A scalable and adaptive fair access protocol for slotted WDM bus network

The recent progress of optical technologies has made it possible to increase the number of wavelengths (channels} practically available in the fiber by almost one order of magnitude. With this rapid growth, access protocols originally designed for systems with a few wavelengths may not be adequate to fully utilize the optical bandwidth that is becoming available through this technological breakthrough. This is the case with access protocols designed for unidirectional fiber bus network. The paper proposes a novel access protocol for multi-channel all-optical folded bus network whose performance scales well with the number of wavelengths. This result is achieved using a load balancing algorithm that runs independently at each node and evenly distributes the traffic among the wavelengths. With the proposed protocol, the packet average access delay at a given bandwidth utilization increases only marginally as the number of wavelengths (and proportionally the offered load} is grown in the system. In addition, at all source nodes fair access delay is guaranteed by the protocol under any stable load condition, including non uniform and bursty traffic.