Method and system for updating an isdn number and an identity code in a cellular digital mobile telephone system

0001METHOD AND SYSTEM FOR UPDATING A ISDN NUMBER AND A IDENTITY CODE IN A CELLULAR DIGITAL MOBILE TELEPHONE SYSTEM

0002TECHNICAL FIELD: The present invention relates to a method of updating data on a mobile phone's SIM, a mobile telephony system for implementing the method, and a SIM adapted to facilitate operation of the method.

0003BACKGROUND OF THE INVENTION: In today^'s vehicles, at least one computerized control unit is normally used for controlling various functions and components in a vehicle. For example, such functions may include the fuel injection and ignition timing of the vehicle^'s engine. Such a control unit is mounted in the vehicle during final assembly of the vehicle.

0004Furthermore, it is common in today^'s vehicles to implement in such a control unit various functions related to mobile radio communication. In this manner, the control unit can be adapted for mobile telephony and on-board navigation and similar functions.

0005Such mobile radio communication functions can furthermore be implemented by arranging a suitable mobile radio communication apparatus in the vehicle. For this reason, a fixed mobile terminal can be mounted in the vehicle during final assembly of the vehicle. In order to allow mobile radio communication, a so-called SIM (Subscriber Identity Module) must also be arranged in the above-mentioned control unit. The SIM is a smart card which comprises information such as for example its International Mobile Subscriber Identity (IMSI). The fact that the SIM is intended to be fixed in the vehicle means that during normal operation, the SIM is never intended to be removed from the vehicle during the lifetime of the vehicle. When a mobile radio communication apparatus, such as a mobile phone or other types of mobile terminals which includes a fixed SIM, is installed in a motor car, at the time of manufacture, the final destination of the car and the mobile phone are usually unknown This means that the mobile network with which the mobile phone will operate, in normal use at its final destination, is unknown Furthermore, "open" SIMs (i e SIMs which are activated and thus are associated with a subscription provided by a network operator) are not acceptable to the vehicle industry for, inter alia, security reasons

0006Thus, the SIM installed in the mobile terminal may well contain data which is inappropriate to the final country of delivery for the car With the GSM cellular mobile telephony system, it would, of course, be possible to operate the mobile phone via the mobile network in the country of origin of the car, by means of the GSM roaming facility This will, however, generate an unacceptable signalling load on mobile telecommunications systems

0007This problem could in principle be solved by modifying subscription information contained in the SIM Various techniques for modifying subscription information contained on a mobile phone SIM, or operating multiple subscriptions are known

0008Japanese patent applications JP 01-300 723 and JP 03-179 936 relate to setting telephone numbers to corresponding service areas by storing a plurality of telephone numbers

0009PCT patent application WO 99/85105 discloses a dual SIM mobile car phone and is directed to a method of ensuring that the permanent SIM is updated on a regular basis with new information

0010PCT patent application WO 98/56201 discloses a method of changing the subscription data on a mobile phone SIM A message is received and date is changed when a mobile station is switched on for the first time with the SIM connected to it Upon receipt of the message, an acknowledgement of receipt of the message is sent, Based on the acknowledgement, the mobile communication system removes the first subscription from the data communication system and from the home location register The acknowledgement is only sent after the SIM has processed the message, thus making sure that the data in the SIM has been changed

0011Consequently, it can be noted that a problem arises in the case where a SIM is permanently mounted in a vehicle and the vehicle is shipped to a final destination country which is not known at the time of manufacturing of the vehicle It can also be noted that the above-mentioned, previously known systems are not adapted for solving this problem in a simple and effective manner

SUMMARY OF THE INVENTION

0013The object of the invention is to provide an improved method of updating data on the SIM being associated with a mobile radio communication terminal, in particular intended for use in the case in which a SIM is mounted in a fixed manner in a vehicle during manufacturing thereof

0014This object is accomplished by means of a method according to subsequent claim 1

0015According to a first aspect of the present invention, there is provided, in a cellular digital mobile telephone system, including at least some mobile transceivers fitted with fixed SIMs having recorded thereon a first identity code and a first ISDN number relating to a first mobile phone operator, a method of updating said first identity code and said first ISDN number, characterised by delivering a second identity code relating to a second operator over an air interface to said given SIM and connecting the second identity code to a second ISDN number at the same time as the first identity code is deactivated, such that no more than one identity code and ISDN number are active on said SIM and any given time

0016Preferably said cellular mobile telephone system is a GSM network

0017Preferably said first and second identity codes are IMSIs and said first and second ISDNs are MSISDNs

