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

List <strong>of</strong> Figures
Figure 2.1: <strong>An</strong> infrastructure network...............................................................7
Figure 2.2: <strong>An</strong> ad-hoc network. ........................................................................7
Figure 2.3: Basic service set. ............................................................................8
Figure 2.4: Independent basic service set. ........................................................8
Figure 2.5: ESS and wireless distribution system.............................................9
Figure 2.6: ESS and wired distribution system...............................................10
Figure 2.7: The IEEE 802 family and OSI model [14]. ..................................10
Figure 2.8: Physical layer logical architecture................................................11
Figure 2.9: IEEE 802.11 MAC architecture [13]............................................14
Figure 2.10: Network allocation vector [14]...................................................15
Figure 2.11: Back<strong>of</strong>f procedure [13]...............................................................17
Figure 2.12: Net throughput <strong>of</strong> IEEE 802.11b [17]. .......................................21
Figure 2.13: Net throughput with 802.11b including RTS/CTS [17]..............22
Figure 2.14: The Fresnel Zone [49]. ...............................................................24
Figure 4.1: WY building layout. .....................................................................41
Figure 4.2: Main configuration menu for AP. .................................................42
Figure 4.3: Performance parameter configuration menu for AP. ....................44
Figure 4.4: AP configuration information.......................................................44
Figure 4.5: Main configuration menu for WLAN adapter. .............................45
Figure 4.6: Parameter configuration menu for WLAN adapter. .....................46
Figure 4.7: WLAN adapter configuration information. ..................................46
Figure 4.8: AP operation mode configuration menu.......................................47
Figure 4.9: The ad-hoc mode measurement (scenario 1)................................49
Figure 4.10: The AP mode measurement (scenario 2). ...................................50
Figure 4.11: The WDS with AP mode measurement (scenario 3). .................50
Figure 4.12: The AP Mode with E<strong>the</strong>rnet measurement (scenario 4).............51
Figure 4.13: The WDS Mode measurement (scenario 5)................................51
Figure 4.14: Phase 1 measurement: an AP at position “A”.............................53
Figure 4.15: Phase 2 measurement: APs at position “A” and “J”...................54
Figure 4.16: Phase 2 measurement: APs at position “E-3M” and “N-3M”. ...55
Figure 5.1: Throughput measurement under ad-hoc mode. ............................60
Figure 5.2: Throughput comparison with different AP configurations...........62
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