Abstract:

Two integer linear programming （ILP） models based on source formulation are developed to effectively address waveband switching（WBS）-related problems, which include the optimization of networks with multigranular optical crossconnects（OXCs） and networks with additional constraint that all wavebands can only contain lightpaths with the same destination. The topology of NSFNET is employed to compare he numbers of variables and constraints of the source-formulation ILP and link-formulation ILP in current research. The study of the comparison on the complexity shows that the computing complexity is significantly reduced by the model based on source-formulation ILP because of the reason that the model only considers the resource utility of the source node. As a result, the source-formulation ILP can be applied to the optimum solution of the optimization calculation, and used to evaluate the effectiveness of optimization algorithm which will debase the optimization target to reduce the calculation cost.

Key words: optical switch, network optimization, integer linear programming, waveband switching