Method and arrangement for communicating subscriber related data in a wireless communications system

[0002] The present invention relates to an arrangement for communication of subscriber identity module related data in a wireless communication system. The arrangement comprises at least one wireless communication terminal with a subscriber identity unit which is adapted to comprise a subscriber identity module to which a subscriber identity is assigned. The present invention also relates to a station comprising a subscriber identity unit. The present invention also relates to a method for communication of subscriber identity module related data in a wireless communication system for implementation in a wireless communication terminal with a subscriber identity unit.

[0003] A subscriber identity is assigned to a terminal in a wireless communication system which uses a subscriber identity media. The wireless communication system determines, via a subscriber identity module (SIM) attached to the terminal, whether or not a subscriber requesting a communication service is a subscriber qualified to receive communication services which the system provides.

[0004] The term ‘terminal’, which also is referred to as a wireless communication terminal, includes all portable radio communication equipment to which a subscriber identity is assigned such as a mobile telephone, a communicator, i.e. a so called electronic organiser, or the like. The wireless communication system can for instance be any cellular mobile phone system such as GSM (Global System for Mobile Communications) or any satellite telecommunication system.

[0005] The SIM will now be described as implemented in a GSM network wherein the SIM is implemented as a card having a ROM (Read Only Memory), a RAM (Read Access Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), a processor unit and an interface to the terminal. The memory of the SIM provides storage of the subscriber identity which is the International Mobile Subscriber Identity (IMSI) in a GSM network. The terminal can only be operated if a valid SIM is present except for emergency calls, when operation is allowed anyway. The SIM supports a security function for verification of the user of the terminal and for authentication of the user to the GSM network; the SIM is able to handle a personal identification number (PIN) which consists of 4 to 8 digits. If an incorrect PIN is entered to the terminal, an indication is given to the user of the terminal. After three consecutive incorrect entries the SIM is blocked. Blocking of a SIM puts it into a status which forbids GSM network operations. The SIM also contains information elements for GSM network operations. These elements can be related to the mobile subscriber, GSM services and information related to the public land mobile network (PLMN).

[0006] In a wireless communication system as described above it is convenient if the wireless communication system allows more than one terminal to share the same subscriber identity without having to pay for more than one subscription.

[0007] EP 711,090 describes a radio communication system wherein a plurality of subscriber identity modules implemented as cards and to be mounted to mobile stations share a single international subscriber identity. Consequently, a radio communication system capable of using a plurality of subscriber identity media sharing a single subscriber identity information is provided. This allows two or more different mobile stations to use the same international mobile subscriber identity without that the user have to pay for more than one subscription.

[0008] WO 94/08433 also describes a radio communication system which allows more than one mobile station to use the same international mobile subscriber identity without that the user have to pay for more than one subscription.

[0009] Though the above mentioned related art describe wireless communication systems which allow more than one terminal to share the same subscriber identity without having to pay for more than one subscription, there is a main disadvantage with the subscriber identity modules described in the above mentioned related art. The subscriber identity module may also be a carrier of other features than those previously described, such as being a card for economical transactions. Hence, the subscriber identity module may also be for instance a credit card and/or a cash card. If so, it is a disadvantage to have the subscriber identity module attached to the terminal. There is a further disadvantage with the subscriber identity modules described in the above mentioned related art. Information, such as mails and information in the address book and the calendar of a mobile station, saved on different subscriber identity modules attached to different mobile stations has to be synchronized in order not to diverge.

[0010] The general problem dealt with by the present invention is to provide an arrangement and a method for communication of subscriber identity module related data for a wireless communication terminal in a wireless communication system.

[0011] A more specific problem dealt with by the present invention is to provide an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals which share a common subscriber identity, wherein the subscriber identity is assigned to one of the wireless communication terminals at a time.

[0012] A further more specific problem dealt with by the present invention is to provide an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals to which the same subscriber identity is assigned simultaneously.

[0013] A further more specific problem dealt with by the present invention is to provide an arrangement and a method for communication of subscriber identity module related data for a wireless communication terminal in a wireless communication system wherein the subscriber identity module is separated from the wireless communication terminal while the wireless communication terminal is communicating in the wireless system.

