A system for locating a device in a wireless network that caches a known location and estimates a location at a given time based on a speed at which the device is moving. The system initially determines plural locations and determines the speed from location. The speed and location information is stored in a cache. The system also includes a mechanism to query the cache. The system extrapolates an estimated location of the device based on the time of the query and speed of the device. Route information may be factored into the determination to account for traffic, transit or travel itinerary.