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

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increases by 100% when <strong>the</strong> height <strong>of</strong> wireless devices changes from 0.4 to 0.8 meter. Figure 2.14: The Fresnel Zone [49]. The impact <strong>of</strong> power management on WLAN throughput was addressed in [17]. Power management is an efficient way to extend battery life. However, it results in low throughput <strong>of</strong> WLAN due to lower transmission power. Enabling power management function will decrease performance <strong>of</strong> WLAN around 240%. The study gives us an insight into power management control during propagation measurement. The highest data rate would have maximum network throughput. RSS and frame error rate are key factors to determine <strong>the</strong> exact data rate [50, 51]. Poor signal strength not only leads to lower throughput, but also small range <strong>of</strong> signal coverage. RSS is an important benchmark for assessing <strong>the</strong> performance <strong>of</strong> WLANs. To sum up, <strong>the</strong> studies give us an insight into experimental measurement design and considering interfering factors. The studies also have an important implication <strong>of</strong> conducting fur<strong>the</strong>r experiment in <strong>the</strong> obstructed <strong>of</strong>fice environment. - 24 -
2.3.2 Base Station Placement <strong>An</strong> accurate base station placement can reduce <strong>the</strong> number <strong>of</strong> base stations, adequate signal coverage <strong>of</strong> desired area, spectral efficiency and lower installation costs. Many studies have already indicated that base station placement has strong influence on network throughput, channel assignment, and efficient spectrum utilization in <strong>the</strong> indoor and outdoor wireless network [52-56]. Maximizing system capacity, utilizing spectrum more efficiently and improving quality <strong>of</strong> service are primary goals <strong>of</strong> WLAN design. <strong>An</strong> effective base station placement plan is necessary prior to practical deployment. The measurement <strong>of</strong> signal strength is an approach to estimate coverage <strong>of</strong> APs. <strong>Signal</strong> strength meter is widely used to measure signal strength <strong>of</strong> WLAN. Some computer s<strong>of</strong>tware (e.g. Wirelessmon [57]) would also provide same functionality <strong>of</strong> signal strength meter. <strong>Signal</strong> strength map is a common technique to present WLAN performance in <strong>the</strong> practical WLAN design. Non-parametric modeling technique was developed for estimating signal strength and conducted measurements to validate a proposed model [58]. The study has a significant implication <strong>of</strong> using realistic signal strength for optimizing AP placement. There are only three non-overlapping channels in <strong>the</strong> IEEE 802.11 networks. Utilising spectrum as efficiently as possible is important in <strong>the</strong> base station placement. Due to overlapping channels, it results in co-channel interference. The effect <strong>of</strong> co-channel interference has already been discussed in chapter 2.2.3. Therefore, base station placement not only concentrates on signal coverage, but also selecting frequency and channel assignment [59, 60]. - 25 -
Page 1 and 2: An Investi
Page 3 and 4: 2.3.5 Signal <stro
Page 5 and 6: Attestation of Aut
Page 7 and 8: Abstract Wireless local area networ
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: As highlighted in [46, 47], distanc
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
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7. Access Point at Position “H”
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Figure B.2: Throughput map for AP a
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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
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60 40 20 0 -20 -40 -60 -80 -100 Acc
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AP at A RX Position Left-Hand Area
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AP at L RX Position Left-Hand Area
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Appendix D Phase 3 Experimental Res
Page 161 and 162:
TX at 2M from E-3M Data File: 153.6
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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
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