Wavelength conversion in shortestpath alloptical networks We consider alloptical networks with shortestpath routing that use wavelengthdivision multiplexing and employ wavelength conversion at specific nodes in order to maximize their capacity usage. We present efficient algorithms for deciding whether a placement of wavelength converters allows the network to run at maximum capacity, and for finding an optimal wavelength assignment when such a placement of converters is known. Our algorithms apply to both undirected and directed networks. Furthermore, we show that the problem of finding an optimal placement of converters is MAX SNPhard in both undirected and directed networks. Finally, we give a lineartime algorithm for finding an optimal placement of converters in undirected trianglefree networks, and show that the problem remains (mathcalNP)hard in bidirected trianglefree planar networks.

Graph Partitioning for Survivability in MultiDomain Optical Networks As optical networking deployments increase, multidomain provisioning and survivability are becoming major concerns. A key challenge in multidomain survivability is the scalability problem. To address this concern, various solutions have already been proposed based upon topology aggregation schemes. However, these mechanisms do not scale well with increasing domain counts and further investigation is required to develop more scalable alternatives. Along these lines, in this paper we propose to use graph partitioning techniques to solve the scalability problem in multidomain optical networks. To demonstrate the efficiency of our method, we also extend the pcycle concept to multidomain settings. Overall simulation results show the efficiency of our proposed solution in terms of resource utilization and the number of pcycle structures.