随着Internet和多媒体业务的爆炸性增长，光网络中越来越多的波长被用于承载业务。然而，随着波长数的增加，光交叉连接器的端口数和相关的管理控制费用以及难度将大幅度增加。尽管WDM技术日趋成熟，大型交换设备的高费用和复杂性以及未证实的可靠性还是阻碍了其应用。在这一背景下，人们提出多粒度交换的概念，即能够同时提供波长、波带以及光纤等多种粒度的交换。 本文比较研究了两种多粒度光交叉连接器(MG-OXC)结构：多层MG-OXC和单层MG-OXC。多层MG-OXC结构和控制相对复杂，但灵活性高，非常适合在动态业务模型下进行的业务流梳理，可以把网络阻塞率降低到规定范围内。而单层MG-OXC结构和控制相对简单，但由于单层MG-OXC结构可以解复用的光纤和波带都是预配置的，如果应用在复杂的动态性比较强的网络中，节点结构不能适应业务流的动态变换，网络阻塞率较高。 在多粒度光网络中，一方面需要有效的路由来合理的利用网络中的交换资源，实现高效的交换互联；另一方面需要有效的波长波带分配来合理使用网络的带宽资源，因此，路由波长/波带分配问题是研究多粒度光网络的重要内容。本文采用一种路由波长/波带分配算法——最大波带通道组合算法处理多粒度波带交换光网络中动态到达的业务需求。仿真比较了两种不同多粒度网络的性能，并研究部分结构参数对网络性能的影响。实验结果表明：(1)在同一波带解复用率 下，由单层MG-OXC构成的网络比由多层MG-OXC构成的网络阻塞率高。(2)增大 有利于降低网络的阻塞率，但当 大于0.5时，继续增大 对于降低网络阻塞率的影响不大。(3)光纤中波长数目一定时，光纤中波带数目越多网络阻塞率越低。(4)在使用的波带分配算法一定的情况下，固定备选路由比固定路由能更有效地减少网络阻塞率，从而提高网络资源的利用和算法的性能。

Along with the explosive growth of Internet and multimedia service, more and more wavelengths are used in bearing service. However, because of the increasing number of wavelengths, pot number of OXC and related management cost and difficulty increased greatly. So, although WDM technology is becoming mature, its applications are hindered by the expensive cost, complexity and uncofirmed reliability of large scale switching equipments. Under such circumstances, the concept of Multi-Granularity Switching appeared. It can provide the switch of wavelength, waveband and multi waveband granularity optical fiber simultaneously. This thesis compared two multi-granularity MG-OXC structures, multi-layer and single-layer MG-OXC. The structure of multi-layer MG-OXC is comparatively complex, the control of it complex accordingly. Nevertheless, the flexible combination of waveband, wavelength and optical fiber is suitable for the traffic grooming under dynamic service model, reducing network congestion rate to a regulated range. Single-layer MG-OXC has a simple structure, and the control is relatively simple. But because the optical fiber and wavebands in single-layer MG-OXC structure that can de-multiplexing are all pre-allocated and fixed, if applied in complex dynamic networks, node structure would not adapt to the dynamic change of service flow and the network blocking rater would be high. In multi-granularity network, effective routing should be used to utilize network switching rationally on one hand, on the other hand, wavelength and waveband should be allocated efficiently to use the network reasonably. Thus, routing wavelength/waveband is the important content in researching multi-granularity network. By using maximal waveband channel combination algorithm, this thesis deal with the service demand in multi-granularity waveband switching optical network. This thesis compares the performance of two different multi-granularity networks, and studied the influence some structure parameters on the performance of the network. Simulating results show that: (1) Under the same waveband de-multiplexing rater , the blocking rate in single-layer MG-OXC network is higher than multi-layer’s. (2) Increasing is beneficial to decrease the blocking rate. But when is larger than 0.5, keep on increasing has little influence on the decreasing of blocking rate. (3) When the number of wavelength in optical fiber is fixed, the higher the number, the lower the blocking rate. (4) Under certain waveband allocating algorithm, blocking rate is reduced efficiently by fixed alternate routing than by fixed routing. Consequently, the utilization of network and the performance of algorithm is enhanced.