Improvement of Multi-hop Packet Transmission Scheduling in WDM Optical Star Networks

This paper addresses the design of multi-hop packet transmissions for the All-to-All Broadcast (AAB) problem in a Wavelength Division Multiplexing (WDM) optical star network. To decrease the optical-electronic-optical (O/E/O) transformations in multi-hop scheduling, the maximum of hop distances of each packet transmission is limited to a constant. Each node consists of a tunable transmitter and a fixed-tuned receiver (TT-FR configuration), and each tunable transmitter needs a non-negligible tuning latency to switch between different wavelengths. To decrease the influence of the tuning latency in multi-hop scheduling and the time of tuning operations on each transmitter, we adopt simpler methods for constructing less logical topologies when all tunable transmitters change their transmitted wavelengths to other channels in scheduling concurrently. Our multi-hop scheduling has not only a shorter schedule period but also a less number of transmitted wavelengths used.