Method for synchronizing a radio network using end user radio terminals
View Patent ↗The present invention discloses a method and system for monitoring a wireless network clock compared to an absolute time scale using the user mobile stations themselves. The major advantage is the capability to transfer GPS time to a Mobile Station in a wireless network, and thus to decrease the time necessary for the mobile receiver to perform position calculations, with minimal additional hardware required by the network.
1. A method for synchronizing an unsynchronized radio network, comprising:
determining GPS time at a mobile GPS receiver which is not synchronized to the radio network;
comparing the determined GPS time to a second time source;
storing an offset between the GPS time and the second time source to synchronize the mobile GPS receiver to the radio network; and
using the stored offset to acquire GPS satellites.
2. The method of claim 1 , wherein the storing is performed at the mobile GPS receiver.
3. The method of claim 2 , wherein the stored offset is used at a second mobile GPS receiver.
4. The method of claim 2 , wherein the comparing is performed at the mobile GPS receiver.
5. The method of claim 4 , wherein the second time source is outside of a cellular infrastructure.
6. The method of claim 5 , wherein the second time source is a time source selected from a group comprising digital television (DTV), GSM time, TDMA cellular time, WCDMA cellular time, or CDMA2000 cellular time.
7. The method of claim 5 , wherein the stored offset is used at the mobile GPS receiver at a later time.
8. The method of claim 5 , wherein the stored offset is used at a second mobile GPS receiver.
9. The method of claim 8 , wherein the stored offset is transmitted from the first mobile GPS receiver to the second mobile GPS receiver through a communication system.
10. The method of claim 9 , wherein the transmitted stored offset is transmitted through a cellular telephone system.
11. The method of claim 9 , wherein the storing is performed other than at the mobile GPS receiver.
12. A method for synchronizing an unsynchronized radio network, comprising:
computing an offset between GPS time and a local time source where the offset is computed by a mobile GPS receiver;
storing the offset; and
using the stored offset at a later time to aid in the acquisition of at least one GPS satellite signal.
13. The method of claim 12 , wherein the local time source is selected from a group comprising: digital television (DTV), GSM time, TDMA cellular time, WCDMA cellular time, or CDMA2000 cellular time.
14. The method of claim 13 , wherein the offset is computed by more than one mobile GPS receiver.
15. The method of claim 14 , wherein the offset is aggregated.
16. The method of claim 14 , wherein the offset computed by each mobile GPS receiver is averaged to determine an average offset.
17. The method of claim 16 , wherein the offset computed by each mobile GPS receiver is used to model the drift of the local time source.
18. The method of claim 16 , wherein the modeled drift is used to determine at least one of a group comprising: rate of change of the local time source, rate of offset of the local time source, and expected error of the local time source.
19. The method of claim 16 , wherein the offset is used in an internet-enable cellular telephone to aid other internet-enabled cellular telephones from the interne server.
20. The method of claim 19 , wherein the offset is transmitted from one cellular telephone to another using one of a group comprising SMS, a cellular telephone infrastructure, and a local area network.