Grooming in unidirectional rings: K4−e designs Original Research Article

In wavelength division multiplexing for unidirectional rings, traffic grooming is used to pack low rate signals into higher rate streams to share a wavelength. The grooming chosen determines the number of add-drop multiplexers used for the optical-to-electronic conversion. The determination of groomings to use the fewest multiplexers is equivalent to a graph design problem, which has been solved when up to four signals can be packed into a stream. We completely settle the case here when five signals pack into one stream, using old and new results on (K4−e)-designs.