Survey of location based wireless services

The penetration of mobile wireless technologies has resulted in larger usage of wireless data services in the recent past. Several wireless applications are deployed by service providers, to attract and retain their clients, using wireless Internet technologies. New and innovative applications like ringtone/wallpaper downloading, MMS-messaging, videoclip delivery and reservation enquiries are some of the popular services offered by the service providers today. The knowledge of mobile user's location by the service provider can enhance the class of services and applications that can be offered to the mobile user. These class of applications and services, termed "location based services", are becoming popular across all mobile networks like GSM and CDMA. This paper presents a brief survey of location based services, the technologies deployed to track the mobile user's location, the accuracy and reliability associated with such measurements, and the network infrastructure elements deployed by the wireless network operators to enable these kinds of services. A brief description of all the protocols and interfaces covering the interaction between device, gateway and application layers, are presented. The aspects related to billing of value added services using the location information and emerging architectures for incorporating this "location based charging" model are introduced. The paper also presents some popular location based services deployed on wireless across the world.