ALTERNATIVE ROUTING SYSTEM FOR MOBILE TELEPHONE CALLS

• US 20030114186A1
• Filed: 03/18/1998
• Published: 06/19/2003
• Est. Priority Date: 03/26/1996
• Status: Active Grant

• Current Assignee: British Telecommunications PLC (BT Group PLC)
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: GOETZ, IAN
• Granted Patent: US 6,643,523 B2
• Time in Patent Office: Days
• US Class Current: 455/552.1
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A cellular telephone is provided with a connector for connecting it to an interface unit. The interface unit can exchange speech and data signals with the telephone as well as providing power. When the telephone is connected to the interface unit, its antenna is effectively disabled. The interface unit provides a link between the telephone and a BTS via a communication path other than the cellular telephone system'"'"'s conventional cell arrangement. The communication path can include telephone or ISDN connections, leased lines, point-to-point microwave links or coaxial cable. In the cases of telephone and ISDN lines and leased lines, baseband speech and data signals pass between the telephone and the interface unit and a modem is used to transmit and receive these signals over the communication path. If a microwave link or coaxial cable is used, RF speech and data signals may be passed between the telephone and the interface unit. A single interface unit may be used to provide connections for a plurality of telephones.

Claims

1. (AMENDED) A cellular telephone system comprising an additional communication path (17, 75, 84) independent of the system of cells of the cellular telephone system, between a mobile telephone (1,61) and a cellular telephone call-switching system (21,26,27,87,90,92), the communication path comprising an interface means (11,41,42a . . . 42h;

71;

79) for providing a communications connection between a mobile telephone and the cellular telephone call-switching system so as to by-pass the telephone'"'"'s radio antenna (3,67).

2. A cellular telephone system according to claim 1, wherein the interface means communicates with the mobile telephone by means of an optical or ultrasonic communications link (96,98).

3. A cellular telephone system according to claim 1, wherein the interface means communicates with the mobile telephone by means of an electrical connection (7,16;

7,46;

65,73).

4. A cellular telephone system according to claim 1, 2 or 3, wherein the interface means provides a communications connection (16,45,98) to the mobile telephone for baseband speech and control data signals.

5. A cellular telephone system according to claim 4, wherein the interface means comprises a modem (14,50).

6. A cellular telephone system according to claim 5, wherein the communications path comprises a switched network.

7. A cellular telephone system according to claim 5, wherein the communications path comprises a fixed point-to-point signal path.

8. A cellular telephone system according to claim 6 or 7, wherein the interface means (41,42a . . . 42h;

71;

79) is arranged for providing communications connections for a plurality of mobile telephones to the call switching system and the bandwidth of the communications path is sufficient for a plurality of simultaneous calls.

9. A cellular telephone system according to claim 1 or 3, wherein the interface means provides a communications connection (74) with the r.f. circuitry (64) of a mobile telephone for r.f. speech and data signals.

10. A cellular telephone system according to claim 9, wherein the communication path includes a transmission line (75) and the interface means comprises means (74,76,77) for connecting said r.f. circuitry to the transmission line.

11. A cellular telephone system according to claim 10, wherein the communication path comprises a point-to-point microwave link (84, 86) and transposer means (80) for transposing the signals on the transmission line (75) to the operating band of the microwave link, and for transposing signals received from the microwave link to the operating band of the mobile telephone and applying them to the transmission line (75).

12. A cellular telephone system according to claim 9, 10 or 11, wherein the interface means (71a . . . 71c;

78) provides a connection to the transmission line (75) from the r.f. circuitry of a plurality of mobile telephones.

13. An interface apparatus for providing a communications connection between a mobile telephone (1) and a cellular telephone call-switching system (21,26,27) so as to by-pass the telephone'"'"'s radio antenna (3), the apparatus comprising a first connector (16,46,73,98) for exchanging speech and data signals with a cellular mobile telephone, a second connector for connecting the apparatus to a transmission line (17,52,75) and means for exchanging said speech and data signals via the second connector.

14. An interface apparatus according to claim 13, wherein the first connector (16, 46, 73) communicates with the mobile telephone by means of an electrical connection (7,16;

7,46;

65,73).

