In April 2001 NASDA launched a new project called "WINDS", Wideband InterNetworking engineering test and Demonstration Satellite, to realize the requirement of Japanese Cabinet IT strategy called "e-Japan Priority Policy Program". The WINDS project is aimed at demonstrating technologies necessary to construct the satellite-based ultra high=speed global fixed wireless communications networks. Based on this objective, NASDA works with CRL to develop the WINDS experiment system to be launched in FY 2005. The WINDS experiment system is planned to demonstrate various experiments, using newly key technology such as multi-beam antenna/multi-port amplifier, Ka band active phased array antenna, on-board ATM switch and so on. This paper describes the concept and outline of the WINDS network experiment system.