Sparse wavelength conversion in wavelength-routed WDM optical networks

A wavelength-routed optical network can suffer inefficiencies due to the wa velength-continuity constraint (under which a signal has to remain on the s ame wavelength from the source to the destination). In order to eliminate o r reduce the effects of this constraint, a device called a wavelength conve rter may be utilized. Due to the high cost of these wavelength converters, many studies have attempted to determine the exact benefits of wavelength c onversion. However, most of these studies have focused on optical networks that implement full wavelength conversion capabilities. An alternative to f ull wavelength conversion is to employ only a sparse number of wavelength c onverters throughout the network, thereby reducing network costs. This stud y will focus on different versions of sparse wavelength conversion-namely, sparse nodal conversion, sparse switch-output conversion, and sparse (or li mited) range conversion-to determine if most of the benefits of full conver sion can be obtained using only sparse conversion. Simulation and analytica l results on these three different classes of sparse wavelength conversion will be presented. In addition, this study will present heuristic technique s for the placement of sparse conversion facilities within an optical netwo rk.