[0014] The problem is solved essentially by an arrangement for communication of subscriber identity module related data in a wireless communication system. The arrangement comprises a wireless communication terminal and a subscriber identity unit. The subscriber identity unit, which includes a subscriber identity module to which a subscriber identity is assigned, is arranged to communicate the subscriber identity module related data with the terminal over a local wireless communication link.

[0015] The arrangement according to the present invention makes it possible to separate the subscriber identity unit from the terminal while the terminal is communicating in the wireless system.

[0016] More specifically, the present invention also relates to a station comprising a subscriber identity unit.

[0017] More precisely, the present invention also relates to a method for implementation in a wireless communication terminal with a subscriber identity unit in a wireless communication system.

[0018] A general object of the present invention is to provide an arrangement and a method for communication of subscriber identity module related data for a wireless communication terminal in a wireless communication system.

[0019] It is another object of the present invention to provide an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals which share a common subscriber identity, wherein the subscriber identity is assigned to one of the wireless communication terminals at a time.

[0020] It is a further object of the present invention to provide an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals to which the same subscriber identity is assigned simultaneously.

[0021] It is a further object of the present invention to provide an arrangement and a method for communication of subscriber identity module related data which allow separating the subscriber identity unit from the terminal while the terminal is communicating in the wireless system.

[0022] A general advantage afforded by the present invention is that an arrangement and a method for communication of subscriber identity module related data for a wireless communication terminal in a wireless communication system are provided.

[0023] A more specific advantage afforded by the present invention is that an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals which share a common subscriber identity, wherein the subscriber identity is assigned to one of the wireless communication terminals at a time, are provided.

[0024] A further more specific advantage of the present invention is that an arrangement and a method for communication of subscriber identity module related data for at least two wireless communication terminals to which the same subscriber identity is assigned simultaneously, are provided.

[0025] A further more specific advantage afforded by the present invention is that an arrangement and a method are provided which allow two or more users of wireless communication terminals to use the same subscriber identity without having to pay for more than one subscription. Also, it is convenient that the same phone number can be used by more than one wireless communication terminal.

[0026] A further more specific advantage afforded by the present invention is that an arrangement and a method for communication of subscriber identity module related data for a wireless communication terminal in a wireless communication system wherein the subscriber identity module is separated from the wireless communication terminal while the wireless communication terminal is communicating in the wireless system are provided.

[0027] A further more specific advantage afforded by the present invention is that a user of a wireless communication terminal does not have to insert the subscriber identity module into the terminal.

[0028] A further more specific advantage afforded by the present invention is that a user of a wireless communication terminal can more easily alter which subscriber identity that shall be assigned to the terminal.

[0029] A further more specific advantage afforded by the present invention is that information saved on the subscriber identity module, such as mails and information in the address book and the calendar of a terminal, can be used by two or more users of wireless communication terminals.

[0030] The invention will now be described more in detail below with reference to the appended drawings which illustrate various aspects of the invention by means of embodiments. The invention is not limited to these embodiments.

[0031] FIG. 1 is a general schematic view of a wireless communication system in which a wireless terminal is located;

[0032] FIG. 2 illustrates in a block scheme a subscriber identity module;

[0033] FIG. 3 illustrates in a block scheme an embodiment of the present invention with a subscriber identity terminal including a subscriber identity unit;

[0034] FIG. 4 illustrates in a block scheme an embodiment of an inventive arrangement with a wireless communication terminal and a subscriber identity terminal;

[0035] FIG. 5 illustrates in a block scheme two inventive arrangements with two wireless communication terminals and one wireless station comprising a subscriber identity unit;

[0036] FIG. 6aillustrates in a block scheme a base station and two inventive arrangements with two wireless communication terminals and one subscriber identity unit;

[0037] FIG. 6billustrates in a diagram a signalling communication according to the present invention between a base station and two wireless communication terminals and between the two wireless communication terminals and one subscriber identity unit;

[0038] FIG. 7 illustrates in a block scheme an embodiment of an inventive arrangement with a wireless communication terminal and a wireless station comprising a subscriber identity unit;

[0039] FIG. 8 illustrates in a flowchart a method according to the present invention for communication of subscriber identity module related data in a wireless communication system;

[0040] FIG. 9 illustrates in a diagram a signalling communication according to the present invention between a wireless communication terminal, a subscriber identity unit and a base station of a wireless communication system.

