We describe a fuzzy-logic-based scheduling algorithm for synchronous optical packet switches that provides quality of service for delay-constrained traffic. The proposed method considers both packet importance as well as delay constraints. One of the advantages of a fuzzy controller is the fact that, regardless of the design complexity, it can be implemented as a simple look-up table. This makes it ideal for high-speed optical switches. We have used two fuzzy controllers: one to select a packet to be forwarded to an output port and another to decide which packet(s) should be buffered or dropped. In a simulation example, video traffic with three priority classes is considered. The results show up to 3dBs of improvement in the quality of the received video, resulting from the packet loss differentiation achieved by employing the proposed fuzzy packet scheduling approach.
© 2008 Optical Society of AmericaPDF Article