الگوریتم های هورستیک برای تخصیص کارآمد از گره های چندپخشی در شبکه های نوری اسپارتاکی

Optical splitters are utilized in optical nodes for splitting the received signal into multiple copies, in order to efficiently provide multicast capabilities in optical networks. In practice, only a fraction of the network nodes are equipped with optical splitters. These nodes are called multicast-capable (MC) and the remaining nodes are called Multicast Incapable (MI). In some networks, if the MI nodes are destinations of the multicast request, they can drop a small fraction of the incoming signal’s power locally and transmit the rest to the next node. This ability is called Drop-and-Continue (DaC) and the relevant networks are called DaC networks. In the absence of the DaC capabilities, the network is called Drop-or-Continue (DoC). The current paper deals with both aforementioned categories of networks, and proposes three heuristic algorithms for the efficient allocation of a limited number of MC nodes in the network, so as to achieve a low average cost of the light-trees that are calculated for routing the multicast requests. It is shown through simulations that the proposed techniques significantly outperform the relevant conventional splitter placement techniques. This work also investigates the impact of networks having DaC rather than DoC capabilities, as well as the impact of the percentage of MC nodes on the network performance, providing guidance for the efficient design of optical networks with sparse multicasting capabilities.