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:
Feb. 28, 1989
Filed:
Mar. 26, 1986
Dieter Gantenbein, Adliswil, CH;
Fritz R Gfeller, Ossining, NY (US);
Eduard P Mumprecht, Meilen, CH;
International Business Machines Corporation, Armonk, NY (US);
Abstract
In an infrared communication system in which many units of different requirements can communicate with each other, transceivers are assigned to different categories, each with its own transmitting power and receiving sensitivity depending on the required distance range. This allows simultaneous independent infrared communications in different local areas between low power/sensitivity devices but enables also transmission over larger distances or over the whole system between larger power/sensitivity devices. Depending on the power/sensitivity relation and distance, a potential receiver may either be able to decode data signals correctly, or it may be only able to detect the presence of a carrier. To allow a clear access protocol in all cases, a unit gets two chances to reenter access competition after having sensed the carrier: Either upon decoding a data end delimiter, or upon a timeout equal to the longest possible packet transmission time. A mixed-media network is obtained by attaching, via respective interface units, subnetworks in which units are interconnected by cables but use the same access protocol as the IR interconnected units.