[0041] FIG. 1 is a general schematic view of a part of a wireless communication system 101 which is a GSM network. The geographical area covered by the wireless communication system 101 is divided into cells C1-C5. Each cell C1-C5 provides radio coverage in a certain area and is allocated a certain set of frequencies for communication in that area.

[0042] Each cell C1-C5 is served by one base station BTS1-BTS5, called base transceiver station (BTS) in GSM terminology. The base transceiver stations are provided with means for transmitting to and receiving from a wireless communication terminal 403. The terminal 403 is currently located in the cell C1 in FIG. 1. The cell C1 in which the terminal 403 is currently located is called the serving cell and the base transceiver station BTS1 serving that cell is called the serving base transceiver station.

[0043] The terminal 403 comprises means for communication with the base transceiver stations BTS1-BTS5 in the wireless communication system 101 and is used by a subscriber to get access to the communication services provided by the wireless communication system 101. Each group of base transceiver stations is controlled by a base station controller BSC1-BSC2. A number of base station controllers BSC1-BSC2 are controlled by a mobile services switching centre MSC. The mobile service switching centre MSC is responsible for switching calls to and from mobile stations located in the area served by the mobile services switching centre MSC.

[0044] When a call is being established to or from the terminal 403, a communication channel CH dedicated for communication between the terminal 403 and the serving base transceiver station BTS1 is allocated for the call.

[0045] The switching centre MSC is adapted to control the traffic within a GSM network, and also between this network and other networks connected thereto, such as a public telephone network PSTN (Public Switched Telephone Network) or a GSM network of another operator (not shown in FIG. 1).

[0046] Two different registers are also connected to the switching centre MSC, namely a home location register HLR containing information on the system's own subscribers, and a visitor location register VLR containing information on active, and consequently registered, visitors found in the coverage area of the GSM network. A visitor is either a home subscriber or a subscriber associated with another GSM operator. The information in the visitor location register VLR is always retrieved from the subscriber's home location register HLR and includes a subscriber identity 902 (see FIG. 9) making it possible to positively identify and address a visitor. In a GSM network the subscriber identity is called the International Mobile Subscriber Identity (IMSI). If a registered visitor ceases to be active in the network associated with the visitor location register VLR, the information of him found in the visitor location register can be erased, in order to be retrieved from the home location register HLR if he becomes active again.

[0047] A billing administration support system BASS might be connected to the switching centre MSC, to the home location register HLR and to the visitor location register VLR. The billing administration support system BASS is an operator service that supports billing administration if a subscriber identity module 201 (see FIG. 2) of the terminal 403 is used as a credit card or a cash card.

[0048] The wireless communication system 101 according to the present invention is not limited to a GSM network. It can for instance be any cellular mobile phone system such as a PCS network, any satellite telecommunication system or any other wireless communication system where the subscriber identity 902 is assigned to each wireless communication terminal which is active in the system. The access method used in a GSM network is time division multiple access (TDMA). However, in a wireless communication system according to the present invention any other access method is applicable such as frequency division multiple access (FDMA) or code division multiple access (CDMA).

[0049] FIG. 2 illustrates in a block scheme a subscriber identity module 201.

[0050] The previously known subscriber identity module 201 in FIG. 2 is described as implemented in a GSM network wherein the subscriber identity module 201 is implemented as a card having a read only memory ROM, a read access memory RAM, an electrically erasable programmable read only memory EEPROM, a processor unit CPU and an interface to the terminal I/O. The memory of the subscriber identity module 201 provides storage of the subscriber identity 902 (see FIG. 9) which is the International Mobile Subscriber Identity IMSI in a GSM network. The terminal 403 can only be operated if a valid subscriber identity module 201 is present except for emergency calls, when operation is allowed anyway. The subscriber identity module 201 supports a security function for verification of the user of the wireless terminal 403 and for authentication of the user to the network. The subscriber identity module 201 is able to handle a personal identification number PIN which consists of 4 to 8 digits. If an incorrect PIN is entered to the terminal 403, an indication is given to the user of the terminal 403. After three consecutive incorrect entries the subscriber identity module 201 is blocked. Blocking of a subscriber identity module 201 puts it into a status which forbids GSM network operations.

