FR2778302A1 - CELLULAR NETWORK MOBILE TELEPHONE FOR USE AS A CORDLESS TELEPHONE FOR HOME USE - Google Patents

Abstract

The invention concerns a mobile telephone designed for communicating through said cellular network (101) and comprising means matching with a wireless telephone private base (30) designed to communicate through another telephone network (100). The mobile telephone (20), thus designed to operate either in cellular mode, or in private mode as a wireless telephone handset apparatus, comprises means (1, 17) for selecting one of the two modes, cellular or private. The means for communicating through the cellular network comprising means for the telephone to be authenticated by the cellular network, the selection means are designed, when the private mode is selected, to inhibit the means for the telephone to be authenticated by the cellular network.

Description

MOBILE TELEPHONE OF A CELLULAR NETWORK,

  USABLE IN WIRELESS TELEPHONE HANDSET A

DOMESTIC USE --

  The field of the invention is that of mobile telephony.

  In mobile telephony, there are essentially two types of telephone.

  The telephones of the first type are cordless telephones, for private use, domestic use, comprising a base and at least one mobile handset paired with the base. The base is connected to a telephone network, the PSTN switched telephone network for example, generally by wired link, and the handset

  mobile is connected to the base by radio link.

  i5 Telephones of the second type are arranged to communicate via a cellular telephone network of base stations, generally by radio link. As an example of cellular networks, one can cite the

GSM, DCS 1800 networks, etc.

  To make a cellular network mobile phone operational, it is generally advisable to introduce a card supporting an electronic chip there, it is generally a standard SIM card, containing authentication data of the telephone through which the network cellular is capable of controlling the access of the telephone to the cellular network so as, in particular, to bill its communications. Without a SIM card, the

phone is unusable.

  A cellular network mobile phone offers great freedom of movement, as the cellular network has wide geographic coverage, while wireless phone usage is limited to the vicinity of the base. On the other hand, for cost reasons, it may be more advantageous, in the vicinity of the base of the cordless telephone, to use it in order to go through the network to which it is connected, rather than

through a cellular network.

  The invention proposes to take advantage of the specific advantages of wireless telephony, which are essentially cost advantages, as well as of those of cellular telephony which essentially reside in mobility. To this end, the invention relates to a mobile telephone of a cellular telephone network comprising means for communicating through said cellular network, characterized in that it comprises means of pairing with a private wireless telephone base. arranged to communicate through another telephone network and, the mobile telephone being thus arranged to operate either in cellular mode, or in private mode like telephone handset of the cordless telephone, provision is made for

  means of selecting one of the two modes, cellular and private.

  0o One can thus use the telephone either, in a traditional way, in cellular mode and, in this case, one passes by the cellular network, or in private mode, like handset of cordless telephone domestic and, in this other case, one passes via the wireless telephone network. Thanks to this, in the vicinity of the base of the cordless telephone, one can switch to private mode in particular in order to take advantage of the lower cost of communications through the

wireless phone network.

  Advantageously, the selection means are arranged, in the case of selection of the private mode, to inhibit the means for communicating to

through the cellular network.

  Advantageously also, the means for communicating through the cellular network comprising means for authenticating the telephone by the cellular network and the selection means are arranged, in the case of selection of the private mode, to inhibit the authentication means of the

  cell phone.

  In private mode, the mobile phone of the cellular network thus functions

  ordinary telephone handset associated with the base of the cordless telephone.

  We transform the mobile phone into a telephone handset

cordless phone.

  In a particular embodiment, the base pairing means comprise means for authenticating the mobile phone by the

based.

  This avoids the risk of a malicious third party using the database without

be authorized to do so.

  Preferably, the telephone comprises means for executing a

  initial identification registration protocol with the base.

  Advantageously, the mobile telephone includes means for, if necessary, notifying the cellular network of the selection of the private mode. More preferably, the means of authentication by the cellular network comprise a support card for a memory for storing authentication data. By inhibiting the authentication means, the telephone is made usable with or without an authentication card, whereas in the prior art it was not

operational than with this card.

