Fast Ethernet Restoration based on Alternative Wavelength Paths

We propose and we experimentally demonstrate a novel fast restoration method for Gigabit Ethernet based on the wavelength recovery. It permits to route the wavelength of a broken link in another existing ling exploiting the wavelength division multiplexing of the fibre. Such a procedure is obtained by means of an optical switch, driven by a Loss of Light signal generated by the router in case of link failure. This way we exploit the fibre capacity by means of the WDM transmission for network reliability. Such a method has been tested in an IP optical network consisting of three core routers with optical Gigabit Ethernet interfaces connected by means of 50 km long single mode fibers between Rome and Pomezia. Comparing with other conventional restoration techniques, as OSPF and MPLS, our method resulted very fast (20 ms) and compatible with real time TV services.