[0051] FIG. 3 illustrates in a block scheme an embodiment of the present invention with a subscriber identity terminal 302 including a subscriber identity unit 303 and a power supply 301. Both the subscriber identity terminal 302 and the subscriber identity unit 303 respectively are hereinafter also referred to as a station. The station is a device which comprises at least the subscriber identity unit and can hence be the subscriber identity unit itself.

[0052] The subscriber identity unit 303 comprises a subscriber identity module 201aand a first communication means 304. The first communication means 304 is a transceiver for communicating different types of data (see FIG. 9) with a second communication means 401 of the wireless communication terminal 403 (see FIG. 4).

[0053] The power supply 301 provides the subscriber identity module 201aand the transceiver with power.

[0054] FIG. 4 illustrates in a block scheme an embodiment of an inventive arrangement 1 with the wireless communication terminal 403 and the subscriber identity terminal 302 including a subscriber identity unit 303aaccording to the present invention. The wireless communication terminal 403 and the subscriber identity terminal 302 are separated from each other. By separated is hereinafter meant at least electrically separated, but in a preferred embodiment of the present invention is meant both electrically and physically separated.

[0055] The subscriber identity terminal 302 and the subscriber identity unit 303arespectively are also referred to as a station. As mentioned previously, the station is a device which comprises at least the subscriber identity unit.

[0056] The wireless communication terminal 403 can for instance be a portable radio communication equipment such as a mobile station i.e. a mobile phone, a pager, a communicator, i.e. a so called electronic organizer, or the like. The wireless communication terminal can as well be a non portable radio communication equipment such as a telefax, a personal computer or an electronic organizer. The wireless communication terminal 403 can for instance be used for transmission and reception of voice, data or video.

[0057] The wireless terminal 403 comprises a second communication means 401. By means of the second communication means 401 which is a transceiver, the wireless terminal communicates different types of data (see FIG. 9) over a local wireless communication link 404 with the first communication means 304 of the subscriber identity unit 303acomprised in the subscriber identity terminal 302. The local wireless communication link 404; 404a; 404b; 404c; 404dis defined as a local link between the first communication means 304 of the subscriber identity unit 303; 303a; 303b; 303c; and a transmitter and/or receiver locally positioned nearby the subscriber identity unit. In FIG. 4 and in a preferred embodiment of the present invention, the transmitter and/or receiver locally positioned nearby the subscriber identity unit is the second communication means 401 comprised in the wireless communication terminal 403. However, in another embodiment of the present invention a transceiver not comprised in the wireless communication terminal 403 is locally positioned nearby the subscriber identity unit (this embodiment is not shown in any Figure). In this embodiment the transceiver locally positioned nearby the wireless communication terminal 403 is transmitting, i.e. repeating, the signal received via the local wireless communication link to the second communication means 401 of the wireless terminal 403.

[0058] In FIG. 4, the wireless terminal 403 comprises the second communication means 401 and a transceiver 402. The terminal 403 communicates via the transceiver 402 with the wireless communication system 101 (see FIG. 1). However, in another embodiment of the present invention the transceiver 402 for communication with the wireless communication system 101 is incorporated in the second communication means 401 of the terminal 403.

[0059] The local wireless communication link 404 can for instance be within a radio frequency range. In an embodiment of the present invention the local wireless communication link 404 is within the frequency range of approximately 2.4 GHz. The local wireless communication link 404 can also be within an infrared frequency range. However, the local wireless communication link can be any wireless link such as an electromagnetic link, a magnetic link or an inductive link. Examples of electromagnetic links are links within the mircowave frequency range, the radio frequency range or the optic frequency range.

