Hierarchical, collaborative wireless energy transfer in sensor networks with multiple Mobile Chargers☆
Section snippets
Introduction and contribution
In Wireless Sensors Networks (WSNs) the sensor nodes are equipped with small batteries and thus, the lifetime of the network is limited. Although there are several approaches that try to address this fundamental problem, the proposed solutions are still limited since the energy that is replenished is either uncontrollable (such as environmental harvesting approaches) or require the nodes to be accessible by people or robots in a very accurate way (such as battery replacement approaches).
Related work and comparison
Wireless energy transfer technology inspired a lot of researchers to investigate how to exploit it in WSNs efficiently. In [5], the authors used a realistic scenario where the sensor nodes are mobile and the Chargers are stationary. They proposed two protocols to address the problem of how to schedule the Chargers activity so as to maximize either the charging efficiency or the energy balance. Also, they conducted real experiments to evaluate the protocols’ performance. In [6], the objective
The model
Our model features four types of devices: N stationary sensor nodes, M Mobile Chargers which charge sensor nodes, S Special Chargers which charge Mobile Chargers and a single stationary Sink. The sensor nodes of wireless communication range r are uniformly distributed at random in a circular area of radius R. The Mobile Chargers and the Special Chargers are initially deployed at the center of circular area. The Sink serves only as data collector.
In our model, we assume that neither the Mobile
The coordination decision problem
Definition 1 Consider a set of S Special Chargers. For each SCk (1 ≤ k ≤ S), we denote by the percentage of its current energy level to the total amount of energy of all Special Chargers i.e.,
Also, consider a set of M Mobile Chargers. For each MCj (1 ≤ j ≤ M), we define the amount of energy that Mobile Charger j can receive until it is fully recharged and denote by εj the percentage of its energy lack to the total energy lack of all Mobile Chargers, i.e.,
The charging protocols
We present a new protocol operating in 1-D networks and four new protocols operating in 2-D networks. Our protocols use hierarchical collaborative charging. Since there is plenty of research on how multiple Mobile Chargers can charge sensor nodes we focus on how we can efficiently use the available Special Chargers. In all protocols we investigate the following three design aspects:
Coordination: a Special Charger consumes its energy according to the energy depletion on its area, i.e. the energy
Performance evaluation
The simulation environment for conducting the experiments is Matlab 7.12. The Sink is placed at the center of the circular area. The number of sensor nodes is set to 2000, the number of Mobile Chargers to 15 and the number of Special Chargers to 3. In the simulations, the number of the Mobile Charges in non-collaborative protocols equals to the sum of the Mobile Chargers and the Special Chargers in the hierarchical protocols, so, in protocols that do not use Special Chargers, the number of
Conclusion and future work
In this work we study the problem of efficient collaborative wireless charging in Wireless Sensor Networks. We propose a new design approach, according to which, the set of chargers is partitioned into two groups, one hierarchically higher, called Special Chargers and one hierarchically lower, called Mobile Chargers. The Mobile Chargers are responsible for charging the sensor nodes whereas the Special Chargers charge Mobile Chargers. This hierarchical structure provides a more controllable and
Acknowledgments
This research was partially supported by the EU/FIRE IoT Lab project – STREP ICT-610477 and the European Social Fund (ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) – Research Funding Program: Thalis-DISFER, investing in knowledge society through the European Social Fund.
Adelina Madhja is an M.Sc. student at the Computer Engineering and Informatics Department, University of Patras, Greece and a Researcher at the Computer Technology Institute & Press “Diophantus”. Her research interests focus on the design of energy efficient algorithms for Wireless Sensor Networks, Distributed Systems, and Internet of Things. She has co-authored two publications in international refereed conferences and a journal.
References (20)
- et al.
Wireless energy transfer in sensor networks with adaptive, limited knowledge protocols
Comput. Netw.
(2014) - et al.
Distributed wireless power transfer in sensor networks with multiple mobile chargers
Comput. Netw.
(2015) - et al.
Minimizing the number of mobile chargers for large-scale wireless rechargeable sensor networks
Comput. Commun.
(2014) - et al.
Hierarchical, collaborative wireless charging in sensor networks
Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC)
(2015) - et al.
Wireless power transfer via strongly coupled magnetic resonances
Science
(2007) - et al.
Electrodes with high power and high capacity for rechargeable lithium batteries.
Science
(2006) - et al.
Collaborative mobile charging for sensor networks
Proceedings of the 9th IEEE International Conference on Mobile Ad-Hoc and Sensor Systems (MASS)
(2012) - et al.
An experimental evaluation of wireless power transfer protocols in mobile ad hoc networks
Proceedings of the IEEE Wireless Power Transfer Conference (WPTC)
(2015) - et al.
P3: joint optimization of charger placement and power allocation for wireless power transfer
Proceedings of the 34th IEEE International Conference on Computer Communications (INFOCOM)
(2015) - et al.
Low radiation efficient wireless energy transfer in wireless distributed systems
Proceedings of the 35th IEEE International Conference on Distributed Computing Systems (ICDCS)
(2015)
Cited by (0)
Adelina Madhja is an M.Sc. student at the Computer Engineering and Informatics Department, University of Patras, Greece and a Researcher at the Computer Technology Institute & Press “Diophantus”. Her research interests focus on the design of energy efficient algorithms for Wireless Sensor Networks, Distributed Systems, and Internet of Things. She has co-authored two publications in international refereed conferences and a journal.
Sotiris Nikoletseas is a Professor at the Computer Engineering and Informatics Department of Patras University, Greece and Director of the SensorsLab at CTI. His research interests include Algorithmic Techniques in Distributed Computing (focus on sensor and mobile networks), Probabilistic Techniques and Random Graphs, and Algorithmic Engineering. He has coauthored over 200 publications in Journals and refereed Conferences, several Book Chapters and two Books (one on the Probabilistic Method and another on sensor networks), while he has delivered several invited talks and tutorials. He has served as the Program Committee Chair of many Conferences, and as Editorial Board Member of major Journals. He has co-initiated international conferences on sensor networking. He has coordinated several externally funded European Union R&D Projects related to fundamental aspects of modern networks.
Theofanis P. Raptis is a Research Engineer at Computer Technology Institute and Press “Diophantus”, Greece and a Ph.D. candidate at the Computer Engineering and Informatics Department, University of Patras, Greece. His current research interests include wireless power transfer algorithms in sensor networks, mobile crowdsensing systems and future internet platforms and testbeds. He has co-authored more than 20 publications in acclaimed international refereed journals, conferences and books and has participated in several relevant European Union funded R&D projects.