Robust, Energy Efficient Wireless Sensor Networks for Outdoor Scenarios by Adaption of Operation Parameters

The opportunities for Wireless Sensor Networks are as well various and challenging. In agriculture, e.g., distributed sensors can be used to measure plant growth or for soil analysis. Here, robustness of single nodes and the whole network is of major importance for successful projects or smart farming approaches. Almost every environmental impact has also direct or indirect influence on the lifetime of the nodes or the network, whereby also huge deviations in environmental conditions occur. Provoked by sun exposure, a single sensor node can show a difference in temperature of 56°C in just one day. Additionally, there is an intense heterogeneity in temperature between the particular nodes within the network.

To enable a long-term operation of sensor networks under such conditions they should be very robust against such influences and energy supply has to be ensured. Besides other things, robustness can be achieved by reducing the energy requirements of the node, respectively by adapting the requirements to the generation or vice versa. Additionally, some tasks (e.g., record, store, or process data) can be postponed or relocated in order to adapt them in the temporal or the spatial dimension, on a single node and/or within the network, and to adjust them to the specific environmental or energy conditions. So, especially in outdoor scenarios we have the situation that a.) Some nodes may work more energy efficient than others - due to their temperature and their individual characteristics (heterogeneity within the network) and b.) Changing environmental conditions (over time - e.g. direct sunlight / shadow or day / night) lead to dynamic shift of the energy efficiency of single nodes or the whole network. Opportunities for Energy Harvesting share this dynamics, as well.

Monitoring the changing environmental conditions allows to benefit from the systems dynamics. Realistic models for energy and reliability will be derived from these measurements. Combined with the knowledge about the characteristics of the nodes in the network, this information can, e.g., be used for routing decisions, task scheduling, and processing within the network. By predicting the environmental variables, a suitable time for performing intensive computations or forwarding data in delay tolerant networks can be determined. Specific scheduling and routing protocols will be developed to achieve a robust wireless sensor network under dynamic conditions. The investigated relations and the implemented algorithms will be evaluated continuously in a real environment.

Subprojects

• Longterm measurement of the soil temperature

  

  This experiment was used to measure the soil temperature in different depths. Using this

• REAPer

  

  The reaper is a test platform for energy harvesting. Its purpose is to provide a generic interface for energy sources and energy storages. Commonly used are super capacitors as storage and solar panels or peltier elements for harvesting.

  Additionally, the platform integrates a programmable voltage supply, a secure co-processor and a generic header for the base board holding the actual MCU.

  The platform allows to test different MCUs in an energy harvesting sensor node.

• Low-Cost Temperature Chamber

  

