Wavelength/Waveband Routing In The Multi-granularity Optical Networks

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 raterβ, the blocking rate in single-layer MG-OXC network is higher than multi-layer's. (2) Increasingβis beneficial to decrease the blocking rate. But whenβis larger than 0.5, keep on increasingβhas 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.