Abstract
To communicate between a train and various destinations were very difficult resent days. But development of radio technologies and 'everything on IP' make it possible. We are aiming 'Unified IP Network' for train drivers, conductors, rail-side workers and passengers boarding the trains to provide data and voice communications, over wireless IP network. But broadband radio network was very expensive and spread spectrum modulation was very special past days. Development of Wireless LAN system makes it real. We are decided to put IEEE802.11b radio stations every 400-600m at wayside to communicate to the rolling stocks to experiment. To keep in touch between ground and rolling stock, the system decides a radio station, which can communicate with best signal quality. And the train pass that station, it hands over to neighbor station. We try 120km/h hand over test and we can communicate smoothly.
