Patent · US Expired

Synchronization system using aging prediction

US6104915A · kind A · utility

14Cited by

8References

15Claims

0Family size

Assignee

Nortel Networks Limited · CA

Inventors

Genzao Zhang · Ottawa, CA
Roland A. Smith · Ottawa, CA
Dan Oprea · Gatineau, CA
Roger Ferland · Gatineau, CA

Key dates

Filing date	Dec 24, 1997
Grant date	Aug 15, 2000
Priority date	—
Expiry date	Dec 24, 2017

Classification

Technology area (CPC H)Electricity
CPC primaryH04L7/0083
WIPO fieldTelecommunications
WIPO sectorElectrical engineering

Abstract

An improved local synchronization module which uses Frequency-phase adaptive double locked loop (FPADLL) to control a stable controllable oscillator is disclosed. A single physical feedback loop is implemented which can operate in either a phase locked loop mode or a frequency locked loop mode. The sync module includes a controller which determines in which mode the feedback loop operates. The controller also uses slipping information from a network reference recovery interface to reduce slipping. Also effects of ageing of the stable controllable oscillator are predicted and compensated for.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.