[0060] However, there is not much radio spectrum available for these kind of (private) applications. For instance, in the United States, the ISM (Industrial, Scientific, Medical) bands at 900 MHz, 2.4 GHz, and 5.7 GHz are unlicensed, and can be used freely, provided the transmission power levels are low or spreading is applied. The 2.4 GHz band is even available globally. In order to avoid interference, spreading should be applied, either by frequency-hopping or direct-sequence spread spectrum.

[0061] Assume that the embodiment of the present invention wherein the 2.4 GHz ISM band, which reaches from 2400 MHz to 2483,5 MHz, is used for the wireless local communication link 404. In order to avoid sharp filters to fulfil out-of-band emission requirements, the applied radio band is preferably placed away from the ISM band edges. Known interference areas, like the section from 2435 MHz to 2465 MHz where micro-wave ovens are operating, are preferably avoided as well. FSK (Fast Shift Keying) can be used to map a user code on the radio frequency carrier. In the FSK modulation scheme, a bit representing ‘zero’ is mapped to the frequency f_RF+Δf and a bit representing ‘one’ is mapped to the frequency f_RF−Δf (the opposite is also possible) where f_RFis the carrier frequency. The frequency deviation Δf should be large enough to combat the frequency offset between transmitter and receiver. For example, if sloppy frequency references with an accuracy of ±PPM (part per million) are used, the worst-case frequency offset can reach up to 240 kHz. In order to receive the burst in this case, the frequency deviation Δf should be larger than 240 kHz.

[0062] The local wireless communication link 404 is encrypted in order to establish a secure wireless communication link that hinders third party interception of sensitive information.

[0063] It shall be mentioned that it is possible to insert at least one repeater (not shown in any Figure) that repeats the information transferred via the wireless communication link 404 between the first communication means 304 and the second communication means 401.

[0064] In an embodiment of the present invention the subscriber identity module 201a(see FIG. 3), comprised in the subscriber identity terminal 302, carries additional features which makes it possible to use the subscriber identity terminal as a credit card or a cash card. It is an advantage if the subscriber identity module 201acarries many features. The billing administration support system BASS (see FIG. 1) then supports billing administration. In this embodiment, it is an advantage of the present invention that the subscriber identity module 201ais separated from the wireless terminal 403, since it then for instance is possible to carry the subscriber identity module 201acomprised in the subscriber identity terminal 302 in a wallet.

[0065] FIG. 5 illustrates in a block scheme two inventive arrangements 1a; 1bwith two wireless communication terminals 403a; 403band a common subscriber identity unit 303bwhich are separated from each other.

[0066] The subscriber identity unit 303bis comprised in a station 403cwhich is a wireless communication terminal. As mentioned previously, the station is a device which comprises at least the subscriber identity unit. The subscriber identity unit 303bis connected to internal circuits 601 of the wireless terminal 403c. The internal circuits 601 include a controller.

[0067] The arrangement 1acomprises the subscriber identity unit 303band the wireless communication terminal 403awhich is a telefax. The wireless terminal 403acomprises both a transceiver 501afor communication in a wireless communication system such as GSM and also a second communication means which is a transceiver 401afor communication with the subscriber identity unit 303b.

[0068] The other arrangement 1bcomprises the subscriber identity unit 303band the wireless communication terminal 403bwhich is an electronic organizer. The wireless terminal 403bcomprises both a transceiver 501bfor communication in a wireless communication system such as GSM and also a transceiver 401bfor communication with the subscriber identity unit 303b.

[0069] The subscriber identity module 201 (see FIG. 2) of the subscriber identity unit 303bcan either function as a subscriber identity module to the wireless terminal 403cor as a subscriber identity module to one of the two arrangements 1a; 1b, wherein the subscriber identity unit 303bcommunicates over a local wireless link 404a; 404bwith one of the two wireless terminals 403a; 403b. In an embodiment of the present invention one of the terminals 403a; 403bget under control of the subscriber identity unit 303bwhen one or both of the transceivers 401a; 401bdetect the presence of the remote subscriber identity unit 303b. In a wireless communication system 101, this results in that all communication with a base transceiver station BTS1 over a communication channel uses either the transceiver 501aor the transceiver 501b(see FIG. 1). In another embodiment of the present invention wherein the wireless terminal 403aand the wireless terminal 403bare physically close to each other, for instance closer than 10 meters to each other, they can have a mutual precedence regarding which one of the terminals 403a; 403bthat shall respond to an incoming call from a base station. However, both of the terminals 403a; 403bshall establish a communication over the local wireless link 404a; 404bwith the subscriber identity unit 303b.

