In all-optical WDM networks, splitters at branch nodes are used to realize multicast trees. The problem of selecting a subset of nodes to place the splitters such that certain performance measure is optimized is called the splitter placement problem. This paper studies the splitter placement problem in all-optical WDM networks in which a light-forest is used to realize a multicast connection. The goal is to place a given number of splitters in the network such that the average per link wavelength resource usage of multicast connections is minimized. An upper bound and a lower bound on the per link average wavelength resource usage are derived. Two splitter placement methods are proposed for this problem. The proposed splitter methods are shown to yield significant lower average wavelength resource usage than the random placement method. One of the methods is shown to produce near minimum average wavelength resource usage.
