MAHO-based cellular location system

More and more cellular carriers are providing location-based services to their customers. Recently, a major cellular carrier proposed a location determination system based on RSS measurements. RSS measurements of the forward control channels, transmitted by the cellular base stations, are implemented in IS-136, IS-54B and other standards as part of the mobile assisted handoff (MAHO) procedure. The system can measure the RSS of up to 24 forward control channels (IS-136.) Hence, the method can be implemented without introduction of new hardware or software in the system and is considered rather attractive. The location determination method relies on the assumption that there is a one to one mapping between RSS measurements and location. In order to obtain this mapping it was proposed to collect measurements over the coverage area using a grid spacing of 50 meters. Another alternative is to use standard commercial RF prediction tools in order to obtain the desired mapping. The aim of this work is to provide theoretical tools for predicting the potential accuracy of RSS based systems.