Load-Balanced Fixed Routing for Wavelength Routed Optical Networks

Abstract—Due to simplicity in lightpath service provisioning, fixed shortest path routing is considered as one of major provisioning strategies in the wavelength routed optical networks. Nonetheless, the employment of fixed shortest routes can cause unbalanced network traffic load distribution and consequentially lead to network congestion. In this paper, we propose a novel Load-Balanced Fixed Routing (LBFR) scheme that can avoid network congestion and retain the operational simplicity of fixed routing. A pre-training process based on a forecasted traffic load matrix is employed to find a (or few) fixed route(s) between each pair of nodes for lightpath service provisioning. For a wavelength path (WP) network subject to the constraint of wavelength continuity, we also develop an analytical model that can effectively estimate lightpath blocking performance under multiple fixed routes between each pair of nodes. Results show that the proposed LBFR can perform much better than traditional fixed shortest path routing in lightpath blocking, and performance improvement becomes more significant with an increasing network nodal degree. Index Terms—Wavelength routed optical networks, wavelength assignment, fixed routing, load-balanced fixed routing. I