Benefits of limited wavelength conversion in WDM ring networks

A number of recent papers have studied the impact of wavelength conversion in wavelength-division multiplexing (WDM) networks. Relatively few works have studied the effect of providing limited wavelength conversion capability in these networks. This paper surveys our recent results on this topic. Consider a ring network of N nodes. We assume bidirectional links and lightpaths, which are typically realized using pairs of counter-propagating connections. For each lightpath we are given a route in the network and must assign a wavelength on each link along its route. Our results apply to the situation where no blocking whatsoever is allowed; in other words, all lightpath requests must be supported.