Opportunistic Sensing in Wireless Sensor Networks
Johan Scholten, Pascal Bakker · University of Twente Research Information · 2011
Abstract—Opportunistic sensing systems consist of changing constellations of wireless sensor nodes that, for a limited amount of time, work together to achieve a common goal. Such constellations are self-organizing and come into being spontaneously. This paper presents an opportunistic sensing system to select a subset of sensor nodes out of a larger set based on a common context. We show that it is possible to use a wireless sensor network to make a distinction between carriages from different trains. The common context in this case is acceleration, which is used to select a subset of carriages that belong to the same train. Simulations based on a realistic set of sensor data establish that the method is valid, but that the algorithm is too complex for implementation. Downscaling reduces the number of processor execution cycles as well as memory usage, and makes the algorithm suitable for implementation on a wireless sensor node with acceptable loss of precision. Actual implementation on wireless sensor nodes confirms the results obtained with the simulations. Keywords-opportunistic sensing, wireless sensor network, context awareness, activity recognition I.