Use of location in handoff in wireless communication systems

• US 6,654,362 B1
• Filed: 11/24/1999
• Issued: 11/25/2003
• Est. Priority Date: 11/24/1999
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Palamara, Maria E.
• Primary Examiner(s): Vo, Nguyen T.
• Assistant Examiner(s): MOORE, JAMES K
• Application Number:
  US09/448,809
• Time in Patent Office: 1,462 Days
• Field of Search: 370/331-334, 455/436-444, 455/456, 455/457, 455/552, 455/553, 455/432, 455/435
• US Class Current: 370/332
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/322 by location data
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method and apparatus that uses the location of a mobile terminal to direct the mobile terminal to a candidate receiver for participation in a handoff of the mobile terminal. The location of the mobile terminal in communication with a first receiver is determined. It is also determined whether the mobile terminal should participate in a handoff. The later can be determined based on the location of the mobile terminal, or it can be determined in any other way. If mobile terminal should participate in the handoff, the location of the mobile terminal is used to direct the mobile terminal to a candidate receiver for participation in the handoff. The characteristics of the candidate receiver and/or transmitter can be obtained from a database that correlates the location of the mobile terminal and the characteristics of the candidate receiver and/or candidate transmitter. The mobile terminal can then be handed off to the candidate receiver. Optionally, the mobile terminal can then perform measurements of the wireless communication system using the candidate receiver, and then be handed off to the first receiver. An optimal receiver for participation in the handoff is identified based on the measurements of the wireless communication system. The mobile terminal is then handed off to the optimal receiver. Using the location of the mobile terminal to direct it to the candidate receiver for participation in the handoff is particularly advantageous for two adjacent or overlapping wireless communication systems that operate at different frequency bands, or comply with different wireless communication standards, or both.

Claims

1. A method for use in a transfer of communication of a mobile terminal that is in communication with a first transceiver in a first communication system to a second transceiver in a second communication system, wherein the first communication system complies with a first communication standard, and the second communication system complies with a second communication standard, the method comprising the step of:

providing the mobile terminal at least one characteristic of the second transceiver as a function of the location of the mobile terminal;

accessing an index using the second transceiver, the index correlating the second transceiver and the at least one characteristic of the second transceiver;

obtaining the at least one characteristic from the index; and

providing the at least one characteristic to the mobile terminal.

2. The method of claim 1, further comprising the steps of:

determining the location of the mobile terminal in communication with the first transceiver; and

determining whether the mobile terminal should participate in a handoff.

3. The method of claim 1, wherein the step of determining whether the mobile terminal should participate in the handoff comprises the step of determining whether the mobile terminal should participate in the handoff based on the location of the mobile terminal.

4. The method of claim 1, wherein the step of determining whether the mobile terminal should participate in the handoff comprises the step of determining whether the mobile terminal should participate in the handoff based on a signal strength of a signal received by the mobile terminal.

5. The method of claim 1, wherein the step of determining the location of the mobile terminal comprises determining the location of the mobile terminal in latitude and longitude.

6. The method of claim 1, wherein the step of determining the location of the mobile terminal comprises the step of determining the location of the mobile terminal using wireless assisted global position system.

7. The method of claim 1, wherein the step of determining the location of a mobile terminal comprises the step of determining the location of the mobile terminal using triangulation.

8. The method of claim 1, further comprising the step of handing off the mobile terminal to the second transceiver.

9. The method of claim 1, wherein the providing step comprises the steps of:

accessing an index using the location of the mobile terminal, the index correlating the location and the at least one characteristic of the second transceiver;

obtaining the at least one characteristic from the index; and

providing the at least one characteristic to the mobile terminal.

10. The method of claim 9, wherein the index comprises a database.

11. The method of claim 1, wherein the providing step comprises the step of:

accessing an index using the location of the mobile terminal, the index correlating the location and the second transceiver for participating in the handoff with the first transceiver; and

obtaining the second transceiver for participation in the handoff from the index.

12. The method of claim 1, wherein the first standard is a CDMA standard and the second standard is AMPS.

13. The method of claim 1, wherein the first standard is IS-95 CDMA and the second standard is a wideband CDMA standard.

14. The method of claim 1, wherein the first standard is a CDMA standard and the second standard is a TDMA standard.

15. The method of claim 1, wherein the first standard is a CDMA standard and the second standard is a GSM standard.

16. The method of claim 1, wherein the first standard is a GSM standard and the second standard is a TDMA standard.

17. The method of claim 1, wherein the first standard is a GSM standard and the second standard is an AMPS standard.

18. A method for use in a transfer of communication of a mobile terminal that is in communication with a first transceiver in a first communication system to a second transceiver in a second communication system, wherein the first communication system complies with a first communication standard, and the second communication system complies with a second communication standard, the method comprising the step of:

providing the mobile terminal at least one characteristic of the second transceiver as a function of the location of the mobile terminal;

handing off the mobile terminal to the second transceiver;

performing measurements of second communication system using the second transceiver;

handing off the mobile terminal to the first transceiver;

identifying an optimal transceiver for participation in the handoff of the mobile terminal based on the measurements of the second communication system; and

handing off the mobile terminal to the optimal transceiver.

19. A method for use in a transfer of communication of a mobile terminal that is in communication with a first transceiver in a first communication system to a second transceiver in a second communication system, wherein the first communication system operates in a first frequency band assigned to a first geographic area, and the second communication system operates in a second frequency band assigned to a second geographic area, the method comprising the step of:

providing the mobile terminal at least one characteristic of the second transceiver as a function of the location of the mobile terminal;

accessing an index using the second transceiver, the index correlating the second transceiver and the at least one characteristic of the second transceiver;

obtaining the at least one characteristic from the index; and

providing the at least one characteristic to the mobile terminal.

20. The method of claim 19, wherein the providing step comprises the steps of:

accessing an index using the location of the mobile terminal, the index correlating the location and the at least one characteristic of the second transceiver;

obtaining the at least one characteristic from the index; and

providing the at least one characteristic to the mobile terminal.

21. The method of claim 20, wherein the index comprises a database.

22. The method of claim 19, wherein the providing step comprises the steps of:

accessing an index using the location of the mobile terminal, the index correlating the location and the second transceiver for participating in the handoff with the first transceiver; and

obtaining the second transceiver for participation in the handoff from the index.

23. The method of claim 19 further comprising the steps of:

determining the location of the mobile terminal in communication with the first transceiver; and

determining whether the mobile terminal should participate in the handoff.

24. A method for use in a transfer of communication of a mobile terminal that is in communication with a first transceiver in a first communication system to a second transceiver in a second communication system, wherein the first communication system operates in a first frequency band assigned to a first geographic area, and the second communication system operates in a second frequency band assigned to a second geographic area, the method comprising the step of:

providing the mobile terminal at least one characteristic of the second transceiver as a function of the location of the mobile terminal;

handing off the mobile terminal to the second transceiver;

performing measurements of second communication system using the second transceiver;

handing off the mobile terminal to the first transceiver;

identifying an optimal transceiver for participation in the handoff of the mobile terminal based on the measurements of the second communication system; and

handing off the mobile terminal to the optimal transceiver.