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:
May. 21, 2002

Filed:

Nov. 30, 1998
Applicant:
Inventor:

Peter William Phelps, Nepean, CA;

Assignee:

Nortel Networks Limited, St. Laurent, CA;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04J 1/16 ;
U.S. Cl.
CPC ...
H04J 1/16 ;
Abstract

A line condition control (LCC) algorithm is disclosed that is implemented within a switching card that chooses, for information transmission, between working and protection fiber optic channels. The disclosed LCC algorithm ensures that a channel with an oscillating signal failure condition will be utilized instead of a channel with a solid signal failure condition. The LCC algorithm, input with an input line condition (ILC) corresponding to one of the fiber optic channels, outputs a corresponding output line condition (OLC) that is input to a decision algorithm within the switching card. The OLC is set to a signal degrade condition if either a protection oscillation control (POC) mechanism is activated or if a specified number of signal failure condition clearances are detected within a set time period which, in turn, activates the POC mechanism. Otherwise, the OLC is set equal to the ILC. A channel with a signal degrade condition will always be chosen by the decision algorithm over a channel with a signal failure condition and therefore, a channel with an oscillating signal failure condition that has its OLC set to a signal degrade condition will be chosen over another channel that has a solid signal failure condition.


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