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:
Nov. 15, 1994
Filed:
Apr. 09, 1992
David J Nicholson, Ottawa, CA;
Donald R Ellis, Ottawa, CA;
John B Mills, Kanata, CA;
Dino C DiPerna, Kanata, CA;
David W Martin, Nepean, CA;
Wang-Hsin Peng, Ottawa, CA;
Kim B Roberts, Kanata, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A communications system is provided having SONET communications channels extending between first and second locations. The channels include pairs of forward and reverse channels for carrying traffic in normal operation between first and second locations and a protection channel for carrying traffic of one channel in the event of a fault. Each pair of forward and reverse channels is provided on a shelf at each location, the shelves having the same relative position at both locations and the protection channel is provided on a protection shelf. The protection channel includes, between the first and second locations, a forward optical link and a reverse optical link and at each of the first and second locations, a single protection loop, coupling the forward and reverse optical links, that forms the protection channel. The protection loop is used to provide, at each location, a local virtual protection loop for indicating the protection requirements and status of the respective location, and a remote virtual protection loop for indicating the protection requirements and status of the location remote from the respective location. The local protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #25 and #2, respectively. The remote protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #26 and #3, respectively.