Slick lightpath reconfiguration using spare resources

This paper presents different methods to solve the network reconfiguration problem in wavelength-switching optical networks. The network reconfiguration problem consists of finding a sequence of operations that can be used to migrate traffic from one lightpath configuration to another. Operations correspond to establishing or tearing down a given lightpath. The methods presented exploit for the first time (to our knowledge) the structure of the underlying combinatorial problems in order to divide the reconfiguration process into independent stages, decreasing the amount of disrupted traffic. Our numerical results show that our approaches can reduce the number of disruptions up to 10% more than the traditional approach (computing the minimum feedback vertex set of the dependency graph), while releasing 40%of seized resources during the reconfiguration process. The methodology presented can be easily adapted to other circuit-switching technologies, such as flexpaths.