Packet burst switch architecture for energy efficient optical networks

Abstract

Unprecedented growth of Internet user and network traffic give rise to concerns of tremendously increasing energy consumption in the information and communications technology industry. This trends lead research interests in energy efficient networks and thus a number of studies on Green IT are being investigated broadly. However, they such investigations are limited to a survey level on current system efficiencies, and do not suggest specific solutions. Therefore, this thesis focuses on specific models and solutions for energy efficient optical networks, especially packet forwarding techniques and high-performance energy saving switching node architecture. This thesis is divided into four parts. First, the concept of a packet burst technique is introduced briefly for reducing energy consumption in packet processing. In the second part, limitations of all optical switching technology are analyzed one by one and requirement for cross-layered design of optics and electronics node design is proposed. A packet burst based optical-transport node model is suggested where energy consumption is dramatically reduced by element saving node architecture. Especially, this part introduces the architecture of a hybrid design of passive medium optical switches with electrical memory buffering for the tera-scale packet burst optical networks while minimizing energy and cost consumptions. Third, novel architecture of add-drop capable Benes networks is proposed as a part of a modular optical switch fabric design for a hybrid optical packet node. Add-drop capable Benes network is achieved by extending a conventional Benes network with small amount of additional switch element. The corresponding switch configuration algorithm and appropriate architectural rule are investigated to mitigate the connection capability limitation of proposed Add-drop capable Benes networks. Single ADBNs are interconnected to form shared-ADBNs for buffer sharing. Merits of the suggested switch models are...