E ects of snowfall on wave propagation along a 7.7 km 18/26 GHz FWA link

It is expected that Wideband Inter-Networking engineering test and Demonstrate Satellite (WINDS) [1], to be launched in 2008, will pave the way to solve a present day digital divide problem [2]. To make the WINDS experiment successful, a 3-year project entitled ‘mitigation of digital divide via fusion of satellite and terrestrial networks’, was started in 2005; several institutions and universities are being participated in this project. As a member of this project, Hokkaido Tokai University (HTU) has been making a propagation experiment using Fixed Wireless Access (FWA) systems in 18 and 26 GHz bands; these frequencies are very close to those to be used by WINDS transponders. In Sapporo, where HTU locates, we have a large amount of snowfall in winter. Therefore, we put an emphasis of our experiment on clarifying propagation characteristics of cm waves in snowfall, which are not well understood because propagation characteristics in snowfall depend on a large number of parameters such as frequency, drop-size distribution, fall speed, shape, density, water content, temperature, and so on (see e.g. [3]). This paper presents a preliminary result of propagation experiment made along a 7.7 km terrestrial path using frequencies in 18 and 26 GHz bands.