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Symbiotic Wireless Autonomous Powered system

Final Report Summary - SWAP (Symbiotic Wireless Autonomous Powered system)

The main objective of SWAP is to combine aspects of energy efficient wireless sensor network and energy harvesting technologies towards the successful implementation of a highly autonomous wireless sensor platform with minimum dependency on battery operation and with minimum impact on the environment.

The limited duration of batteries as well as their performance degradation over time is the most critical phenomenon that limits the possibility for a user of being always wirelessly interconnected. Furthermore, waste management associated with the substitution of spent batteries becomes a critical issue when one considers the increasingly larger number of wireless sensors that are being employed towards a smarter environment. The results of SWAP can not only lead to technological benefits but also to an improved quality of service for the users, thereby achieving social welfare improvements. Limiting energy consumption to when really necessary as well as exploiting renewable energy sources in the most efficient manner is key to move forward on the green network communication paradigm. Furthermore, the close collaboration of the different institutions under SWAP project has a significant impact to the education of the seconded researchers. On one hand secondments have allowed researchers to gain complementary expertise in communication protocols and RF design. On the other hand researchers have had the opportunity to combine a more practical expertise obtained by secondments to the SMEs, with a more theoretical background obtained through secondments to the research institutions which allowed them to learn new modeling and validation tools. The seconded researchers also contributed to the exchange of information with other team members not directly involved into SWAP who have benefited from scheduled seminars and invited presentations of the seconded members from the other institutions.

The proposed work is distributed in six work-packages. WP0 and WP5 deal with management and administrative issues (WP0), and with the dissemination and exploitation of the results (WP5). The project website (http://fp7-swap.dei.unipd.it/) is the main reference point of the project and contains information about the project progress, vision and objectives. Additionally, it allowed the members to advertise open positions and provides a database for the project results. Work-packages 1-4 contain the technical work associated with SWAP. WP1 produced a State-of-the-Art analysis and identified critical application scenarios motivated both by world market needs as well as in more detail by specific market interests of the two SME SWAP members. WP2 Investigation and Design defined the goals of the project beyond the existing state-of-the-art as well as preliminary analysis and design of low power protocols and harvesting modules. In this second period of SWAP, two work-packages WP3 and WP4 were completed. WP3 dealt with the validation of the designs and preliminary module integration, while WP4 included the implementation of the final sensor board exploring solar and electromagnetic energy harvesting. The obtained research results have led to the incorporation into commercial products of the SME partners of some of the evaluated components and protocol designs.

Obtained results include: a) analysis of wireless devices and their batteries in the presence of energy harvesting by means of properly dimensioned Markov chains and stochastic processes, b) derivation of practical guidelines to drive the operation policy of a wireless sensor device when only partial information is known about the surrounding communication and energy availability scenario, c) characterization of existing lossy compression algorithms explicitly tailored to Wireless Sensor Networks, d) design and optimization of multi-band and broadband electromagnetic harvesting modules, as well as the design of multi-technology, solar-electromagnetic energy harvesters on flexible textile, PET and paper substrates, e) integration of solar and electromagnetic energy harvesting module with sensor board demonstrating battery-less operation under different scenarios of energy availability.

SWAP focused on realizing a novel energy efficient sensor board platform. To this aim, work was performed in two areas: hardware design and communication software optimization. In the first area, a successful design combining outstanding computational capability with reduced power consumption was achieved. In the second area a protocol stack which is compliant with IEEE/IETF standards, offering multiple tunable parameters to be provided to the energy management module was realized. This second period constituted the practical phase of the project where each of the individual components of the proposed sensor system has been tested and integrated into a single board solution. The sensor node selected for a final demonstration of battery-less operation has been WorldSensing’s industrial product, Load Sensing. LoadSensing (LS) is a datalogger for geotechnical sensors, delivering real time data wirelessly. Cooperation among all SWAP partners has been key to integrate the multiple solutions into a single system. Battery-less operation of LoadSensing has been demonstrated by harvesting light energy as well as electromagnetic energy from a Wi-Fi router. A video demonstration of the LoadSensing sensor operation is available at the SWAP website (http://fp7-swap.dei.unipd.it/).

SWAP researchers have organized 10 workshops at International Conferences (IoT Week 2011, RWW 2012, EUMW 2011, IMS 2011, IoTech 2012, RWW 2014, EUMW 2013 (x3), IMS 2012), as well as 3 special sessions (EuCAP 2011, EuCAP 2012, EuMW 2013). Furthermore, SWAP researchers organized 1 Training School jointly with EU COST Action IC0803, and 1 two-day demo at IoT Week 2011. During the demo, a wireless sensor network deployed at the Department of Engineering of the University of Padova has been remotely managed using Web technology according to the RESTful communication paradigm. Furthermore, the SWAP Coordinator organized the 2011 IEEE RFID-TA Conference, which has been organized for the first time in Europe.

The publications produced during project SWAP include 25 papers in peer reviewed journals, 54 conference papers at international conferences, 2 book chapters and 2 technical reports. SWAP researchers organized 3 journal special issues, including a Special Issue on Energy Harvesting and Scavenging at the Proceedings of the IEEE, to be published in Nov. 2014. Finally, SWAP researchers produced 1 edited book on Microwave and Millimeter Wave Circuits and Systems: Emerging Design, Technologies and Applications (ISBN-13: 978-1119944942).

The results of SWAP project have led to award winning publications. One conference paper by SWAP researchers received a 3rd best paper award at the 2012 IEEE RFID-TA conference, and a second conference paper was a student contest finalist at the 2012 IEEE WiSNeT Conference and finally a third paper received the best paper award at 2014 IEEE RFID-TA conference.

SWAP fellows have been involved in a number of communication and outreach activities. SWAP participated in the PEOPLE Marie Curie Conference 2012, 5-6 Nov. 2012, in Nicosia Cyprus, and was selected as a success story and published at the H2020 website in March 2014 (https://ec.europa.eu/programmes/horizon2020/en/news/smart-sensors-harvest-power-sun-heat-or-vibrations). Furthermore, CTTC researchers participated in the Barcelona Science Week 2013 (Setmana de la Ciencia 15-23 Nov 2013) where high school students visited CTTC and were informed about research activities in the framework of SWAP project.