A new scheme for lightpath restoration in wdm networks

All-optical networks with wavelength division multiplexing capability are the promising candidates for the next generation Internet. As these networks carry enormous bandwidth, it is not optional for them to be survivable. Although the available proactive restoration schemes provide 100% restoration guarantee, they require a huge extra capacity and usually result in an extremely high blocking probability. In this paper, we propose a novel active scheme that uses multiple predefined but not reserved backup paths along a working path to restore the lightpath in the event of link-failure. Simulation results based on two typical networks indicate that our new restoration method can reduce blocking probability and capacity requirement significantly while guaranteeing a very high restoration probability.