NEW FIBER DELAY LINE USAGE STRATEGY IN OPTICAL BURSTSWITCHING NODE

摘要

Optical Burst Switching (OBS) is a new paradigm forfuture all-optical networks. In an OBS node, a FiberDelay Line may be used to delay a burst, effectivelyincreasing its offset time. Traditionally, FDLs were usedin contention resolution, i.e. a burst was only buffered ifit would otherwise been dropped. We propose a differentapproach, where delay lines are used also to better arrangebursts in time. In our strategy both outgoing channelsand FDL channels are assigned a price, according to theirsuitability for a particular burst. When a control packetarrives at a core node, all the possible ways of handling thecorresponding burst are found (the outgoing channel, withor without a FDL), and the one with a lowest total price ischosen. This makes it possible to use most FDL channelsfor the majority of the time, reducing the probability offuture contention. We present simulation results, showinghow node performance depends on the size of a FDL bank,using either Last Available Unused Channel with VoidFilling (LAUC-VF) and the traditional FDL usage strategyor our algorithm.