Poster

Publications

• Ulf Kulau, Silas Müller, Sebastian Schildt, Felix Büsching and Lars Wolf: Investigation & Mitigation of the Energy Efficiency Impact of Node Resets in RPL, in Ad Hoc Networks, June 2021 (Kulau:AdHoc-Networks-2021, DOI, BibTeX)
• Sven Pullwitt, Robert Hartung, Ulf Kulau and Lars Wolf: Towards Accurate Bit Error Simulation in Wireless Sensor Networks Including Environmental Influences, in Journal of Computer Science and Technology, Vol. 35, No. 4, pages 809, Journal of Computer Science and Technology, 2020 (pullwitt:jcstcooja, DOI, BibTeX)
• Robert Hartung, Rasmus Antons, Ulf Kulau and Lars Wolf: DUO: Integration of Dependable Undervolting in Operating Systems, in Proceedings of the 7th International Workshop on Energy Harvesting & Energy-Neutral Sensing Systems, ENSsys'19, New York, NY, USA, pages 56-57, ACM, 2019 (Hartung:2019:DID:3362053.3363487, DOI, BibTeX)
• Sven Pullwitt, Robert Hartung, Ulf Kulau and Lars Wolf: Towards Accurate Bit Error Simulation in Wireless Sensor Networks Including Environmental Influences, in 2019 IEEE 16th International Conference on Mobile Ad Hoc and Sensor Systems (MASS), pages 82-90, 2019 (PullwittHartungCoojaBitErrors, BibTeX)
• Robert Hartung, Jan Käberich, Lars C. Wolf, Laura Marie Feeney, Christian Rohner and Per Gunningberg: Demo: Integration of a Platform for Energy Storage Experiments into a Generic Testbed Framework, in Proceedings of the 12th International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, WiNTECH '18, New Delhi, India, pages 77-78, ACM, November 2018 (Hartung:2018:DIP:3267204.3268069, DOI, BibTeX, Poster)
• Robert Hartung, Ulf Kulau, Niels Lichtblau and Lars C. Wolf: A Flexible Software Framework for Real-World Experiments and Temperature-Controlled Testbeds, in Proceedings of the 12th International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, WiNTECH '18, New Delhi, India, pages 30-37, ACM, November 2018 (Hartung:2018:FSF:3267204.3267207, DOI, BibTeX, Slides)
• Robert Hartung, Jan Käberich, Lars C. Wolf, Laura Marie Feeney, Christian Rohner and Per Gunningberg: A Platform for Experiments with Energy Storage Devices for Low-power Wireless Networks, in Proceedings of the 12th International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, WiNTECH '18, New Delhi, India, pages 68-76, ACM, November 2018 (Hartung:2018:PEE:3267204.3267208, DOI, BibTeX)
• Robert Hartung: On the Challenges in Energy-Constrained Outdoor Wireless Sensor Networks: Trade off between Efficiency and Robustness, Doctoral Collquium, Shenzhen, China, November 2018 (hartung:sensys18:dc, BibTeX, Slides)
• Ulf Kulau, Daniel Szafranski and Lars Wolf: Effective but Lightweight Online Selftest for Energy-Constrained WSNs, in Thirteenth IEEE Workshop on Practical Issues in Building Sensor Network Applications 2018 (IEEE SenseApp 2018), Chicago, USA, October 2018 (kulau:SenseApp:2018, BibTeX, Slides, Best Paper Award)
• Jana Huchtkötter, Andreas Reinhardt and Ulf Kulau: PulseHV: Opportunistic Data Transmissions over High Voltage Pulses for Smart Farming Applications, in Proceedings of the 14th IEEE International Conference on Distributed Computing in Sensor Systems, DCoSS 2018, New York, USA, June 2018 (Kulau:DCOSS2018, BibTeX, Runner-up for best paper)
• Sven Pullwitt, Ulf Kulau, Robert Hartung and Lars C. Wolf: A Feasibility Study on Energy Harvesting from Soil Temperature Differences, in Proceedings of the 7th International Workshop on Real-World Embedded Wireless Systems and Networks, RealWSN'18, Shenzhen, China, pages 1-6, ACM, 2018 (Pullwitt:2018:FSE:3277883.3277886, DOI, BibTeX)
• Robert Hartung, Ulf Kulau and Lars Wolf: Adaptive Wireless Sensor Networks: Robust but Efficient, in Proc. IDEA League Doctoral School on Transiently Powered Computing, Delft, The Netherlands, IDEA League (TU Delft, RWTH Aachen University, ETH Zurich, Chalmers University, Politecnico di Milano), November 2017 (hartung:tpc2017, BibTeX)
• Ulf Kulau, Daniel Bräckelmann, Felix Büsching, Sebastian Schildt and Lars Wolf: REAPer - Adaptive Micro-Source Energy-Harvester for Wireless Sensor Nodes, in Twelfth IEEE Workshop on Practical Issues in Building Sensor Network Applications 2017 (IEEE SenseApp 2017), Singapore, October 2017 (kulau:SenseApp:2017, BibTeX, Slides, Runner-up for best paper)
• Ulf Kulau, Silas Müller, Sebastian Schildt, Arthur Martens, Felix Büsching and Lars Wolf: Energy Efficiency Impact of Transient Node Failures when using RPL, in Proceedings of the 18th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WoWMoM 2017, Macau, China, June 2017 (Kulau:WOWMOM2017, BibTeX, Slides)
• Ulf Kulau, Stephan Rottmann and Lars Wolf: Demo: Brzzz - A Simplistic but Highly Useful Secondary Channel for WSNs, in Proceedings of the International Conference on Embedded Wireless Systems and Networks, EWSN 2017, Uppsala, Sweden, February 2017 (Kulau:EWSN2017, BibTeX, Slides, Poster, Best Demo Award)
• Robert Hartung, Ulf Kulau, Björn Gernert, Stephan Rottmann and Lars Wolf: On the Experiences with Testbeds and Applications in Precision Farming, in Proceedings of the First ACM International Workshop on the Engineering of Reliable, Robust, and Secure Embedded Wireless Sensing Systems, FAILSAFE'17, Delft, The Netherlands, pages 54-61, ACM, 2017 (Hartung:Sensys:2017:FAILSAFE, DOI, BibTeX, Slides)
• Ulf Kulau, Johannes van Balen, Sebastian Schildt, Felix Büsching and Lars Wolf: Dynamic Sample Rate Adaptation for Long-Term IoT Sensing Applications, in IEEE World Forum on Internet of Things 2016 (WF-IoT), Reston, USA, December 2016 (kulau:wf-iot:2016, BibTeX, Slides)
• Georg von Zengen, Robert Hartung, Ulf Kulau, Felix Büsching and Lars Wolf: Low Cost Temperature Controlled Testbed for WSNs, Augsburg, Germany, September 2016 (FGSN:2016, BibTeX)
• R. Hartung, U. Kulau and L. Wolf: Distributed Energy Measurement in WSNs for Outdoor Applications, in 2016 13th Annual IEEE International Conference on Sensing, Communication, and Networking (SECON), pages 1-9, June 2016 (Hartung:Secon:2016, DOI, BibTeX)
• R. Hartung, U. Kulau and L. Wolf: Demo: PotatoScope - Scalable and Dependable Distributed Energy Measurement for WSNs, in 2016 13th Annual IEEE International Conference on Sensing, Communication, and Networking (SECON), pages 1-3, June 2016 (Hartung:Secon:2016:Demo, DOI, BibTeX)

Project members at IBR

Theses

If you are interested in writing a thesis regarding this project, please feel free to contact Robert Hartung.

Supporters

This research project is funded by the German Research Foundation (DFG) under grants no. BU 3282/2-1.