[0070] An incoming call from a base station to a wireless terminal 403a; 403bwill be routed to the terminal 403a; 403bthat get under control of the subscriber identity unit 303b.

[0071] In an embodiment of the present invention, the subscriber identity unit 303bcomprises information in a memory 502 about which wireless communication terminals 403a; 403bthat have the authority to communicate the subscriber identity module related data 901 (see FIG. 9) over the local wireless communication link 404a; 404bwith the subscriber identity unit 303b. In a GSM network the International Mobile station Equipment Identity (IMEI) is used to uniquely identify the wireless terminals 403a; 403b. The subscriber identity unit 303bmay also contain information about the mutual precedence regarding which one of the terminals 403a; 403bthat shall respond to an incoming call from a base station. The mutual precedence may vary depending on which type of services that an incoming call from a base station to a wireless terminal 403a; 403bprovides; for instance there may be a first mutual precedence for voice services, a second mutual precedence for data services such as short message services SMS and a third mutual precedence for telefax services. For instance an incoming telefax call may be answered automatically by the tele-fax 403a. The mutual precedence may either be determined automatically by the subscriber identity unit 303bor manually by a user. The mutual precedence may be determined manually by a user via a user interface (not shown in FIG. 5) of either the subscriber identity unit 303bor of one of the wireless terminals 403a; 403b; 403c. A subscriber identity of an incoming call may also determine the mutual precedence.

[0072] The mutual precedence regarding which one of the terminals 403a; 403bthat shall send an outgoing call from the wireless terminal 403a; 403bto a base station may be determined in accordance with which one of the transceivers 401a; 401bthat is first to establish communication over a local wireless link 404a; 404bwith the subscriber identity unit 303b. Accordingly the mutual precedence regarding reading information from and/or writing information on the subscriber identity module 201 (see FIG. 2) may be determined in accordance with which one of the transceivers 401a; 401bthat is first to establish communication over the local wireless link 404a; 404bwith the subscriber identity unit 303b. Such information may for instance be information in the address-book or Short Message Services.

[0073] In an embodiment of the present invention both the terminals 403a; 403bcommunicate in the wireless communication system 101 simultaneously wherein both the terminals 403a; 403bestablish communication over both the local wireless links 404a; 404bsimultaneously. In this embodiment particular identity information attached to each terminal 403a; 403b, which is the International Mobile station Equipment Identity (IMEI) in a GSM network, is used to distinguish the terminals 403a; 403bfrom each other.

[0074] In a preferred embodiment of the present invention, the memory 502 is protected by means of the personal identification number PIN (see FIG. 2). If information stored in the memory 502 about a terminal is to be deleted or if information about yet another terminal (not in FIG. 5) beside the terminals 403a; 403bis to be added to the memory 502, the personal identification number PIN must first be entered for instance via a keypad.

[0075] FIG. 6aillustrates in a block scheme a base station BTS1 and two inventive arrangements 1c; 1dwith two wireless communication terminals 403; 403fand one subscriber identity unit 303a.

[0076] The subscriber identity unit 303ais comprised in a station 302 which is a subscriber identity terminal 302. The subscriber identity terminal 302 comprises the first communication means 304 which is a transceiver.

[0077] The inventive arrangement 1ccomprises the subscriber identity unit 303aand the wireless communication terminal 403 which is a mobile phone. The mobile phone comprises the second communication means 401 and the transceiver 402. The mobile phone communicates via the transceiver 402 over a communication channel CHa with the base transceiver station BTS1 of the wireless communication system 101 (see FIG. 1). The mobile phone communicates via the second communication means 401 over a local wireless communication link 404cwith the first communication means 304.

