Estimated accuracy of location in mobile networks using E-OTD

Abstract

This master thesis was performed for Telenor Research and Development, department Fornebu, Norway. The assignment was to evaluate the accuracy of the Enhanced Observed Time Difference (E-OTD) location method. Location related services are described as the next revolution on services and functionality in the mobile network. Location technology will help the operator to estimate the location of a mobile station in the network. But different location services require different accuracy of the location estimate. It is therefore important to find out what location method(s) is suitable for the operators needs. This report will give an overview of the most important location technologies for the GSM network on the market today and examples of the most common location services. It will also describe the network architecture needed to implement the E-OTD method. The main subject of the report is evaluation of the E-OTD location method. The basics and the calculation methods are described in detail. A simulation model for the E-OTD method was also created during the work of this master thesis. This model and the results of the simulation runs are explained and shown. The E-OTD method requires network update in the form of Location Measurement Units (LMUs) to compensate for the GSM network not being synchronised. These units will provide the operator with upgrade costs. It was therefore evaluated the requirements for LMUs in the work of this master thesis, and the results is shown and discussed in this report.