  The invention also relates to a private cordless telephone base arranged to communicate through a telephone network, base comprising means for communicating with at least one telephone handset by air link, characterized in that it comprises pairing means with a mobile telephone, such as that defined above, arranged to communicate through another telephone, cellular network, for use of the mobile telephone, in private mode, such as

  cordless telephone handset, paired with the base.

  Advantageously, the pairing means comprise means

  authentication of the telephone by the base.

  The invention finally relates to a method of pairing between, on the one hand, a mobile telephone, such as that previously defined, arranged to communicate through a telephone, cellular network, and, on the other hand, a private base, such as defined above, of a wireless telephone arranged to communicate through another telephone network, process during which the mobile telephone identifies itself with the base which controls access

  from the mobile telephone to another telephone network.

  The invention will be better understood using the following description of the

  mobile telephone and cordless telephone base, according to a particular embodiment of the invention, and of a particular embodiment of the method of the invention, with reference to the appended drawing in which: - Figure 1 shows a functional block diagram of the mobile telephone, according to the particular embodiment; FIG. 2 represents a functional block diagram of the base according to the particular embodiment and FIG. 3 represents a diagram of the mobile telephone, of the private base and

  two telephone communication networks.

  The mobile telephone 20 is intended to communicate through a cellular network 101, in this case a GSM network, comprising a plurality of

0o base stations.

  The mobile telephone 20 comprises, in a conventional manner, a human-machine interface comprising an input keyboard 1, a display screen 2, a microphone 3, a speaker 4 and a memory 5 containing a man-machine interface software comprising including menus and

  commands to display on the display screen 2.

  The loudspeaker 4 is connected to a decoding block 6 for digital / analog conversion, itself connected to a channel decoder 7 for the selection of a communication channel. The microphone 3 is connected to an analog / digital conversion encoder 8, itself connected to an encoder

  channel 9 for selecting a communication channel.

  The encoder 7 and the decoder 9 are respectively connected to a radio reception block 10 and to a radio transmission block 11, both connected to a radio antenna 12. The reception block 10 and the transmission block 1 1 have two operational radio frequencies, one specific to cellular telephony for using the telephone in cellular mode, and the other specific to wireless telephony for using the telephone in private mode,

  domestic, as will be explained later.

  A control block 15, to which all the elements of the mobile telephone 20 are connected, is provided for controlling the operation of the mobile telephone 20. The mobile telephone 20 further comprises a housing for receiving a card supporting an electronic chip, in this case a standard SIM card 13, and connectors 16 for linking the chip to the telephone, and more precisely to a switch 17, explained below. The chip contains in memory authentication data of the mobile phone 20 by the cellular network 101, an authentication protocol by the cellular network

  101 and a GSM communication protocol.

  In addition, the mobile telephone 20 comprises a memory block 14 containing authentication data of the mobile telephone 20 by the private base 30 of FIG. 2, a pairing protocol with the base 30, a communication protocol with the base 30 , in this case the standard wireless telephony protocol CT2, and an initial identification registration protocol with the base 30. The pairing protocol comprises

  1o an encryptor, an encryption program using an encryption key.

  Finally, the memory 14 and the electronic chip of the SIM card 13 are connected to the control block 15 with the interposition of the switch 17 which is a switch with two positions: a cell mode position and a private mode position. In the cellular mode position, the switch 17 connects the electronic chip of the SIM card 13 to the control block 15, via the connector 16, and, in the private mode position, it connects the

  memory 14 to the control block 15 thereby inhibiting the SIM card 13.

  The input keyboard 1 comprises two keys for selecting cellular mode and private mode respectively, under the control of which the switch 17 switches either to the cellular mode position or to the private mode position, and a key for activating the protocol.

  initial identification registration with base 30.

  The mobile telephone 20 is thus arranged to operate either in cellular mode, in other words in a conventional manner by radio link with the cellular network 101, and more precisely by radio link with a base station of the cellular network 101, or in private mode, by air link, here radio, with the private base 30, as will be more precisely explained below. The private base 30 is a home cordless telephone base, intended to be paired with a cordless telephone handset. The term "cordless telephone" is intended to denote the assembly comprising the domestic base 30 and the telephone handset connected to each other by air link, here radio. The wireless telephone is arranged to communicate through a telephone network 100 other than the cellular network 101 of the mobile telephone 20,

  in this case the switched telephone network PSTN 100.

