Traffic grooming and scheduling, wavelength routing and assignment, and multicast in WDM networks

In this research, we investigate several important and fundamental design issues of WDM networks---traffic grooming, scheduling, wavelength assignment and multicast, considering different aspects such as network topology, traffic pattern, switching technique, etc.; We first consider unicast static traffic in simple network topologies (e.g. rings), and start with traffic grooming and wavelength assignment in SONET/WDM networks where each connection only requires bandwidth less than that of one wavelength. We propose effective and comprehensive solutions to minimize the number of SONET add/drop multiplexers or the number of wavelengths or both so that the network system cost is dramatically reduced.; As another way to support a given traffic pattern with limited resources, we also study the traffic scheduling problem in which only a subset of all the connections can be set up simultaneously, and the connections have to be scheduled into multiple rounds. Two traffic scheduling schemes, namely, non-pipelined and pipelined scheduling, are considered, and their performance are compared in terms of both schedule length and throughput. The schedule algorithms we propose can achieve optimal or near optimal schedules which fully utilize either bandwidth or I/O capacity or both. In addition, cost-effective system design issue for traffic scheduling is also addressed.; When each connection requires full bandwidth of one wavelength, one will have to either support all connections at the same time for static traffic, or dynamically allocate bandwidth to connection requests whenever they are generated. We examine the routing and wavelength assignment (RWA) problem for unicast dynamic traffic in arbitrary networks, and propose a new intelligent RWA algorithm which gives better performance than other previously proposed ones.; Since multicast services are becoming increasingly popular and are making up a large portion of the network traffic, considering only unicast traffic in network design is not sufficient. As a natural extension, we investigate the problem of supporting multicast at WDM layer and propose new multicast tree formation algorithms to avoid branching points at switches that are not multicast capable. Furthermore, we address IP over WDM internetworking multicast, and propose approaches/protocols to support IP multicast at WDM layer.