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:
Sep. 30, 2003
Filed:
Dec. 29, 1999
Applicant:
Inventor:
Richard Epworth, Sawbridgeworth, GB;
Assignee:
Nortel Networks Limited, St. Laurent, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04J 1/400 ;
U.S. Cl.
CPC ...
H04J 1/400 ;
Abstract
An optical packet is provided with an amplitude modulated (ASK) payload and a differential phase shift keyed (DPSK) header so that a routing address in the header can be read and modified at a network node without having to inject light at this node to do this modification. With ASK, though it is easy to convert a high-level bit to a low-level bit by simple attenuation, the conversion of low-level bit to high-level bit requires light injection. With DPSK, bit conversion can be effected without light injection, merely requiring passage through a phase modulator.