弹性光网络可大幅度提高频谱利用率并为用户提供灵活的带宽粒度.为改进已有弹性光网络的选路与频谱分配算法，建立了描述弹性光网络中选路与频谱分配问题的整数线性规划模型，提出两种分别基于最多频隙数优先和最长路径优先与业务疏导结合的启发式算法，以进一步提高频谱利用率，设计了所提算法的重排序准则和流程.对小型6结点、中型14结点和大型19结点等三种不同网络拓扑进行仿真实验，结果表明，所提算法可有效提高已有算法的频谱利用率.

Elastic optical networks could increase the sprectrum usage ratio greatly and provide users with flexible bandwidth granularity compared to the traditional wavelength division multiplexing networks. To improve the existing algorithms of routing and spectrum assignment in EONs, An integer linear programming model was set up to formulate the Routing and Spectrum Assignment problem, and two heuristic algorithms were proposed, which combine the traffic grooming with most solts first and longest path first, respectively, thereby increasing the spectrum resource utilization further. The reordering rule and procedure of the proposed algorithms were designed. The expermients under the smallsize network (6node simple network), mediumsize network (14node NSFNET) and largesize network (19node telecommunication backbone network) show that the proposed algorithms could increase the spectrum resource utilization effectively when compared with existing algorithms.