An Investigation of the Impact of Signal Strength on Wi-Fi Link ...

More documents

Recommendations

Info

Acknowledgements First <strong>of</strong> all, I would like to express my sincere gratitude to my supervisor Nurul I. Sarkar. Without his kind guidance, comments and encouragement during my research, I would not complete my dissertation. Especially, because <strong>the</strong> experimental measurements cannot be performed during weekdays and it is a time consuming task, my supervisor spent more than 10 weekends to help me in data collection. I take advantage to thank all <strong>of</strong> my friends: Sandeep Patil, Kang Sun, Dun Yong Jin, Ryan Sentosa and Feng Liu. They also provide many supports and inspire me during my research. I would like to express special gratitude to Colligo Networks Inc. for providing me two licenses <strong>of</strong> Colligo Workgroup Edition S<strong>of</strong>tware and PassMark S<strong>of</strong>tware Pty Ltd for a license <strong>of</strong> WirelessMon s<strong>of</strong>tware to support my research. Finally, I would like to thank my parents and family who are always playing an important role no matter <strong>the</strong> distance to encourage me during my difficult time. Without all <strong>of</strong> <strong>the</strong>ir support, I could not achieve my goals. - v -
Abstract Wireless local area networks (WLANs) play an increasingly significant role in providing ubiquitous network services in contemporary society due to <strong>the</strong>ir mobility and cable free usage. It is more challenging to maintain higher throughput <strong>of</strong> WLANs than wired networks. In this dissertation, an experimental investigation <strong>of</strong> <strong>the</strong> impact <strong>of</strong> signal strength on Wi-Fi link throughput in an obstructed <strong>of</strong>fice environment is reported. Due to <strong>the</strong> complexity and unpredictable nature <strong>of</strong> radio signal propagation, it is difficult to derive real and accurate signal strength and link throughput by analytical modeling and computer simulation. The received signal strength (RSS), attenuation and path loss depends on <strong>the</strong> propagation environment. The location <strong>of</strong> an access point (AP) has a significant effect on WLAN performance. <strong>An</strong> appropriate AP placement is required to obtain greater performance <strong>of</strong> WLANs. Through extensive radio propagation measurements, <strong>the</strong> results demonstrated both <strong>the</strong> relationship <strong>of</strong> signal strengths with <strong>the</strong> Wi-Fi link throughput; and optimum AP placement. This research carried out some significant contributions. Firstly, <strong>the</strong> results revealed that not only WLAN throughput depends on RSS, but also on factors such as <strong>the</strong> distance and <strong>the</strong> obstruction between a transmitter and a receiver, and <strong>the</strong> nature <strong>of</strong> radio - vi -
Page 1 and 2: An Investi
Page 3 and 4: 2.3.5 Signal <stro
Page 5: Attestation of Aut
Page 9 and 10: List of Abbreviati
Page 11 and 12: List of Figures Fi
Page 13 and 14: List of Tables Tab
Page 15 and 16: Chapter 1 Introduction There has be
Page 17 and 18: WLAN performance evaluation and ana
Page 19 and 20: Chapter 2 Background and Related Wo
Page 21 and 22: The IEEE 802.11 networks have two o
Page 23 and 24: The coverage of a
Page 25 and 26: 2.2.1 Physical Layer Figure 2.8 sho
Page 27 and 28: throughput significantly at higher
Page 29 and 30: DCF is designed to provide “best-
Page 31 and 32: Figure 2.11: Backof</strong
Page 33 and 34: modulation in [37]. According to si
