Positioning LTE wireless base stations using aggregated OTDOA assistance data

1. A method in a mobile device to facilitate the building of a base station almanac, the method comprising:

sending a seed location from the mobile device to a first location server requesting observed time difference of arrival (OTDOA) assistance data;

receiving, at the mobile device, the OTDOA assistance data from the first location server; and

sending, from the mobile device, the OTDOA assistance data and the seed location to a second location server for building the base station almanac.

2. The method of claim 1 , wherein the first location server comprises a location server operated by a network operator of the mobile device.

3. The method of claim 1 , wherein the second location server comprises a location server disassociated from a network operator of the mobile device.

4. The method of claim 1 , wherein the seed location comprises a coarse location.

5. The method of claim 1 , wherein the seed location comprises a GPS location.

6. The method of claim 1 , wherein the seed location comprises a externally generated location.

7. A mobile device for facilitating building of a base station almanac, the mobile device comprising:

a receiver; and

a processor comprising a memory and coupled to the receiver;

wherein the memory comprises code to be executed by the processor for:

sending a seed location from the mobile device to a first location server requesting observed time difference of arrival (OTDOA) assistance data;

receiving, at the mobile device, the OTDOA assistance data from the first location server; and

sending, from the mobile device, the OTDOA assistance data and the seed location to a second location server for building the base station almanac.

8. The mobile device of claim 7 , wherein the second location server comprises a location server disassociated from a network operator of the mobile device.

9. The mobile device of claim 7 , wherein the seed location comprises a coarse location.

10. The mobile device of claim 7 , wherein the seed location comprises a GPS location.

11. The mobile device of claim 7 , wherein the seed location comprises a externally generated location.

12. A mobile device for facilitating building of a base station almanac, the mobile device comprising:

means for sending a seed location from the mobile device to a first location server requesting observed time difference of arrival (OTDOA) assistance data;

means for receiving, at the mobile device, the OTDOA assistance data from the first location server; and

means for sending, from the mobile device, the OTDOA assistance data and the seed location to a second location server for building the base station almanac.

13. The mobile device of claim 12 , wherein the seed location comprises a coarse location.

14. The mobile device of claim 12 , wherein the seed location comprises a externally generated location.

15. A computer-readable storage medium including non-transient program code stored thereon for:

sending a seed location from the mobile device to a first location server requesting observed time difference of arrival (OTDOA) assistance data;

receiving, at a mobile device, the OTDOA assistance data from the first location server; and

sending, from the mobile device, the OTDOA assistance data and the seed location to a second location server for building a base station almanac.

16. A method in a non-carrier location server for building a base station almanac, the method comprising:

receiving, at the non-carrier location server, observed time difference of arrival (OTDOA) assistance data and a seed location from a mobile device, wherein the OTDOA assistance data was received by the mobile device from a first location server distinct from the non-carrier location server; and

saving, at the non-carrier location server, the OTDOA assistance data and the seed location to a non-carrier OTDOA library for building the base station almanac;

wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations.

17. The method of claim 16 , wherein the first location server comprises a location server provided by a network operator of the mobile device.

18. The method of claim 16 , wherein the non-carrier location server comprises a location server disassociated from a network operator of the mobile device.

19. The method of claim 16 , further comprising:

extracting the OTDOA assistance data and seed locations from the non-carrier OTDOA library;

computing locations based in part on the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

saving the locations to the base station almanac.

20. The method of claim 19 , wherein computing the locations comprises computing a location for each base station of a plurality of pairs of base stations.

21. The method of claim 19 , wherein computing the locations comprises solving a system of equations wherein:

known variables comprise at least five different seed locations and the expected time difference of arrival of signals for each of the at least five different seed locations; and

unknown variables comprise the locations of the pair of base stations and a time difference between the pair of base stations.

22. A non-carrier location server for building a base station almanac, the non-carrier location server comprising:

means for receiving, at the non-carrier location server, observed time difference of arrival (OTDOA) assistance data and a seed location from a mobile device, wherein the OTDOA assistance data was received by the mobile device from a first location server distinct from the non-carrier location server; and

means for saving, at the non-carrier location server, the OTDOA assistance data and the seed location to a non-carrier OTDOA library for building the base station almanac;

wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations.

23. The non-carrier location server of claim 22 , wherein the first location server comprises a location server provided by a network operator of the mobile device.

24. The non-carrier location server of claim 22 , wherein the non-carrier location server comprises a location server disassociated from a network operator of the mobile device.

25. The non-carrier location server of claim 22 , further comprising:

means for extracting the OTDOA assistance data and seed locations from the non-carrier OTDOA library;

means for computing locations based in part on the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

means for saving the locations to the base station almanac.

26. A non-carrier location server comprising a processor and a memory wherein the memory includes code to be executed by the processor for:

receiving, at the non-carrier location server, observed time difference of arrival (OTDOA) assistance data and a seed location from a mobile device, wherein the OTDOA assistance data was received by the mobile device from a first location server distinct from the non-carrier location server; and

saving, at the non-carrier location server, the OTDOA assistance data and the seed location to a non-carrier OTDOA library for building a base station almanac;

wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations.

27. A computer-readable storage medium including non-transient program code stored thereon for:

receiving, at a non-carrier location server, observed time difference of arrival (OTDOA) assistance data and a seed location from a mobile device, wherein the OTDOA assistance data was received by the mobile device from a first location server distinct from the non-carrier location server; and

saving, at the non-carrier location server, the OTDOA assistance data and the seed location to a non-carrier OTDOA library for building a base station almanac;

wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations.

