Alcatel Lucent

Nokia of America Corporation

Simon Paul Creasy

Steven G Driediger

Paul J Brown

Fabien Letourneau

Michel Patoine

Various embodiments relate to a network node and method thereof including a high stability oscillator and a holdover phase-locked loop ('PLL') wherein the holdover PLL is configured to perform a holdover function by receiving a system clock signal, disciplining the high stability oscillator using the system clock signal to generate a local reference signal, and providing the local reference signal as the system clock signal when the system clock signal becomes unavailable.

Method and apparatus for performing a holdover function on a holdover line card

A method and apparatus are provided for conveying low level signals from a first circuit card to a second circuit card. The low level signals are encoded using a simple integer value N, and the low level signals are then communicated to the second circuit card as a sequence of N alternating values. A binary counter is used to generate the sequence of alternating values using the output of a single pin of the counter, although a second pin may be used to generate a clock signal. The invention allows all low level signals to be communicated in a robust yet simple way, minimizing the chance of spurious signals being generated upon hot insertion or extraction without complicated ad hoc solutions.

Simple identification of low-level signals between circuit cards

A printed circuit board card comprising: a printed circuit board having a first thickness and having first and second edges for inserting into respective channels of card guides, the channels of the card guides for receiving printed circuit boards having a second thickness, the second thickness being greater than the first thickness; and, first and second thickness adaptors each having a third thickness applied at the first and second edges, respectively, a sum of the first and third thicknesses approximating the second thickness, to thereby align the printed circuit board in the channels of the card guides.

Printed circuit board thickness adaptors

One embodiment of the disclosures made herein is a method of detecting a transmission unit fault condition in a network system. In accordance with such a method, an operation is performed for designating transmission units received at a first counting location of a datapath, during a first duration consisting of a first specified counting interval and a first specified settling interval after the first specified counting interval elapses, as first designated transmission units. An operation is performed for determining a first datapath ingress transmission unit count for the first designated transmission units at a first counting location during the first duration. An operation is performed for determining a first datapath ingress transmission unit count, an operation is performed for determining a first datapath egress transmission unit count for the first designated transmission units at a second counting location of the datapath during the first duration. After determining the first datapath ingress transmission unit count and the first datapath egress transmission unit count, an operation is performed for indicating a transmission unit fault condition associated with the first specified counting interval when a difference is determined between the first datapath ingress transmission unit count and the first datapath egress transmission unit count after the first specified settling interval elapses.

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Ottawa, Canada

Simon Paul Creasy