Performance improvement of an optical network providing services based on multicast

Abstract

International audienceWe focus on circuit switching optical networks and on repetitive multicast demands whose source and destinations are à priori known by an operator. He may have corresponding trees \ready to be allocated" and adapt his network infrastructure according to these transmissions. This adjustment consists in setting branching routers in the selected nodes of a predefined tree. The branching nodes are opto-electronic nodes which are able to duplicate data and retransmit it in several directions. We are interested in the choice of nodes of a multicast tree where the limited number of branching routers should be located to minimize the amount of required bandwidth. After formally stating the problem we solve it by proposing a polynomial algorithm whose optimality we prove. We perform computations for different methods of the tree construction and conclude by giving dimensioning guidelines