Location-Based Services: A Primer

LBS encompass all applications that rely on position information in a mobile context, from basic 911 subscriber calls, to personal navigation, in-vehicle telematics or commercial asset tracking. In most instances, the ability to quickly and accurately calculate a position is paramount to customer satisfaction and revenue potential.
Legacy Positioning Techniques IssuesEver wondered what happens when you call 911 on your mobile? A few years ago, several regulatory agencies worldwide, including the US and the FCC’s E911 program, mandated mobile operators be able to relay a subscriber’s position to emergency response personnel. Until recently, the accuracy of these positions, approximated from nearby cell sites, remained of the order of a city-block in urban centers, but could be several kilometers off in rural settings or along highways. Operator compliance remained low as no valuable commercial services could be derived from infrastructure investments required in these legacy techniques.
Assisted-GPS—The New StandardGPS technology already enables cost-effective, street-corner position accuracy. Conventional GPS technologies however do not meet LBS requirements given potentially long initial position calculation delay, ongoing battery consumption and poor “in-building” performance. Assisted-GPS represents an evolution of GPS that relies on rough position information readily available from the network at no cost (i.e. the nearest cell site) and the ability to then download useful data to the handset to help it quickly determine its position. AGPS chips consume very little battery power and yield quick and accurate location information. This helps operator meet their regulatory requirements and enables them to deploy more valuable applications from which additional subscriber revenues can be derived.