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dc.contributor.advisorJenkins, Lawrence
dc.contributor.authorDas, Sudipta
dc.date.accessioned2017-11-27T15:24:36Z
dc.date.accessioned2018-07-31T04:56:58Z
dc.date.available2017-11-27T15:24:36Z
dc.date.available2018-07-31T04:56:58Z
dc.date.issued2017-11-27
dc.date.submitted2013
dc.identifier.urihttp://etd.iisc.ac.in/handle/2005/2808
dc.identifier.abstracthttp://etd.iisc.ac.in/static/etd/abstracts/3581/G25542-Abs.pdfen_US
dc.description.abstractFirm real time system with Poisson arrival process, iid exponential service times and iid deadlines till the end of service of a job, operated under the First Come First Served (FCFS) scheduling policy is well studied. In this thesis, we present an exact theoretical analysis of a similar (M/M/1 + G queue) system with exact admission control (EAC). We provide an explicit expression for the steady state workload distribution. We use this solution to derive explicit expressions for the loss ratio and the sojourn time distribution. An exact theoretical analysis of the performance of an M/M/1 + G queue with preemptive deadlines till the end of service, operating under the Earliest Deadline First (EDF) scheduling policy, appears to be difficult, and only approximate formulas for the loss ratio are available in the literature. We present in this thesis similar approximate formulas for the loss ratio in the present of an exit control mechanism, which discards a job at the epoch of its getting the server if there is no chance of completing it. We refer to this exit control mechanism as the Early job Discarding Technique (EDT). Monte Carlo simulations of performance indicate that the maximum approximation error is reasonably small for a wide range of arrival rates and mean deadlines. Finally, we compare the loss ratios of the First Come First Served and the Earliest Deadline First scheduling policies with or without admission or exit control mechanism, as well as their counterparts with deterministic deadlines. The results include some formal equalities, inequalities and some counter-examples to establish non-existence of an order. A few relations involving loss ratios are posed as conjectures, and simulation results in support of these are reported. These results lead to a complete picture of dominance and non-dominance relations between pairs of scheduling policies, in terms of loss ratios.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG25542en_US
dc.subjectFirm Real-time Systemsen_US
dc.subjectReal Time Systemsen_US
dc.subjectLoss Ratio Comparisonen_US
dc.subjectFirst Come First Served (FCFS) Schedulingen_US
dc.subjectExact Admission Control (EAC)en_US
dc.subjectEarliest Deadline First (EDF) Schedulingen_US
dc.subjectEarly Job Discarding Technique (EDT)en_US
dc.subjectReal-time System Analysisen_US
dc.subjectM/M/1 Queue Systemen_US
dc.subjectQueing Theory Modelen_US
dc.subjectService Time Dependent Schedulingen_US
dc.subject.classificationElectrical Engineeringen_US
dc.titleLoss Ratios of Different Scheduling Policies for Firm Real-time System : Analysis and Comparisonsen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Engineeringen_US


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