Page 35 and 36: Figure 2.12: Net throughput <strong
Page 37 and 38: As highlighted in [46, 47], distanc
Page 39 and 40: 2.3.2 Base Station Placement <stron
Page 41 and 42: gained an insight that this would m
Page 43 and 44: proposed to improve WLAN performanc
Page 45 and 46: specifications of
Page 47 and 48: dynamic and complicated. As argued
Page 49 and 50: In addition, we surveyed and review
Page 51 and 52: 4.1 Performance Metrics A stopwatch
Page 53 and 54: Model: DWL-G132 Specification: Sta
Page 55 and 56: Figure 4.1: WY building layout. - 4
Page 57 and 58:
Figure 4.2 shows wireless configura
Page 59 and 60:
4.4.2 Wireless Adapter Configuratio
Page 61 and 62:
4.4.3 AP Operation Mode Two APs (D-
Page 63 and 64:
meeting room with different distanc
Page 65 and 66:
Scenario 4 In figure 4.12, two APs
Page 67 and 68:
“(H-3.5m)F-H” is the</s
Page 69 and 70:
Figure 4.16: Phase 2 measurement: A
Page 71 and 72:
performed the prop
Page 73 and 74:
The receiver sensitivity is an impo
Page 75 and 76:
In table 5.1, the
Page 77 and 78:
Ethernet connectio
Page 79 and 80:
sufficient signal coverage and thro
Page 81 and 82:
throughput decreases along with low
Page 83 and 84:
In table 5.1, when RSS is larger th
Page 85 and 86:
(for example, measurement point “
Page 87 and 88:
AP at Position “R” Figure 5.13
Page 89 and 90:
The measurement results indicated t
Page 91 and 92:
5.2.2 Throughput An</strong
Page 93 and 94:
impact on RSS and throughput. Resul
Page 95 and 96:
The throughput of
Page 97 and 98:
The RSS of “WDS
Page 99 and 100:
The average throughput of</
Page 101 and 102:
The average data size of</s
Page 103 and 104:
5.6.1 SOHO Environment Due to <stro
Page 105 and 106:
The following notes are needed to b
Page 107 and 108:
when APs were placed at positions
Page 109 and 110:
Real and accurate results for AP pl
Page 111 and 112:
Chapter 7 Summary and Conclusions W
Page 113 and 114:
planning. Propagation measurement (
Page 115 and 116:
deployment. Many WLANs are deployed
Page 117 and 118:
placement in indoor wireless system
Page 119 and 120:
Communications, vol. 2, no. 5, pp.
Page 121 and 122:
[56] J. K. L. Wong, M. J. Neve, and
Page 123 and 124:
eceived signal strength of<
Page 125 and 126:
Appendix A Preliminary Experimental
Page 127 and 128:
2. AP Mode Measurement in t
Page 129 and 130:
7. The Ad-Hoc Mode Measurement on <
Page 131 and 132:
Appendix B Phase 1 Experimental Res
Page 133 and 134:
(P-1.5m)O-P 32.78 -86 193.6 0.453 N
Page 135 and 136:
3. Access Point at Position “E-3M
Page 137 and 138:
(C-5m)C-D 21.63 -83 46.8 1.875 NLOS
Page 139 and 140:
J 9.00 -44 8.2 10.703 LOS (J-1.5m)J
Page 141 and 142:
7. Access Point at Position “H”
Page 143 and 144:
Figure B.2: Throughput map for AP a
Page 145 and 146:
60 40 20 0 -20 -40 -60 -80 -100 Acc
Page 147 and 148:
(N-3m)N-O 15.00 -72 15.6 5.626 NLOS
Page 149 and 150:
(C-3m)C-D 14.32 -74 13.6 6.453 NLOS
Page 151 and 152:
Figure B.8: Throughput map for AP a
Page 153 and 154:
60 40 20 0 -20 -40 -60 -80 -100 Acc
Page 155 and 156:
AP at A RX Position Left-Hand Area
Page 157 and 158:
AP at L RX Position Left-Hand Area
Page 159 and 160:
Appendix D Phase 3 Experimental Res
Page 161 and 162:
TX at 2M from E-3M Data File: 153.6
Page 163 and 164:
IEEE 802.11 b/g Access Point DWL-21
Page 165 and 166:
Standards • IEEE 802.11g • IEEE
Page 167 and 168:
1 Maximum wireless signal rate deri
Page 169 and 170:
Wireless 108G Standards • 802.11b
Page 171 and 172:
Wireless 108G Add 802.11g Wireless
Page 173:
2.4GHz Omni-Directional 7dBi Indoor
show all

An Investigation of the Impact of Signal Strength on Wi-Fi Link ...

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

Delete template?

Save as template?