0018According to a second aspect of the present invention, there is provided, in a GSM cellular digital mobile telephone system, including at least some mobile transceivers fitted with fixed SIMs having recorded thereon a first IMSI and a first MSISDN relating to a first mobile phone operator, a method of updating said first IMSI code and said first MSISDN, characterised by delivering a second IMSI relating to a second operator over an air interface to said given SIM and connecting the second IMSI to a second MSISDN at the same time as the first IMSI is deactivated, such that no more than one IMSI and MSISDN are active on said given SIM and any given time

0019Said mobile transceivers may be fitted in motor vehicles and said first IMSIs and MSISDNs may be loaded on to said SIMs prior to installation of said mobile transceivers in said motor vehicle Said first and second operators may be located in different countries or different geographic regions

0020According to a third aspect of the present invention, there is provided a digital mobile cellular telephone system characterised in that said digital mobile cellular telephone system is adapted to implement a method as set forth in any previous paragraph

0021According to fourth aspect of the present invention, there is provided a SIM for use in a mobile transceiver, characterised in that said SIM is adapted to implement a method as set forth in any previous paragraph The present invention overcomes these problems by activating the SIM when the car reaches its final destination with an OTA signal The mobile telecommunications industry operates internationally, so the appropriate mobile network operator could be any one of a large number of companies As stated above, it is not economic to have a large number of roaming mobiles in each home country because of the excessive signalling that would be generated

0022None of the above-mentioned previously known documents discloses a procedure in which

0023an IMSI number is held in a SIM, at the time a mobile telephone to which the SIM is fitted is installed in a car, and an MSISDN relating to an operator in the country of manufacture of the car is held on the SIM,

0024when the car is delivered, a new IMSI number, relating to a local operator, is delivered OTA to the SIM,

0025the new IMSI is connected to a new MSISDN at the same time as the old IMSI is deactivated, and

0026no more than one IMSI and MSISDN is active on the SIM at the same time

0027BRIEF DESCRIPTION OF DRAWINGS An embodiment of the invention will now be described with reference to the appended drawings, in which

0028Fig 1 shows schematically how a vehicle such as a motor car is equipped with a SIM, and Fig 2 shows schematically the manner in which data is updated on said SIM, in accordance with the present invention, so as to change the information in the SIM and change the operator to which it is associated

PREFERRED EMBODIMENT

0030An embodiment of the invention will now be described, by way of example

0031In order to facilitate an understanding of the present invention, a glossary of the abbreviations used herein is set out below

0032BC - Bearer Capability

0033BTS - Base Transceiver Station

0034GSM - Global System for Mobile communications GW - Gateway

0035HLR - Home Location Register

0036IMSI - International Mobile Subscriber identification

0037LUP - Locating Update

0038MSISDN - Mobile Subscriber International ISDN number MSC - Mobile services Switching Centre

0039OTA - Over The Air

0040SIM - Subscriber Identity Module (Smart Card)

0041SMSC - Short Message Service Center

0042VIN - Vehicle Identity Number VLR - Visitor Location Register

0043The invention is a method of, and system for, changing the subscription information held on the SIM of a GSM mobile radio communication apparatus, for example a car phone (i e a mobile transceiver) or another type of mobile terminal The invention is particularly, but not exclusively, suitable for use together with a mobile terminal which is intended to be permanently mounted in a car during final assembly of the car When a car fitted with a GSM phone is manufactured In Sweden, say, the phone will have a SIM containing subscription details relating to a Swedish mobile phone operator, such as TELIA Mobile Sweden However, the car may be sold in a territory controlled by another operator, e g Cellnet If the subscription is not changed, the car phone will, for most of the time it is in use, operate in roaming mode This places a heavy signalling load on the mobile networks in which the home location and visitor location registers are located

0044The SIM, in a mobile phone, contains a subscriber identity code in the form of a so-called International Mobile Subscriber Identity (IMSI) and a secret key k, (which is intended to be used for authentication during operation of the mobile terminal) Typically, a mobile telephone network will have a subscriber register for maintaining a register of subscriber identity codes and a message transmission, system for the transmission of messages in the mobile telephone network A record is created in the subscriber register when the first subscription for a subscriber is opened This record comprises a call number specific to the subscription, an encryption code and a subscriber identity code associated with the subscription In addition, services specified for the subscriber in the mobile communication network can be stored in a home location register The home location register contains subscriber specific information relating to the right of use and functions of mobile telephones When the subscriber enters the area of a mobile communication switching centre, the mobile station reports to its visitor location register (VLR) The mobile communication switching centre then fetches the subscriber data from the subscriber's home location register and sends them to the visitor location register of its own area and simultaneously updates the location data for the subscriber