  The base 30 includes a line interface 31 connected on one side to the PSTN network, by wire connection, and on the other side to a codec 32 comprising an analog / digital conversion encoder 33 and a decoder of

  digital / analog conversion 34.

  The base 30 also includes a channel switching matrix 35 comprising an encoder 36 for selecting the channel for radio transmission and a decoder 37 for selecting the channel for radio reception, the base 30 here comprising eight channels, or channels communication between base 30 and a telephone handset using one of the eight channels

temporal.

  The routing matrix 35 is connected to a radio transmission / reception unit 38 comprising a radio transmitter 39 connected to the encoder 36 and a radio receiver connected to the decoder 37. A radio antenna 41 is connected to the block

radio transmission / reception 38.

  The base 30 also comprises a memory block 42 containing an initial registration protocol for identifying the mobile phone 20, a pairing protocol with the mobile phone 20, authentication data for the mobile phone 20 and a communication protocol. wireless telephony, in this case the standard CT2 protocol. The matching protocol includes an encryption program,

  identical to that of the mobile telephone 20.

  Finally, a control block 43 is provided to which all the elements of the base 30 are connected, and intended to control the operation of the base 30.

  After the structural description of mobile phone 20 and base 30,

  their operation will now be described.

  Initial registration of identification of the mobile telephone 20 by the base To communicate through the PSTN network 100, via the private base 30, with the mobile telephone 20, the mobile telephone 20 must first identify and register with of the base 30. For this, the user of the cordless telephone presses the key for activating the initial registration protocol with the base 30, and brings the telephone closer

  mobile 20 near the base 30.

  The mobile telephone 20 and the base 30 dialog with each other and, during this dialog, execute the initial recording protocol

  o0 identification of telephone 20 by base 30.

  It will be recalled here that the mobile telephone 20 and the base 30 communicate with each other by radio link, at a radio frequency specific to wireless telephony, the blocks 10 and 11 of radio reception and radio transmission of the mobile telephone 20 and the transmit / receive block 38 of the base 30 using a radio frequency specific to wireless telephony. For confidentiality reasons, the registration procedure is carried out at low power. During the recording, the mobile telephone 20 provides the base 30 with its identity, contained in the memory 14, and the latter assigns it in return

  a secret identification key, constituting an encryption key.

  The identity and the secret identification key of the telephone 20 are recorded in the memory block 14 of the mobile telephone 20 as well as in the block

memory 42 of base 30.

  The mobile telephone 20 thus contains, in its memory block 14, its identity associated with the secret identification key allocated by the base 30, the identity and the secret key constituting authentication data of the telephone 20 by the base 30 Similarly, the base 30 contains, in its memory block 42, the identity of the mobile telephone 20 associated with the secret key which

has been assigned to it.

  Operation of the mobile telephone in cellular mode To communicate through the cellular network 101, a user of the telephone selects the cellular mode using the specific key on the input keyboard 1 and, under the control of this selection, the switch

  17 switches to cell mode position.

  In cellular mode, the mobile telephone 20 operates in a conventional manner, like an ordinary mobile telephone. Using the content of the electronic chip of the SIM card, the mobile telephone 20 executes the authentication protocol by the cellular network 101 by supplying the latter with its authentication data, in order to be authenticated by the cellular network 101. After authentication, the mobile telephone 20 can communicate with a correspondent, through the cellular network 101, using the GSM communication protocol and the radio frequency specific to the

1o GSM network.

  Operation of the mobile telephone in private mode In order to communicate through the PSTN network 100, and when it is in the vicinity of the private base 30, in the coverage area thereof, the user of the mobile telephone 20 selects the private mode using the

  specific key on the input keyboard 1.

