ENHANCED ZONE DETERMINATION

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.

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.

14 . (canceled)

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.

17 . (canceled)

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.

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 . (canceled)

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

25 - 30 . (canceled)