Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wireless sensors share intelligence

27.06.2007
Wireless sensor networks find their way in logistics, in product quality control and even in the Great Barrier Reef where they monitor the quality of water. But how do hundreds of sensors communicate without consuming too much battery power? Lodewijk van Hoesel of the Centre for Telematics and Information Technology (CTIT) of the University of Twente lets sensors ‘speak’ to their neighbours without the need of a central director.

Wireless sensor networks are hot. In any application in which wires used to cause problems, autonomous and wireless sensors can be positioned. An example of a project Van Hoesel is involved with, is monitoring the water quality in the fragile ecology of the Great Barrier Reef without the need of an ‘intrusive’ infrastructure. But also for climate control in buildings and for monitoring industrial processes, wireless sensor networks have been introduced. The sensors exchange information and form ‘multi hop’ connections. Because they sometimes stay in place for years, the use of battery power must be kept to a minimum.

The sensors don’t just constantly transmit their data to a central server; that would cost far too much energy. Communication is expensive in terms of energy consumption, therefore intelligence is added locally to each sensor node: the sensors know when to transmit their data and when to pass data through, coming from neighbouring sensors. For this, they have to be ‘on speaking terms’, as Van Hoesel calls it. In this way, the network itself can carry out complex tasks.

He therefore designed a so-called Medium Access (MAC) protocol, based on self organization of the network. The sensors keep an eye on their neighbours and autonomously decide whether to start transmitting or not. This also holds for the neighbours next-door to the closest neighbours: in this way, Van Hoesel avoids conflicts in the network and keeps energy use to a minimum.

This approach can be further improved by introducing passive sensors in the network: they provide data but they don’t actively participate in the multi hop communication. Passive sensors use less energy and thus extend the lifetime of the network as a whole. As wireless networks in general can be vulnerable to attacks from the outside, Van Hoesel presents adequate countermeasures.

Lodewijk van Hoesel, who defended his PhD thesis ‘Sensors on speaking terms’ on June 21 is also the cofounder –together with Paul Havinga and Stefan Dulman- of Ambient Systems, a company specialized in wireless sensor networks. The young company recently was awarded the Dutch ICTRegie Award and the Van den Kroonenberg Award, an award of the University of Twente for young entrepreneurs. Ambient Systems started cooperation with the Australian Institute of Marine Science for monitoring the water quality around the Great Barrier Reef using wireless sensor networks.

Wiebe van der Veen | alfa
Further information:
http://www.ambient-systems.net

More articles from Power and Electrical Engineering:

nachricht The role of Sodium for the Enhancement of Solar Cells
17.07.2018 | Max-Planck-Institut für Eisenforschung GmbH

nachricht Behavior-influencing policies are critical for mass market success of low carbon vehicles
17.07.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>