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Title: Classified cloning for QoS provisioning in OBS networks
Author: Askar, Shavan K.
ISNI:       0000 0004 2740 5307
Awarding Body: University of Essex
Current Institution: University of Essex
Date of Award: 2012
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This thesis investigates the challenges underlying QoS provisioning over OBS networks, considering both absolute and relative cases. Novel QoS provisioning schemes are proposed, and their effectiveness in minimizing loss probability is demonstrated in a range of network scenarios, while either minimizing or maintaining latency. Firstly, the important aspects of optical network evolution are discussed, and justification is provided for the deployment of WDM telecommunication systems in backbone networks. Insight is provided into the contention problem, facilitating the discussion and categorisation of loss reduction mechanisms and how they deal with contention. Our novel scheme for burst loss reduction, referred to as CCS, is then introduced. Comprehensive simulation results are presented which evaluate CCS and compare it to other proposals, demonstrating the superiority of CCS. Furthermore, two novel schemes to improve the quality of streamed video over OBS are introduced. The first of these yields an average PSNR gain over existing proposals of 4.2 dB and 2.4 dB with 10% and 30% network loads respectively. The second scheme is less affected by the increased percentage of video traffic, and an average improvement of 5 dB is obtained in the worst- case scenario with 50% video traffic and medium/high network loads. Finally, the relationship between loss rate, ETE-delay and the aggregation parameters are studied in detail in order to inform the design of a novel absolute QoS provisioning scheme. Adaptive aggregation is combined with admission control at the ingress nodes, together with the CCS scheme, to produce the ACCS scheme, which is evaluated through extensive simulations. It exhibits superior loss rate and maintains acceptable bounds on ETE-delay when compared to CCS, basic cloning, and standard OBS.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available