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ΔημοσίευσεOtos Mola Τροποποιήθηκε πριν 10 χρόνια
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Wireless Broadcast-based Communications Systems: Overview of Current and Future Research of C.A.C.LAB, A.U.Th. Prof. Georgios Papadimitriou, Liaskos Christos Aristotle University of Thessaloniki Department of Informatics Email: {gp, cliaskos}@csd.auth.gr
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2 Contents Ι. Introduction Past Research Objectives - Motivation ΙΙ. Theoretical Background Push vs Pull, The Broadcast Problem Client Models Related Work ΙΙΙ. Research of the CACLAB team Published, Submitted, Completed Current ΙV. Future Research New Research Objectives - Justification Time Schedule
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3 Ι. Introduction ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Definition of the specifications of the optimal, cost-efficient Wireless Broadcast System 4 Past Research Objectives Analytical Minimization of the mean client serving timne Cost Minimization (CPU, RAM) CONVERGENCE #1 #2 Perform. Cost ImpactImpact Perf. Cost Perf Cost ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη DEPRECATED!!
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5 Motives Inexpensive and Efficient Communications System for: The continued education of borderland doctors. The exchange of hospital patients between neighborly states. INTERREG IIIA GREECE- BULGARIA, Decision 300531/ΥΔ4388 01/11/2005, CrossBorderHealth project INTERREG IIIA/ARCHIMED grand, C.N. Α.1.087, IntraMed Project Honorable Praise, 5 th Scientific Conference of the Department of Medicine, A.U.Th. Honorable Praise, 5 th Scientific Conference of the Department of Medicine, A.U.Th. ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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6 ΙΙ. THEORETICAL BACKGROUND ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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7 Push? Pull? Broadcast? ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη Server Client OnQuery Send Answer Server Client ? Usefull Drop Pros: -Best Performance -Good Channel Utilization -Application Range Cons: -Server Load (Scalability)? -Cost? -Client –side Hardware? -Security? (DoS - Impersonation) Pros: -Minimal Cost -Architecture Simplicity -Lightweight Clients -Absolute Server Security Cons: -Non-optimal performance -Maximum Channel Utilization(++) -Application Range (Adaptivity?)
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8 The Broadcast Problem ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη - Data item = page - Uniform or not pages - Page Broadcast “Cost” -Define the Broadcast Schedule that minimizes the mean client serving time AND the mean broadcast cost. ++ For Adaptive Push Systems --Minimal Schedule Size --QoS: Guaranteed Serving Time
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Each client accesses a portion (Range) of the available pages. Pages in Range are divided in sets of pages called Region, with common access probability. The Regions follow the zipf p.d.f : Each combination of the Range, Region and θ parameters, defines a p.d.f. and therefore a distinct Client Case Each combination of the Range, Region and θ parameters, defines a p.d.f. and therefore a distinct Client Case 9 Client Probabilistic Model ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη Common but not confining!!
