Next generation WDM networks with multi-channel protection, recovery and equalization

The next generation WDM optical network, in addition to link protection includes fast channel protection and service restoration. For this to be accomplished, high-bandwidth channels that transport in excess of 2.5 Gbps, need be continuously monitored for performance parameters. Performance may be degraded for a number of reasons, such as attenuation, dispersion, insertion loss and others that depend by en large on temperature variations and other non-linear interactions in the fiber medium. As a consequence, the speed of detecting severe degradations or failures, determines the speed of protecting a channel. In several cases however, channel equalization may be adequate thus avoiding switching to protection. In WDM networks, because of the multiplicity of optical channels in a fiber, It may be needed to switch to protection or equalize multiple channels in parallel. To date, this parallel and simultaneous channel remedy has not been done; only one channel at a time in a serial manner. In this paper we present a novel in-service performance monitoring method, which in conjunction with a fast and intelligent protocol lends itself to multiple channel self-restoration or multiple channel equalization. Performance parameters such as power, BER, SNR and Q-factor are monitored in-service and in real-time so that fast remediation action is taken as performance approaches a low acceptable threshold level.