Optical transmission system including performance optimization

Abstract

Vulnerability of an optical network to channel impairments or the like, is addressed by utilizing real-time monitoring and control of prescribed optical channel impairments. The impairments are compensated for by employing an optimization process in the optical network such that the optical signals from the source or sources of the impairments are controllably adjusted at any particular node in the network. The optical signals are attenuated more or less at the source node of the associated optical channel in order to optimize performance of the corresponding optical channel in the network. A variable optical attenuator (VOA) is used at the &lgr; laser source of optical channel having the impairment to obtain the attenuation. The optical signal impairment is measured at a receiving node and the source node of the associated optical channel is determined. Then, a control message is transmitted to the identified source node indicating that a VOA associated with the corresponding optical channel &lgr; laser source is to be adjusted to insert more or less attenuation as the case may be. This process is iterated until the corresponding optical channel yields optimum performance for the impairment being measured. A VOA in a remote node associated with the &lgr; laser source of the associated optical channel is first adjusted. Then, a VOA in the local node associated with the optical channel being monitored is adjusted to further optimize the prescribed metric of the optical channel being monitored. This adjustment is iterated until the performance of the associated channel is optimized.