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.