1x HDP Enhancements
Enhanced Location Based Services Support in cdma2000
Enhance Downlink Positioning in WiMAX/16m
How Wide A Widband Channel Should Be?
IEEE ICC 2008 Tutorial, Location Based Services for Mobiles
Location Based Services for Mobiles: I. Introduction
There are many ways locating a mobile in a cellular network. The basic methods include dead reckon, proximity sensing, signal signature tracking, trilateration, multilateration, triangulation, etc. Some major approaches for cellular networks can be illustrated in Figure 1.
|Figure 1. Mobile Positioning Techniques, IEEE ICC 2008 "Location Based Services for Mobiles"|
Positioning performance is understood through quantifying the two parameters, hearability and accuracy. Hearability indicates how many hearable good references a terminal can track in a single snapshot. A typical number should be not less than 4. Accuracy is a well-known parameter for understanding the stability of each fix. Usually it is quantified through the 2nd order statistics of fixes. A comparison of several mobile positioning schemes is shown in Figure 2.
|Figure 2. A comparison of mobile positioning schemes|