Idealog: Indoor positioning system

GPS and GLONASS are satellite based positioning systems which work wonderfully outdoors however, due to wall penetration issues, indoors is a different story. This is a problem if you are trying to get to a place in a huge Railway station, Airport or a mall. Briefly, positioning with GPS works is as follows –

  1. Satellites broadcast a signal at the speed of light containing two information i.e. transmit time-stamp and its own location
  2. GPS receivers in devices e.g. smart phones, car devices receive these signals
  3. If signals are available from at least 3 satellites, an algorithm in the receiver calculates its distance from all the satellites and hence, the is able to derive its own location
  4. The accuracy of this is within 10 meters

Think of a system which is made up of beacons installed within a premise transmitting a similar signal and leading to devices being able to locate themselves within an indoor infrastructure. Ideally such system should rely on the current radios within the devices to provide them location information so as to minimally disrupt the landscape however, that seems unlikely as if light transmission is used, the travel time would be too less to actually be able to calculate location based on travel time and distance.An app on the device would need to provide user interface for map and navigation using this location information and perhaps that’s where other radios could be used to process a slower signal.How about it?