Extending path computation element for lightpath restoration in wavelength-switched optical networks

<正>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 deflection routing scheme is proposed to achieve fast restoration. It uses the expanded PCE component to compute and assign the backup paths for lightpath recovery. Numerical results demonstrate that this scheme is effective and low cost.     

Wavelength pre-assignment collision schedule for wavelength-routed optical networks

A novel wavelength assignment scheme called the wavelength pre-assignment collision schedule （WPCS） is proposed for wavelength-routed networks. The WPCS pre-assigns the wavelength at the forward detection phase, and schedules the potential collision by priority. The potential collision is scheduled at the forward detection phase and the blocking of the wavelength assignment is reduced. Simulation is conducted with several other existing schemes. The numerical results show that WPCS performs better than other schemes in blocking probability under various traffic conditions.