Algorithm Research Of Routing And Spectrum Allocation In Elastic Optical Network

The Internet traffic has been undergoing exponential growth with the rapidly development of broadband service such as cloud computing and internet of things which has challenged existing optical network. Conventional wavelength-division-multiplexing (WDM) systems suffer from the drawbacks of low bandwidth utilization and inflexibility own to its coarse granularity and rigid wavelength assignment. The future optical network is demanding large capacity, flexibility and scalability. The proposed elastic optical network can provide efficient as well as flexible spectrum assignment by providing fine granularity. But the new technology also bring challenges in routing and spectrum allocation. This paper mainly focus the problem of Routing and Spectrum Assignment (RSA) which can be decomposed into two sub problems:the routing sub problem and the sub problem of spectrum assignment, and proposed optimization algorithm for the two sub problems respectively:We proposed the Genetic Algorithm using Priority-based Encoding (GAPE) for RSA. This algorithm can cover the shortage of the widely used K-shortest routing strategy with providing complete routing space. Experiment results testify the proposed algorithm can help to obtain lower blocking probability and optimize the performance of networks.The maximization of Spectrum-Overlap-Degree (SOD) based algorithm is proposed to assign spectrum. The SOD algorithm take the spectrum condition of adjacent links into consideration when assign resources and utilize the fragmented spectrum effectively. When compare several existing spectrum assign algorithms, the SOD can help to reduce the spectrum fragments and achieve lower blocking probability.