Protection and Restoration Schemes in Optical Networks: A Comprehensive Survey

Fault management has become critical in managing survivability of high speed networks. Impact of failure is aggravated with extremely high volume of traffic carried on WDM (Wavelength Division Multiplexing) networks. In a WDM network, failure of a network element may cause failure of several optical channels leading to large data loss which can interrupt communication services. In this paper, existing protection and restoration techniques proposed for optical network are critically reviewed and analyzed. It is concluded that a hybrid of existing protection schemes can be implemented depending on service differentiation, type of optical network and tradeoffs in speed, efficiency, restoration time and cost. Existing work has to be expanded on incorporating intelligence in Optical Networks which can result into efficient management of faults thereby providing protection and restoration.