The need for wavelength converters in all-optical transport network

This paper describes the need of wavelength conversion in an all-optical transport network. It focuses on the comparison of wavelength paths (WP) and virtual wavelength paths (VWP) in terms of non-hierarchical all-optical networks with blocking and with waiting queues. I study the system, where the requests for a free wavelength path arrives randomly and I assume that it has a Poisson distribution. The calculations of the blocking and delaying are made, and are shown in the traffic diagrams. This paper presents the benefits of wavelength conversion in the WDM optical network. It turns out that VWP has a larger routing freedom than WP in both analysed systems. Clearly, the use of wavelength conversion reduces the blocking or delaying probability for a given utilization and size of a cross-connect. The results of our study show that the VWP with waiting queue can significantly improve the traffic performance of the network