[0078] The inventive arrangement 1dcomprises the subscriber identity terminal 302 and the wireless communication terminal 403fwhich is an electronic organizer. The electronic organizer comprises the second communication means 401aand a transceiver 402a. The electronic organizer communicates via the transceiver 402aover a communication channel CHb with the base transceiver station BTS1 of the wireless communication system 101 (see FIG. 1). The electronic organizer communicates via the second communication means 401aover a local wireless communication link 404dwith the first communication means 304.

[0079] It shall be mentioned that several wireless communication terminals (two terminals 403; 403fin FIG. 6) can communicate with one subscriber identity unit 303a. Also one and the same terminal can communicate with different subscriber identity units (not shown in any Figure). Hence, it is possible for several different subscribers of different subscriber identity units to communicate in a wireless communication system 101 (see FIG. 1) even if only one wireless terminal is used.

[0080] FIG. 6billustrates in a diagram an inventive signalling communication between the base station BTS1 and the two wireless communication terminals 403; 403fand between the two wireless communication terminals 403; 403fand the subscriber identity unit 303a. The base station BTS1, the two wireless communication terminals 403; 403fand the subscriber identity unit 303aare illustrated in a block scheme in FIG. 6a. For voice-communication, the wireless terminal 403 which is a mobile phone is a master over the subscriber identity unit 303aand over the wireless terminal 403fwhich is an electronic organizer. Accordingly, for data- and telefax-communication, the electronic organizer 403fis a master over the subscriber identity unit 303aand over the wireless communication terminal 403 which is a mobile phone.

[0081] In the signalling communication diagram illustrated in FIG. 6bthe local wireless link 404c(see FIG. 6a) between the mobile phone 403 and the subscriber identity unit 303aand also the local wireless link 404dbetween the electronic organizer 403fand the subscriber identity unit 303aare already established.

[0082] FIG. 6billustrates a signalling communication for a data-call between the base station BTS1 and the electronic organizer 403f. In a first step 601ba request for a data-call from the base station BTS1 to the mobile phone 403 is made. In a next step 602ba data-call notification from the mobile phone 403 to the subscriber identity unit 303ais made. In a next step 603ba data-call notification from the subscriber identity unit 303ato the electronic organizer 403fis made. In a next step 604bthe subscriber identity unit 303ais signalling to the mobile phone 403 that the subscriber identity unit 303ais busy. In a next step 605bthe electronic organizer 403fanswers the data-call from the base station BTS1. During the step 605bsubscriber identity module related data 901 such as the subscriber identity 902 is communicated. In a signalling communication in a GSM network as in FIG. 6b, the subscriber identity 902 is the International Mobile Subscriber Identity (IMSI). In a next step 606ba data-call signalling communication is set-up between the electronic organizer 403fand the base station BTS1. In a next step 607ba data-call signalling communication is set-up between the electronic organizer 403fand the subscriber identity unit 303a. When the data call is to terminate, the data-call signalling communication between the electronic organizer 403fand the subscriber identity unit 303ais hang-up in a next step 608b. In a next step 609bthe data-call signalling communication between the electronic organizer 403fand the subscriber identity unit 303ais hang-up. Finally, in a next step 610b, the subscriber identity unit 303ais signalling to the mobile phone 403 that the subscriber identity unit is idle.

[0083] FIG. 7 illustrates in a block scheme an inventive authentication arrangement 1ewith a wireless communication terminal 403eand a subscriber identity unit 303cwhich are separated from each other.

[0084] The subscriber identity unit 303cis comprised in a station which is the wireless communication terminal 403d. As mentioned previously, the station is a device which comprises at least the subscriber identity unit. The subscriber identity unit 303cis connected to internal circuits 601 of the wireless terminal 403d. The internal circuits 601 include a controller.

[0085] The subscriber identity unit 303ccomprises the first communication means 304 which is a transceiver. The transceiver 304 communicates over the local wireless link 404cwith the transceiver 401 of the wireless terminal 403e. The wireless terminal 403eincludes a voice activity detector VAD which is connected to an external microphone 602. Also an external speaker 603, an external processor 604, an external antenna 605, an external keypad 606 and an external display 607 are connected to the wireless terminal 403e. The external processor 604 includes a Ground Positioning System GPS which registers the position of the wireless communication terminal 403e.

