DOWNLOAD MY Ph.D Thesis - UNAM

More documents

Recommendations

Info

Chapter 6Optimisation of CRA using adaptive CSAs pthroughput. This makes the Forced-CSA the optimal slot allocator for different trafficconfigurations.6.3 Dynamics of the DVB Contention Resolution AlgorithmsIn this section, we pay attention to the details of the exponential backoff algorithm andthe splitting tree algorithm adopted by the DVB/DAVIC communications protocol.6.3.1 Exponential backoff algorithm optimisationFor CATV networks that make use of the exponential backoff algorithm, theperformance of such networks is also determined by the initial and truncated backoffvalues defined (also referred to as backoff window: Bw[i-t]). Thus, the aim of thissection is to provide a performance analysis for different backoff windows and toindicate which windows offer the highest system performance. Two trafficconfigurations (mixed traffic and VoIP traffic) will be used.In order to achieve optimum system performance, the Forced-CSA (introduced inSection 6.2.3.1) will be utilised. With the exception of the minimum and maximumbackoff values, for this analysis we have used the same simulation parameters presentedin Table 5.4 (Chapter 5).6-17
Chapter 6Optimisation of CRA using adaptive CSAs pa) Results for mixed traffic using the exponential backoff algorithmThis analysis deals with mixed traffic at 41.7 kbps per station (32 kbps Internet plus 9.7kbps VoIP traffic). Figure 6.11 presents the cumulative probability plotted againstaccess delay close to saturation. This performance was recorded with 34 stations,producing an offered load of 46% of the channel capacity.From Figure 6.11, it can be seen that by defining short values for the initial backoffexponent (e.g. Bw[2-3] or Bw[2-5]) a poor system efficiency is obtained. Up to 33% ofall packets generated were transmitted in less than 100 ms. This is because thebacklogged NIUs are forced to transmit in any of the next 4 contention slots, therebyincreasing the risk of collision with new incoming packets.Similar inefficiencies are seen with large values for the initial and truncated backoffexponent parameters (e.g. Bw[5-7). The consequence of this being to cause backloggedNIUs to wait for a relatively long period before they can transmit a request, whichresults in many contention slots passing without being used.6-18
Page 6 and 7:
I would like to thank all the peopl
Page 10:
CHAPTER 6: OPTIMISATIO OF CRA ALGOR
Page 13 and 14:
FIGURE 5.17 - SYSTEM THROUGHPUT VS.
Page 15 and 16:
LIST OF TABLESTABLE 2.1 - NEXT GENE
Page 17 and 18:
Chapter 1Introduction pBecause of h
Page 19 and 20:
Chapter 1Introduction pA first step
Page 21 and 22:
Chapter 1Introduction passumption i
Page 23 and 24:
Chapter 1Introduction ppolynomial b
Page 25 and 26:
Chapter 1Introduction pIn general,
Page 27 and 28:
Chapter 1Introduction pminislots to
Page 29 and 30:
Chapter 1Introduction pThe authors
Page 31 and 32:
Chapter 1Introduction prate access
Page 33 and 34:
Chapter 1Introduction p1.4 Overview
Page 35 and 36:
Chapter 2OVERVIEW OF CURRENT CATVNE
Page 37 and 38:
Chapter 2Overview of current CATV n
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Chapter 3THE DVB/DAVIC PROTOCOL3.1
Page 57 and 58:
Chapter 3The DVB/DAVIC protocol pEu
Page 59 and 60:
Chapter 3The DVB/DAVIC protocol pMA
Page 61 and 62:
Chapter 3The DVB/DAVIC protocol pTh
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Chapter 3The DVB/DAVIC protocol p3.
Page 69 and 70:
Chapter 4Simulation and analytical
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Chapter 5Upstream channel capacity
Page 107 and 108: Chapter 5Upstream channel capacity
Page 143 and 144: Chapter 6Optimisation of CRA using
Page 157: Chapter 6Optimisation of CRA using
Page 171 and 172: Chapter 7PERFORMANCE OPTIMISATION F
Page 173 and 174: Chapter 7Performance optimisation f
Page 201 and 202: aChapter 7Performance optimisation
Page 209 and 210:
Chapter 8Final conclusions p8.2 Gen
Page 211 and 212:
Chapter 8Final conclusions pWe have
Page 213 and 214:
Chapter 8Final conclusions pperform
Page 215 and 216:
Chapter 8Final conclusions pslots i
Page 217 and 218:
Chapter 8Final conclusions pfocused
Page 219 and 220:
Chapter 8Final conclusions preserva
Page 221 and 222:
Chapter 8Final conclusions pbandwid
Page 223 and 224:
Chapter 8Final conclusions pThe opt
Page 225 and 226:
Chapter 8Final conclusions p8.4 Fut
Page 227 and 228:
Chapter 8Final conclusions pApplica
Page 229 and 230:
Chapter 8Final conclusions pTCIS st
Page 231 and 232:
Referencesp[17] I. Cidon, and M. Si
Page 233 and 234:
Referencesp[50] N. F. Huang, C. A.
Page 235 and 236:
Referencesp[85] V. Rangel, R. Edwar
Page 237 and 238:
Referencesp[112] K. Sriram, “Meth
Page 239 and 240:
APPEDIX A: GLOSSARYAALABRADSLATMBCB
Page 241 and 242:
Appendix AGlossary pkbpsLANLLCMACMA
Page 243 and 244:
Appendix AGlossary pUSBUWVDSLVoDVoI
Page 245 and 246:
Appendix BProtocol stack and packet
Page 247 and 248:
Appendix BProtocol stack and packet
Page 249 and 250:
APPENDIX C: D VERIFICATION TEST FOR
Page 251 and 252:
Appendix D Verification test p209 2
Page 253 and 254:
Appendix EResults for a 6 Mbps upst
Page 255:
Appendix FGuide to CD-ROM p IEEE802
show all

DOWNLOAD MY Ph.D Thesis - UNAM

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?