Method and system of handoff

• US 7,965,684 B2
• Filed: 08/21/2003
• Issued: 06/21/2011
• Est. Priority Date: 08/21/2003
• Status: Active Grant

• Current Assignee: Bell Mobility Incorporated (BCE Incorporated)
• Original Assignee: Bell Mobility Incorporated (BCE Incorporated)
• Inventors: Gauthier, Dominique, Lanoue, Martin
• Primary Examiner(s): Rao; Seema S
• Assistant Examiner(s): Russell; Wanda Z
• Application Number:
  US10/644,932
• Publication Number:
  US 20050041621A1
• Time in Patent Office: 2,861 Days
• Field of Search: 370/329, 370/331, 455436-445, 455/552.1, 455/553.1
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present invention provides a novel method and system for effecting CDMA handoff transitions. In an embodiment, a converter is provided that converts a conventional CDMA trigger signal at a first frequency into the same handoff trigger signal but at second frequency. Where a subscriber station is operating in a coverage area at the second frequency, the received CDMA re-direction signal can be used to trigger the handoff of the subscriber station from the second frequency to the first frequency.

Claims

1. A device for integration into a base station of a type that includes at least one radio-transceiver for receiving and transmitting radio communications to a plurality of subscriber stations;

the device comprising;

an input device configured to be coupled to the at least one radio-transceiver for receiving a handoff signal from the at least one radio-transceiver at a first mode respective to a first coverage area of the communication system;

an output device for delivering the handoff signal at a second mode respective to a second coverage area;

a converter coupled to said input device and said output device for translating the handoff signal from the first mode into the second mode;

the second mode handoff signal for indicating to a subscriber station operating in the second mode within both of the coverage areas to switch from the second mode to the first mode so that the subscriber station operates in the first mode;

wherein said first mode is a first frequency and wherein said second mode is a second frequency different from said first frequency.

2. The device according to claim 1 wherein said first coverage area and said second coverage area of said system are each based on a respective protocol selected from the group consisting of CDMA, TDMA, GSM, GPRS, AMPS and FDMA.

3. The device according to claim 2 wherein said protocols respective to said coverage areas are different.

4. The device according to claim 1 wherein said handoff signal is a conventional CDMA re-direction signal, and wherein said first mode is a first frequency and said second mode is a second frequency different from said first frequency.

5. The device according to claim 4 wherein said first coverage area and said second coverage area are served by respective CDMA base stations.

6. The device according to claim 4 wherein said converter comprises a down-converter configured to receive said handoff signal from said input device and for converting said handoff signal from said first frequency to an intermediate frequency and an up-converter for converting said intermediate frequency to said second frequency.

7. The device according to claim 6 further comprising a microcontroller operably connected to said down-converter and said up-converter such that said first frequency and said second frequency is user-selectable.

8. The device according to claim 7 wherein said microcontroller is further configured to perform at least one of logging various conversions performed by said converter, and generating alarms upon occurrence of a pre-determined event.

9. The device according to claim 1 wherein said output device is configured to transmit said handoff signal to a base station power combiner for delivering said converted handoff signal to a base station antenna for outputting said handoff signal.

10. A base station that incorporates the device according to claim 1.

11. The base station according to claim 10 wherein the base station further comprises a base station power combiner and a base station antenna coupled to said base station power combiner for transmitting radio communications to a plurality of subscriber stations;

said output device further configured to transmit said handoff signal to said base station power combiner.

12. The base station according to claim 10 wherein said first coverage area and said second coverage area of said system are each based on a respective protocol selected from the group consisting of CDMA, TDMA, GSM, GPRS, AMPS and FDMA.

13. The base station according to claim 12 wherein said protocols respective to said coverage areas are different.

14. The base station according to claim 10 wherein said handoff signal is a conventional CDMA re-direction signal.

15. The base station according to claim 14 wherein said base station is a first CDMA base station and said second coverage area is served by a second CDMA base station different from said first CDMA base station.

16. A method for generating a handoff signal at a base station of a type that includes at least one radio-transceiver for receiving and transmitting radio communications with respect to a plurality of subscriber stations, the method comprising:

receiving a handoff signal from the at least one radio-transceiver at a first mode respective to a first coverage area;

converting said handoff signal from said first mode to a second mode respective to a second coverage area; and

, outputting said handoff signal into said second coverage area, the second mode handoff signal for indicating to a subscriber station operating in the second mode within both of the coverage areas to switch from the second mode to the first mode so that the subscriber station operates in the first mode;

wherein said first mode is a first frequency and wherein said second mode is a second frequency different from said first frequency.

17. The method according to claim 16 wherein said first coverage area and said second coverage area are each based on a respective protocol selected from the group consisting of CDMA, TDMA, GSM, GPRS, AMPS and FDMA.

