Feature Issue on Waveband Switching, Routing, and GroomingWavelength switching is used in current light-path networks to set up connections between node pairs. With the increase in the number of wavelengths per fiber, waveband switching has been proposed for decreasing the number of switching ports in optical nodes. Another concept called a 'light trail' allows the intermediate nodes along a light path to access the wavelength channel, aiming at the reduction of the total number of wavelengths. Both techniques apply traffic grooming on different levels of a WDM network. We combine and compare these two switching techniques: waveband switching light path (WBS-LP) and waveband switching light trail (WBS-LT). For both WBS-LP and WBS-LT networks, auxiliary graph models are proposed to exploit not only the wavelength resources in the fiber links but also the limited waveband port resources inside multigranular optical cross connect (MG-OXC) nodes. The proposed algorithms are compared with shortest path, least-weighted path, and K-least-weighted path algorithms. Numerical simulations show that the proposed algorithms based on the auxiliary graph models (LPlowbarAG-LTlowbarAG) have better performance than other algorithms. For different algorithms, WBS-LT can have better blocking performance than WBS-LP, especially when add-drop waveband ports are critical resources.
© 2006 Optical Society of AmericaPDF Article