Optical path strategies in WDM all-optical networks: minimization of wavelength converters in optical cross-connects

There is a significant debate in progress about the need of translating the wavelength of a signal within an optical network and on the comparison of performance of WP and VWP approaches. This paper aims at investigating more in depth in this direction. An analysis of the algorithms allowing VWP and WP schemes is reported. Their performances are compared in terms of number of ports of each network node. A wavelength rearrangement algorithm is proposed which allows the performance of VWP scheme to be reached, with a strongly reduced total number of wavelength converters with respect to that corresponding to VWP. The results show a drastic reduction of wavelength converters in each node, permitting a significant reduction of the OXC costs.