DOWNLOAD MY Ph.D Thesis - UNAM

More documents

Recommendations

Info

Chapter 1Introduction pare granted according to the scheduling mechanism adopted. Classification of datapackets (or requests) is needed to support multimedia applications and QoS services,which require relatively low access delays.Limb and Sala [72] studied the performance of a Centralised Priority Reservation(CPR) mechanism for the transmission of multimedia traffic for the IEEE 802.14protocol. In this mechanism a station maintains separate queues for each priority ofdata traffic, and the priority is indicated in the type field of the request message.Requests with higher priority have precedence over requests with lower priority. Theheadend maintains separates queues for each priority and schedules in the first placehigher priority requests before serving a queue of a lower priority.Sdralia et al. [102] also studied the performance of a prioritised-scheduling algorithm(at the headend), using up to 8 levels of priorities for the DOCSIS protocol. The mainimplication of this prioritised-scheduling mechanism is that high-priority traffic willalways take precedence over low-priority traffic. More priority can be given to lowprioritytraffic by scheduling it to have more than one slot into the future. Thistechnique is referred to as Scheduling Advance (SA) in [72] and Ivanovich andZukerman [60].Different techniques can also be used. For example, Nichols and Laubach [78]proposed a scheduler algorithm with three levels of priorities, for the transmission ofConstant Bit Rate (CBR), Committed Information Rate (CIR) and Best Effort traffic(BE). Each of these traffic types has preference over the others with a fixedfrequency (e.g. 20% of channel capacity for CBR, 80% for CIR and 5% for BEtraffic).Sala et al. [94] studied a scheduler algorithm with a Self Clock Fair Queuing (SCFQ)discipline, in which every reservation request is attached with a finish service timeand placed in a queue with increasing order of service time. This finish time isdefined as the deadline time to serve (or grant) the request and is computedaccording to the traffic type characteristics (e.g. station’s data rate, packet size,arrival time) and the round trip delay.1-13
Chapter 1Introduction pThe authors of [73] analysed a scheduler algorithm for the IEEE 802.14 protocol,using three different strategies. In the first strategy (SJF) the shortest jobs (withminimum bandwidth request) are served first. In the second strategy (LJF) the largestjobs take precedence over short jobs, and in the last one (MSJF), the shortest jobs areserved first but the data minislots are allocated into several bursts. From these threestrategies it was found that by adopting SJF lower end-to-end access delays areproduced, but a larger delay for contention access is obtained.Research in this area focuses on the implementation or analysis of schedulingalgorithms at the headend. Corner et al. [20] argue that the headend schedulingalgorithm is not sufficient and that a system at the station’s premises integrated alsowith a scheduler algorithm is needed to efficiently support multimedia traffic andQoS services. The authors proposed a new priority scheme for the IEEE 802.14protocol, which separates and resolves collisions in a priority order.In this new system, a priority usage for each contention minislot is allocated by theheadend. Upon packet arrival, a station initially transmits in minislots exactlymatching their priority level, so the headend knows that all stations participating in aparticular collision are of the same priority level. The headend allocates three slots inthe next signalling frame for each collided request. These slots are reserved forrequests of the same priority as with the first collision.Golmie et al. [43] used the same idea of Corner to evaluate the performance of apriority scheme for the DOCSIS protocol. In this prioritised scheme, Golmieproposed a slight modification to the exponential backoff algorithm (used by theDOCSIS protocol), where the backoff value was set equal to the number ofcontention slots reserved for high priority stations.Both mechanisms ensure that in case of collision, high priority stations retransmitrequests in a timely manner.d) Registration after power-up disruption; In this area of research several strategieshave been proposed to optimise the recovery time after a service disruption (causedby power failures or maintenance services). In Sdralia et al. [103] and [104] anevaluation of the recovery of the DOCSIS 1.0 protocol after a large-scale power1-14
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: Chapter 1Introduction pminislots to
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 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 67 and 68: Chapter 3The DVB/DAVIC protocol p3.
Page 69 and 70: Chapter 4Simulation and analytical
Page 79 and 80:
Chapter 4Simulation and analytical
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:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Chapter 7PERFORMANCE OPTIMISATION F
Page 173 and 174:
Chapter 7Performance optimisation f
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
aChapter 7Performance optimisation
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
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?