Location Services


Geolocation is the use of network attributes to identify (or estimate) the physical position of a device.

  • A mobile device operates a location service to determine its current position
    • can make use of two systems:
      • Global Positioning System (GPS)
        • means of determining the device’s latitude and longitude based on information received from orbital satellites via a GPS sensor
        • not all mobile devices are fitted with GPS sensors
        • can be slow
          • most smartphones use Assisted GPS (A-GPS)
            • obtain coordinates from the nearest cell tower and adjust for the device’s position relative to the tower
            • uses cellular data
        • GPS satellites are operated by the US government
        • satellites are also operated by:
          • the European Union (Galileo)
          • Russia (GLONASS)
          • or China (BeiDou)
      • Indoor Positioning System (IPS)
        • works out a device’s location by triangulating its proximity to other radio sources
          • cellular radio towers, Wi-Fi access points, and Bluetooth/RFID beacons
  • only available to an app where the user has granted specific permission to use it
  • Some mobile devices are additionally fitted with a magnetometer sensor
    • enables more accurate compass directions