Synchronization of mobile station location measurement with CDMA service

1. A method of synchronizing measurement of a mobile station location comprising:

transmitting a synchronization message from a mobile station to a base station to indicate that the mobile station will be unavailable for communications service during a selected time interval;

resetting a fade timer to the selected time interval to avoid dropping a call during the selected time interval; and

measuring the mobile station location during the selected time interval.

2. The method of claim 1 further comprising transmitting the mobile station location or raw data measurements for calculating the measured mobile station location from the mobile station to the base station at the end of the selected time interval.

3. The method of claim 1 further comprising performing communications service between the mobile station and the base station outside the selected time interval.

4. The method of claim 1 wherein transmitting the synchronization message includes indicating a system time at which the selected time interval starts.

5. The method of claim 4 wherein transmitting the synchronization message includes indicating a system time of a duration or end time at which the selected time interval ends.

6. The method of claim 1 further comprising synchronizing the selected time interval with a system time kept by the base station.

7. The method of claim 6 wherein the system time has units of about 80 milliseconds each.

8. The method of claim 1 further comprising using common radio frequency components in the mobile station for both communications service and measuring the mobile station location.

9. The method of claim 1 further comprising withholding forward channel traffic from the base station to the mobile station during the selected time interval.

10. The method of claim 1 wherein measuring the mobile station location comprises receiving signals from a Global Positioning System.

11. The method of claim 1 wherein performing the communications service comprises transmitting and receiving data packets and control messages according to code division multiple access protocol.

12. The method of claim 11 wherein the code division multiple access protocol comprises a CDMA_OFF_TIME defining a total time during which a mobile station is not available for performing the communications service.

13. The method of claim 11 wherein the mobile station enables, disables, and resets the fade timer to support global positioning functions.

14. The method of claim 11 further comprising defining a format for a code division multiple access off time report message to support global positioning functions.

15. The method of claim 11 further comprising defining a format of an Extended System Parameters Message to support global positioning functions.

16. The method of claim 11 further comprising defining a format of a System Parameters Message to support global positioning functions.

17. The method of claim 1 wherein transmitting the synchronization message includes indicating a periodic search.

18. The method of claim 1 wherein the mobile station performs a function on a channel other than that used by the base station to communicate with the mobile station.

19. The method of claim 18 wherein the function is two-way radio or walkie-talkie.

20. The method of claim 1 wherein the base station allocates the selected time interval for communication with another mobile station.

21. The method of claim 1 wherein the base station disables transmission to the mobile station.