Method and apparatus for determining virtual cell area

• US 6,014,564 A
• Filed: 07/15/1997
• Issued: 01/11/2000
• Est. Priority Date: 09/19/1996
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Nortel Networks Corporation
• Inventors: Donis, Gerardo, Munoz, David, Basu, Kalyan
• Primary Examiner(s): Hudspeth, David R.
• Assistant Examiner(s): ABEBE, DANIEL DEMELASH
• Application Number:
  US08/892,828
• Time in Patent Office: 910 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/440, 455/441
• US Class Current: 455/436
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 36/326 by proximity to another entity

Abstract

The method and apparatus of the architecture of the present invention is accomplished in an embodiment of the present invention by establishing a high speed network interconnection layer between the base station and the mobile switching office. This high speed interconnected network may be an asynchronous transfer mode (ATM) switch. This architecture allows for a dynamic virtual cell area to be configured around a mobile subscriber as a mobile subscriber moves within the network. As a subscriber leaves a previously defined virtual cell area into a new virtual cell area, the high speed switching network sets up a new virtual cell area around the mobile subscriber in his new area. The network is designed to anticipate a user'"'"'s mobility pattern and to set up the new virtual cell area in advance of the mobile subscriber moving into the that new area. The network is able to predict the mobile subscriber'"'"'s future location ahead of time, thus enabling the network to accomplish much of the overhead processing and setup used to accommodate the mobile subscriber before arrival in the new area, thus ensuring a smooth handoff and transition period during a call.

Claims

1. A method of call processing in a wireless network comprising the steps of:

initiating a hand-off procedure from a first base station to a second base station;

defining a coverage area to include a predetermined number of unit areas within said coverage area based on predetermined uniform characteristics wherein said predetermined uniform characteristics are a function of predefined user specific activity; and

completing said hand-off procedure.

2. A method of call processing in a wireless network as in claim 1 further comprising:

establishing a coverage area surrounding a predetermined focal point with approximately the same number of unit areas of a previous coverage area upon detection of a mobile unit traversing an edge of a previous coverage area.

3. A method of call processing in a wireless network as in claim 2 wherein said predetermined focal point approximates the center of a circle around a detected location of a mobile unit.

4. A method of call processing in a wireless network as in claim 3 further comprising:

establishing a unit area based on distance.

5. A method of call processing in a wireless network as in claim 4 further comprising:

establishing a call area with a predetermined number of microcells per coverage area.

6. A method of call processing as in claim 1 wherein said predetermined characteristics include a function of the network.

7. A method of call processing as in claim 6 wherein said predetermined characteristics further include a predetermined number of unit areas N dependent upon network topology.

8. A method of call processing as in claim 6 wherein said function of the network further includes a function dependent upon geographic considerations.

9. A method of call processing in a wireless network as in claim 6 further including:

calculating the number of probable microcells to be used in a coverage area by calculating the travel time beginning when a call user answers a call until the call is finished;

calculating the average time which is a predetermined number that is characteristic of the system;

calculating the approximate distance traveled by a mobile subscriber as a function of the distance between base stations;

calculating the average speed of the mobile subscriber travels within the coverage area;

calculating a remainder time which is the difference between the average time and the travel time;

calculating distance a new distance D traveled by a mobile subscriber by multiplying the average speed by the remainder time; and

calculating the number of microcells in a coverage area as equal to the distance D divided by a predetermined known distance.

10. A method of call processing in a wireless network as in claim 9 wherein said predetermined known distance is the distance between base stations.

11. A method of call processing as in claim 1 wherein said predefined user specific activity includes a predefined travel pattern specific to a user and generic to a group of users.

12. An apparatus for call processing in a wireless network comprising:

means for initiating a hand-off procedure from a first base station to a second base station;

means for defining a coverage area to include a predetermined number of unit areas within said coverage area based on predetermined uniform characteristics wherein said predetermined uniform characteristics are a function of predefined user specific activity; and

means for completing said hand-off procedure.

13. An apparatus for call processing in a wireless network as in claim 12 further comprising:

means for establishing a coverage area surrounding a predetermined focal point with approximately the same number of unit areas of a previous coverage area upon detection of a mobile unit traversing an edge of a previous coverage area.

14. An apparatus for call processing in a wireless network as in claim 13 wherein said predetermined focal point approximates the center of a circle around a detected location of a mobile unit.

15. An apparatus for call processing in a wireless network as in claim 14 further comprising means for:

establishing a unit area based on distance.

16. An apparatus for call processing in a wireless network as in claim 15 further comprising means for:

establishing a call area with a predetermined number of microcells per coverage area.

17. An apparatus for call processing as in claim 12 wherein said predetermined characteristics include a function of the network.

18. An apparatus for call processing as in claim 12 wherein said predetermined characteristics further include a predetermined number of unit areas N dependent upon network topology.

19. An apparatus for call processing in a wireless network as in claim 13 further including means for calculating the number of probable microcells to be used in a coverage area by calculating the travel time beginning when a call user answers a call until the call is finished;

calculating the average time which is a predetermined number that is characteristic of the system;

calculating the approximate distance traveled by a mobile subscriber as a function of the distance between base stations;

calculating the average speed of the mobile subscriber travels within the coverage area;

calculating a remainder time which is the difference between the average time and the travel time;

calculating distance a distance D traveled by a mobile subscriber by multiplying the average speed by the remainder time; and

calculating the number of microcells in a coverage area as equal to the distance D divided by a predetermined known distance.