DOWNLOAD MY Ph.D Thesis - UNAM

More documents

Recommendations

Info

Chapter 7Performance optimisation for the support of TCIS pIn addition, during long idle periods, the continuous piggyback mechanism fails due tothe excessive number of slots that remain unused. A timer function stops thismechanism after a time threshold is exceeded. Time periods of up to 2.286s can bebridged without using contention slots [35].7.2.6 Unsolicited Grant Slot (UGS)The ‘Unsolicited Grant Slot (UGS)’ mechanism provides a station with a fixed numberof slots at periodic intervals, using the reservation grant message. The stations must useonly unsolicited grant slots for upstream transmissions. The number of slots needed by astation and the periodic intervals can be negotiated during the connection set-up. Thismechanism can be used only when the CBR parameters are satisfied regarding theactual data rate, packet size and packet interval. In addition, the UGS mechanismcompletely avoids the transmission of reservation requests and allocates morebandwidth to the reservation-based region, thereby reducing significantly the packetaccess delay and increasing the overall system throughput.The continuous reserved request, piggyback request and continuous piggyback requestmechanisms were first reported in [43], where a comprehensive performance analysis interms of the cumulative probability of packet delay was presented. Due to theirenhanced performance these three mechanisms have now been integrated into the latestversion of the DVB/DAVIC standard ‘ETSI EN 200 800’ [35].The unsolicited grant slot, enhanced pure reservation access and reservation requestmechanisms are novel and have been developed in this project. Results derived fromthis research show that the UGS mechanism significantly outperforms the othermechanisms in terms of system performance and can be easily adopted in the ETSIEN 200 800 protocol specification.7-6
Chapter 7Performance optimisation for the support of TCIS p7.2.7 Performance comparison of Enhanced-Reservation-RequestMechanismsTwo different traffic situations are presented in order to give an overview of theperformance of the enhanced-reservation-request mechanisms in reservation-accessmode. For this analysis both contention resolution algorithms were used.The traffic types were as previously seen and consisted of VoIP traffic at 9.7 kbps andmixed traffic at 41.7 kbps. Table 7.1 shows the values of the simulation parameters thatwere shown to have provided optimum system performance in Chapters 5 and 6.Table 7.1 – Optimised simulation parameters.Simulation ParameterValueUpstream data rate (QPSK)3.088 MbpsDownstream data rate (64-QAM, In band)42 MbpsBuffer capacity per NIU3000 ATM cellsHeadend and NIU processing delay2 microseconds eachMaximum contention access message length0 ATM cellsMaximum number of active NIUs (EuroModems) 180Maximum reservation/piggyback32 for PRA, EPRA, RR, CRR, and 256 for EPRArequest length (in slots)0,3,6,12 for PG and 1,3,6,12 for CPGBackoff windows (exponential backoff algorithm)[4-6] for Mixed traffic and [5-7] for VoIP trafficMinimum CSs per signalling frame (exponential backoff algorithm) 3 for PRA, EPRA, RR, PG and 1 for CRR, CPG, UGSContention slot allocator used (exponential backoff algorithm)ForcedEntry spreading factor (splitting tree algorithm) 6Minimum CSs per signalling frame (splitting tree algorithm)2 for PRA, EPRA, RR, PG and 1 for CRR, CPG, UGSPropagation delay (coax and fibre)5 µs/KmSimulation time for each run60sDistance from nearest/farthest NIU to the Headend10-16 Km, randomly distributedTransmission time (cycle) of the signalling frame3 ms7-7
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:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126: Chapter 5Upstream channel capacity
Page 143 and 144: Chapter 6Optimisation of CRA using
Page 171 and 172: Chapter 7PERFORMANCE OPTIMISATION F
Page 173 and 174: Chapter 7Performance optimisation f
Page 175: 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?