This paper investigates multicasting in such context with the objective of minimizing the cost of using wavelengths in network links. Without splitters, a set of light-spiders starting from the multicast source covering all the destinations is known as the traditional solution. This paper argues that the exact solution for the problem is a set of non-elementary spiders called light-spider hierarchies. Two efficient heuristic algorithms are proposed to compute the light-spider hierarchies to illustrate our findings. |
