Reliability differentiation in energy efficient optical networks with shared path protection

Abstract

Energy and resource efficiency are two contrasting objectives to optimize in dynamic and survivable optical networks. Known solutions for improving the energy efficiency include the use of the shared path-protection (SPP) mechanism and of a low power consuming mode (i.e., sleep) for protection resources. On the other hand, resource efficiency can be improved by introducing the concept of Differentiated Reliability (DiR) which can be combined with SPP in order to match the level of provisioned protection resources to the reliability requirements for each specific demand. This paper assesses the energy efficiency of the DiR concept combined with SPP and sleep mode support. A multi-objective optimization algorithm is proposed with the intent of jointly optimizing the energy and resource efficiency when dynamically establishing lightpaths with specific reliability levels. Simulation results show that when the proposed multi-objective cost function is properly tuned, not only the SPP-based DiR approach reduces the blocking probability but it is also able to save power for any network load. By enabling sleep mode additional power savings can be achieved at low loads, leading to an overall saving of up to 25%.