  Under the control of the selection of the private mode, the switch 17 being in the cellular mode position, the mobile telephone 20 sends to the cellular network 101 a warning signal, accompanied here by the telephone call number of the base 30 on the network PSTN 100, previously recorded in memory block 14, to command the cellular network 101 to switch incoming calls addressed to the mobile telephone 20 through the cellular network 101, on the private base 30, that is to say to the number

  call transmitted via the PSTN 100 network.

  Under the control of the control block 15; the switch 17 is then switched to the private mode position so as to connect the memory block 14 to the

  control block 15 and to inhibit the SIM card 13.

  Then the mobile telephone 20 and the base 30 pair with one another, by executing the pairing protocol contained, on the base side 30, in the memory block 42, and, on the telephone side, in the memory block 14. During this pairing step, the telephone 20 identifies itself with the base 30 by supplying it with its identity contained in the memory block 14. The base 30 compares this identity with that contained in the memory 42 and, the identity provided by the mobile telephone 20 being identical to that stored in the base 30, the latter sends in response to the mobile telephone 20 a number

9 2778302

  random. The mobile telephone 20 and the base 30 both encrypt the random number each by means of the common encryption program and using the key as the encryption key.

  identification code assigned to mobile phone 20 by base 30.

  After encrypting the random number provided by the base 30, the mobile telephone 20 sends it back to the base 30 in its encrypted form, and the base 30 compares it to the result which it itself obtained by encryption. In the event of identity, the base 30 validates the access of the mobile telephone 20 to the base 30 and

therefore to the PSTN 100 network.

  The mobile telephone 20, paired with the base 30, functions as a cordless telephone telephone handset, the cordless telephone being understood, it is

  recalls here, of the assembly comprising the base 30 and the mobile telephone 20.

  During a communication, through the PSTN network 100, between the mobile telephone 20 and a correspondent, via the private base 30, the base 30 receives, by the PSTN network 100, the information originating from the correspondent and retransmits it, by its radio antenna 41, to the mobile telephone 20. The base 30 moreover receives, by its radio antenna 41, information transmitted by the mobile telephone 30 and retransmits it to the correspondent, through the PSTN network 100. During the communication between base 30 and mobile phone 20, base 30 and mobile phone 20 communicate with each other using the CT2 communication protocol. Everything happens as if the mobile phone 20 were a simple cordless telephone handset paired with the base 30 and communicating with

her over the radio.

  In the event of an incoming call for the mobile telephone 20, on the cellular network 101, the latter, previously warned of the passage of the mobile telephone 20 in private mode, directs the call to the private base 30, through the PSTN network 100 Upon receiving the call, the user "picks up" the line by pressing a specific key on the keypad of the mobile phone 20 and communicates with the caller, through the PSTN network 100 and through the base. 30, using mobile phone 20 as a

  cordless telephone handset paired with base 30.

  In the event of an outgoing call, the user dials the number on the keypad of the mobile telephone 20 and establishes a communication with a correspondent, through the PSTN network 100, via the private base 20, the

2778302

  mobile phone 20 functioning as a cordless telephone handset

matched to the private base 20.

  During a communication between the mobile telephone 20, paired with the base 30, and a correspondent, through the PSTN network 100, the base 30 plays a role analogous to that of a base station of a cellular network 101, to which the mobile telephone 20 connects, by radio link, to communicate through the cellular network 101. The base 30 acts as a private base station of the PSTN network, to which the mobile telephone 20 connects to communicate either with through its usual network, but at

  through another network, in this case the PSTN 100 network.

  Note that the mobile phone 20, in private mode, can be used

  with or without the SIM card inserted in the phone 20.

  In the event of an outgoing call, instead of pressing a specific key for selecting the operating mode of the mobile telephone, one could consider adding a distinctive element to the telephone number dialed on the mobile telephone keypad. example the element "*" prefixed to the normal telephone number. In this case, the phone would be able to recognize the element "*" and interpret it as a

  private mode selection command.

  Of course, the base could contain in memory the authentication data of a plurality of mobile telephones capable of pairing with the base and authorized to access the PSTN network 100 through it. The base could also be paired with ordinary telephone handsets, that is to say unable to communicate through

  another network than the base.

