2) ZigBee Modules: ZigBee (over IEEE 802.15.4) technology is based on short range WSN and it was selected for this
battery-operated sensor network because of its low cost, low
power consumption, and greater useful range in comparison
with other wireless technologies like Bluetooth (over IEEE
802.15.1), UWB (over IEEE 802.15.3), and Wi-Fi (over IEEE
802.11) [67]. The ZigBee devices operate in industrial, scientific, and medical 2.4-GHz radio band and allow the operation
in a so-called mesh networking architecture, which can be
differentiated into three categories: 1) coordinator; 2) router;
and 3) end device.