Location Based Services (LBS)

An LBS, for example, can point a user to the nearest restaurant. In another example, an LBS can send an SMS message advertising a sale at a nearby shopping mall.

To specify the mobile user's location, one method involves using the mobile phone network. For example, the current cell ID can be used for identifying the base transceiver station (BTS) that the phone is communicating with. Once that is determined, the only thing left is to pinpoint the location of the BTS.

Other systems use GPS satellites. This method is much more accurate than the one previously mentioned and are now made easier by some smartphones that already have built-in GPS receivers. Another common method is the use of short-range positioning beacons. Such devices typically employ WiFi or Bluetooth technologies and are ideal for indoor LBS applications.

These services can be classified into two types: Push and Pull. In a Push type of service, the user receives information from the service provider without requesting it at that instant, although the user may have originally subscribed to the service at an earlier time. The LBS advertisement mentioned earlier is an example of a Push service. In a Pull type, the user has to actively request for information. The restaurant query example belongs to this type.

Software development platforms, particularly those used for creating mobile applications, such as J2ME and Android, have specialized APIs that support LBS.