  In the description which has just been made, it has been provided that the telephone and

  the base 30 communicate with each other using the CT2 wireless telephone protocol. We could consider that they use another wireless telephone communication protocol, a communication protocol

  cell phone or any other communication protocol.

  In place of memory block 14, containing the authentication data of the mobile telephone by the private base, the base pairing protocol, the communication protocol with the base and the initial identification registration protocol with the internal base of the mobile telephone 20, on lh 1 2778302 could provide a memory, of electronic chip for example, supported by a card intended to be inserted in a removable manner in the telephone,

as it is for card 13.

  Finally, in the particular example of the above description, the telephone

  mobile is arranged to communicate through a cellular 101 GSM network and the private base is arranged to communicate through the PSTN 100 network. The invention obviously applies to a mobile telephone arranged to communicate through any other cellular network and to a

  io base arranged to communicate with any other telephone network.

12 2778302

Claims (12)

  1- Mobile telephone of a cellular telephone network comprising means (13, 6-12) for communicating through said cellular network (101), characterized in that it comprises means for pairing with a private base (30 ) a cordless telephone arranged to communicate through another telephone network (100) and, the mobile telephone (20) being thus arranged to operate either in cellular mode or in private mode as a cordless telephone telephone, provision is made of   means (1, 17) for selecting one of the two modes, cellular and private.   2- Telephone according to claim 1, wherein the selection means (1, 17) are arranged, in case of selection of the private mode, to inhibit the   means (13, 6-12) for communicating through the cellular network (101).   3- Telephone according to one of claims 1 and 2, wherein the means   (13, 6-12) for communicating through the cellular network (101) comprising means (13) for authentication of the telephone by the cellular network (101) and the selection means (1, 17) are arranged, in the event selection of the private mode, to inhibit the means (13) of authentication of the   telephone via the cellular network (101).   4- Telephone according to one of claims 1 to 3, wherein the means   matching base (30) include means for authenticating the   mobile telephone (20) via the base (30).   - Telephone according to claim 4, comprising means for executing an initial identification registration protocol with the base (30).   6- Telephone according to one of claims 1 to 5, comprising means   to, if necessary, notify the cellular network (101) of the selection of the private mode.   7- Telephone according to one of claims 3 to 6, wherein the means   cellular network authentication (101) include card   support (13) for storing memory for authentication data. 13 2778302   8- Private cordless telephone base arranged to communicate through a telephone network (100), base (30) comprising means for communicating with at least one telephone handset by air link, characterized in that it comprises means ( 42) matching   with a mobile telephone (20), according to one of claims 1 to 7, arranged   to communicate through another cellular telephone network (101), for use of the mobile telephone (20), in private mode, such as   cordless telephone handset, paired with base (30).   9. Base according to claim 8, in which the pairing means comprise means for authenticating the telephone (20) by the base (30). - Base according to claim 9, comprising recording means   initial telephone identification (20).   11- Method of pairing between, on the one hand, a mobile telephone (20),   according to one of claims 1 to 7, arranged to communicate through a   telephone network (101), cellular network, and, on the other hand, a private base (30),   according to one of claims 8 to 10, a cordless telephone arranged for   communicate through another telephone network (100), process in which the mobile telephone (20) identifies itself to the base (30) which controls the access of the mobile telephone (20) to said other telephone network (100).   12- The method of claim 11, wherein, during an initial registration step, the mobile phone (20) registers its identity at the base (30).   13- The method of claim 12, wherein during said initial registration step, the base (30) assigns to the mobile telephone (20) a secret encryption key.   14- The method of claim 13, wherein during the pairing of the mobile phone (20) and the base (30), the base (30) transmits to the mobile phone (20) a random number as the mobile phone (20 ) and the base (30) both encrypt, using said secret encryption key, the mobile telephone (20) transmits the random number thus encrypted to the base (30) which compares it to number that she obtained herself and, in case 14 2778302   identity, authorizes access from the mobile telephone (20) to said other network telephone (100).   - Method according to one of claims 11 to 14, wherein, in case   incoming call intended for the mobile telephone (20), on the cellular network (101), the latter switches the call to the private cordless telephone base (30)   through said other telephone network (100).