systems, especially of the GSM type, in which a subscriber identity module (SIM) is assigned to at least two identities (IMSI 1, IMSI 2), which are selectively activated by the user. A preferred embodiment of a subscriber identity module is in the form of an active card, which is insertable in two different positions, corresponding to one and the other identity, respectively. The positions preferably refer to one or the other end of the card.

PRV 328 ALLF 138 9 132 AA

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The numbers in brackets indicate the international identification code. INID code Letters within clamps indicate international document code.

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PROCEDURE FOR PHONE SYSTEMS

Technical area

The present invention relates to telephone systems, preferably mobile telephone systems, wherein incoming subscriber units, preferably mobile units or stations, are controlled by a subscriber identity module. More particularly, the invention relates to a method of a telephone system of said kind, wherein the subscriber identity module is utilized in a new way and a subscriber identity module which is particularly suitable for use in connection with the method.

The invention can advantageously be applied in connection with a telephone system of the so-called GSM type (Global System for Mobile Communication). Although the invention is not limited thereto, it will continue to be described with particular reference to a system of this kind.

Technical background

GSM means a uniform, intelligent digital mobile phone system, which is not geographically limited to a country. A subscriber can use an arbitrary subscriber unit (Mobile Station - MS) by controlling it with a subscriber identity module (Subscriber Identity Module SIM), which may be in the form of an active card or plug-in unit, which is inserted into the subscriber unit and provides user identity (IMSI). This is assigned a subscriber number (Mobile Station International ISDN number MSISDN). Information about IMSI and MSISDN and other subscriber information is stored in a home location register (CPR) at the operator of the network in which the subscriber is included. The system includes visitor databases (Visitor Location Register - VLR) and switches (Mobile Services Switching Center - MSC). Information about an activated subscriber unit MS is temporarily stored in the VLR belonging to the area where the subscriber unit MS is located.

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The above-mentioned concepts, as well as the other structure and operation of the system, are subject to far-reaching standardization, which is why a more detailed description thereof should not be required.

A system of the kind mentioned above is used extensively by persons for service calls, but there will also be talk of private calls. Splitting the costs of service and private calls usually poses problems or causes extra work.

The same subscription can also be used by different people, for example within one and the same company. Here, too, the division of costs into the various people can cause problems or cause extra work.

Object of the invention

The object of the present invention is to eliminate the above-mentioned problems and also otherwise allow a more flexible use of subscriptions and subscriber identity modules.

Summary of the Invention

The above object is achieved by a method and a subscriber identity module which exhibit the features set forth in the appended claims.

Thus, the invention is based on an understanding that a subscriber identity module can be assigned to at least two different identities which are selectively activatable by users. As can be seen, for example, there may be two identities (for example, service identity and private identity) for one and the same user, which currently seems to be the preferred case. However, it could also be a matter of different identities corresponding to a number of different persons who may be considered for use of the subscriber identity module.

It is preferred that only one identity can be activated at a time, that is, the change of identity means that previously activated identity must first be deactivated, before the new identity can be considered activated. The home database of 467 559 is preferably brought to store information about which identity is activated, so that call connection, cost data storage etc. can be done correctly.

The subscriber identity module may be arranged so that the selective identity activation, ie selection of identity function in the subscriber identity module, can be effected using keys or the like on the subscriber unit or by means of special means arranged on the subscriber identity module, for example so-called touch contacts in connection with a module in the form of an active card. In this case, activation can be done, for example, in connection with the input of a so-called PIN code. Each respective identity can then be assigned a special code. This means that a number of different users (corresponding to the number of different identities) can share the use of the subscriber identity module in question. It is also possible to allow a user's PIN code to be supplemented with code elements for selecting the desired identity (for example, service or private).

In a preferred embodiment of the subscriber identity module according to the invention, it has the form of an active card arranged to be inserted into the subscriber unit in two different positions, preferably with one and the other end first, each position corresponding to an assigned identity. This gives the possibility of an embodiment in which the respective identity function is clearly marked on the card, while the handling becomes easy. Change of identity is simply done by removing the card and then re-introducing it in the second mode, for example when switching from service call to private call or vice versa.

