Traffic optimization and reconfiguration management of multiwavelength multihop broadcast lightwave networks

Abstract

Lightwave network architectures have emerged that aim to go far beyond simply exploiting the huge point-to-point transmission capabilities of fiber optics. One of the most powerful and promising feature of optical networks is their ability to be dynamically reconfigured by retuning the optical transmitters/receivers. This ability to realize a logical connectivity among network nodes independently of the physical infrastructure allows to (1) increase network utilization while providing better network performance by adapting the bandwidth allocation to changing traffic loads and (2) react to failure by bypassing those elements that failed (fault-tolerant/self-healing capabilities). In this paper, we study and review the literature on the two main research problems raised by dynamic reconfiguration of multiwavelength multihop broadcast lightwave networks. The two problems are (1) traffic optimization to find the “best” configuration for a given traffic pattern, and (2) reconfiguration management to go from one configuration to another. We present mathematical formulations for the problems, reference NP-completeness results, and describe and compare heuristic algorithms. We also discuss open research problems. This work is limited to broadcast optical networks, and does not directly apply to wavelength-routed optical networks, where the wavelengths making up the logical connectivity among nodes have to be allocated and routed.