Wireless Sensor and Actuator Networks for Lighting Energy ...

are expected to autonomously configure into a connected network to relay information
to the data sink. Under circumstances where the wireless connection is compromised
due to noisy links, malfunctioning nodes or moving nodes, the network should be able
to hop onto different carrier frequencies or rebuild routing paths to ensure the
connectivity. Furthermore, as a consequence of the dense deployment and the failureprone
nature of the wireless sensor nodes, the information these nodes can observe has
become much more important than the reading from any particular node.
2.2.3 Popular Applications of Sensor Networks
Technologies surrounding wireless sensor networks have become attractive
research areas. Active research topics include the development of networking protocol
stack, hardware, operating systems, communication privacy and security, localization,
simulator, data aggregation and processing methods, energy scavenging, applications
and deployment, and so on.
The progress of MEMS and CMOS (complementary metal-oxidesemiconductor)
processing technology is the key to the ultimate dust-sized wireless
sensor nodes that integrate the components onto a single chip [35]. Researchers have
been devoted to the design and fabrication of components such as low power RF
transceivers [36] and sensors [37, 38] based on these technologies. Before the
technology becomes mature enough to deliver the single-chip dust sensors, researchers
and manufacturers have developed a variety of matchbox-sized macro wireless sensor
platforms, generally referred to as motes, by integrating off-the-shelf components.
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