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.

Date of Patent:
Sep. 06, 1994

Filed:

May. 07, 1993
Applicant:
Inventor:

Tohru Ogawa, Kawasaki, JP;

Assignee:

Fujitsu Limited, Kawasaki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04J / ; H04B / ;
U.S. Cl.
CPC ...
370 13 ; 370 76 ; 371 201 ; 375-8 ; 375 13 ;
Abstract

A frequency multiplexing control system includes a first modem unit connected to a transmission line, and a second modem unit connected to the transmission line. The first and second modem units communicate with each other via a plurality of primary channels and a secondary channel. The primary and secondary channels have different frequency bands. A plurality of signal detection units are respectively provided in the first and second modem units, to detect an abnormal primary channel and send to the second and first modem units, information concerning the abnormal primary channel via the secondary channel. A plurality of disabling units are respectively provided in the first and second modem units, to disable the abnormal primary channel in response to the received information and to send a training signal for recovering the abnormal primary channel to the transmission line.


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