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Title: Scheduling in optically based ATM switching fabrics
Author: Gordon, D. L.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 1999
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The recent explosion in the application of networking technology in many environments and on many scales has been facilitated by advances in both electronic and optical technology. The use of optical fibre transmission has increased greatly the data capacity of networks and at the same time reduced their cost. The increase in speed and complexity and the reduction in cost associated with VLSI electronic technology has brought about cheaper and more intelligent network components. In particular, faster and denser electronic memory means that buffering within the network is now prevalent and the increased speed of electronic gates has enabled a finer granularity of switching. The multiplexing strategy, Asynchronous Transfer Mode (ATM), takes advantage of these developments to integrate a variety of high bandwidth streams onto a single network whilst minimising inter-stream interference. The growth in transmission bandwidth requirements can be met by the increased capacity of glass fibre, but optical technology is insufficiently advanced for the more complex tasks involved in switching. Unfortunately, the buffering and control of data are currently impractical in the optical domain. Interconnects, which form the basis of all communications switches, can benefit from optical technology, particularly where they are large. The reduced complexity of an optical solution has many advantages. However, when compared to their electronic counterparts, many of the components used to build such devices have a relatively long path reconfiguration period during which no data can be transferred and this can seriously reduce the usable bandwidth of the interconnect. This dissertation shows how and where optical components can best be used in the construction of a hybrid opto-electronic ATM switch. It shows how the large bandwidth associated with optical interconnects can be used to overcome the problems of matching inputs to outputs during the arbitration process. It describes three new scheduling schemes for such a switch that take into account the reconfiguration penalty. Simulations involving a single switch and two switches in series are performed to measure the effects the schemes have on throughput and delay, and a new switching strategy, based on these schemes, is proposed especially for switches constructed from optical components. Finally, a simulation of a passive optical network shows how the granularity of scheduling, and therefore the quantity of control information, in such systems can be reduced using a similar scheme.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available