Research Of Defragmentation Algorithm In Bandwidth Flexible Optical Networks

Due to the rapid penetration of broadband access services and various new network services, the rise of social networking sites, such as high definition video (HDTV,3DTV) on-demand, as well as a sharp rise of mobile data services and microblog content sharing applications appearing, allowing IP traffic doubling every two years, and eventually leading to the telecommunications network which supports the entire digital world to encounter unprecedented load. But our existing optical network essentially not only is difficult to adapt to the tri-networks for the business information leading to the massive spread demand, but also it is difficult to meet the future network of low power consumption, environmental protection and other social needs. The face of the increasing burden on future backbone transmission and how to respond to a series of complex issues become an urgent problem to explore and resolve. Now international research on a new type of optical transport network system is very hot, and the spectrum flexible optical network system is an important research direction.The new spectrum slices flexible optical network of high spectral efficiency and high scalability has been proposed, the business spectrum resources in the elastic optical network contain three conditions, it is wavelength continuity, spectral continuity, and spectral conflict constraints. At the same time, the distance adaptive resource allocation which provides flexible optical network optimization strategies becomes more complex. In a dynamic network environment, the service is assigned in accordance with the order of arrival corresponding path and spectrum, which results in frequent business establishment and removal process, will be left out the continuous spectrum which not in the optimal path, generate a lot of spectrum fragmentation so that the utilization of the network spectrum is very low. The mechanism of the wavelength and the signal size is not fixed in the flexible optical network brings efficient spectrum utilization, defragmentation on the network as the network running will be effective to clean up it on time, improve network performance.We proposed a fragmentation spectrum flexible optical network reconstruction algorithm facing the problems of defragmentation, Best Fit Decreasing (BFD) based defragmentation algorithm, the algorithm is applicable to defragment in semi-dynamic network and make network more effective, more sequential and better performance in future session, make the optical network in the future more flexibility, more utilization, and more scalability.At last, we develop a RSA simulation platform which provides convenient user interface to input the network topology, to do cluster, to develop RSA algorithm and to run simulation. After the simulation data processed, it is also proved the correctness of the Best Fit Decreasing (BFD) based defragmentation algorithm.