CMU-RI-TRThesis.pdfAbstractList of FiguresList of TablesAbbreviations1 Introduction1.1 Precision Agriculture1.2 Scope1.3 Research Objectives1.4 Research Methodology1.5 Overview2 Wireless Sensor Networks2.1 Evolution of Wireless Sensor Networks2.2 WSN vs Ad-hoc networks2.3 Wireless Networking Standards2.3.1 IEEE 802.15.1 and Bluetooth2.3.2 IEEE 802.15.3a and Ultra-wide band2.3.3 IEEE 802.15.4 and ZigBee2.3.4 Wi-Fi2.3.5 IEEE P1451.5 project2.3.6 Wibree2.4 Comparison of WSN Standards2.5 Factors Influencing WSN Design2.5.1 Reliability2.5.2 Scalability2.5.3 Production Costs2.5.4 Hardware Constraints2.5.5 Network Topology2.5.6 Operating Environment2.5.7 Transmission Media2.5.8 Energy Consumption2.5.9 Data Aggregation2.5.10 Fault Tolerance2.6 Applications of WSN3 Wireless Sensor Network Routing Protocols3.1 Factors Influencing the Design of WSN Routing Protocols3.2 Classification of WSN Routing Protocols3.3 Flat Routing Protocols3.3.1 Flooding and Gossiping3.3.2 Sensor Protocols for Information via Negotiation3.3.3 Direct Diffusion3.3.4 Rumor Routing3.3.5 Minimum Cost Forwarding Algorithm3.3.6 Gradient-Based Routing3.3.7 Energy Aware Routing3.3.8 Routing Protocols with Random Walks3.3.9 Advantages and Disadvantages of Flat Routing Protocols3.3.10 Comparison of Flat Routing Protocols3.4 Hierarchical Routing Protocols3.4.1 Low Energy Adaptive Clustering Hierarchy3.4.2 Hierarchy-based Anycast Routing3.4.3 Hierarchical Energy Aware Routing3.4.4 Threshold Sensitive Energy Efficient Sensor Network Protocol3.4.5 Balanced Aggregation Tree Routing3.4.6 Advantages and Disadvantages of Hierarchical Routing Protocols3.5 Comparison of Flat and Hierarchical Routing4 Link Quality Estimation4.1 Classification of Link Quality Estimators4.2 Link Quality Estimation Algorithms4.2.1 Packet Reception Ratio4.2.2 Required Number of Packet Retransmissions4.2.3 Expected Number of transmissions4.2.4 Window Mean with Exponentially Weighted Moving Average4.2.5 Four-bit4.3 Comparison of Link Quality Estimators4.4 Link Quality Estimation Algorithm for Distributed SensorWebs Routing Protocol5 Hardware Description5.1 Sensor Node5.2 Base Station5.3 Power Supply5.4 Analog Circuitry5.5 CPU Signals5.6 Radio5.7 USB5.8 Other Components5.9 Supported Sensors5.10 Decagon EM50 Data Logger6 Protocol Design6.1 Design Choices6.1.1 Scalability6.1.2 Reliability6.1.3 Energy Efficiency6.1.4 Simplicity6.1.5 Practicality6.1.6 Special Hardware Independent6.2 Protocol Operation6.2.1 Link Quality Estimation6.2.2 Network Setup6.2.3 Transmitting and Forwarding Data6.2.4 Network Maintenance and Neighborhood Table Management6.2.5 Configuring the Node Settings6.3 Design Summary7 Programming Methodology7.1 Software Design of Sensor Nodes7.1.1 Main Loop Thread7.1.2 Do Sensor Scan7.1.3 Send All Data7.1.4 Timer Threads7.1.5 Digital Sensor I/O Thread7.1.6 Routing Data Packets Thread7.2 Software Design of the Base Station7.2.1 Base Station Main Loop Thread7.3 Development Environment7.4 Diagnostics8 Results and Discussion8.1 Three Node Multi-Hop Test8.2 New Node's Joining the Network After Network Setup8.3 Rerouting Packets upon Node Failure8.4 Five Node Multi-Hop Test8.5 Latency Due to Multi-Hop Routing8.6 Network Setup Time8.7 Number of Acknowledgements Received During Link Quality Estimation8.8 Network Stress Testing8.9 Battery Lifetime9 Conclusion9.1 Conclusion9.2 Future WorkA Network Setup TimeB Latency due to Multi-Hop RoutingC Number of Acknowledgements Received During Link Quality EstimationD Battery LifetimeBibliographyDesign and Development of aWireless Sensor Network System forPrecision AgricultureAbhinav Valada David Kohanbash George KantorCMU-RI-TR-10-21June 2010Robotics InstituteCarnegie Mellon UniversityPittsburgh, Pennsylvania 15213c Carnegie Mellon UniversityAbstractWireless Sensor Networks (WSNs) have attracted much attention in recent years.The potential applications of WSNs are immense. They are used for collecting, stor-ing and sharing sensed data. WSNs have been used for various applications includinghabitat monitoring, agriculture, nuclear reactor control, security and tactical surveil-lance. The WSN system developed in this project is for use in precision agricultureapplications, where real time data of climatological and other environmental propertiesare sensed and control decisions are taken based on it to modify them. The architectureof a WSN system comprises of a set of sensor nodes and a base station that commu-nicate with each other and gather local information to make global decisions about thephysical environment. The sensor network is based on the IEEE 802.15.4 standard anda new multi-hop routing protocol was designed suited for monitoring and control ap-plications.The aim of this research is to adapt the flat and hierarchical architectures to create anew hybrid that draws on current protocol theories. The protocol uses a hybrid networkstructure to achieve scalability and is source initiated along with event driven reportingto reduce the number of packet transmissions. The protocol incorporates a link qualityestimation algorithm, which enables only the nodes with high quality symmetric linksto be chosen for routing. Route selection is calculated using both hop count and linkquality as routing metrics. The protocol is also designed such that it is computationalsimple, reliable, energy aware, does not impose any special hardware prerequisites andmost importantly credible. Its credibility was verified by performing a series of fieldtests in a real world operating environment.Another aspect of the work was to make the necessary changes on the existing CMUSensorWeb platform to make it compatible with the EM50 data loggers of DecagonDevices, Inc. The base station responds to the confirmed delivery requests made bythe EM50 and forwards the parsed packets to the control computer. The SensorWebbase station can receive packets from the EM50 in both Confirmed Delivery mode andTransmit Only mode. This system is currently being used to monitor water status andcontrol irrigation for ornamental crops.ContentsAbstract iList of Figures viiList of Tables ixAbbreviations x1 Introduction 11.1 Precision Agriculture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.3 Research Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.4 Research Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.5