Mobile device geolocation
View Patent ↗GPS receivers are included in many mobile communications devices; however, there are circumstances where GPS is unavailable or undesirable to use. In an implementation, a device identifies nearby wireless signals, such as Wi-Fi access points and cell towers, and compares them to a database of known signals to determine an approximate location for the device. Because such a database can be large and change rapidly, it may not be appropriate to store the database entirely on a device. Instead, a server may store the database. In an implementation, to minimize the time required to determine a device's location, the device may first transmit location-related information to a server and receive a subset of the database corresponding to an area near the device so that future locations nearby can be determined without needing to communicate with the server.
1. A method comprising:
transmitting to a server remote from a computing device first location-related information associated with a current location of the computing device, the first location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the current location;
after the transmitting to the server, receiving at the computing device second location-related information from the server, wherein the server utilizes an external location service accessible via a Hypertext Transfer Protocol (HTTP) application programming interface (API) to estimate a location of the computing device based on the first location-related information, wherein the second location-related information represents a portion of a database of location-related information stored at the server that corresponds to an area around the device's estimated location, and wherein the second location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower at or near the estimated location of the computing device;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information; and
at the computing device, estimating a new location of the computing device based on the second location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information.
2. The method of claim 1 wherein the new location is determined without the computing device receiving further communications from the server beyond the second location-related information.
3. The method of claim 1 comprising:
transmitting to the server third location-related information associated with a second current location of the computing device, the third location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the second current location;
receiving at the computing device fourth location-related information different from the second location-related information from the server, wherein the server utilizes the external location service accessible via the HTTP API to estimate a second location of the computing device based on the third location-related information, wherein the fourth location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower at or near the estimated second location;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the fourth location-related information; and
estimating at the computing device a second new location of the computing device using the fourth location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the fourth location-related information.
4. The method of claim 1 comprising:
transmitting to the server location-related information associated with the new location of the computing device;
receiving at the computing device third location-related information from the server, wherein the server utilizes the external location service accessible via the HTTP API to estimate a second location of the computing device based on the location-related information associated with the new location of the computing device, and wherein the third location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower at or near the estimated second location;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the third location-related information; and
in response to a request to determine a location of the computing device, estimating at the computing device the location using the third location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the third location-related information.
5. The method of claim 4 wherein the request is from the server.
6. The method of claim 4 wherein the request is from an application program on the computing device.
7. The method of claim 1 wherein the first location-related information includes GPS information.
8. The method of claim 1 wherein the first location-related information includes Wi-Fi access point signal information.
9. The method of claim 1 wherein the first location-related information includes cell-tower signal information.
10. A method comprising:
transmitting from a computing device first location-related information associated with a current location of the computing device to a server remote from a computing device, the first location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the current location;
after the transmitting to the server, receiving at the computing device second location-related information from the server, wherein the server utilizes an external location service accessible via an HTTP API to estimate a location of the computing device based on the first location-related information, wherein the second location-related information represents a portion of a database of location-related information that corresponds to an area around the device's estimated location, and wherein the second location-related information includes identification of at least one Wi-Fi access point and of at least one cell tower at or near the estimated location of the computing device;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information; and
at the computing device, estimating a new current location of the computing device based on the second location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information.
11. The method of claim 10 wherein the database includes information identifying the at least one Wi-Fi access point at or near the current location of the computing device and information identifying other Wi-Fi access points.
12. The method of claim 11 wherein the database is stored at a location remote from the computing device.
13. The method of claim 10 wherein the information identifying the at least one cell tower at or near the current location of the computing device includes information identifying other cell towers.
14. The method of claim 13 wherein the database is stored at a location remote from the computing device.
15. A method comprising:
transmitting to a server from a computing device first location-related information associated with a first current location of the computing device, the server being remote from the computing device, and the first location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the first current location;
after the transmitting to the server, receiving at the computing device second location-related information from the server, wherein the server utilizes an external location service accessible via an HTTP API to estimate a first location of the computing device based on the first location-related information, wherein the second location-related information represents a portion of a database of location-related information stored at the server that corresponds to an area around the device's estimated location, and wherein the second location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower in an area around the estimated first location of the computing device;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information; and
at the computing device, estimating a second location of the computing device based on the second location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information when the computing device is within the area around the estimated first location of the computing device.
16. The method of claim 15 wherein the database includes information identifying the at least one Wi-Fi access point or identifying a plurality of cell towers.
17. The method of claim 15 wherein the second current location is determined without the computing device receiving a GPS satellite signal.
18. The method of claim 15 further comprising:
transmitting to the server from the computing device third location-related information associated with a third current location of the computing device, the third location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the third current location;
receiving at the computing device fourth location-related information different from the second location-related information from the server, wherein the server utilizes the external location service accessible via the HTTP API to estimate a third location of the computing device based on the third location-related information, wherein the fourth location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower in an area around the estimated third location of the computing device;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the fourth location-related information; and
estimating at the computing device a fourth location of the computing device using the fourth location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the fourth location-related information.
19. The method of claim 15 wherein the area around the first current location is a first area and the method further comprising:
when the computing device is in a second area, outside the first area, transmitting a request from the computing device to the server to receive third location-related information, the third location-related information including identification of at least one Wi-Fi access point or of at least one cell tower in the second area;
at the computing device, measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the third location-related information; and
estimating at the computing device a third location within the second area at which the computing device is located using the third location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the third location-related information.
20. A method comprising:
receiving at a server from a computing device first location-related information associated with a first current location of the computing device, the server being remote from the computing device, and the first location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the first current location; and
upon the receiving at the server, transmitting to the computing device from the server second location-related information, the server utilizing an external location service accessible via an HTTP API to estimate a first location of the computing device based on the first location-related information, wherein the second location-related information represents a portion of a database of location-related information stored at the server that corresponds to an area around the device's estimated location, and wherein the second location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower at or near the estimated first current location of the computing device, thereby enabling the computing device to locally process the second-location related information to determine a second location of the computing device by measuring signal strengths received from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information and estimating the second current location of the computing device based on the second location-related information and the measured signal strengths from the at least one Wi-Fi access point or from the at least one cell tower included in the second location-related information.
21. The method of claim 20 further comprising:
receiving at the server third location-related information associated with a second current location of the computing device, the third location-related information including identification and signal information for nearby Wi-Fi access points and cell towers and associated signal characteristics detected by the computing device at the second current location; and
transmitting to the computing device fourth location-related information different from the second location-related information, the server utilizing the external location service accessible via the HTTP API to estimate a third location of the computing device based on the third location-related information, wherein the fourth location-related information includes identification of at least one Wi-Fi access point or of at least one cell tower at or near the second current location of the computing device.
22. The method of claim 20 further comprising:
receiving at the server a second current location of the computing device; and
transmitting to the computing device from the server third location-related information, the third location-related information including identification of at least one Wi-Fi access point or of at least one cell tower at or near the second current location.
23. The method of claim 20 wherein the first location-related information includes GPS information.
24. The method of claim 20 wherein the first location-related information includes Wi-Fi access point signal information.
25. The method of claim 20 wherein the first location-related information includes cell-tower signal information.
26. The method of claim 1 wherein the portion of the database of location-related information stored at the server corresponds to the current location of the computing device.
27. The method of claim 3 wherein the fourth location-related information represents a portion of the database of location-related information different from the portion received for the second location-related information.