Post on 14-Oct-2014
description
Toward Precision Agriculture: Building a Soil WetnessMulti-Hop WSN from First Principles
Aggelos Bletsas, Aikaterini Vlachaki, Eleftherios Kampianakis,George Sklivanitis, John Kimionis, Konstadinos Tountas, Megasthenis
Asteris and Panagiotis Markopoulos
Telecom LabDepartment of Electronic and Computer Engineering (ECE)
Technical University of Crete (TUC)
April 5, 2011
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 1 / 20
Outline
1 Why
2 What
3 Comparison
4 The BIG picture
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 2 / 20
WHY?
Why reinventing the wheel?
Cost reduction: from e120 per WSN node → e20 per node!
Research: Low-cost testbed for telecom research(localization, cognition, mobility, etc).
Research: New sensors, new applications.
Teaching: Telecom Synthesis course.
FUN :)
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 3 / 20
Outline
1 Why
2 What
3 Comparison
4 The BIG picture
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 4 / 20
WHAT? (Hardware - (1))
iCubes are WSN nodes.
SiLabs C8051F320 MCU.
TI/Chipcon CC2500.
2× AA battery operation.
Custom PCB design.
Emphasis to simplicity andflexibility.
Extension Board (XT) for iCube(power jack, UART, JTAG andMCU pinouts).
iCube + XT = iCube Gateway.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 5 / 20
The Humidity Sensor (Hardware - (2))
Ultra low power (300µA max), low cost (×5 cheaper compared to prior art).
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 6 / 20
The iCubes Software
Flexibility of C routinesBOOL send packet(BYTE destination id, bit pack type, bit wait for ack,UINT16 timeout, BYTE max tries, BYTE sn)BOOL receive packet(BYTE *length, BYTE source id, bit type, BYTEpacket acceptance level, UINT16 timeout, BYTE sn)
Over the air programming capability (OTAP) has beendeveloped.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 7 / 20
The WSN application towards water management
Successful iCubes WSN demo set up takinghumidity and temperature measurements(built-in thermistor).
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Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 8 / 20
The Gateway Interface - collected information
Due to simple gateway - PC interface (single UART buffer), developmentof another UI is trivial.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 9 / 20
MAC / Routing
Packet driven multi-hop TDM/FDM routing protocol.
No need for clock synchronization.
Packet-driven with highlyunsynchronized WSN nodes.
Tree-based hierarchy.
Exploiting multiple carriers(one for each subtree).
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 10 / 20
Outline
1 Why
2 What
3 Comparison
4 The BIG picture
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 11 / 20
Comparison
iCubes cost: ∼ 30e(quantities of 10)Prior art: ∼ 120e(of similar functionality).
Power consumption: comparable to prior art.
iCube humidity sensor is power/cost competitive to commercialproducts.
iCubes development cycle: short(simple C based on structured and embedded programming).
OTAP - capable without the use of RTOS!
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 12 / 20
Outline
1 Why
2 What
3 Comparison
4 The BIG picture
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 13 / 20
GPRS-enabled WSN gateway
Capability of sending data through GPRS to remote database.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 14 / 20
Renewable energy sources
Solar/Wind power utilization.
Website: http://www.telecom.tuc.gr/∼aggelos/tel412 fall2010/
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 15 / 20
Testing Emergency Radio Applications
Perhaps first of a kind collaborativebeamforming demonstration.
Zero-feedback, zero CSIdistributed beamforming.
Ideal for reachbackcommunication in low-cost WSNs.
iC iC iC
WSN iCube nodes
Single transmission
Beamfroming Gain
Low-cost testbed(iCubes and USRP BS).
A. Bletsas, A. Lippman and J.N. Sahalos, “Simple, Zero-Feedback,Distributed Beamforming with Unsynchronized Carriers”, IEEEJournal on Selected Areas of Communications (JSAC), SpecialIssue on Simple Sensor Networking Solutions, Vol. 28, No. 7,
pp.1046-1054, Sept. 2010.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 16 / 20
Backscatter Sensor Networks
Single transistor WSN radio.Ultra low cost.Ultra low power.Ideal for environmental WSNs.Challenge: increase range.
A. Bletsas, A.G. Dimitriou and J.N. Sahalos, “Improving BackscatterRadio Tag Efficiency”, IEEE Transactions on Microwave Theory
and Techniques (MTT), Vol. 58, No.6, pp. 1502-1509, June 2010.
G. Vannucci, A. Bletsas and D. Leigh, “A Software-Defined RadioSystem for Backscatter Sensor Networks”, IEEE Transactions onWireless Communications (TWC), Vol. 7, No. 6, pp. 2170-2179,
June 2008.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 17 / 20
The BIG picture
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 18 / 20
Conclusion
WSNs can be low cost, easy, modular and fun!
New disruptive technologies are being developed @ TUC/TelecomLab.
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 19 / 20
Thank YOU! Questions?
Eleftherios Kampianakis (kampianakis@gmail.com)
Contact info: Aggelos Bletsas
Assistant ProfessorTelecom LabElectronic & Computer Engineering Dept.Technical University of Crete, Greece
aggelos@telecom.tuc.graggelos@media.mit.edu
website: http://www.telecom.tuc.gr/∼ aggelos
Bletsas et al. (TUC) Ecosense 2011, Belgrade, Serbia April 5, 2011 20 / 20