0045As stated above, large mobile communication networks comprise several home location registers Furthermore, the range of subscriber identity codes (IMSI) for a single home location register can be divided into several sections, which means that in respect of control of subscriber identity modules, a single physical subscriber register device may comprise several subscribe registers (different IMSI) ranges)

0046Considering the case of Telia Mobile Sweden, the company distributes GSM mobile phones, with built in SIMs, to Swedish car manufacturers for installation in their cars The eventual destination of the car is unknown and could, for example be the UK, France, or Germany The built in SIM is, of course, loaded with a Swedish IMSI - the International Mobile Subscriber Identity, a code which identifies the mobile telephone to a mobile network This IMSI is used for the first update of the SIM

0047After the SIM has been updated, Telia Mobile Sweden downloads a new IMSI number over the GSM air interface, i e OTA, together with a new MSISDN for an appropriate local operator in the territory, or country, where the car is located If appropriate, the SIM can be updated a second, third, etc , time with new IMSI numbers and MSISDNs, again over the GSM air interface, if another operator is to be used

0048It should be noted that, at the present time, most mobile phone operators work on a national basis and have roaming agreements with operators in other countries The present invention provides, inter alia, a SIM which supports OTA and, thereby, facilitates downloading of new IMSI numbers and MSISDNs, thus supporting greater international connectivity

0049The invention will now be described in greater detail with reference to the appended drawings, in which Fig 1 shows how a vehicle 1 is equipped with a particular SIM 2 and Fig 2 shows the manner in which subscription information being stored on the SIM is changed in accordance with the invention Fig 1 indicates in a schematical manner that said vehicle 1 is equipped with a SIM 2 during final assembly of the vehicle 1 More precisely, the SIM 2 is normally arranged as a fixed component forming part of an electronic control unit 3 which is arranged in the vehicle 1 together with other vehicle components such as the chassis and body structure 4 The control unit 3 is used in the vehicle for controlling, for example, the injection timing and the fuel injection of the vehicle^'s 1 engine The control unit 3 is also adapted for radio communication To this end, it comprises a mobile radio communication terminal of the above-mentioned kind In a manner which is known per se, said SIM 2 is used in such a mobile terminal

0050After final assembly of the vehicle 1 , it can be shipped to other countries, for exemple to Denmark (indicated by means of reference numeral 1 a) or to Italy (indicated by means of reference numeral 1 b) As mentioned initially, this situation gives rise to certain problems, in particular due to the fact that the final destination country for the vehicle 1 is normally not known at the time of final assembly

0051The SIM 2 is "personalized", i e it is provided with a predetermined IMSI number (International Mobile Subscriber Identity) It is also provided with its secret authentication key k, and its OTA key, which is another key used by the company issuing the SIM 2, during transmission between said company and the SIM 2

0052The SIM 2 is supplied to the car manufacturer in question and is mounted in the corresponding car 1 , i e in its control unit 3 The IMSI number and the corresponding vehicle identity number (VIN) are stored in a database of the company supplying the SIM At this stage, the SIM 2 cannot yet be used

0053Furthermore, when the car 1 is finally assembled and ready for delivery from the factory, its control unit 3 is mounted However, the radio communication operation of the control unit 3 is not yet activated At this stage, it can be assumed that the final destination of the car i e the country in which it is eventually sold, is not yet known However when the car 1 has finally reached its final destination, the company distributing or selling the car sends a request to the above-mentioned supplying company to carry out a change of the subscription information in the SIM This is because it is now desired that the SIM 2 be associated with an appropriate "domestic" network operator, i e an operator which is located in its final destination country

0054Fig 2 indicates in greater detail how the information of the SIM 2 is shifted, so that the SIM and, as a result, the mobile terminal in the car 1 can be associated with a particular network operator in the final destination country However, the invention is not limited for use in such a manner that the new network is located in another country A principle behind the invention is that the SIM 2 is initially associated with a first, initial network operator and that the information in the SIM 2 can be shifted so as to be associated with an additional (second, third or further) network operator It can be noted that the first, initial network operator is normally not intended to allow normal radio communication via the mobile terminal in question The initial network is preferably a first temporary "operator" which is subsequently changed for a second operator when the vehicle has reached its final destination In this regard, and for the purpose of describing the present invention, it is assumed that the car is assembled in Sweden and then shipped to Italy, in order to be sold in Italy

