A mobile device operating in a cellular communication network determines its current location via the cellular communication network, for example, by triangulation of the base stations of the cellular communication network. At its current location, the mobile device also detects a wireless local area network (WLAN) such as a Wi-Fi network. The mobile device then sends the location information and an ID of the WLAN to a network based database server, which creates an entry to store data associating the location information with the WLAN. The mobile device can also store data associating the location with the WLAN in a local storage.