Research On RWA Algorithm Application In High Speed Railway Optical Transport Network

The rapid development of Chinese high-speed railway constantly has brought new challenges to the construction and development of high-speed railway optical transport network.As the guarantee of fast,stable and safe operation of high-speed railway,OTN(Optical Transport Network)is responsible for providing business services for train operation scheduling,train operation status monitoring,environmental monitoring along the railway,fault emergency treatment and voice and video demand among all parties.Once the network breaks down,resulting in business interruption during the transmission process,it will affect the normal operation of the railway network,and even threaten the safety of people's lives and property.Therefore,in order to ensure the stable and safe operation of OTN network,this paper proposes an optimization algorithm combining KSP(K-Shortest Paths)algorithm and RWA(Routing and Wavelength Assignment)algorithm.The specific work of this paper is as follows:(1)In order to improve the protection switching time,this paper proposes FSRA(Fast Service Recovery Algorithm)based on a fast service recovery algorithm.When the link fails in the network,the protection switching process and the time required for the service switching from the working path to the protection path are analyzed to improve the protection switching time.At the same time,when allocating network resources for services,the nodes and links of the protection path and the working path are separated to improve the success probability of service switching.The FSRA algorithm and MTW(Minimum the Total Weight)are simulated and analyzed.Under 10 business requests and 20 business requests,the routing resources configured by FSRA algorithm for business need significantly shorter time for switching than MTW algorithm.At the same time,the FSRA algorithm also has some improvement in network resource occupation and average route hops.In general,the performance of FSRA algorithm is better than that of MTW algorithm.(2)Aiming at the problems of static RWA algorithm in optical network,a CL-SRWA(Capacity Limited-Static Routing and Wavelength Assignment)algorithm based on link capacity limitation is proposed.When routing static services,link capacity limitation is added to the alternative path,which can make the network resource load more balanced and reduce the probability of blocking.In this paper,CL-SRWA algorithm and traditional static RWA algorithm are simulated.After 15 static services are configured,by comparing the improved blocking probability and equilibrium degree,the blocking probability is reduced by 25%,and the equilibrium degree is also less than the traditional algorithm.In general,CL-SRWA is better than traditional RWA algorithm.