Location caching with expiration based on location

• US 7,346,360 B1
• Filed: 08/03/2005
• Issued: 03/18/2008
• Est. Priority Date: 08/03/2005
• Status: Expired due to Fees

• Current Assignee: Cingular Wireless II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Cenciarelli, Fulvio, McNamara, Justin, Mikan, Jeffrey Clinton
• Primary Examiner(s): Nguyen; Duc M.
• Assistant Examiner(s): Addy; Anthony S.
• Application Number:
  US11/196,015
• Time in Patent Office: 958 Days
• Field of Search: 455/404.1, 4554561-457, 455/404.2
• US Class Current: 455/456.1
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 88/18 Service support devices; Network management devices

Abstract

A system for locating a device in a wireless network that caches a known location and sets an expiration time based on the location. The system correlates the location with known places, such as movie theaters, restaurants, etc. to set the expiration time. For example, if a device was known to be at a movie theater, the expiration time would be set to a longer period of time. However, if the device was determined to be in a moving location, the expiration time would be set to a shorter period of time. The system also includes a mechanism to query the cached location based on a current time of the query and a granularity variable the accounts for a geographic area in which the device is located. The system also accounts for special locations where the mobile device will likely not be moving for long periods of time, or locations where the mobile device may move great distances between determinations of actual location.

Claims

1. A method of providing information in response to a query of a database containing cached data regarding a location of a mobile device, comprising:

receiving a query of a database containing cached data regarding a location of a mobile device, said cached data including a time at which said location data was cached and said query having a desired granularity, said granularity representing a size of a geographic area to be returned by said query;

determining a granularity variable, said granularity variable representing a time value based on the size of the geographic area associated with said desired granularity;

determining a time of said query;

determining an adjusted time of said query, said adjusted time being based on the time of said query and said granularity variable;

comparing said adjusted time to said cached data time;

determining characteristics of said location; and

providing said cached data in response to said query in accordance with said desired granularity, said adjusted time of said query and said characteristics of said location.

2. The method of claim 1, said determining characteristics of said location further comprising determining if said location is special.

3. The method of claim 2, further comprising determining whether said location has a granularity restriction, said granularity restriction preventing an adjustment to said time of said query.

4. The method of claim 3, further comprising:

determining if the mobile device is at a moving location;

determining if information regarding one of traffic and transit associated with the moving location is available;

determining a speed at which the mobile device is moving; and

adjusting said cached location data based on said speed and one of said traffic and transmit information.

5. The method of claim 1, further comprising:

determining if said cached data has expired; and

querying a location service for said location associated with said mobile device if said cached data has expired.

6. The method of claim 1, wherein said mobile device is a wireless handset communicatively connected to a wireless telephony network.

7. The method of claim 1, wherein said granularity variable represents a time required to leave said geographic area represented by said granularity of said requested location data.

8. The method of claim 1, further comprising:

determining a first granularity variable, said first granularity variable representing a first time value based on a size of a first geographic area associated with said desired granularity;

determining a second granularity variable, said second granularity variable representing a second time value based on a size of a second geographic area associated with said desired granularity;

wherein said adjusted time of said query is based on said time of said query and at least one of said first and said second granularity variables.

9. The method of claim 8, wherein said second geographic area is larger than and encompasses said first geographic area.

10. The method of claim 1, wherein said granularity variable represents a maximum time required to leave said geographic area represented by said granularity of said requested location data.

11. The method of claim 1, wherein said granularity variable defines a maximum boundary of a validity of said cached location data to identify said location of said mobile device.

12. The method of claim 1, further comprising:

determining a plurality of granularity variables, each of said plurality of granularity variables being associated with a size of a geographic area associated with said desired granularity to be returned by said query;

determining an adjusted time of said query, said adjusted time being determined based on the time of said query and at least one of said plurality of said granularity variables; and

providing said cached data in response to said query of said database for said location of said mobile device, said desired granularity of said query representing a maximum boundary of the size of a geographic area associated with one of said plurality of granularity variables.

13. A system for determining a present location of a device in response to a query, comprising:

a radio network capable of communicating with said device;

a location database configured to cache data regarding a cached location of said device, said cached data including a time at which said cached location data was cached; and

a position determining engine capable of receiving a query of said location database, said query having a desired granularity, said granularity representing a size of a geographic area to be returned by said query;

said position determining engine being further capable of determining a granularity variable, said granularity value representing a time value based on the size of the geographic area associated with said desired granularity, determining a time of said query, determining an adjusted time of said query, said adjusted time being based on the time of said query and said granularity variable, comparing said adjusting time to said cached data time, determining characteristics of said location, and providing said cached data in response to said query in accordance with said granularity, said adjusted time of said query, and said characteristics of said location.

14. The system of claim 13, wherein if said characteristics of said location indicate that said location is special, it is determined if said location has a granularity restriction that prevents an adjustment to said time of said query.

15. The system of claim 13, said position determining engine being further capable of determining whether said mobile device is moving.

16. The system of claim 13, wherein if a cached location in said location database has expired based on said time, said system determines an actual position of said mobile device via said radio network.

17. A method of caching data to be used to respond to a query for a location of a mobile device, comprising:

receiving information regarding a location of a mobile device, said information having a granularity associated with a size of a geographic area of said present invention;

determining a granularity variable associated with said granularity, said granularity variable representing a time value based on the size of the geographic area associated with said granularity;

determining characteristics about said location, said characteristics including information regarding whether said location is a special location;

determining whether said location of said mobile device matches a cached location; and

storing said location in a cache database together with a current time and an expiration time value associated with said location, said expiration time value being based on said granularity of said location, said granularity variable, and an adjusted time of a query for said location, said adjusted time being based on a time of said query and said granularity variable, said characteristics of said location, said characteristics including whether said location is a special location.

18. The method of claim 17, further comprising storing said location in said location database in accordance with a number of times said mobile device is determined to be at said location.

19. The method of claim 17, further comprising:

setting said expiration time to a first expiration time based on a first determination that said mobile device is at said location; and

setting said expiration time to a second expiration time based on a second determination that said mobile device is at said location.

20. The method of claim 19, further comprising setting said expiration to a subsequent expiration time based on a subsequent determination that said mobile device is at said location.