Design and evaluation of optical ATM switches.

摘要

Today's electronic ATM switches are the bottleneck of ATM networks; ATM cells are not switched fast enough to match the transmission speed of the optical channels. It is expected that the gap between the electronic switching and optical transmission speeds will continue to increase as optical transmission technology matures. A solution is to implement ATM switches using optical technology. The major functions of an ATM switch are to route incoming cells to the appropriate output channels and to provide buffering for the cells if necessary. The buffering of ATM cells using optical delay fibers is the focus of this dissertation.; The number of fibers is the key limiting factor in an optical buffer architecture since the end points of an optical fiber are costly to fabricate and the number of switching crosspoints increases rapidly with the number of fibers. The processing complexity is another limiting factor due to the high throughput required of an optical ATM switch. Although packet switch architectures using optical delay fibers as buffers have been proposed in the literature, studies on how to design an optical switch that addresses ATM-specific requirements while requiring few fibers and low processing complexity do not exist. In this dissertation, the design of a novel optical ATM switch architecture is presented. The switch requires few fibers, and yields low cell loss rates and latencies across a diverse set of time-correlated and heavily loaded traffic profiles. Moreover, the control algorithm of the switch is computationally efficient, and can be executed in real time. The switch also guarantees that the cell sequence integrity of each input-output channel pair is maintained, and that the maximum latency is below a specified threshold.