It will be appreciated that subscriber identity modules according to the invention can be provided with specially programmed circuits which integrally contain the various identity functions, or in parallel, separate identity functions. In connection with an active card with two different modes, this can be achieved very easily later

467 559 by providing a first circuit at one end of the card and a second circuit at the other end of the card with respective associated contact means, all in accordance with the applicable card standard for the location of the contact members, etc. The one side of the card can hereby identify one identity and identify the other side of the card. the other identity.

Regarding the assignment of subscriber numbers in a home database, there are various alternatives according to the invention.

According to a first alternative, the different identities of the subscriber identity module are assigned one and the same subscriber number. The home database is hereby arranged to connect calls to and register cost information etc for the respective current combination of subscriber number and identity. In order for this to happen in an appropriate way, the home database should be given information about which identity is activated. This can be done because only one identity can be activated at a time, whereby in connection with the activation of a new identity, the previous identity is always deactivated with information to the home database. Such deactivation can be achieved, for example, by using a Cancel IMSI type function, which is found in GSM type systems. This deactivation means that information about the identity is removed from the current delete database and that the home database is always informed when the identity is reactivated.

When incoming calls, the call is set against the activated identity, controlled by the information in the home database.

If information on activated identity is missing, an incoming call can first be set against a selected identity of the possible identities. If this selected identity is not activated, call forwarding can take place so that the call is set up against the next possible identity, etc., in accordance with the information in the home database.

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It should be noted that a network operator can modify the function of its home database without conflicting with the standard, which applies, for example, for a GSM-type system.

According to a second alternative, the different identities of the subscriber identity module are assigned to each unique subscriber number. Of these, a particular number is the subscriber's external telephone number, while the other number (s) are only stored in the home database and may be unknown to the subscriber and the general public. It is also appropriate here that only one identity can be activated at a time and that the home database has information on this, for example as in the first option.

In connection with outgoing calls, selected and activated identity is used together with assigned subscriber numbers, in the usual way.

Incoming calls are always set against the identity assigned to the particular subscriber number, provided that this identity is activated. Otherwise, redirection can be made to the subscriber's next subscriber number with associated identity. It will be appreciated that this redirection can take place directly, without any attempt to connect to the first mentioned identity, if the home database has information about which identity is activated.

According to the invention, for the call forwarding, one can advantageously use a function called Call Forwarding Unconditional (CFU), which is a well known standard function and is intended to be controlled by the subscriber. By expanding the home database with a corresponding function, controlled by the network operator, one or more of the subscriber's subscriber numbers can be supplemented for direct call forwarding in the event that the associated identity is not activated and provided that the subscriber himself has not made any other direct call forwarding.

According to a third alternative, which is a further development of the second alternative, two of the subscriber's subscriber numbers constitute external telephone numbers, one of which is suitably

467 559 is a first telephone number and the other a private telephone number. Information about activated identity and mutual direct redirection can be done in the same way as in the second alternative.

Thus, it will be appreciated that the present invention allows a choice of a variety of solutions for a subscriber in terms of different identities and different numbers of external telephone numbers, all utilizing a single subscriber identity module.

The invention will continue to be further described by non-limiting embodiments with reference to the accompanying drawing.

Brief description of the drawing

Fig. 1 is a diagram illustrating very clearly an embodiment of the invention.

Fig. 2 is a diagram of the same kind as in Fig. 1 and. illustrating another embodiment of the invention.

Fig. 3 is a diagram which illustrates very clearly the information flow in connection with identity activation and deactivation according to an embodiment of the invention.

Fig. 4 is an arrangement illustrating a supplement of a home database in accordance with an embodiment of the invention.

Fig. 5 is a flow chart illustrating an example of utilizing a Call Forwarding Unconditional function in accordance with the invention.

Fig. 6 is a schematic plan view of an active card modified for use as a subscriber identity module in accordance with one embodiment of the invention.

