Offline Geolocation is a technique for determining the geographical location of a phone without using an Internet connection, or GPS satillite positioning. It is ideal as a failover system when a user has no Internet connection, due to roaming or coverage issues, and GPS has not been turned on, or is not available indoors.
This system works by detecting nearby cell tower transmitters, and comparing these details with known geographic locations of these cell towers. This data is stored locally on the device, which can perform a quick lookup to determine the location of the user.
Worldwide cell tower data is quite large (cerca 240Mb), and will considerably increase download times of your app, however we do recommend, that if your app is designed to cater for a country-specific audience, that you download only the data for that country only. Currently either UK or Worldwide data is available, but more countries can be added upon request.
This service is currently in beta development, and for the moment is being offered completely free of charge. All we ask is that you let us know who you are, and what you intend to use the service for.