Cordless telephone arranged for operating with multiple portable units in a frequency hopping system

• US 5,809,417 A
• Filed: 11/03/1994
• Issued: 09/15/1998
• Est. Priority Date: 07/05/1994
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Nealon, William J., Rajan, Heidi Anne
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US08/333,705
• Time in Patent Office: 1,412 Days
• Field of Search: 379/58, 379/59, 379/60, 379/61, 379/63, 455/33.1, 455/33.2, 455/34.1, 455/51.1, 455/426, 455/450-452, 455/464, 455/509, 455/526
• US Class Current: 455/426.1
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 1/7156 Arrangements for sequence synchronisation
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04B 2001/71563 Acquisition
• CPC Class Codes: H04M 1/72511 Searching for available channels

Abstract

A cordless telephone arranged for operation in a frequency hopping system includes an arrangement which achieves optimum utilization of multiple cordless telephone portable units by permitting these units to access a common base unit and also access each other. The portable units are configured for subsequent operation with the base unit and each other during a registration process by having the base unit select from a plurality of communication channels available in the frequency hopping system a different starting channel for each one of the portable units. The portable units are thereby advantageously selectably addressable by the base unit and by each other. Any one of the registered portable units, for example, is capable of selectively paging and communicating with any other one of the registered portable units over selected ones of the plurality of communication channels. Once a base unit establishes a communication link with a portable unit, or a portable unit establishes a communication link with another portable unit, using set-up channels designated for such purpose, both units move away from these channels. Another two units, two unoccupied or free portable units, for example, may then advantageously also use these set-up channels for establishing another communication link.

Claims

1. In a cordless telephone, a base unit connectable to a telephone line and a plurality of handset units for communicating with the base unit over any one of a plurality of communication channels, the base unit comprising:

means for transmitting a broadcast signal for simultaneous receipt by each one of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from one of the plurality of handset units;

means for monitoring each one of a second set of channels within the plurality of communication channels for said response signal, each channel in the second set of channels being respectively assigned to one of the plurality of handset units; and

means for establishing communications with a first responding handset unit, said first responding handset unit providing said response signal over its assigned channel in said second set of channels.

2. The base unit of claim 1 further comprising means for pseudo-randomly selecting said first set of channels from the plurality of communication channels.

3. The base unit of claim 2 wherein said selecting means selects from the plurality of communication channels a starting channel within the first set of channels for transmitting the broadcast signal.

4. The base unit of claim 3 wherein said selecting means generates subsequent communication channels within said first set of channels from said starting channel for use by said base unit in transmitting said broadcast signal.

5. The base unit of claim 4 wherein said selecting means includes means for generating a pseudo-random number seed, said number seed being used by the base unit for generating the starting channel for said base unit.

6. The base unit of claim 5 wherein said pseudo-random number seed is used as a basis for generating a first subsequent pseudo-random number, said first subsequent pseudo-random number being used to generate a first subsequent communication channel for use by the base unit for transmitting the broadcast signal.

7. The base unit of claim 6 wherein each subsequent pseudo-random number generated by a preceding pseudo-random number is in turn used as a basis for generating its subsequent pseudo-random number, each pseudo-random number being used to generate a corresponding communication channel for use by the base unit in transmitting the broadcast signal.

8. The base unit of claim 1 wherein, responsive to the monitoring means receiving said response signal from the responding handset unit over a channel in said second set of channels, the establishing means reconfigures said base unit for communicating with the responding handset unit over a third set of communication channels assigned to said responding handset unit.

9. The base unit of claim 8 further comprising means for pseudo-randomly selecting said third set of channels from the plurality of communication channels, said selecting means including means for generating a pseudo random number seed for use by the base unit in generating a starting channel within said third set of channels for establishing communications with the responding handset unit.

10. The base unit of claim 9 wherein each subsequent pseudo-random number generated by a preceding pseudo-random number is in turn used as a basis for generating its subsequent pseudo-random number, each pseudo-random number being used to generate a corresponding communication channel for use by the base unit in communicating with the responding handset unit.

