Mobile location tracking in DS CDMA networks using forward link time difference of arrival and its application to zone-based billing

Due to the FCC requirement that operators of mobile communications networks be able to accurately locate mobile callers requesting emergency assistance via 911 by the year 2001, there has been substantial research and development activities dedicated to examining cellular positioning options. Fueled by this new requirement, the network operators are also considering other, profitable services that make use of the mobile location. With code-division multiple access (CDMA) being deployed by a variety of cellular and PCS providers in the form of the IS-95 standard, developing an approach for location in CDMA networks is imperative. This paper is concerned with developing a solution that does not require any changes to the existing cellular standard nor any changes to the mobile station architecture. Results of field trials conducted in boroughs of New York City are introduced to show the accuracy and shortcomings of the technique. Application of this technique to provide a zone-based billing service is also introduced in this paper.