Network Resource Scheduling and Management of Optical Grids

Abstract

Advance reservation of lightpaths in an optical network has become a popular concept of reserving network resources in support of Grid applications. In this thesis, we have evaluated and compared several algorithms for dynamic scheduling of lightpaths using a flexible advance reservation model. The main aim is to find the best scheduling policy that improves network utilization and minimizes blocking. The scheduling of lightpaths involve both routing and wavelength assignment. Our simulation results show that minimum cost adaptive routing where link costs are determined by the current and future usage of the link provides the minimum blocking. Moreover, searching for k alternate paths within the scheduling window significantly improves the performance. For wavelength assignment, we have used a scheme that reduces fragmentation by minimizing unused leading or trailing gaps. We have also analyzed approaches for failure recovery and lightpath re-optimization. Finally, an advance reservation scheme needs timely information regarding the status of the optical links. To this end, we have surveyed various monitoring tools and techniques and we have proposed a monitoring framework to support fast restoration.