Multicast partitioning protocol designs for WDM optical star networks

We first propose a simple and efficient multicast partitioning protocol, called Lookback protocol, for employment in an asynchronous WDM single optical star network. Network nodes use random access schemes to send reservation packets over a dedicated packet reservation channel. A central traffic scheduler is allocated to coordinate message transmissions. It executes the Lookback scheduling scheme in real time by searching (back into the input queue) for a candidate multicast message that can be received by all of the intended recipients. Such an approach effectively reduces the head-of-line blocking effects. Performance results conducted via simulations have shown that networks employing such scheduling mechanisms can exhibit superior network throughput levels and delay performances. To apply this mechanism to a wider range of networking environments, we further consider an interconnected dual-star architecture and propose the Modified Lookback (Mlookback) mechanism. By using a simple heuristic approach, the Mlookback scheme is able to successfully exploit the inter data channels and properly utilize the wavelength reuse property of the intra data channels. Performance results have demonstrated the merits of deploying the underlying Mlookback multicast algorithm in such a dual-star structure.