Abstract:

To solve the problem of the increased service request blocking rate and bandwidth blocking rate caused by the fragmentation of the elastic optical network spectrum,the causes of spectrum fragmentation is analyzed in detail.According to the characteristics of optical network carrying services,an elastic optical network fragmentation algorithm based on multi-criteria decision-making is proposed from the perspective of improving spectrum utilization.The algorithm uses the multi-criteria decision-making method to deal with the selectivity problems encountered in the process of defragmentation,and makes decisions by comprehensively considering various evaluation indexes,so as to defragment spectrum fragments.In the traffic routing stage,the algorithm is divided into five stages.In each stage,according to the current state of the optical network,the best decision is made to sort out the spectrum fragments.Each stage marks different types of connections with different labels,and judges them according to the weights set by the multi-criteria decision-making method.Finally,the best scheme is adopted to achieve the best defragmentation effect.Simulation verification is carried out through specific examples,with the results showing that the proposed algorithm has a lower bandwidth blocking rate (36% blocking rate under high load) and high spectrum utilization (up to 65% under high load),which can effectively improve the network request blocking rate under high network load conditions,and provide a theoretical reference for the processing of the spectrum fragmentation of the elastic optical network under actual conditions.

Key words: elastic optical network, spectrum fragmentation, multi-criteria decision-making, bandwidth blocking rate, spectrum utilization