11. In a cordless telephone, a plurality of handset units for communicating with a base unit over any one of a plurality of communication channels, at least one first handset unit within the plurality of handset units comprising:

means for transmitting a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from one of said other of the plurality of handset units;

means for monitoring each one of a second set of channels within the plurality of communication channels for said response signal, each channel in the second set of channels being respectively assigned to one of the plurality of handset units; and

means for establishing communications with a second handset unit within the plurality of handset units, said second handset unit providing said response signal over its assigned channel in said second set of channels.

12. The first handset unit of claim 11 further comprising means for pseudo-randomly selecting said first set of channels from the plurality of communication channels.

13. The first handset unit of claim 12 wherein said selecting means selects from the plurality of communication channels a starting channel within the first set of channels for transmitting the broadcast signal.

14. The first handset unit of claim 13 wherein said selecting means generates subsequent communication channels within said first set of channels from said starting channel for use by said handset unit in transmitting said broadcast signal.

15. The first handset unit of claim 14 wherein said selecting means includes means for generating a pseudo-random number seed, said number seed being used by the handset unit for generating the starting channel for said handset unit.

16. The first handset unit of claim 15 wherein said pseudo-random number seed is used as a basis for generating a first subsequent pseudo-random number, said first subsequent pseudo-random number being used to generate a first subsequent communication channel for use by the handset unit for transmitting the broadcast signal.

17. The first handset unit of claim 16 wherein each subsequent pseudo-random number generated by a preceding pseudo-random number is in turn used as a basis for generating its subsequent pseudo-random number, each pseudo-random number being used to generate a corresponding communication channel for use by the handset unit in transmitting the broadcast signal.

18. The first handset unit of claim 11 wherein, responsive to the monitoring means receiving said response signal from said second handset unit over one of said second set of channels, the establishing means reconfigures said first handset unit for communicating with the second handset unit over a third set of communication channels assigned to said second handset unit.

19. The first handset unit of claim 18 further comprising means for pseudo-randomly selecting said third set of channels from the plurality of communication channels, said selecting means including means for storing a pseudo random number seed for use by the first handset unit in generating a starting channel within said third set of channels for establishing communications with the second handset unit.

20. The first handset unit of claim 19 wherein each subsequent pseudo-random number generated by a preceding pseudo-random number is in turn used as a basis for generating its subsequent pseudo-random number, each pseudo-random number being used to generate a corresponding communication channel for use by the first handset unit in communicating with the second handset unit.

21. A cordless telephone including a plurality of handset units for communicating with a base unit over any one of a plurality of communication channels, the cordless telephone comprising:

means in a first handset unit for transmitting a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from one of said other of the plurality of handset units;

means in a second handset unit for receiving said broadcast signal from said first handset unit and for transmitting said response signal to said first handset unit, said response signal being transmitted over a communication channel in a second set of channels within the plurality of communication channels and said communication channel being assigned to said second handset unit; and

means in said first handset unit for establishing direct communications with said second handset unit over said second set of channels upon receipt of said response signal.

22. The cordless telephone of claim 21 further including means in the first handset unit for monitoring each channel in a second set of channels within the plurality of communication channels, each channel in the second set of channels being respectively assigned to one of the plurality of handset units.

23. The cordless telephone of claim 22 wherein the establishing means in said first handset unit establishes direct communications with said second handset unit transmitting the response signal over one of said second set of channels.

24. The cordless telephone of claim 22 further including means in the first handset unit and the second handset unit for communicating over the plurality of communication channels in a synchronous frequency hopping cycle.

25. In a cordless telephone, a plurality of handset units for communicating with a base unit over any one of a plurality of communication channels, at least one handset unit within the plurality of handset units comprising:

means for transmitting a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from a selected one of said other of the plurality of handset units;

means for monitoring a specific channel within the plurality of communication channels for said response signal, said specific channel being assigned to said selected one of other of the plurality of handset units; and

means for establishing communications with said selected one of other of the plurality of handset units over a second set of channels within the plurality of communication channels upon receiving said response signal from said selected handset unit over said specific channel.

