Multicasts on WDM all-optical butterfly networks

On the wavelength-division multiplexing (WDM) optical networks, when the number of wavelengths for realizing a set R of routing requests is beyond the number of wavelengths supported by an optical link, multiple rounds of routing for R are required. R = {(u, v)} is a set of multicasts if each source u sends a message to at least one destination v and each destination v receives a message from exactly one source u. In this paper, we propose routing algorithms for a set of multicasts on n-dimensional WDM all-optical butterfly networks. For a network with wavelength converters, we give algorithms which realize any set of multicasts by 2([(n-1)/(k+1)]) wavelengths in k rounds of routing. For k = 1, the upper bound is tight to the lower bound.