In future smart environments, wireless sensor networks will play a key role in sensing, collecting, and
disseminating information about environmental phenomena. Sensing applications represent a new paradigm for
network operation, one that has different goals from more traditional wireless networks. This paper
examines this emerging field to classify wireless micro-sensor networks according to different
communication functions, data delivery models, and network dynamics. This taxonomy will aid in defining
appropriate communication infrastructures for different sensor network application sub spaces, allowing
network designers to choose the protocol architecture that best matches the goals of their application. In
addition, this taxonomy will enable new sensor network models to be defined for use in further research in
A wireless sensor network (WSN) consists of spatially distributed autonomous sensors to cooperatively
monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or
pollutants. The development of wireless sensor networks was motivated by military applications such as
battlefield surveillance. They are now used in many industrial and civilian application areas, including
industrial process monitoring and control, machine health monitoring, environment and habitat monitoring,
healthcare applications, home automation, and traffic control.
In addition to one or more sensors, each node in a sensor network is typically equipped with a radio
transceiver or other wireless communications device, a small microcontroller, and an energy source,
usually a battery. A sensor node might vary in size from that of a shoebox down to the size of a grain of
dust, although functioning “motes” of genuine microscopic dimensions have yet to be created. The cost
of sensor nodes is similarly variable, ranging from hundreds of dollars to a few pennies, depending on the
size of the sensor network and the complexity required of individual sensor nodes. Size and cost
constraints on sensor nodes result in corresponding constraints on resources such as energy, memory,
computational speed and bandwidth.
A sensor network normally constitutes a wireless ad-hoc network, meaning that each sensor supports a
multi-hop routing algorithm (several nodes may forward data packets to the base station).
In computer science and telecommunications, wireless sensor networks are an active research area with
numerous workshops and conferences arranged each year.