Highly accurate PHS location service system

摘要

This paper overviews our highly accurate Location Service (LCS) System for the Personal Handy Phone System (PHS) [1][2] infrastructure. It is an enhanced version of the PHS location service that commenced service in Mau 1998. The system concept, system configuration, and position estimate algorithm are described. Field test results are also presented. We show that the proposed position estimate algorithm reduces the position estimation error by about 50 % compared to the conventional cell-ID-based algorithm. NTT DoCoMo Inc. started the enhanced PHS LCS in February 2001.