Wireless Sensor and Actuator Networks for Lighting Energy ...

MICA mote [31], Tmote Sky [29], BTnodes [39], Intel Mote [40], Dust Networks [41],
Sensicast [42] are a few examples.
The networking protocol for wireless sensor networks follows the typical ISO
OSI (open system interconnection) seven layer model – physical, data link, network,
transport, session, presentation and application layers. The first three layers (physical,
data link, and network) have attracted the most attention since they are more generic to
all applications whereas the other layers are more application-specific. The key issue for
the physical layer is standardization. Physical layer protocols that support wireless
sensor networks include Bluetooth (IEEE 802.15.1), IEEE 802.15.4, IEEE 802.15.4a,
ultra-wideband (UWB), etc.; IEEE 802.15.4 currently dominates the market and is the
building block of other mesh networking technologies such as Zigbee. Research on the
data link layer mostly focuses on MAC (medium access control) protocols for high
communication throughput under ultra low duty cycle operation such as LEACH [12],
Sensor-MAC (S-MAC) [9], DMAC [8], B-MAC [13], etc. Network layer concerns
energy-efficient routing and dissemination protocols for constructing self-configuring
networks. Since routing in wireless sensor networks also has to build on low power
operation, which is defined in the MAC protocol, it cannot be designed independent of
the MAC protocol. LEACH [12] and PEGASIS [43] are two renowned examples.
Wireless sensor networks have become a promising solution for numerous
sensing and monitoring applications where their wired counterparts are not applicable
due to large coverage or a harsh environment for running wires. The potential areas of
application include, but are not limited to, environmental monitoring, health care,
positioning and animal tracking, entertainment, logistics, transportation, home and
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