28. A method in a non-carrier location server comprising a non-carrier observed time difference of arrival (OTDOA) library and for building a base station almanac, the method comprising:

extracting OTDOA assistance data and seed locations from the non-carrier OTDOA library, wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations;

computing locations from the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

saving the locations to the base station almanac.

29. The method of claim 28 , wherein computing the locations comprises computing a location for each base station of a plurality of pairs of base stations.

30. The method of claim 28 , wherein computing the locations comprises solving a system of equations wherein:

known variables comprise at least five different seed locations and the expected time difference of arrival of signals for each of the at least five different seed locations; and

unknown variables comprise the locations of the pair of base stations and a time difference between the pair of base stations.

31. A non-carrier location server for building a base station almanac, the non-carrier location server comprising:

a non-carrier observed time difference of arrival (OTDOA) library; and

processor and a memory comprising code in the memory to be executed by the processor for:

extracting OTDOA assistance data and seed locations from the non-carrier OTDOA library, wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations;

computing locations from the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

saving the locations to the base station almanac.

32. A non-carrier location server for building a base station almanac, the non-carrier location server comprising:

means for extracting observed time difference of arrival (OTDOA) assistance data and seed locations from a non-carrier OTDOA library, wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations;

means for computing locations from the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

means for saving the locations to the base station almanac.

33. A non-carrier location server for building a base station almanac, comprising a processor and a memory coupled to a non-carrier observed time difference of arrival (OTDOA) library, wherein the memory includes code to be executed by the processor for:

extracting OTDOA assistance data and seed locations from the non-carrier OTDOA library, wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations;

computing locations from the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

saving the locations to the base station almanac.

34. A computer-readable storage medium including non-transient program code stored thereon to be executed by a processor for:

extracting observed time difference of arrival (OTDOA) assistance data and seed locations from a non-carrier OTDOA library, wherein the OTDOA assistance data comprises an expected time difference of arrival of signals at a seed location from a pair of base stations;

computing locations from the OTDOA assistance data, wherein the locations comprise a location for each base station of the pair of base stations; and

saving the locations to a base station almanac.

35. A position determination method in a mobile device, the position determination method comprising:

sending a seed location from the mobile device to a non-carrier location server, wherein:

the non-carrier location server is distinct from a network providing service to the mobile device and distinct from a carrier's location server that offers service to the mobile device, and

the non-carrier location server comprises a non-carrier observed time difference of arrival (OTDOA) library and a base station almanac;

receiving, at the mobile device, at least part of the base station almanac from the non-carrier location server, wherein the base station almanac was derived at least in part from observed time difference of arrival (OTDOA) assistance data from the carrier's location server; and

computing a position estimate of the mobile device based on the at least part of the base station almanac.

36. The position determination method of claim 35 , wherein the part of the base station almanac received by the mobile device comprises a location of neighboring base stations.

37. The position determination method of claim 36 , wherein the location of neighboring base stations comprises the location of neighboring base stations for a combination of networks, including the network providing service to the mobile device.

38. The position determination method of claim 35 , wherein computing the position estimate of the mobile device based on the at least part of the base station almanac further comprises measuring a time of arrival, at the mobile device, of a reference signal from one or more of neighboring base stations.

39. A mobile device comprising

a transmitter and receiver;

a processor comprising a memory and coupled to the transmitter and to the receiver;

wherein the memory comprises code to be executed by the processor for:

sending a seed location from the mobile device to a non-carrier location server, wherein:

the non-carrier location server is distinct from a network providing service to the mobile device and distinct from a carrier's location server that offers service to the mobile device, and

the non-carrier location server comprises a non-carrier observed time difference of arrival (OTDOA) library and a base station almanac;

receiving, at the mobile device, at least part of the base station almanac from the non-carrier location server, wherein the base station almanac was derived at least in part from observed time difference of arrival (OTDOA) assistance data from the carrier's location server; and

computing a position estimate of the mobile device based on the at least part of the base station almanac.

40. The mobile device of claim 39 , wherein the part of the base station almanac received by the mobile device comprises location of neighboring base stations.

41. The mobile device of claim 40 , wherein the location of neighboring base stations comprises the location of neighboring base stations for a combination of networks, including the network providing service to the mobile device.

42. The mobile device of claim 39 , wherein the code for computing the position estimate of the mobile device based on the at least part of the base station almanac further comprises measuring a time of arrival, at the mobile device, of a reference signal from one or more of neighboring base stations.

43. A mobile device configured for position determination operations, the mobile device comprising:

means for sending a seed location from the mobile device to a non-carrier location server, wherein:

the non-carrier location server is distinct from a network providing service to the mobile device and distinct from a carrier's location server that offers service to the mobile device, and

the non-carrier location server comprises a non-carrier observed time difference of arrival (OTDOA) library and a base station almanac;

means for receiving, at the mobile device, at least part of the base station almanac from the non-carrier location server, wherein the base station almanac was derived at least in part from observed time difference of arrival (OTDOA) assistance data from the carrier's location server; and

means for computing a position estimate of the mobile device based on the at least part of the base station almanac.

44. A non-transitory computer-readable storage medium comprising program code stored thereon to be executed by a processor for:

sending a seed location from a mobile device to a non-carrier location server, wherein:

the non-carrier location server is distinct from a network providing service to the mobile device and distinct from a carrier's location server that offers service to the mobile device, and

the non-carrier location server comprises a non-carrier observed time difference of arrival (OTDOA) library and a base station almanac;

receiving, at the mobile device, at least part of the base station almanac from the non-carrier location server, wherein the base station almanac was derived at least in part from observed time difference of arrival (OTDOA) assistance data from the carrier's location server; and

computing a position estimate of the mobile device based on the at least part of the base station almanac.