26. A method of communicating in a cordless telephone including a base unit connectable to a telephone line and a plurality of handset units, the base unit communicating with the plurality of handset units over any one of a plurality of communication channels, the method comprising the steps of:

transmitting in the base unit a broadcast signal for simultaneous receipt by each one of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from one of the plurality of handset units;

monitoring in the base unit each one of a second set of channels within the plurality of communication channels for said response signal, each channel in the second set of channels being respectively assigned to one of the plurality of handset units; and

establishing communications between said base unit and a first responding handset unit, said first responding handset unit providing said response signal over its assigned channel in said second set of channels.

27. The method of claim 26 further comprising the step of pseudo-randomly selecting said first set of channels from the plurality of communication channels.

28. The method of claim 27 wherein said selecting step selects from the plurality of communication channels a starting channel within the first set of channels for transmitting the broadcast signal.

29. The method of claim 28 wherein said selecting step generates subsequent communication channels within said first set of channels from said starting channel for use by said base unit in transmitting said broadcast signal.

30. The method of claim 26 wherein, responsive to the monitoring step receiving said response signal from the responding handset unit over one of said second set of channels, the establishing step reconfigures said base unit for communicating with the responding handset unit over a third set of communication channels assigned to said responding handset unit.

31. The method of claim 30 further comprising the step of pseudo-randomly selecting said third set of channels from the plurality of communication channels, said selecting step selecting from the plurality of communication channels a starting channel within the third set of channels for communicating with the responding handset unit.

32. The method of claim 31 wherein said selecting step generates subsequent communication channels within said third set of channels from said starting channel for use by said base unit in communicating with the responding handset unit.

33. A method of communicating in a cordless telephone including a plurality of handset units for communicating with a base unit, the plurality of handset units communicating with the base unit over any one of a plurality of communication channels, the method comprising the steps of:

transmitting in a first handset unit a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from one of said other of the plurality of handset units;

monitoring in said first handset unit each one of a second set of channels within the plurality of communication channels for said response signal, each channel in the second set of channels being respectively assigned to one of the plurality of handset units; and

establishing communications between said first handset unit and a second handset unit providing said response signal over its assigned channel in said second set of channels.

34. The method of claim 33 further comprising the step of pseudo-randomly selecting said first set of channels from the plurality of communication channels.

35. The method of claim 34 wherein said selecting step selects from the plurality of communication channels a starting channel within the first set of channels for transmitting the broadcast signal.

36. The method of claim 35 wherein said selecting step generates subsequent communication channels within said first set of channels from said starting channel for use by said handset unit in transmitting said broadcast signal.

37. A method of communicating in a cordless telephone including a plurality of handset units for communicating with a base unit, the plurality of handset units communicating with the base unit over any one of a plurality of communication channels, the method comprising the steps of:

transmitting in a first handset unit a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from a specific one of said other of the plurality of handset units;

receiving in a second handset unit said broadcast signal from said first handset unit and for transmitting said response signal to said first handset unit, said response signal being transmitted over a communication channel in a second set of channels within the plurality of communication channels and said communication channel being assigned to said second handset unit; and

establishing direct communications in said first handset unit with said second handset unit over said set of channels upon receipt of said response signal.

38. The method of claim 37 further including the step of monitoring in the first handset unit each one of a second set of channels within the plurality of communication channels, each channel in the second set of channels being respectively assigned to one of the plurality of handset units.

39. The method of claim 38 wherein the establishing step in said first handset unit establishes direct communications with said second handset unit over a starting channel for said second handset unit within said second set of channels.

40. The method of claim 38 further including the step of communicating in the first handset unit and the second handset unit in a synchronous frequency hopping cycle over the plurality of communication channels.

41. A method of communicating in a cordless telephone including a plurality of handset units for communicating with a base unit, the plurality of handset units communicating with the base unit over any one of a plurality of communication channels, the method comprising the steps of:

transmitting in at least one first handset unit within the plurality of handset units a broadcast signal for simultaneous receipt by each one of other of the plurality of handset units, said broadcast signal being transmitted sequentially over each one of a first set of channels within the plurality of communication channels until a response signal is received from a selected one of said other of the plurality of handset units;

monitoring in said first handset unit a specific channel in a second set of channels within the plurality of communication channels for said response signal, said specific channel being assigned to said selected one of other of the plurality of handset units; and

establishing communications between said first handset unit and said selected one of other of the plurality of handset units over said second set of channels upon receiving said response signal from said selected handset unit over said specific channel.