Optical networking based on wavelength division multiplexing (WDM) has drawn significant attention from the research community. An issue that has received special attention is that of transmitting data over WDM networks, with the majority of the researchers focusing on wavelength routing, optical packet switching, and optical burst switching techniques.

The authors of this paper investigate the problem of optimizing the network throughput as well as the network delay in buffered WDM networks. Particularly, they study optical packet switching networks with buffering capabilities as a way to cope with contention since different packets arriving on the same wavelength have to be transmitted to the same output link using the same wavelength. An efficient scheduling algorithm is proposed in order to assign wavelengths to the incoming packets. Furthermore, instead of losing the constraint of using a “full range wavelength convert,” they assume, for cost reasons, that the WDM interconnects have “limited range wavelength” conversion capabilities.

The main contribution of this paper is the proposed scan and swap algorithm, which achieves an optimal schedule for buffered WDM interconnects. The proposed algorithm solves the problem in O(kB) time, where k is the number of wavelengths per fibers and B is the buffer length, significantly improving the time needed by other existing algorithms.

The authors present their work in a precise way without including a lot of mathematics. For those interested in studying scheduling in WDM networks with an adequate background in graphs and matroid theory, this paper is worth reading.