GPS Location Guidance System for the Visually Impaired using Mobile Telephone Communication

Abstract

To develop a portable location guidance system for the visually impaired for use outdoors, we improved the GPS and mobile telephone based guidance system. The basic system consisted of a user terminal (Mobile station), a location data processor (Base station), and a modem for data exchange. In this paper, a new communication method using DIME (Dual Tone Multi-Frequency) for GPS data transmission was used to reduce the initial communication set-up time before the beginning of speech information. Consequently, the set-up time was reduced from 30 seconds to 10 seconds. Restarting a communication link after a telephone line interruption became easy making it possible to continue sequential speech information corresponding to GPS data. Furthermore, the modem unit was removed.