# Energy-Efficient Wireless Sensor Networks for Precision Agriculture: A Review
## 2 Wireless Communication Technologies for Agriculture
### Performance Comparison of Wireless Communication Protocols
From the above discussion and the comparison results presented in Table 1 and Figure 1 and as will be shown in Tables 2-8 the ZigBee and LoRa wireless protocols have been identified as the most suitable wireless protocols for agricultural applications because of their low power consumption, communication range (acceptable for ZigBee and long for LoRa), small size, easy network implementation, simplicity, low latency (for ZigBee), scalability, and network size. PA using sensors, actuator, processor, wireless transceiver, and other information technologies, potentially permits manufacturers to computerize site-specific management for automated agriculture. In terms of precision, the considered wireless protocols for agricultural applications have improved the agriculture domain. Precision irrigation is frequently regarded as optimizing irrigation accuracy due to its ability to control the optimum amount of water and irrigation time. The water savings of 90% (based on ZigBee), 33% (based on ZigBee), 50% (based on Bluetooth), and 90% (based on Bluetooth) were achieved for precision irrigation systems relative to traditional irrigation systems in research [17; 28; 30; 40], respectively. Animal behavior, such as laying down, standing, grazing, walking, and other modes, was monitored in [18] using ZigBee wireless protocol. The authors found that laying down and grazing could be improved by 83.5% compared with the findings from similar studies. In another study that has adopted a proposed algorithm that depended on the ZigBee wireless protocol [20], an accuracy rate of 95.4% was expected for the proposed algorithm to monitor the honey bee and the agricultural and environmental aspects. In [23], the automation of the irrigation system based on ZigBee saved the system cost between 1.24% and 6.72% relative to the entire cost of the water user associations, with energy savings of 2.05 to 8.21% and water savings of 0.71 to 6.46%. The proposed model in [35] utilized a smartphone platform (based on Bluetooth and GSM technologies) and permitted three types of irrigation systems. The efficiency factors were improved by 90% for subsurface drip type and 85% and 75% for high- and low-pressure overhead sprinkler types, respectively, to compute for drift and evaporation before the water droplets approached the soil. 3G technology was adopted by Libelium based on Waspmote wireless sensor devices to monitor the vineyards in Northwest Spain [57]. Phytosanitary treatments, such as fungicides and fertilizers, were minimized by 20% and growing yields were enhanced by 15% based on PA. In [8], LoRa wireless protocol was considered to monitor the agriculture environments with 90% power efficiency. The cost of pumping and water for precision irrigation system in green areas was reduced by 30% based on SigFox wireless protocol [58]. The preceding survey for different agricultural applications revealed that PA can be achieved in terms of water savings, animal behavior, accuracy, power efficiency, and reducing system cost for various wireless protocols. Consequently, agriculture can be improved based on agricultural automation systems compared with traditional agriculture systems. Figure 1: Different wireless technologies in terms of power consumption and communication distance.