System and method for balancing communication traffic loading between adjacent base stations in a mobile communications network

1. A method comprising:

measuring, by a mobile communication device, a received signal strength indicator, RSSI, from a base station;

calculating an adjusted signal strength indicator, RSSI-ADJ, for the base station as a function of both the RSSI and a traffic indicator received from the base station; and

determining, based on the calculated RSSI-ADJ, whether the mobile communication device should roam.

2. The method of claim 1 wherein the calculating and determining steps are performed by the mobile communication device.

3. The method of claim 1 wherein the determining step includes determining, based on the calculated RSSI-ADJ, whether the mobile communication device should roam from the base station.

4. The method of claim 1 wherein the determining step includes determining, based on the calculated RSSI-ADJ, whether the mobile communication device should roam to the base station.

5. The method of claim 1 wherein said base station is a first base station, and the method further comprises measuring a received signal strength indicator, RSSI, for a second base station, and calculating an adjusted signal strength indicator, RSSI-ADJ, for the second base station from both the second base station's RSSI and a traffic indicator received from the second base station, and said determining is based on a comparison of the second base station's RSSI-ADJ to the first base station RSSI-ADJ.

6. The method of claim 5 wherein said determining is based on whether the second base station's RSSI-ADJ exceeds the first base station's RSSI-ADJ.

7. The method of claim 5 wherein said determining is based on whether the second base station's RSSI-ADJ exceeds the first base station's RSSI-ADJ by a minimum threshold.

8. The method of claim 5 wherein said determining is based both on the comparison of the second base station's RSSI-ADJ to the first base station's RSSI-ADJ and on the second base station's RSSI exceeding a minimum threshold.

9. The method of claim 1 further comprising:

receiving the traffic indicator from the base station;

storing the traffic indicator; and

progressively reducing the stored traffic indicator with time.

10. The method of claim 1 wherein the traffic indicator used in the calculating step is reduced by an amount related to the length of time since the indicator was received from the base station.

11. The method of claim 1 wherein said base station is one of multiple base stations, and the measuring step includes measuring a received signal strength indicator, RSSI, from each of the base stations, and the calculating step includes calculating an adjusted signal strength indicator, RSSI-ADJ, for each of the base stations as a function of the respective base station's RSSI and a traffic indicator received from the respective base station, and the determining step includes determining which of the base stations has the highest RSSI-ADJ.

12. The method of claim 11 further including roaming to the base station having the highest RSSI-ADJ.

13. The method of claim 1 wherein the traffic indicator is a trafnum value.

14. The method of claim 1 wherein, during the measuring and calculating steps, said base station is not the current base station, and the traffic indicator used in the calculating step is a value of the traffic indicator that was received from the base station when the base station was the current base station at a time previous to the calculating and measuring steps.

15. A method performed by a mobile communication device, comprising:

receiving a traffic indicator value from a base station;

calculating a reduced traffic indicator value by reducing the received traffic indicator value by an amount related to the length of time since the traffic indicator value was received from the base station;

measuring a received signal strength indicator, RSSI, from the base station; and

calculating an adjusted signal strength indicator, RSSI-ADJ, for the base station as a function of both the base station's RSSI and the reduced traffic indicator value.

16. The method of claim 15 further comprising:

determining, based on the calculated RSSI-ADJ, whether to roam.

17. The method of claim 16 wherein the determining step includes determining, based on the calculated RSSI-ADJ, whether to roam from the base station.