Patent 無線ゾーン構成法 上原一浩, 鹿子嶋憲一, 関智弘 Application no. 特願平06-242440 Date applied Sep 12, 1994 Announcement no. 特開平08-84367 Date announced Mar 26, 1996 Patent/Registration no. 特許3166024 Date registered Mar 9, 2001 Date issued