Image Processing Reference
In-Depth Information
extraction mechanisms independent from the networking layer and the specific topology of a given
network.
This chapter addresses the architecture of sensor networks. We build our argumentation incre-
mentally as follows: we introduce the layered design approach for sensor networks, then we move
on to the concept of a data-centric architecture and its flexible interfacing system, and we end the
description with a detailed discussion on data extraction mechanisms.
4.1 Sensor Node Architecture
Current existing technology already allows integration of functionality for information gather-
ing, processing, and communication in a tight packaging or even in a single chip (e.g. Figure .
presents the EYES sensor node []). []).The four basic blocks needed to construct a sensor node are (see
Figure .):
•
Sensor and actuating platform
:hesensorsaretheinterfacestotherealworld.heycollect
the necessary information and have to be monitored by the central processing unit. he
platforms may be built in a modular way such that a variety of sensors can be used in the
same network. A wide range of sensors (monitoring characteristics of the environment
such as light, temperature, air pollution, pressure, etc.) is already employed in the various
applications. Lately, the sensing unit of devices is increasingly extended to contain one
or more actuators. This practice slowly moves our perception on sensor networks from
being “our eyes” in the environment to being also a means of changing some aspects of
the environment.
•
Processing unit
: It is the intelligence of the sensor node. his not only collects the infor-
mation detected by the sensor but also communicates with the network the device is
FIGURE .
EYES sensor node. (From Consortium: EYES European project. http://eyes.eu.org, .)