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10 Related Work ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Defines a scheduling framework, ensuring the periodicity and proportionality characteristics of the final broadcast program. A feedback mechanism provides a metric of the pages’ access probabilities. A Clustering Algorithm groups the pages by access probability, into teams called “Disks” The Virtual Disks rotate around a common axis. Appropriate rotating speeds are chosen. Pages are serially extracted The Broadcast Schedule is produced. The mean client serving time depends on all of the above steps. 11 Broadcast Disks ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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12 Calculate a max_chunks parameter as the LCM of the virtual disks’ speeds Divide each disks into a number of chunks: Serialize the chunks: for i = 0..(max_chunks - 1) for j = 1..NoD Broadcast chunk C ji (i mod num_chunks(j)) end -LCM calculation??? -Integer division? -Zero padding extend? BDISKS: Schedule construction algorithm ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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13 ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη Mathematical Analysis of the no-BC problem
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14 Mathematical Analysis of the no-BC problem ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη Lagrange Parameters Method (CACLAB Extended Analysis)
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15 ΙΙΙ. Research of the CACLAB team ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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TitlePublicationShort Description «Clustering-driven Wireless Data Broadcasting» SCVT 2008 WCM, to appear.Clustering+BD method.New feedback scheme.Complete procedure (CWDB).Checked 54 client cases «An Analytical Approach to the Design of Wireless Broadcasts Disks Systems» ISADS 2009.Introducing Disk Workload Distribution (DWD) concept.Mathematical Analysis (under DWD+ assumptions).Introducing Optimization Based Procedure (OBP).Checked 1 DWD, 54 client cases «On the Analytical Performance Optimization of Wireless Data Broadcasting» TVT, to appear.General BD Mathematical Analysis (DWD assumptions only) & Updated Optimization Based Procedure (UOBP).Checked 30 DWD *90 c lient cases «A New Approach to the Design of Wireless Data Broadcasting Systems: An Analysis- Based Cost-Effective Scheme» ICUMT 2009 BTS, submitted.Faster UOBP convergence algorithm.Memory Efficient Broadcast Sequence Constructor Algorithm Implementation 16 Overview (part 1) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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TitlePublicationShort Description «Towards Realizable Wireless Broadcast Systems» TNET, submitted MELECON2010, submited.Extended, client p.d.f agnostic, BS length aware mathematical analysis of no-bc broadcast problem.Introduction of cost-efficient scheduling algorithm.Deprecation of BDISKS model and State-of-art scheduling algorithms with respect to realizability. «Maximizing Adaptivity of dynamic Wireless Broadcast Systems» Completed.Analysis on BS length minimization, which achieves minimal serving times. Analysis on the connection between adaptivity and BS length..Advanced Cost efficient, Adaptivity oriented algorithm «QoS on wireless broadcast Systems: Guaranteeing Serving time for real-time applications» Completed.Analysis on BS construction aimed at guaranteeing serving time with X% certainty..Impact on the client set. 17 Overview (part 2) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Presentation of a complete, BDISKS based, push system that incorporates: i. A new feedback mechanism ii. A K-means based Virtual Disk formation approach iii. A new Disk speed definition algorithm Comparison with other related, popular schemes More than 50 client cases examined for the first time. 18 A. The CWDB scheme ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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19 A. Feedback Scheme ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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20 A. Clustering-driven Wireless Data Broadcasting- ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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21 A. GREEDY Based Broadcasting Procedure- GBBP ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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22 A. CWDB and GBBP Comparison ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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23 Range/Region 30/1 30/3 30/5 1000/30 1000/50 2000/50 2000/100 3000/50 4000/50 Θ 0.3 0.5 0.7 0.95 1.1 1.5 54 Client cases 54 Client cases For each client case … CWDB NoD2 3 4 5 6 7 Δ1 2 3 4 5 6 7 8 15 20 50 80 100 U N-1 10 30 50 100 GBBP NoD2 3 4 5 6 7 Δ1 2 3 4 5 6 7 8 15 20 50 80 100 … compare the best results achieved by each algorithm A. Client Case Definition ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Range=30, Region=5 Range=1000, Region=30 24 A. Results (Ι) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Range=1000, Region=50 Range=2000, Region=100 25 A. Results (ΙΙ) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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26 Definition of optimal model parameters Broadcast Disks Model Mathematical Analysis Optimal Disk Sizes Optimal Disk Sizes Optimal U i Optimal U i Projectiono f m.c.r.t D Validation of