Active monitoring of all-optical networks

This paper shows that it possible to decrease the amount of hardware needed to monitor the quality of transmission (QoT) of lightpaths in all-optical networks by establishing carefully selected ldquoactive lightpathsrdquo, without sacrificing estimation accuracy. The QoT of lightpaths that are not directly measured by monitoring equipment is estimated with the help of additional ldquoactive lightpathsrdquo. We gain extra information about the unobserved lightpaths by measuring the QoT of the carefully chosen active lightpaths, which are activated solely for the purpose of monitoring. We demonstrate with simulations the possibility to trade-off the amount of costly hardware monitoring equipment with cheaper, temporary ldquoactive lightpathsrdquo, while still achieving accurate monitoring.