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:
Jun. 11, 2002
Filed:
Dec. 17, 1996
Shigeru Murata, Kawasaki, JP;
Takamitsu Shirai, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In an exchange including: a call processing unit for processing a call occuring at any one of plural subscriber lines, a main line, or a private line; a switch unit for establishing the call route determined by the call processing unit; and a plurality of trunks for separately connecting to any one of these lines; wherein the exchange comprises: a single or plural decision units for determining whether an audio frequency signal or line signal which separately indicates a state of change of level of the call signal, is received or not, in the route formed by these lines; and a single or plural variable units separately provided between each of routes and a corresponding port of the switch, and performing the change of the level based on the state indicated by the audio frequency signal or line signal which gives a result of decision by the decision unit, for the level of the call signal transmitted toward the route in which the result of the decision is true.