Patent · US Expired

Method and apparatus for channel equalization in wavelength division multiplexed systems

US6040933A · kind A · utility

133Cited by
2References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 19, 1997
Grant dateMar 21, 2000
Priority date
Expiry dateDec 19, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04J14/0221
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus for channel performance equalization in wavelength division multiplexed (WDM) systems is disclosed. Performance of the channels is estimated from optical power measurements of each signal transmitted by the channels. The measurements are taken at the inputs of optical amplifiers in the transmission path of the system. The channels are equalized by adjusting the optical power of the channel transmitters. The method is applicable to point-to-point networks as well as more complex network configurations such as those having an add-drop multiplexer (ADM) for inserting and extracting channels from the transmission path. The method can compensate for signals having different bit rates by applying an offset to the amount of optical power adjustment of the channel transmitters. Furthermore, if different types of optical amplifiers are used in the transmission path, the method can accommodate different noise characteristics of the amplifiers by using their noise figures in determining the amount of optical power adjustment of the transmitters that is required to equalize channel performance.

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