0055The initial International Mobile Subscriber Identity (IMSI) code of the mobile terminal is referred to as "IMSI-A" This IMSI-A code is associated with a particular Mobile Station ISDN Number (MSISDN), which in this case is referred to as "MSISDN-A" This operation is carried out by the company which supplies the SIM and which is indicated by means of reference numeral 5 in Fig 2 This company 5 is normally cooperating with different network operator in various countries Each foreign operator will then accept and store (in their Home Location Registers) certain IMSI codes which can be used when assigning the SIM 2 to a new operator in its final destination country

0056When the mobile terminal in the car is to be used for the first time in its final destination country (in this case Italy), it will use its IMSI-A in order to issue a so-called Locating Update (LUP) from its position in Italy (reference numeral 6) This LUP is sent via a Base Transceiver Station (BTS) 7 to a Mobile services Switching Centre (MSC) 8 in Italy The MSC 8 will indicate that no information regarding the SIM in question is registered in its Visitor Location Register (VLR) For this reason, the MSC will signal the IMSI-A to Sweden so as to indicate that said LUP has been made (reference numeral 9) This will be carried out via a second Mobile services Switching Centre (MSC) 10 in Italy This MSC comprises a so-called Gateway (GW), which in this regard will operate as a transit or relay station During this stage, the VLR address will also be signalled The second MSC 10 will forward this message to a corresponding, third MSC 11 in Sweden This third MSC 11 also comprises a Gateway, and is arranged for forwarding the message to the correct Home Location Register 12 in the country of origin (i e in this case Sweden) of the car 1 , i e the HLR which is associated with the IMSI-A

0057The HLR 12 with which the SIM is associated comprises information regarding the MSIDSN-A code corresponding to the SIM in question, and also information regarding any occurring Bearer Capability (BC) This information is transmitted back to Italy, to the MSC 8 in which the above- mentioned Visitor Location Register is arranged (reference numeral 13) As a result, the MSC 8 in Italy updates its VLR with information regarding the identity of the Swedish Home Location Register 12 as well as information regarding the MSISDN-A and the BC This will result in the MSC VLR 8 transmitting a new Locating Update to the mobile terminal in the car 1 (reference numeral 14) At this stage also, the company 5 supplying the SIM transmits data regarding a new IMSI number (referred to as "IMSI-B") intended for a local network operator in Italy (reference numeral 15) This message is preferably sent via a Short Message Service Center (SMSC) 16 As mentioned above the HLR 18 in Italy has previously been supplied with the IMSI-B codes It has also been supplied with MSISDN-B codes which are associated with said IMSI-B codes These IMSI-B and MSISDN-B codes have consequently been reserved for the local network operator in Italy

0058Furthermore, the company supplying the SIM transmits data instructing the mobile terminal in the vehicle 1 to shift the contents in the SIM from IMSI-A to IMSI-B and to reboot the mobile terminal (reference numeral 17)

0059After rebooting, the mobile terminal makes a new Locating Update (LUP) This time, the LUP will be made using IMSI-B The IMSI-B is associated with a HLR 18 located in Italy This means that the HLR 18 in Italy sends back a LUP, including information related to the subscription and MSISDN-B to the VLR More precisely, the HLR 18 will uppdate the MSC VLR 8 upon request from the MSC/VLR 8, which in turn will be initiated when the mobile terminal sends its LUP Consequently, the mobile terminal in the vehicle 1 b is now updated with changed subscription information and is associated with a new network operator in Italy

0060Consequently, according to the invention, subscription information held on the SIM of a GSM phone, particularly a car phone, can be changed When a car fitted with a GSM terminal is manufactured in for example Sweden, the terminal will have a SIM containing subscription details relating to a Swedish mobile phone operator However, the car may be sold in a territory controlled by another operator If the subscription is not changed, the car phone will, for most of the time it is in use, operate in roaming mode As has been explained, the present invention overcomes these problems by activating the SIM when the car reaches its final destination with an OTA signal The SIM will then be associated with an additional, local network in its final destination

0061The invention is not limited to the embodiment described above, but may be varied within the scope of the appended claims Although the present invention has been described with reference to a GSM mobile telephone system, it has application to digital cellular mobile telephone systems compliant with other standards Equally, the use of the present invention is not limited to car phones, but can be applied to any mobile phone, having a built in SIM, which is distributed in a territory unknown at the time of manufacture, and/or for use with a network operator unknown at the time of manufacture