15. An interface apparatus according to claim 14, further comprising power supply means (15,45,72) for supplying electrical power to the mobile telephone through the first connector (16,46,73).

16. An interface apparatus according to claim 13, wherein the first connector (98) is arranged for exchanging speech and data signals by means of an optical or ultrasonic carrier.

17. An interface apparatus according to any of claims 13, 14, 15 or 16 wherein the first connector (16,46,98) is arranged to exchange baseband signals with the mobile telephone, and the means for exchanging said signals via the second connector is a modem (14,50).

18. An interface apparatus according to claim 17, including control means (12,47) and dialling means (14,50), wherein the control means is responsive to cellular telephone data signals from the first connector to cause the dialling means to output telephone or ISDN dialling signals via the second connector.

19. An interface apparatus according to claim 17 or 18, comprising one or more further connectors (46) for exchanging speech and data signals with further cellular mobile telephones, and a multiplexer (49) for multiplexing signals from the first and further connectors, wherein the modem (50) is arranged for transmitting the output of the multiplexer (49).

20. (AMENDED) A telephone for a cellular telephone system including processing circuitry (4) and an externally accessible connector (7, 96), the connector being coupled to the processing circuitry to exchange baseband speech and data signals therewith, and having radio frequency transceiver circuitry (2) for coupling to the processing circuitry to exchange baseband speech and data signals therewith, the processing circuitry including means for detecting whether the externally accessible connector (7, 96) is in communication with a complementary connector, and switch means (6) under the control of the processing circuitry to disconnect the processing circuitry from the transceiver circuitry when the externally accessible connector is so connected wherein the first connector (16, 46, 73) communicates with the mobile telephone by means of an electrical connection (7;

65), further comprising a power supply connection for supplying electrical power to the mobile telephone through the electrical connection (7, 65).

21. A telephone according to claim 20, including r.f. circuitry (2) for transmitting and receiving speech and data signals, and switching means (6), responsive to a signal applied to the connector (7, 96) to disable the r.f. circuitry.

22. DELETED

23. DELETED

24. DELETED

25. (AMENDED) A method of connecting a mobile telephone to the call-switching system of a cellular telephone system comprising the step of establishing an additional communication path, independent of the system of cells of the cellular telephone system, between the mobile telephone and a fixed part of the cellular telephone system, by putting the mobile telephone in communication with an interface means, the interface means being connected to the call-switching system of the cellular telephone system by a communications path.

26. A method according to claim 25, wherein communication between the mobile telephone and the interface means disables the radio transceiver functions of the mobile telephone.

27. A method according to claim 25 or 26 wherein the communications path comprises a switched network, and the method comprises the step of allocating a path on the switched network between the mobile telephone and the fixed part of the cellular radio system.

28. A method according to claim 27, wherein the communications path is a channel on an existing high bandwidth switched connection.

29. A method according to claim 27, wherein a call is set up by setting up a switched connection.

30. A method according to claim 28 or 29, wherein when a call ends, the switched connection is released only if both:

no other channel of the switched connection is currently in use, and

no further calls or call attempts are made to or from the mobile telephone within a predetermined period of the end of the call.

31. A method according to claim 25 or 26, wherein the communications path comprises a fixed point-to-point signal path.

32. A method according to any of claims 25 to 31, wherein the fixed part is a cellular radio base transceiver site, the base transceiver site having channel allocation means for allocating mobile telephones to channels in order to set up calls to and from said mobile telephones, wherein when a call is set up to a mobile telephone by way of the system of cells, a channel is allocated having an associated radio frequency channel, selected from a plurality of channels allocated to the cell, and when a call is set up to a mobile telephone by way of the additional communication path, the call is allocated to a dedicated channel not associated with such a radio frequency channel.

33. A method according to any one of claims 25 to 32, wherein the communication between the mobile telephone and the interface means is by means of an optical or ultrasonic carrier.

34. A method according to any one of claims 25 to 32, wherein communication between the mobile telephone and the interface means is by means of an electrical connection.

35. A cellular telephone system substantially as described with reference to the accompanying drawings.

36. An interface apparatus substantially as described with reference to the accompanying drawings.

37. A method of connecting a mobile telephone to a call-switching system of a cellular telephone network, substantially as described with reference to the accompanying drawings.