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:
Dec. 30, 2003
Filed:
Jul. 05, 2000
Other;
Abstract
Disclosed is a telephone circuit in which two simultaneously available telephones are connected by use of a pair of twisted-paired cables. A PBX and a digital multi-function telephone are connected by a pair of twisted-paired cables, a digital signal channel of 2B+D is established bidirectionally between the PBX and the digital multi-function telephone , and user information and a control signal are sent and received therebetween. The digital multi-function telephone and an analog telephone are connected by a pair of twisted-paired cables, and a signal is sent and received between the digital multi-function telephone and an analog telephone by an analog signal of a voice band and a DC/AC control signal. A B1-channel on a 2-wire digital line is allocated for user information transmission of the digital multi-function telephone , and a B2-channel is allocated for user information transmission of the analog telephone . A D-channel signal is shared by control signals of both the telephones. A bidirectional 2B+D digital signal is sent and received by a proper transmission system such as a ping-pong transmission system.