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A Sensor Data Gathering Framework for Agricultural-Fields: - - PowerPoint PPT Presentation
A Sensor Data Gathering Framework for Agricultural-Fields: - - PowerPoint PPT Presentation
A Sensor Data Gathering Framework for Agricultural-Fields: Implementation and Experiment Report Hideya Ochiai The University of Tokyo / NICT, JAPAN 1 Background Weather stations at remote sites How can we collect sensor data ?
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Background
- Weather stations at remote sites
- How can we collect sensor data ?
引用: http://www.twin.ne.jp/~saineria/flowerknowledge/flowerknowledge01.html 引用: http://www.edu.city.yokohama.jp/sch/es/hie/6-1ho-mu/page1.htm
Weather Station Mechanical observation
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<< Background >>
By making use of PHS or 3G Network
Agricultural Field
PHS Access Point
PHS PHS PHS PHS PHS
○ Easy to deploy × Communication fee for carrier □ Real-time is not always important Real-time data collection from remote sites
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<< Proposal >> DTN-Based Data Gathering
Agricultural Field
WiFi WiFi WiFi WiFi WiFi WiFi WiFi WiFi
Use the movement of truck as a network carrier ○ Easy to deploy ○ No communication fee for carrier △ Delivery delay is physically bound to the movement of the truck
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What is DTN ???
- Delay or Disruption Tolerant Networking
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Intermittent Connectivity
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Isolated Networks Mobile Node
A B
Message
Circle: Transmission Range
Features
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Sensor Truck Data Server
To deliver sensor readings to the data server
Potential
Data Flow Data Flow
: Wireless device
Routing in DTN: Potential-Based Routing (PBR)
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Experiment Scenario
Sensor Deploy (#1) Sensor Deploy (#2)
Data Server (#99) Mobile Node (#3) Mobile Node (#4) Mobile Node (#5)
- 1. The sensors and the server are isolated.
- 2. The sensors continuously send data to the server.
- 3. The movement of "mobile nodes" carries data to
the server.
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Armadillo220 Battery(6.0V 2100mAh) Power Circuit Wifi 802.11g Storage(2GByte)
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Implementation
- Software: http://sourceforge.net/projects/pear/files/
- IP packet buffer: 4096 entries
- Source code: 3225 lines in C.
- Foot print: 34kbyte (object code)
- OS: linux-2.6.12.3-a9-15
- Hardware: Armadillo-220 (Atmark Techno)
PEAR for sensor data gathering
PEAR: potential-based entropy adaptive routing
- 1. Autonomously develops routing information
- 2. Adaptively changes message delivery form according
to the physical mobility pattern.
"Mobility entropy and message routing in community-structured delay tolerant networks", ACM AINTEC 2008.
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Weather Station with DTN
RS232C(Serial)
Weather Sensor (WXT510/520)
- Temperature
- Humidity
- Pressure
- Rain Fall
- Wind Direction
- Wind Speed
DTN node (#1, #2)
Observe and send data to the data server (#99) (every ten second)
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Mobile Node -- Carry by hand!!
DTN node
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Data Server
50m
40 [min]
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The number of received neighbor advertisement packets. e.g., node 8 received 45 advertisement from sensor 1.
Contact Graph
Mobility Entropy2.1
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Potential for the Data Server
Potentials developed by PEAR potential construction algorithm
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Message Flow (1/2)
Red arrow: messages from sensor 1 (#1) Blue arrow: messages from sensor 2 (#2)
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Message Flow (2/2)
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Distribution of Delivery Latency
E.g., 50 = [0,100]
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Collected Temperature Data from Sensor 1
Delivery Rate = 100 %
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Collected Temperature Data from Sensor 2
Delivery Rate = 100 %
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Conclusion
- DTN-Based Sensor Data Gathering
– Data server Truck Sensors
- Implementation
– DTN-Communication Boxes – Potential-Based Entropy Adaptive Routing (PEAR)
- Experiment
– in the University of Tokyo – 100% delivery (with 20min – 30min delay)
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Thank you ...
DTN Communication Boxes Sensor data delivery pattern DTN-Based Sensor Data Gathering