We consider the problem of wavelength assignment in reconfigurable WDM networks with
wavelength converters. We show that for N-node P-port bidirectional rings, a minimum
number of/spl lceil/PN/4/spl rceil/wavelengths are required to support all possible connected
virtual topologies in a rearrangeably nonblocking fashion, and provide an algorithm that
meets this bound using no more than/spl lceil/PN/2/spl rceil/wavelength converters. This
improves over the tight lower bound of/spl lceil/PN/3/spl rceil/wavelengths required for such …

Through the use of configurable wavelength-division-multiplexing (WDM) technology
including tunable optical transceivers and frequency selective switches, next-generation
WDM networks will allow multiple virtual topologies to be dynamically established on a
given physical topology. For N node P port networks, we determine the number of
wavelengths required to support all possible virtual topologies (PN lightpaths) on a
bidirectional ring physical topology. We show that if shortest path routing is used …