Better detection with self-healing wireless sensor network

Published 9 February 2009

New self-forming, self-healing wireless mesh sensor network can detect railway embankment landslides, humidity in art museums, water quality in water treatment facilities — and has military and security applications such as a perimeter network that can detect intrusion through breaking a light beam, or triggering a tripwire, or proximity sensor

Those concerned with protection of critical infrastructure facilities, or entrusted with setting up sensor networks to detect chemical or biological attack, should be interested in this. A University College London spinout has launched a versatile wireless sensor network inspired by the behavior of creatures that act together, such as flocks of birds, termite mounds, or beehives. London-based Senceive’s Flatmesh product allows hundreds of sensors to form a robust, non-hierarchical radio network mesh, in which each unit communicates with its neighbors rather than via central routers. In the same way as a biological network of a mass of animals acts together, simple rules applied to each component part allow behavior more intelligent than the sum of its parts.

Flatmesh components can be fitted with a variety of sensors which allow them to be used for applications as diverse as monitoring railway embankments for slippage or preventing precious artworks being exposed to excess levels of light.

The Engineer reports that the original concept sprang from a UCL project investigating novel ways of building short-range radio networks for applications where a great deal of sensors are needed in a densely packed area. The Self-Organizing Collegiate Sensor Networks (SECOAS) project deployed a dense network of sensors mounted on buoys in the North Sea to monitor factors such as the turbidity of the water that could indicate a sandbank shifting near a wind farm. Each buoy carried a short-range radio — just enough to get to the next two or three buoys.

Dr. Matthew Britton, chief executive officer and co-founder of Senceive, said: “The idea is that instead of building a big radio that blasts information back to a central point, you have just one of them that does that and the others can be miniaturized so they only need to talk to each other. As our network modes are miniature, the challenge was to give these very limited components simple rules to allow a network of them to behave cleverly together. The individual sensors collaborate, and if they observe something interesting, only then do they communicate that.”

Steven Schooling, director of physical science and engineering at UCL Business, added: “The rationale for the research was the deficiency observed in current wireless systems such as Zigbee.”

Zigbee can be complicated for customers to set up, and the remote battery-operated sensors need to be within range of a constantly powered coordinating device. Senceive developed its own network architecture where each