Placement of Light Splitters in Optical Networks

For a multicast routing algorithm to be applicable in optical networks, it must route data only to group members, optimize and maintain loop-free routes, and concentrate them on a subset of links. In order to do this, light trees must be generated to route data in the optical layer to all the group members. To apply this, optical nodes have to branch one incoming light wave to more than one output port. Optical nodes must be equipped with light splitters that split one light wave to more than one output. The output light waves may conserve the same wavelength, or use another. Due to its complex design, a light splitter is very expensive equipment, thus, equipping all optical nodes with splitters will increase the cost of the optical network setup. This leads to a consensus that not all optical nodes on the network will possess this splitting capability. In this paper, we study the required density of nodes in the optical networks that must possess light splitting capability. This study is done in order to assure good performance of multicast trees. Also, we discuss the optimal placements of optical splitters, and how this can increase the efficiency of the multicast signaling and routing techniques