Extending path computation element for lightpath restoration in wavelength switc

Current generalized multi-protocol label switching (GMPLS) standards do not include adequate models for wavelength-switched optical networks (WSON) in recovery mechanisms. In this letter, GMPLS/path computation element (PCE) extensions are applied for the restoration of the lightpaths disrupted by collision or optical impairment. A reserved de°ection routing scheme is proposed to achieve fast restoration. It uses the expanded PCE component to compute and assign the backup paths for lightpath rec