Project #1 Improved RF Signal Propagation through Water via Waveforms Student:Ritesh J....
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Transcript of Project #1 Improved RF Signal Propagation through Water via Waveforms Student:Ritesh J....
Project #1 Improved RF Signal Propagation through Water via Waveforms
Student: Ritesh J. Patel Electrical and Compute Engineering ACCEND Justin Jantzen Aerospace Engineering
Mentor: Dr. Dharma Agrawal, D.Sc. Distinguished ProfessorAnagha Jamthe Graduate Student Mentor
NSF Type 1 STEP GrantSponsored By
The National Science FoundationGrant ID No.: DUE-0756921
College of Engineering and Applied Science
University of Cincinnati
Index
Experiment PurposeBackgroundMaterialsTest MethodTest ResultsConclusion
Experiment Purpose
Improvement in RF (Radio Frequency) signal propagation between a wireless transmitter/receiver pair through a pipe filled with air vs. RF signal propagation through water
A hollow pipe can be used to propagate signal through air rather than water and could significantly improve the signal quality and transmission range
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Background
RF waves are used by cell phones to communicate with a microwave tower
Such signals attenuates quickly in water due to absorption/attenuation properties
Such wireless devices communicating with RF signals could be used in off-shore oil-drilling platforms, submarines, and marine life applications
A hollow pipe can be used to propagate signal through air rather than water and could significantly improve the signal quality and transmission range
Background
3 Major Methods of Transmission Radio Frequency Acoustic Optical
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Background
From “Re-Evaluation of RF Electromagnetic Communication in Underwater Sensor Networks”
Materials
• Copper & PVC pipes of varying diameters cut into 1m segments• 1 m PVC pipe with diameter: 1.5 inch, 2 inch and 3
inch
• Trash-can filled with water
• RF Sensors operating at 2.4 GHz• Texas Instrument eZ430-RF2500-SHE
Test Method
• Transmit signal through pipe (copper & PVC) and two plastic bags in air
• Transmit signal through pipe (copper & PVC) and two plastic bags by placing pipe and plastic bags in water
• Compare the RSSI percentage of copper, PVC and two plastic bags in air
• Compare the RSSI percentage of copper, PVC and two plastic bags in water
• Use different diameter (1.5 inch, 2 inch, & 3 inch) of pipes to see diameter’s effect on RSSI percentage
Air Water
Test Method
ReceiverStation
TransmitterStation
ReceiverStation
StationTransmitter
Test Results
Stacked Histogram of RSSI Percentages of the 3 Methods When Not Submerged in Water
Test Results
3-D Histogram of RSSI Percentages of the 3 Methods When Not Submerged in Water
Test Results
Figure 3: Stacked Histogram of RSSI Percentages of the 3 Methods When Submerged in Water
Test Results
3-D Histogram of RSSI Percentages of the 3 Methods When Submerged in Water
Test Results: Summary
Average Percent Signal ReceivedPlastic Bags 1.5" Copper Pipe 1.5" PVC Pipe 2" PVC Pipe 3" PVC Pipe
Not Submerged 59.62 35.68 66.52 65.30 58.31
Not Submerged σ 0.997 2.408 1.040 2.347 2.735
Submerged 32.77 0.00 43.02 40.26 43.01
Submerged σ 1.17 0.00 0.61 2.08 2.54
Average Percent Signal LostPlastic Bags 1.5" Copper Pipe 1.5" PVC Pipe 2" PVC Pipe 3" PVC Pipe
Not Submerged 40.39 64.32 33.49 34.70 41.69
Submerged 67.24 100.00 56.98 59.74 56.99
Average RSSI, in Percentage of Maximum RSSI, where σ is Standard Deviation
Average RSSI Lost, compared to Maximum RSSI
Conclusion
• Signals subject to large attenuation through water without waveform
• Waveform reduces signal somewhat in air• In water, PVC waveform reduces signal loss
by up to 10%• Submerged copper pipe subjects signal to
complete loss at 1m• Larger pipe diameters have a small, but
negative, effect on signal strength
Questions?
Background
Conclusion
Test Result Comparisons in Air
• Radio Frequency signals are commonly used in communications, from radio and cellphones to Wi-Fi
• RF signals lose strength quickly in water due to absorption/attenuation properties
• Wireless devices communicating with RF signals could be used in off-shore oil-drilling platforms, submarines, and marine life applications
Experiment Purpose
Test Result Comparisons in Water
Test Methods
Materials
Outcome
• Improvement in Radio Frequency signal propagation between a wireless transmitter/receiver pair through a pipe filled with air vs. RF signal propagation through water
• A hollow pipe can be used to propagate signal through air rather than water and could significantly improve the signal quality and transmission range
• Copper & PVC pipes of varying diameters cut into 1m segments
• Trash can filled with water
• RF Sensors operating at 2.4 GHz
• Transmit signal through pipe (copper & PVC) and two plastic bags in air• Transmit signal through pipe (copper & PVC) and two plastic bags by
placing pipe and plastic bags in water• Compare the RSSI percentage of copper, PVC and two plastic bags in air• Compare the RSSI percentage of copper, PVC and two plastic bags in
water• Use different diameter (1.5 inch, 2 inch, & 3 inch) of pipes to see
diameter’s effect on RSSI percentage
Average RSSI, in Percentage of Maximum RSSI, where σ is Standard Deviation
Average RSSI Lost, compared to Maximum RSSI
• Signals subject to large attenuation through water without waveform
• Waveform reduces signal somewhat in air
• In water, PVC waveform reduces signal loss by up to 10%
• Submerged copper pipe subjects signal to complete loss at 1m
• Larger pipe diameters have a small, but negative, effect on signal strength