Distribution-based bandwidth access scheme in slotted all-optical packet-switched networks

The common approach in an ingress switch to access a slotted all-optical packet-switched network is the TTA (timer-based/threshold-based bandwidth access) bandwidth access scheme in which packet differentiation is provided by a time-out mechanism. In contrast, we propose in this paper the DA (distribution-based bandwidth access) to access the slotted all-optical packet-switched network within a DiffServ domain. Each torrent (the traffic between each pair of ingress and egress switches) is given a bandwidth measured in slots within a frame at an ingress switch. The slots from each torrent are evenly distributed throughout the frame and among the output wavelengths/fibers of the ingress switch. Comparing to the most commonly used technique TTA, we demonstrate that our DA approach can achieve the following: (1) provide each traffic torrent a fairer access to the network bandwidth; (2) reduce the probability of the slot drop rate at the optical network; (3) reduce the excessive bandwidth allocation by the bursty torrents; (4) balance the traffic load much better on wavelength channels; and (5) guarantee a stable edge switch operation to service traffic in which the traffic generation rate to the optical network is lower than the traffic service rate.