Description of Embodiments

Fig. 1 shows schematically how an embodiment of the present invention can be implemented in a GSM mobile telephone system. The home database HLR and the away database VLR communicate with each other as suggested by az «7 crn η-o / υ o?

arrows 1, 3. The remote database VLR has wireless communication with the mobile station MS, which is controlled by a SIM card, which is activatable to give the identity IMSI 1 or IMSI 2. The subscriber number MSISDN corresponds to these. In the home database HLR, information about MSISDN and the association with the two identities IMSI 1 and IMSI 2 is stored.

When activating IMSI 1 or alternatively IMSI 2 by means of the SIM card in the mobile station MS, information on this is transmitted to the home database HLR. This transmits information regarding the current combination MSISDN-IMSI 1 or MSISDN-IMSI 2 to VLR in the usual manner. Calling is then done in the usual way, taking into account the chosen combination.

In Figure 2, another embodiment of the invention is schematically shown, each having the identity IMSI 1 and IMSI 2 assigned to each subscriber number MSISDN 1 and MSISDN 2, respectively, both subscriber numbers being external telephone numbers. For the activated combination MSISDN-IMSI, call connection etc takes place in the usual way.

Figure 3 illustrates the essential steps of the information flow that can be utilized to ensure that the home database HLR has information on which of the identities IMSI 1 and IMSI 2 is activated.

In the initial state (at the top), IMSI 1 is believed to have been activated by inserting the SIM card into the mobile station with one end first. The user now pulls out the card and reinsertes it with the other end first in and for activation of IMSI 2. IMSI 2 is signaled to the remote database VLR, which notes that it is an unregistered IMSI and consequently sends update signals to the home database HLR. CPR stores information that IMSI 2 is activated and deactivates IMSI 1 by sending a signal Cancel IMSI 1. This removes the temporary activation of IMSI 1 in the current remote database VLR, which belongs to the area where the mobile station MS is located. Subsequently, IMSI 2 data is sent to the remote database. It is now ready for call 467 559 connection using the combination MSISDN 2-IMSI 2. When the user again turns on the SIM card, that is, the identity is changed again, a corresponding activation of

IMSI 1 and declassification of IMSI 2.

When incoming calls to the subscriber number, whose identity is not activated, a direct redirect is made to the other subscriber number using Call Forwarding Unconditional. For this purpose, the home database is extended by a field for each subscriber number, as illustrated in Fig. 4. The added field is the bottom field. For MSISDN 1, here is a call forwarding to MSISDN 2 and vice versa. The call forwarding according to these added fields is provided that the user has not initiated any call forwarding of this kind himself, as will be seen in the field immediately above.

The entry in the extra field of the home database is conveniently done simultaneously with the signaling sequence of Figure 3. The entry is exemplified in the flowchart of Figure 5.

In this way, it becomes possible to implement Call Forwarding Unconditional only when the subscriber himself has not requested such redirect to another number. In other words, the subscriber still has the opportunity to use this subscriber service as usual. Otherwise, the home database HLR will provide the call forwarding of a call received to the unactivated combination MSISDN-IMSI to the last activated and registered combination.

It will thus be appreciated that it will be possible for the subscriber to choose from a variety of options: one or two external telephone numbers; automatic forwarding of service calls to the private number and vice versa; independently controlled other call forwarding.

Fig. 6 shows schematically an example of an active card modified in accordance with the invention to provide two identity functions. The card 11 has at its one end in a conventional manner a circuit for providing a first

467 559 identity function, when the card is inserted into a mobile station as indicated by arrow 15. The displayed side of the card may be a service page and be provided with appropriate, clear marking thereon.

The other side of the card is a private page. For this purpose, an aridra completely separate circuit 17 is provided at the other end of the card and on the private side, in accordance with the current standard for circuit and contact location, whereby when using the private side the card must be inserted with said second end first, as indicated by arrow 19 on private page. This can also be provided with appropriate clear identity marking.

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