Research On Routing And Spectrum Allocation Algorithm In Elastic Optical Networks

In recent years,with the rapid development of network and the increasing number of users,the demand for resources in optical networks is increasing.Among them,routing and spectrum allocation in elastic optical networks have been widely studied.This paper mainly studies the routing and spectrum allocation problem on simple network topology and proposes the correlation spectrum allocation algorithms on chain network and ring network.The paper analyzes the approximate ratio of the algorithms.Then the routing and spectrum allocation problem is studied in the general network.It is proved that the routing and spectrum allocation problem can be transformed into graphs coloring.The algorithm of graph coloring model is designed,and the effectiveness of the algorithm in solving the routing and spectrum allocation problem is analyzed by numerical calculation.In this paper,the routing and spectrum allocation problem on a simple network topology is studied.In the chain network,because the path of each request is uniquely determined by their source and destination nodes,the routing and spectrum allocation in the chain network degenerates into the spectrum allocation problem.On the chain network,it is first proved that the spectrum allocation is NP-complete.Then,according to the number of edges on the link,the request set is classified,and a spectrum allocation algorithm is proposed on the four edges chain network,and it is proved that the approximate ratio of the spectrum allocation on the four edges links is 1.5 times the optimal solution.In the ring network,the complexity of the spectrum allocation is further analyzed.First,by deleting a node randomly,the original network structure is degraded into chain network.The analysis of the complexity of the spectrum distribution on the chain network is analyzed.A 2.5 times approximate optimal solution is proposed on the six edges ring network.In this paper,the routing and spectrum allocation problem in the general network topology is studied.As the above routing and spectrum allocation problem has been proved to be NP-complete,it is difficult to solve the problem directly or to propose algorithms for solving the routing and spectrum allocation problems.The problem of routing and spectrum allocation is investigated.We first prove that the routing and spectrum allocation problem can be transformed into a graph coloring model.Then,the algorithm of graph coloring is designed from the point of view of graph coloring,and the proposed algorithm can analyze the routing and spectrum allocation problem.Finally,the algorithm performance analysis is analyzed.Examples and numerical simulations prove that this algorithm mentioned in this paper is effective in solving routing and spectrum allocation problems.