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. 31, 2002
Filed:
Jan. 29, 1999
Richard G. C. Williams, San Diego, CA (US);
3Com Corporation, Santa Clara, CA (US);
Abstract
A method of transmitting a quite, or zero, signal in a PCM communication system. The zero signal is specified universally in ordered set terms for either &mgr;-Law or A-Law PCM systems, which has minimal energy in the A-Law system, and contains no energy within the &mgr;-Law system. The signal is preferably specified as a repetition of six intervals (or multiple thereof) because the DTN can modify PCM codes on a six interval period by the robbed-bit signaling mechanism. The zero signal may be used to detect network elements that produce single-signed zero outputs from zero inputs of either sign. In addition, by examination of the zero signal the receiver may determine whether the channel includes an analog link or connection.