Survivable fiber optical network design

Abstract

This thesis presents a study on a survivable extension of a network design problem of one of the largest Internet service providers operating in Turkey. In a previous study, this problem is defined as the "Green Field Network Design Problem" where the aim is to design a cost effective fiber optical network that will provide high speed and high quality Internet access from a prelocated central station to a set of aggregated demand nodes. In order to attain a required service level, insertion loss, speed level and distance limitations are considered simultaneously. The Internet access from the central station to the demand nodes can be provided either directly by installing fiber optical wires or indirectly by utilizing special telecommunication devices called "Passive Splitters". Passive splitters copy and split the data into the output ports, and they can be considered as hubs since they consolidate and disseminate the data. In this study, we consider the survivable version of this problem: "Survivable Green Field Network Design Problem". In order to ensure survivability, we seek to find 2-node disjoint paths for every demand node such that the fixed costs of installing passive splitters and the fiber wiring costs are minimized. A mathematical model is constructed. In order to solve problems with higher dimensions, heuristic algorithms are also proposed. A data set belonging to Kartal district of İstanbul is used to test the performances of mathematical model and the heuristics, and the results of the computational study are reported.