[0086] The subscriber identity module 201a(see FIG. 3) of the subscriber identity unit 303ccan either function as a subscriber identity module to the wireless terminal 403dor as a subscriber identity module of the authentication arrangement 1e. In an embodiment of the present invention the wireless terminal 403eget under control of the subscriber identity unit 303 when the transceiver 401 detects the presence of the remote subscriber identity unit 303c. In a GSM network, this results in that all communication with the base transceiver station BTS1 over a communication channel CH uses the antenna 605 (see FIG. 1).

[0087] The wireless communication terminal can for instance be installed in a car wherein the transceiver 401, the microphone 602, the speaker 603, the processor 604, the antenna 605, the keypad 606 and the display 607 are all equipment of the car. Dialling, answering and other operations can be made by either using the keypad 606 built into the car or by voice control using the microphone 602 built into the car. Alternatively, a keypad of the wireless terminal 403dcan be used for dialling, answering and other operations. It is an advantage that an excellent hands-free environment is achieved in the car. It is a further advantage that no cables or electronics are necessary to use in order to connect the equipment of the car to the wireless terminal 403e, i.e. it is a further advantage that the wireless terminal 403edoes not have to be physically connected to the equipment of the car.

[0088] FIG. 8 illustrates in a flowchart a method according to the present invention for communication of subscriber identity module related data 901 (see FIG. 9) in a wireless communication system. The reference signs referred to in the following text are found in the previous Figures.

[0089] The method in FIG. 8 starts at a start position 801. In a next step 802 the subscriber identity 902 is assigned to the subscriber identity module 201. In a next step 803 the subscriber identity unit 303 is separated from the first wireless communication terminal 403. In a next step 804 communication is established over the local wireless communication link 404 between the first communication means 304 of the subscriber identity unit 303 and the second communication means 401 of the first wireless communication terminal 403. In a next step 805 subscriber identity module related data 901 is communicated via the first communication means 304 arranged in the subscriber identity unit 303 with the second communication means 401 arranged in the first wireless communication terminal 403 over the local wireless communication link 404. Finally, the method ends in an end position 806.

[0090] FIG. 9 illustrates in a diagram a signalling communication between the wireless communication terminal 403, the subscriber identity unit 303aand the base station BTS1 of the wireless communication system 101 which is a GSM network (see FIG. 1).

[0091] The base station BTS1, the wireless communication terminal 403 and the subscriber identity unit 303aare illustrated in a block scheme in FIG. 6a.

[0092] In a first step 903 and a second step 904 the subscriber identity unit 303aand the wireless terminal 403 are inititating communication with each other over the local wireless link 404 (see FIG. 4). Subscriber identity module related data 901 such as the subscriber identity 902 is communicated during the steps 903 and 904. Also, the wireless communication terminal 403 is given authentication to communicate in the wireless communication system 101 during the steps 903 and 904. Also, the wireless communication terminal 403 is assigned to be the default terminal for incoming calls from the base station BTS1, i.e. incoming calls from the base station BTS1 will be routed to the wireless communication terminal 403, during the steps 903 and 904. In a signalling communication in a GSM network as in FIG. 9, the subscriber identity 902 is the International Mobile Subscriber Identity (IMSI). In a next step 905 a communication is established via the local wireless link 404c(see FIG. 6a) between the subscriber identity unit 303aand the wireless terminal 403.

[0093] In a next step 906 a call is made from the base station BTS1 to the wireless communication terminal 403. In a next step 907 the wireless communication terminal 403 answers the call from the base station BTS1. Finally, in a next step 908, a call signalling communication is set-up between the base station BTS1 and the wireless communication terminal 403.

[0094] It shall be mentioned that the subscriber identity module (see FIG. 3) of the subscriber identity unit 303acontains different types of data; the subscriber identity 902, temporary network data and service related data. The subscriber identity 902 has been entered by the network operator and can not be changed by the user. Temporary network data, such as location information, is updated by the wireless terminal 403 with information sent by the network. Service related data, such as abbreviated dialling numbers, is handled by the user when access conditions are fulfilled.