Dynamic Waveband Switching In WDM Mesh Networks

Optical networks using wavelength division multiplexing (WDM) technology, which divides the enormous fiber bandwidth into a large number of wavelengths, is a key solution to keep up with the tremendous growth in data traffic demand. However, as the WDM transmission technology matures and fiber deployment becomes ubiquitous, the significantly large cost and complexity associated with management and control of the optical cross-connect (OXC) is becoming a new problem, and hinders the development of WDM technology seriously. In particular, the rapid advance and use of dense WDM technology has brought about a tremendous increase in the size of photonic (both optical and electronic) cross-connects. The number of ports in a cross-connect is the most significant contributor to the cross-connect size. In this background, the concept of waveband switching (WBS) has been proposed to reduce the ports required and complexity of multi-granular optical cross-connect (MG-OXC) nodes. The main idea of WBS is to group several wavelengths together as a band and switch the band using a single port. Since Routing and Wavelength Assignment (RWA) is one of the core problems in WDM networks. We mainly focus on dynamic RWA problem in WBS networks.As the main work of dynamic WBS is to deal with the large traffic and to achieve a tolerable blocking probability, it is crucial that how to group wavelengths into a waveband and how to assign ports efficiently while considering the policy of balancing traffic in WBS networks. Little literature has considered the problem of balancing traffic in on-line WBS networks, which is potentially at the high risk of exhausting resources on some fibers or nodes, consequently increase the blocking probability. In this paper, we propose a dynamic balancing traffic WBS algorithm based on the three-layer MG-OXC. We compare the performance of our scheme in various traffic scenarios by extensive simulations. Our results demonstrate a significant reduction in blocking probability and port save.In a WBS network, a component failure may cause the failures of several waveband-paths and light-paths, and result in the loss of large amounts of data and revenue. Thus, fault management in WBS networks is of paramount importance.