Study On Survivability And Traffic Grooming In WDM Optical Networks

Wavelength Division Multiplexing (WDM) optical networks, based on wavelength division multiplexing and wavelength-routed technology, are one of the most competitive candidates for next generation high speed WAN backbone and MAN. It features not only on the huge bandwidth, but also on the transparency of different transport code rates, data formats and modulations. WDM optical networks can be reconfigured to improve the resource efficiency. Its logical topology can be changed to meet the demand of traffic. WDM optical networks can recover infected traffic from failure in a short time. Good survivability is its favorable merit.The thesis focuses on the investigation of network survivability and low-rate traffic grooming problem in WDM optical networks, including four sub-problems of dynamic routing and wavelength assignment, dynamic survivable routing of dynamic traffic, survivability of mesh networks based on the Shared Risk Link Groups (SRLG) and traffic grooming. By solving these problems in a proper way, network resources can be best configured. Further, optimization of these problems can obtain the greatest network performance, and even if the some failure takes place, the network performance can still maintain in a high level and provide the kinds of quality of service.The introduction is given in the first chapter. Most of work is described from chapter 2 to 5. The main work in this thesis is dated as follows.The second chapter discusses the dynamic resource allocation problem of multi-fiber WDM optical networks. Aiming to reduce the ILP calculating complexity, a new and efficient heuristic algorithm based on the layered-graph is presented. Considering the concurrency of connection requests and the speed of responding in the real network, a new policy of choosing the alternate path is introduced, that is both the best path and a random one are selected. Numerical results show that the heuristics perform well in term of both the calculating cost and blocking probability.In chapter three, many suitable mesh protection/restoration schemes are investigated. A new protection scheme is proposed based on the primary-backup multiplexing technique. Considering the load balancing problem, a new link metrics is introduced. Also a kind of performance evaluation system of survivability policies is established in mesh optical network which includes network blocking probability models of dedicate/share path-based protection schemes and restoration efficiency...