Locata with Femtocell: Secure Dual Connectivity in Areas with Medium to Weak Mobile Connectivity

The Global Positioning System (GPS) is a reliable, versatile, generally available and comparatively accurate positioning technology, able to operate anywhere across the globe. Nevertheless, the most severe limitation of GPS performance will still remain - the accuracy of positioning deteriorates very rapidly when the user receiver loses direct view of the satellites, which typically occurs indoors or in severely obstructed urban environments. In such environments, the majority of receivers do not function at all, and even the high-sensitivity receivers have difficulty in providing coordinates with sub-decameter level accuracies. A new terrestrial radio frequency (RF)- based distance measurement technology, known as 'Locata', has now overcome the technical challenges required to create "a localized autonomous terrestrial replica of GPS". This paper describes some of the technical aspects of this Australian technology and discusses the possible role Locata can play as part of the National Positioning Infrastructure. Locata has developed a new type of antenna which allows industrial-grade, centimeter-level positioning indoors by mitigating multipath by forming and pointing tight beams at the Locata transmitters, significantly reducing the effects of multipath corruption of the direct positioning signal. This paper briefly describes Locata tests conducted in a number of conditions, including indoors, at an open-cut mine, airborne flight testing, and on Sydney Harbour. A new system can be proposed that will be composed of locata along with femtocell to provide users both GPS and GSM services.