Wavelength conversion architectures in OBS networks

Most studies about Optical Burst Switched (OBS) networks have assumed availability of full wavelength conversion throughout the network. In an optical network with fan wavelength conversion capability, every output on each node is provided with a wavelength converter, resulting in the lowest bound for blocking probability. However, full wavelength conversion capability requires a large number of wavelength converters, which is, and will remain, quite expensive in the foreseeable future. Therefore, it is expected that conversion capability will be limited and only sparsely deployed. In this work we apply to OBS networks the main architectures for wavelength conversion proposed for circuit switched networks. These architectures operate with limited wavelength conversion capability. We also investigate the cost benefit and the gain factor related to full complete wavelength conversion for each architecture. In addition, we propose a new methodology to define the number of wavelength converters in order to achieve the best cost benefit, regardless of the traffic load.