18. The method according to claim 17 wherein said protocols respective to said coverage areas are different.

19. The method according to claim 16 wherein said handoff signal is a conventional CDMA re-direction signal, and wherein said first mode is a first frequency and said second mode is a second frequency different from said first frequency.

20. The method according to claim 19 wherein said first coverage area and said second coverage area are served by respective CDMA base stations.

21. The method according to claim 19 further comprising receiving an input signal identifying at least one said frequencies for use in performing a remainder of the steps.

22. The method according to claim 16 wherein outputting of said handoff signal comprises transmitting said handoff signal to a base station power combiner for delivering said converted handoff signal to a base station antenna for outputting said handoff signal into said second coverage area.

23. A system for performing handoff comprising:

a first base station operating at a first mode and comprising at least one radio-transceiver for receiving and transmitting radio communications to a plurality of subscriber stations;

said at least one radio-transceiver configured to generate a handoff signal at said first mode;

a second base station operating a second mode;

a handoff device including an input device for receiving said handoff signal from said at least one radio-transceiver at said first mode;

an output device for delivering said handoff signal at said second mode in a coverage area respective to said second base station;

a converter coupled to said input device and said output device for translating the handoff signal from the first mode into the second mode;

the second mode handoff signal for indicating to a subscriber station operating in the second mode within both of the coverage areas to switch from the second mode to the first mode;

wherein said first mode is a first frequency and wherein said second mode is a second frequency different from said first frequency.

24. The system according to claim 23 wherein said first base station and said second base station of said system are based on a protocol selected from the group consisting of CDMA, TDMA, GSM, GPRS, AMPS and FDMA.

25. The system according to claim 24 wherein said protocols respective to said coverage areas are different.

26. The system according to claim 23 wherein said handoff signal is a conventional CDMA re-direction signal, and wherein said first mode is a first frequency and said second mode is a second frequency different from said first frequency.

27. The system according to claim 26 wherein said converter comprises a down-converter configured to receive said handoff signal from said input device and for converting said handoff signal from said first frequency to an intermediate frequency and an up-converter for converting said intermediate frequency to said second frequency.

28. The system according to claim 27 further comprising a microcontroller operably connected to said down-converter and said up-converter such that said first frequency and said second frequency is user-selectable.

29. The system according to claim 28 wherein said microcontroller is further configured to perform at least one of logging various conversions performed by said converter, and generating alarms if said converter operates outside of desired specifications.

30. The system according to claim 23 wherein said first base station further comprises a base station power combiner and a base station antenna coupled to said base station power combiner for transmitting radio communications to a plurality of subscriber stations;

said output device further configured to transmit said handoff signal to said base station power combiner.

31. A device for use in a wireless communication system comprising:

an input device coupled to a base-station radio-transceiver for receiving a handoff signal from said base-station radio-transceiver at a first mode respective to a first coverage area of the communication system;

an output device for delivering the handoff signal at at least one additional mode respective to at least one additional coverage area;

a converter for translating the handoff signal from the first mode into the at least one additional mode;

the handoff signal for each of the at least one additional mode indicating to a subscriber station operating at the respective additional mode within the respective coverage area to switch from the respective additional mode to the first mode so that the subscriber station operates in the first mode;

wherein said first mode is a first frequency and wherein said second mode is a second frequency different from said first frequency.

32. A base station for use in a wireless communication system comprising:

a radio-transceiver for receiving and transmitting radio communications with respect to a plurality of subscriber stations;

data-processing equipment for carrying at least a portion of said communications over a backhaul; and

a device for performing handoff comprising an input device for receiving a handoff signal from said radio-transceiver at a first mode respective to a first coverage area of the communication system;

an output device for delivering the handoff signal at a second mode respective to a second coverage area;

a converter coupled to said input device and said output device for translating the handoff signal from the first mode into the second mode;

the second mode handoff signal for indicating to a subscriber station operating in the second mode within both of the coverage areas to switch from the second mode to the first mode so that the subscriber station operates in the first mode;

wherein said first mode is a first frequency and wherein said second mode is a second frequency different from said first frequency.

33. The base station according to claim 32 wherein said base station is based on the CDMA protocol.

34. The base station according to claim 32 wherein the radio-transceiver is configured to receive and transmit radio communications with respect to the plurality of subscriber stations in the first mode.

35. A handoff device for use in a wireless CDMA communication system and configured to be coupled to a radio-transceiver of a base station, the handoff device comprising an input device for receiving a CDMA re-direction signal from the radio-transceiver at a first frequency respective to a first coverage area of said communication system;

a first converter connected to said input device for converting said CDMA re-direction signal from said first frequency to an intermediate frequency;

a second converter connected to said first converter for converting said CDMA re-direction signal from said intermediate frequency to a second frequency;

an output device connected to said second converter for delivering said CDMA re-direction signal at said second frequency within a second coverage area;

said CDMA re-directional signal for indicating to a subscriber station operating in said second frequency and within both of said coverage areas to switch from said second frequency to said first frequency.