The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 1990
Filed:
Jan. 11, 1989
Seiji Hattori, Tokyo, JP;
Akihide Kasukawa, Tokyo, JP;
Yoshizo Shibano, Osaka, JP;
Yoshinobu Kobayashi, Osaka, JP;
Shinji Suzuki, Osaka, JP;
The Tokyo Electric Power Company Ltd., Tokyo, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A mobile station receives radio waves from all signposts through the positioning channels while making communications using the voice channels. The signal levels of the radio waves thus received are subjected to comparison, so that a zone switching request is made to a signpost with the highest signal level, whereby a mobile station can make communication through that signpost which covers the zone where the mobile station is located, even while traveling. The positioning channels are so set that the frequencies assigned to the signposts are switched every frame in a time series mode, and none of the signposts transmit one and the same frequency at the same time. Therefore, the mobile station can receive radio waves from all the signposts without signal interference (which may be caused when a plurality of stations transmit signals equal in frequency). In the system of the invention, the transmission zones of adjacent signposts overlap each other. When a zone switching request is made, a mobile station can therefore make communications with both of the signposts; that is, the switching of zones can be positively achieved.