Research On Protectionalgorithm Based On P-Cycle In WDM

With the development of economy and advancement of society,the tremendous required demand in bandwidth issue is a serious challenge to our communication networks,however the emergence of optical communication technology has brought the vigorous developmental opportunities to communication,which is the background of development of WDM that supports huge bandwidth in a single fiber.of course,the damage of a single of fiber also lead to loss of huge datas in the WDM optical network.Therefore it is significant to research deeply the network survivability.Pre-configured cycles,short for p-Cycles,which has the restoration speed like ring-based network and resource utilization like mesh-based network,has become one of hot topics in research of optical network survivability recently.Traditional protect algorithms about p-cycle mainly configure through two steps,one step for generating candidate p-cycles and the other step for capacity configuration with selecting high-priori-efficient candidate p-cycles.one classic generating-p-cycles-algorithm is Grow algorithm,however,which did not consider the expanding orders of cycle-link,thus losing some efficient cycles.so,a novel generating algorithm is presented,which selects the K-highest-priori efficient cycles by setting the parameter K as candidate cycles,expanding each selected cycle in the same way until all links can not be expanded in the network.It is also considered the hop-constrain in order to test ability of this algorithm.Through simulating,the results show that the algorithm can efficiently add priori efficiency,decrease the number of equipped p-cycles,and achieve better capacity utilization.The candidate p-cycles with high prior efficiency are merely of potently protecting efficiency which can not be configured into the truly network until distributing capacity for them.Tradition protect algorithma about p-cycle always need two steps,which also means more computing time. The thesis presents a novel heuristic algorithm,which considers redundancy as criterion,proposes unprotected-link-ratio efficiently controlling the expansion of p-cycles under the circumstance of the few numbers of links,calculates excellent p-cycles with only one step and ensures 100% prot- ection for optical network. Through simulating,the results show that the algorithm can efficiently reduce the number of p-cycles for configuration,cut down the running time and achieve better capacity utilization.