This paper researches the routing and wavelength assignment (RWA) problem in wavelength routed optical WDM networks with the wavelength conversion capability at different network nodes. We studied the static case in which all connection requests are known in advance, thus a routing decision can be made based on the complete knowledge of the traffic to be served by the network. The Bee Colony Op...

This work focuses on the Routing and Wavelength Assignment (RWA) problem in all-optical DWDM networks with Sparse Wavelength Conversion (SWC) capabilities. By sparse wavelength conversion, we mean that nodes within the optical network domain might or might not support optical wavelength conversion. For these nodes that support optical wavelength conversion, the number of wavelength converters m...

In this paper, we propose an integrated Quality of Service (QoS) routing algorithm for optical networks. Given a QoSmulticast request and the delay interval specified by users, the proposed algorithm can find a flexible-QoS-based cost suboptimal routing tree. The algorithm first constructs the multicast tree based on the multipopulation parallel genetic simulated annealing algorithm, and then a...

that the blocking probabilities for networks with wavelength conversion are lower than for networks without wavelength conversion. This is because the alternate routes are of length two hops and thus blocking due to the wavelength continuity constraint is experienced on the alternate routes. Figure 6 shows that at high ooered loads, the blocking probability experienced with wavelength conversio...

The design of WDM optical networks is an issue for telecom operators since the spreading of this technology will not occur unless enough performance guarantees are provided. Motivated by the quest for efficient algorithms for the Routing and Wavelength Assignment problem (RWA), we address approximations of the fractional multicommodity flow problem which is the central part of a complex randomi...

In this paper, we address the routing and wavelength assignment problem for the core-based tree (CBT) service in a wavelength-division-multiplexing (WDM) network, where k sources need to send data to a common core node. We formally model the problem as a problem of finding k shortest lightpaths from sources to the core with the constraint of wavelength collision free. To address different objec...

The routing and wavelength assignment problem is one of the most important issues in optical transport networks based on the Wavelength Division Multiplexing (WDM) technique. In this paper, a novel approach using path conflict graphs and an algorithm for finding all edge disjoint paths is proposed. The performance of the proposed algorithm is compared with that of the bounded greedy approach fo...

We present a review of the various integer linear programming (ILP) formulations that have been proposed for the routing and wavelength assignment problem in WDM optical networks with a unified and simplified notation under asymmetrical assumptions on the traffic. We show that all formulations proposed under asymmetrical traffic assumptions, both link and path formulations, are equivalent in te...