Patent 無線通信システムおよび無線通信方法 松井宗大, 芝宏礼, 赤羽和徳, 上原一浩 Application no. 特願2008-012745 Date applied Jan 23, 2008 Announcement no. 特開2009-177403 Date announced Aug 6, 2009 Patent/Registration no. 特許5030805 Date registered Jul 6, 2012 Date issued