Distribution of positioning satellite information

1. A method of operating a wireless communication system comprising:

receiving and processing a position assistance request from a wireless communication device to determine a time of the request and a location of the wireless communication device;

processing the time of the request and the location of the wireless communication device to determine if a wireless communication system database stores positioning satellite information for the time and the location after having received the positioning satellite information from a location assistance system in response to a previous position assistance request;

if the wireless communication system database stores the positioning satellite information for the time and the location, then transferring the positioning satellite information for delivery to the wireless communication device; and

if the wireless communication system database does not store the positioning satellite information for the time and the location, then transferring the position assistance request for delivery to the location assistance system, receiving a response including the positioning satellite information for the time and the location, and transferring the positioning satellite information for delivery to the wireless communication device.

2. The method of claim 1 wherein the positioning satellite information comprises Global Positioning System (GPS) satellite ephemeris data.

3. The method of claim 1 wherein the positioning satellite information comprises GPS satellite almanac data.

4. The method of claim 1 wherein the positioning satellite information is for the time when the time of the request does not exceed a time of receipt of the positioning satellite information in the wireless communication system database by more than an expiration period.

5. The method of claim 4 further comprising monitoring a loading of the location assistance system and determining the expiration period based on the loading of the location assistance system.

6. The method of claim 1 wherein the location assistance system comprises a position determining entity (PDE).

7. The method of claim 1 wherein the position assistance request comprises an IS-801 message.

8. The method of claim 1 wherein the location comprises a location of a wireless base station.

9. A method of operating a wireless communication system comprising:

receiving and processing a position assistance request from a wireless communication device;

determining a spatial relationship between a location of the wireless communication device and a geographic region associated with positioning satellite information contained in a wireless communication system database after having been received by the wireless communication system database from a location assistance system in response to a previous position assistance request;

determining a validity period based on a position assistance request time;

if a time of receipt of the positioning satellite information in the wireless communication system database is within the validity period and the spatial relationship meets a criteria, then transferring the positioning satellite information for delivery to the wireless communication device; and

if the time of receipt of the positioning satellite information is not within the validity period or the spatial relationship does not meet the criteria, then transferring the position assistance request for delivery to the location assistance system, and receiving a response including the positioning satellite information for the location and the position assistance request time, and transferring the positioning satellite information for delivery to the wireless communication device.

10. The method of claim 9 wherein the positioning satellite information comprises GPS satellite ephemeris data.

11. The method of claim 9 wherein the location assistance system comprises a PDE.

12. The method of claim 9 wherein the position assistance request comprises an IS-801 message.

13. The method of claim 9 further comprising determining the validity period based on an availability of the location assistance system.

14. The method of claim 9 wherein the spatial relationship meets the criteria if the location of the wireless communication device is within the geographic region.

15. The method of claim 9 wherein the spatial relationship meets the criteria if the distance between the location of the wireless communication device and the geographic region is less than a buffer distance.

16. The method of claim 15 further comprising determining the buffer distance based on a loading of the location assistance system.

17. A wireless communication system comprising:

a wireless communication device configured to transmit a position assistance request; and

a wireless communication system database configured to receive and process the position assistance request to determine a time of the request and a location of the wireless communication device, process the time and the location to determine if the wireless communication system database stores positioning satellite information for the time and the location after having received the positioning satellite information from a PDE in response to a previous position assistance request, transfer the positioning satellite information for delivery to the wireless communication device if the positioning satellite information is for the time and the location, and transfer the position assistance request for delivery to the PDE if the wireless communication system database does not store the positioning satellite information for the time and the location.

18. The wireless communication system of claim 17 wherein the positioning satellite information comprises GPS satellite ephemeris data.

19. The wireless communication system of claim 17 wherein the positioning satellite information is for the time when the time of the request does not exceed a time of receipt of the positioning satellite information in the wireless communication system database by more than a validity window.

20. The wireless communication system of claim 19 wherein the validity window is determined based on a loading of the PDE.