ENHANCED ZONE DETERMINATION

• US 20100087194A1
• Filed: 03/12/2008
• Published: 04/08/2010
• Est. Priority Date: 03/13/2007
• Status: Abandoned Application

• Current Assignee: Wavemarket Incorporated (Gen Digital Inc.)
• Original Assignee: Wavemarket Incorporated (Gen Digital Inc.)
• Inventors: Drane, Christopher Ridgway, MacNaughtan, Malcolm David, Brown, Stephen Frank, Scott, Craig Andrew
• Application Number:
  US12/450,109
• Publication Number:
  US 20100087194A1
• Time in Patent Office: Days
• US Class Current: 455/435.200
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method and system for determining whether a mobile radio terminal is in or out of a zone in a radio communications network by relying at least partially on a serving cell identity. The method provides for generating a profile representative of the zone using measurements taken by the mobile radio terminal, the network, and/or using predicted values. A comparison is then made to determine whether the mobile radio terminal is in or out of the zone.

Claims

1. A method for generating a profile representing a geographic region in a radio communications network comprising the steps of:

obtaining a probability for each of a plurality of cells that the cell will be selected as a serving cell by a mobile radio terminal in the geographic region; and

processing at least one probability to generate a profile representing the geographic region.

2. The method of claim 1 wherein obtaining a probability for each of a plurality of cells that the cell will be selected as the serving cell by a mobile radio terminal in the geographic region further comprises the steps of:

receiving a plurality of serving cell identities within the geographic region;

calculating a relative probability of receiving each serving cell identity; and

calculating an unmatched cell probability that represents the probability that the mobile radio terminal in the geographic zone might select a serving cell that was not a received cell identity.

3. The method of claim 1 wherein obtaining a probability for each of a plurality of cells that the cell will be selected as the serving cell by a mobile radio terminal in the geographic region further comprises the steps of:

determining a received signal power in the geographic region for each of the plurality of cells;

determining a signal power variation; and

calculating a probability for each of the plurality of cells that the cell will be selected as the serving cell by a mobile radio terminal in the geographic region based on the received signal power and the signal power variation.

4. The method of claim 3 further comprising the step of eliminating from the profile at least one cell, wherein said at least one cell to be eliminated has a probability of being selected as the serving cell that is below a threshold.

5. The method of claim 4 wherein the threshold is a complement of the zone reliability.

6. The method of claim 4 wherein the threshold is an unmatched cell probability.

7. The method of claim 4 wherein the threshold is based on a comparison between a predicted received signal power and a system limitation.

8. The method of claim 7 wherein the system limitation is receiver sensitivity.

9. The method of claim 1 further comprising the steps of:

receiving a plurality of serving cell identities within the geographic region;

calculating a relative probability of receiving each serving cell identity;

converting each relative probability into a relative received signal power;

determining a predicted signal power in the geographic region for each cell;

determining a signal power variation;

correcting the predicted signal power with the corresponding relative received signal power for each cell; and

calculating a probability for each cell that the cell will be selected as the serving cell by a mobile radio terminal in the geographic region based on the corrected signal power and the signal power variation.

24. A processor readable medium containing instructions to cause a processor to perform the method of claim 1.

10. A method for determining whether a mobile radio terminal is within a predefined geographic region comprising the steps of:

receiving a serving cell identity;

comparing a profile representing the predefined geographic region with the serving cell identity;

determining whether the mobile radio terminal is within the predefined geographic region based on the comparison;

calculating a cost associated with the received serving cell identity; and

comparing the cost with a zone detection probability threshold.

11. The method of claim 10 wherein the serving cell identity is received by a mobile radio terminal.

12. The method of claim 10 wherein the serving cell identity is received by a radio communications network device.

13. The method of claim 10 wherein the profile includes an unmatched cell probability and a probability for each of a plurality of cells that the cell will be selected as a serving cell by a radio terminal in the predefined geographic region.

15. The method of claim 10 further comprising the step of adjusting the zone detection threshold probability with a hysteresis offset.

16. The method of claim 10 wherein the cost is a probability that the cell corresponding to the serving cell identity will be selected as a serving cell by a mobile radio terminal in the predefined geographic region.

18. The method of claim 10 wherein determining whether the mobile radio terminal is within the predefined geographic region further comprises the step of applying a difference between the cost and the zone detection probability threshold to a filter to suppress short-term fluctuations.

14. (canceled)

17. (canceled)

19. A method of adjusting a profile representing a geographic region in a radio communications network, the method comprising the steps of:

obtaining a profile having a probability for each of a plurality of cells that the cell is selected as a serving cell by a mobile radio terminal in the geographic region;

adjusting a parameter of the profile; and

re-calculating a probability for each of the plurality of cells that each cell will be selected as a serving cell by a mobile radio terminal in the geographic region based on the adjusted parameter.

20. The method of 19 wherein the parameter is an assumed variation in signal levels.

21. The method of 19 wherein the parameter is a zone detection probability threshold.

22-23. -23. (canceled)

25-30. -30. (canceled)