DOWNLOAD MY Ph.D Thesis - UNAM

More documents

Recommendations

Info

Chapter 7Performance optimisation for the support of TCIS pminislot can be used either for contention, contention/data, initial maintenance or stationmaintenance. A CM with data to send issues a request, using contention minislots. Inthe case of a collision, this protocol applies the exponential backoff algorithm and theinitial and truncated backoff values of this algorithm are indicated in each signallingframe called as MAP. This frame also describes the usage of the upstream bandwidth.7.4.1.2 PHY layer comparisonThe basic characteristics at the physical layer are summarised in Table 7.3. In this tablethe downstream and upstream spectrum allocations and the slight variations in thefrequency ranges for the DVB/DAVIC and DOCSIS standards are shown. Thedownstream channels support the legacy analogue broadcast television (frequency rangeare ≈ 80-450 MHz) and multiples of 1-6 MHz (for DOCSIS) or 1-8 MHz channels (forDVB/DAVIC and EuroDOCSIS) in the 450-860 MHz region for transmission of digitaldata. The upstream channels are also divided into 1-6 MHz but poor SNR limits the datacapacity to 1-10 Mbps per channel for DOCSIS and 1-6 Mbps for DVB/DAVIC. This isa low data rate compared to the downstream channel where 28-40 Mbps and 42-52Mbps are available for DOCSIS and DVB/DAVIC, respectively.In terms of modulation schemes, most manufacturers have implemented 64 and 256-QAM for the downstream and QPSK for the upstream channels. DOCSIS also supportsa 16-QAM modulation in the upstream direction.For upstream transmission at the physical layer, DOCSIS MAC PDUs (which arecomposed of Ethernet packets) are segmented into PHY codewords, which are ofTable 7.3 – Frequency allocation and modulation characteristics.UpstreamDownstreamFeature DVB/DAVIC DOCSISModulation QPSK, 16-QAM under development QPSK, 16-QAMFrequency 5 – 65 MHz DOCSIS: 5–42MHz, EuroDOCSIS: 5-65MHzSpacing 200 kHz, 1 MHz, 2 MHz, 4 MHz 200, 400, 800 kHz, 1.6, 3.2MHzData rates Mandatory: 3.088 Mbps,320 kbps, 640 kbps,Optional: 256 kbps, 1.54 kbps, 6.176 Mbps 1.28 Mbps, 2.56 Mbps, 5.12 Mbps, 10.24 kbpsModulation IB: QPSK, OOB: 16, 32, 64, 256-QAM 64-QAM or 256-QAMFrequency OOB: 70-130 MHz / 300-862 MHz,80 – 860MHzIB: 300-862 MHzSpacingOOB: 1 MHz, 2 MHz,DOCSIS: 6MHz, EuroDOCSIS: 8 MHzIB: 7/8 MHzData rates 52 Mbps (256-QAM), 42 Mbps (64-QAM) 42 Mbps (256-QAM), 30 Mbps (64-QAM)7-26
Chapter 7Performance optimisation for the support of TCIS pvariable size (ranging from 16 to 253 bytes). These codewords contain FEC parity, alsoof variable size (from 0 to 10 bytes). Both a preamble and guard time fields of variablelength are then added at the beginning and at the end of all the codewords forsynchronization purposes between the CM and the CMTS. Such codewords aretransmitted as a continuous series of minislots. The size of the minislot is set by theCMTS during initialisation but can be varied. The length of a minislot is a multiple of6.25µs (i.e. 8, 16, 32 bytes etc.).In the upstream, DVB/DAVIC uses a 64-byte slot format for the transmission of data atthe physical layer. The slot format consists of a Unique Word which provides a burstmode acquisition method, a payload area that contains a single ATM cell and a Reed-Solomon parity field [34], which provides 3-bytes of FEC over the payload area and aGuard Band field for synchronization. The basic characteristics of these two protocolsare outlined in Table 7.4.Table 7.4 – Technical characteristics.Feature DVB/DAVIC DOCSISServicesInternet access, high speed interactive Settop-box,Internet access, low speed interactive Set-top-VoIP, SNMPbox, VoIP,SNMPUpstream Packet Format 64-byte Slot based on a ATM cell transport Variable Length (based on 64-1500 byteswith IP adaptation layer translationEthernet packets), Native IP with QoSQoS Granularity 53 bytes + 11 bytes PHY overhead 8-16 bytesQoS ServicesCollision ResolutionBE plus ATM derived class of services:CBR, ABR.Exponential backoff and Splitting treealgorismBE, CIR and prioritisation in DOCSIS 1.0 andRTP, nrt-RTP, UGS added in DOCSIS 1.1Exponential backoff algorithmATM Support Mandatory OptionalAccess Modes Ranging, contention, reservation and fixed Contention and reservationSecurity RSA/DES Encryption and clone detection RSA/DES Encryption and clone detectionCommercial Deployment DVB/DAVIC EM: Q3-99, Q3-00. DOCSIS 1.0: Q2-99; DOCSIS 1.1 Q4-997.4.2 Performance comparisonsThe performance comparison to follow addresses some of the fundamental propertiesand scalability of the upstream channel for both protocols. The analysis focuses on theperformance comparison for the upstream channel, which is the limiting factor onCATV networks (as stated in Section 1.2.2), and is critical in the delivery of services toindividual subscribers on demand. Key issues of the analyses address the followingperformance comparisons: protocol efficiency and volumetric data at the physical layer,7-27
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:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Chapter 6Optimisation of CRA using
Page 145 and 146: Chapter 6Optimisation of CRA using
Page 171 and 172: Chapter 7PERFORMANCE OPTIMISATION F
Page 173 and 174: Chapter 7Performance optimisation f
Page 195: 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?