中文摘要：

在采用密集波分复用技术的骨干网中，通过建立动态多粒度业务模型对由大粒度（光纤和波带）和小粒度（波长）组成的三阶多粒度光交叉连接所构成的节点的网络特性（阻塞概率和带宽阻塞比）进行了研究和仿真分析，并由此对三阶多粒度节点的结构参数和网络中的系统参数进行了优化设计．从仿真结果可以看出，所提出来的优化设计方案能够显著的减少节点结构的复杂度并改善阻塞性能，从而减小了网络中设备的规模和成本．

英文摘要：

A dynamic multi-granularity traffic model is built in the backbone network adopting dense wavelength division multiplexing （DWDM） technology. Furthermore, the blocking performance including blocking probability and bandwidth blocking ratio of the optical network which consists of three-stage multi-granularity optical cross-connects based on coarse granularity （i. e., fiber and band） and fine granularity （i. e., wavelength） is studied. The associated architecture parameters in the three-stage multi-granularity optical cross-connects （MG-OXC） and system parameters in the system are analyzed in detail and optimized by simulations. The proposed optimization design significantly reduces the node complexity and improves the blocking performance of arriving requests, which translates to smaller device size and lower cost in optical networks.