Seminar by Oya Karaşan Department of Industrial Engineering Bilkent University
In a telecommunications network the reach of an optical signal is the maximum distance it can traverse before its quality degrades. Regenerators are devices to extend the optical reach. The regenerator placement problem seeks to place the minimum number of regenerators in an optical network so as to facilitate the communication of a signal between any node pair. In this talk, the regenerator location problem is revisited from the hub location perspective and two new facets of it involving the challenges of survivability are introduced. Under partial survivability, our designs hedge against failures in the regeneration equipment only whereas under full survivability failures on any of the network nodes are accounted for by the utilization of extra regeneration equipment. All three variations of the problem are discussed in a unifying framework involving the introduction of individual flow-based compact formulations as well as cut formulations and the implementation of branch and cut algorithms based on the cut formulations. We report computational results evaluating the performances of the proposed solution methodologies and propose possible future research extensions in flexible optical networks. (Joint work with B. Yıldız)
