Satellite Communications for Large Scale Disasters: In search of a robust society

摘要

2011年3月11日の東日本大地震によって東北地方の広大な地域において通信網が壊滅的な被害を受けた。壊滅した通信網の早期復旧のためにあらゆる努力が払われ、セルラー通信の基地局機能と電源設備を備える自動車が広く展開された。セルラー通信網のェントランス回線の復旧に予想外の時間がかかることが明らかになると衛星通信回線に対する需要が急増した。そのため利用可能なあらゆる衛星通信網が総動員された。IPSTARは被災地の高速インターネットの早期復旧に広く利用された。またエントランス回線の提供によりセルラー通信網の早期復旧に大きな貢献をする事ができた。千年に一度の大災害により衛星通信の果たせる役割が明確になった。本稿においては衛星通信が災害復旧に果たした役割とぶっかった問題を報告し、将来に向けての改善策を提案する。%The Great earthquake and tsunami on 11,March, 2011 destroyed the communications infrastructure over wide areas in Tohoku regions. Great efforts were made for prompt recovery of the communication infrastructure; many emergency vehicles with power supply and transportable BTS functions were dispatched in the disaster areas. It was soon recognized that recovery of the damaged optical fiber entrance links would take so long that the demand for satellite communication suddenly surged. The satellite communication systems available in Japan were fully mobilized. IPSTAR system was also widely used for the entrances links for mobile communication operators and also for the Internet connections in the emergency facilities. The great natural disaster clarified the essential roles of satellite communications in emergency situations. In this paper we will report how satellite communications including IPSTAR were used for the relief efforts, review the problems and propose a few improvements and new applications of satellite communications for the future.