Time-, wavelength-, and code-domain optical reflection monitoring for next-generation access-metro networks

Distributed optical reflectors are proposed to implement essential fault management operations such as fault detection, localization, and notification, in next generation all-optical access-metro networks in the optical layer. Fixed time-slots, wavelengths, or optical codes are assigned to selected key network locations along the path of a monitoring signal where corresponding mirrors are placed. The reflection received at a transmitting node enables online all-optical monitoring of the selected locations. After detailing the network architecture, we explore fundamental system design issues such as real-time fault localization algorithms, fault notification delay upperbounds, and delay line calculation algorithms for synchronous operation. Our simulation results showcase standard and long-reach passive optical networks, and demonstrate that our algorithms achieve fault notification at light speed using off-the-shelf components.