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 Look-back 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 inlet-connected 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.