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:
Aug. 14, 2001
Filed:
Jun. 30, 1999
Kevan P Jones, Totnes, GB;
Roger M Gibb, Paignton, GB;
Robert A Baker, Newton Abbot, GB;
Martin P Poettcker, Totnes, GB;
Mark E Bray, Paignton, GB;
Barrie Flintham, Paignton, GB;
James Regan, Staverton, GB;
Toby J Reid, Torquay, GB;
Alan A Solheim, Kanata, CA;
Robert W Keys, Stittsville, CA;
Mark R Hinds, Ottawa, CA;
Joseph Mun, London, GB;
Nigel E Jolley, Herts, GB;
Alan Robinson, Harlow, GB;
Jonathan P King, Epping, GB;
Simon P Parry, Harlow, GB;
Nortel Networks Limited, Montreal, CA;
Abstract
In a WDM optical transmission system employing optical amplifiers in its transmission path, a supervisory signal channel, used for monitoring and controlling the operation of the amplifiers and spectrally separated from the data transmission, may be multiplexed with the data. A construction of amplifier is disclosed which is capable of being upgraded with an upgrade of the transmission system to include additional data handling capacity, for instance data transmission in an additional waveband and/or in the opposite direction, without interruption of the pre-upgrade data transmission path through the amplifiers. This is accomplished by the use of channel dropping and insertion filters disposed so that the amplifying data transmission path extends via the drop/insertion channel of those filters.