Analysis’ Conclusion B. Optimization Based Scheduling Υπόθεση #1 Υπόθεση #2 ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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27 Out of them approximately: refer to pages belonging to Disk #i, and correspond to an aggregate delay of and thus the approximate mean delay time will be Positioning of the d i is in accordance with assumption #1 B. Mathematical Analysis ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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28 Due to Assumption #2: Which is expressed in matrix form as: And usually, thus B. Mathematical Analysis (ΙΙ) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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29 Define Value Sets for Δ and ΝοD S Δ, S NoD For each pair (S Δ x S NoD ) calculate the approximate mean delay (CAUTION! L varies!) Keep the pair (Δ optimal, NoD optimal ) that achieves the minimum Calculate corresponding d i values Thus [Disk Sizes] optimal is also defined. Objective #1 Completed Optimal Parameter values are set (Δ optimal, NoD optimal, [Disk Sizes] optimal ). An approximation of the mean response time is calculated ( D ) B. Optimized Broadcast Scheduling Procedure-OBSP ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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30 Range/Region 30/1 30/3 30/5 1000/30 1000/50 2000/50 2000/100 3000/50 4000/50 Θ 0.3 0.5 0.7 0.95 1.1 1.5 54 client cases 54 client cases Optimization Based Procedure S NoD [2 – 15] SΔSΔ [1 – 150] GREEDY [2] Based Procedure S NoD 2 3 4 5 6 7 SΔSΔ 1 2 3 4 5 6 7 8 15 20 50 80 100 For each case …. Run ANALYSIS for parameters’ value sets: Run ANALYSIS for parameters’ value sets: For each case …. Run SIMULATION for parameters’ value sets: Run SIMULATION for parameters’ value sets: Keep Optimal NoD o, Δ o D t Keep Optimal NoD, Δ D s 16 SIMULATION D t (NoD o, Δ o ) D s (NoD o, Δ o ) SIMULATION D t (NoD o, Δ o ) D s (NoD o, Δ o ) Equal ? VALIDATION Compare B. Client Cases Definition ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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31 Typically, ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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32 Equally distributed Workloads Not Working! ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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33 Analytical means of research on the Broadcast Disks Method were introduced. A new and very efficient broadcast scheduling scheme was presented, based on workload distribution assumptions. Was found to be dominant over traditional choices in the vast majority of test cases. Other Workload distributions need to be tested. Analytical means of research on the Broadcast Disks Method were introduced. A new and very efficient broadcast scheduling scheme was presented, based on workload distribution assumptions. Was found to be dominant over traditional choices in the vast majority of test cases. Other Workload distributions need to be tested. ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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34 Non-Deterministic, Page-Grouping or NDPG-Variant. Non-Deterministic, Region-Grouping or NDRG-Variant Deterministic, Page-Grouping or DPG-Variant Deterministic, Region-Grouping or DRG-Variant ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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Range 3000 5001500 2000 3500 4500 out of 5000. Region=50 ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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requires 4Ν +2 computations.. Thomas Method (better alternative): 8N-4 Thus was proven that the new method requires 50% the computational power in any case. ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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TitlePublicationShort Description «Towards Realizable Wireless Broadcast Systems» TNET, submitted MELECON2010, submited.Extended, client p.d.f agnostic, BS length aware mathematical analysis of no-bc broadcast problem.Introduction of cost-efficient scheduling algorithm.Deprecation of BDISKS model and State-of-art scheduling algorithms with respect to realizability. «Maximizing Adaptivity of dynamic Wireless Broadcast Systems» Completed.Analysis on BS length minimization, which achieves minimal serving times. Analysis on the connection between adaptivity and BS length..Advanced Cost efficient, Adaptivity oriented algorithm «QoS on wireless broadcast Systems: Guaranteeing Serving time for real-time applications» Completed.Analysis on BS construction aimed at guaranteeing serving time with X% certainty..Impact on the client set. 38 CACLAB Research Overview (part 2) ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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39 ΙV. Future Research ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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40 ΙV. New Research Objectives ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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41 Time Schedule R.S. YEAR 20102011 #1√√ #2√√ #3√√ #4√√ ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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42 Why Hybrids? ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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43 Questions?? ΠροηγούμενηΠροηγούμενη - Περιεχόμενα - ΕπόμενηΠεριεχόμενα Επόμενη
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