NETWORK OPTIMIZATION AND ITS APPLICATIONS IN OPTICAL NETWORK DESIGN

Abstract

Network optimization is an active subfield of Operational Research (OR) that focuses mainly on network flow problems. Network optimization is the subject of extensive research for its wide range of applications and specialized techniques. Optical network design is one of such applications which can be viewed as a complex version of the well-known multi-commodity flow problem of this field.

Optical networks has gained more importance lately since it is widely considered to be the next generation networks and the solution for the continuous growth of high­ speed and bandwidth requirements. Optical networks deployment is motivated by the advantages of optical fibers, and the evolution of Wavelength Division Multiplexing (WDM) technology that supports it.

Routing and Wavelength Assignment (RWA) problem is an optical network design problem. In such problem it is required to benefit from the huge offered bandwidth to satisfy connection requests while maintaining the cost as minimum as possible. Specifically, the problem is to determine for each connection request of a given set, a specific route and an associated wavelength, and thus is called Routing and Wavelength Assignment (RWA) problem

In this thesis a categorization of the RWA problems according to the different assumptions involved is given. In addition, a classification of the available approaches is presented along with a brief comparison and overview of each, based on the concepts of the network optimization problems.

Also, this thesis introduces a new approach targeting the RW A problem for static traffic and under the general case of multiple requests between the same SD pairs and mulifiber links. The case of network growing is also discussed and integrated into our frame work. The proposed approach is tested by applying it to different network models such as NSFNET and cost239 networks. The results are compared with a recent efficient approach, which shows the effectiveness of the proposed approach.