Satellite broadband system: Its needs and technology

This paper focuses on the needs of satellite broadband systems in the time frame of end-20th Century to mid-21st Century and discusses the necessary technology development. First, the outline of the Japanese experimental broadband satellite, WINDS (Wideband InterNetworking engineering test and Demonstration Satellite) is described. The needs of broadband stems from the research of requirement for bridging digital divide, disaster mitigation and Pan-Pacific applications in 1990s-2000s. Second, the future needs in the next 30 years is shown in correspond to recent rapid increase of capacity of terrestrial link in terms of three generations of communications satellite: 2000-2010; the first generation (1G) satellite having a capacity of 5-50 Gbps per satellite, 2010-2020; the second generation (2G) satellite 50-500 Gbps, and 2020-2030; the third generation (3G) satellite 0.5-5 Tbps. Third, the communication needs for Mars human community is considered as far future needs. It describes the necessity of creating the mirror database of Earth on the Mars for the Mars human community in connection with the recent Internet movement to the Web 2.0. It is shown that the transmission rate needs 8 Gbps and such a high data rate communication link between Earth and Mars can be constructed by using optical communications technology.