Tim Ireland, Adam Nyzio, Michael Zink, Jim Kurose Department of Computer Science University of...
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Transcript of Tim Ireland, Adam Nyzio, Michael Zink, Jim Kurose Department of Computer Science University of...
Tim Ireland, Adam Nyzio, Michael Zink, Jim Kurose
Department of Computer Science
University of Massachusetts Amherst
The Impact of Directional Antenna Orientation, Spacing, and Channel
Separation on Long-distance Multi-hop 802.11g Networks: A Measurement Study
WiNMee’07, April 20th 2007
Motivation
General SurveillanceRain Prediction
ComputationRain Mapping
Multiple 15 dBi directional antennas
• Motivation• Measurement Setup• Antenna Orientation• Antenna Separation• Routing vs. Non-routing• Conclusion and Outlook
Overview
Measurement Setup
Link 3
Node 1 Node 2
Wireless 802.11g link, Distance: 157 meters,
ESSID=“pair1”
Link 1
Node 3 Node 4Wireless 802.11g link, Distance: 265 meters,
ESSID=“pair2”
Link 2
2 meters distancebetween antennas
Node 4
45°
Distance: 172 meters
Node 4
90°
Distance: 197 meters
• Laptops• Proxim 802.11 b/g WLAN• 14.5 dBi Yagi antennas
• TCP-based throughput measurements (Iperf)
• 10 times 30 seconds for each setup
Antenna Orientation
• 10 Mbps increase depending on antenna orientation
• Almost full channel capacity with fully separated channels
• The answer lies in the antenna gain pattern
Antenna Separation
• 8.2 Mbps increase through 2 meters vertical separation
• Throughput increase independent from azimuthal orientation
Top view:
Side view:
Top view:
Side view:
Routing vs. Non-routing
Node 3 Node 4Node 1 Node 2
Link 1 Link 2
Node 3 Node 4Node 1 Node 2
Link 1 Link 2
Conclusions & Future Work• Orientation and separation have significant
impact on throughput• Influence of data handling at the multi-hop node• Antenna beam pattern• Max. throughput for complete channel
separation
• Impact of weather and terrain on link quality• Analysis of MAC layer traces from
measurements• Develop models based on measurement results
CDF
Retransmission Burst
F(x
)