Minimizing drop cost for SONET/WDM networks with 1/8 wavelength requirements

SONET/WDM networks using wavelength add-drop multiplexing can be constructe d using certain graph decompositions used to form a "grooming," consisting of unions of certain primitive rings, The existence of such decompositions when every pair of sites employs no more than 1/8 of the wavelength capacit y is determined, with few possible exceptions, when the ring size is a mult iple of four. The techniques developed rely heavily on tools from combinato rial design theory. (C) 2001 John Wiley & Sons, Inc.