# Energy-Efficient Wireless Sensor Networks for Precision Agriculture: A Review
## 4 Agriculture Requirements for IoT
\begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Reference** & **Sensors/Actuators** & **IoT End Device Wireless Protocol** & **IoT Platform/Device** & **IoT Application Layer** \\ \hline
[159]/2016 & Web camera, ultrasonic ranging, infrared heat sensor, and ultrasonic sound repeller & Wind connection to PC & PTC’s ThingWorx’s & User application, web services, and http and several Internet protocols \\ \hline
[160]/2016 & Temperature, humidity carbon dioxide, soil moisture light intensity, and pH value & Bluetooth and mobile device & 4G and cloud computing & Intelligent management (neural network) \\ \hline
[161]/2016 & Ultrasonic, air humidity, air temperature, LDR sensor, and soil moisture/pumps, solenoid valve, fogger system, lights, and peltier & RFID tags & GSM sim900a and WiFi & SMS, e-mail, google spreadsheet, e-commerce website \\ \hline
[162]/2016 & Air temperature/ fan, curtain, and shutter & ZigBee & GPRS & Web applications \\ \hline
[163]/2016 & Temperature, soil moisture, light, and humidity/water pump & nRFALDI & GPRS/GSM & Microsoft active server pages and MVSQL \\ \hline
[164]/2016 & Relative humidity, barometric pressure, temperature, light intensity, camera, and proximity sensing/buzzer, SMS alerts & IEEE 802.15.4/ ZigBee & Wireless connection & Web application, Android application, and cloud storage \\ \hline
[165]/2016 & Temperature & Off-the-shelf mesh WSN & SmartMesh IP Manager & Server applications and database \\ \hline
[166]/2016 & Air temperature, illumination intensity, and relative humidity & Mc2 (CC1000) & 2G/ 3G and cloud computing & User applications (display terminal, PC, PDA, remote monitoring device) and GUI \\ \hline
[167]/2017 & Temperature, illumination, camera, and humidity/ vaporization system & ZigBee & WiFi & Data mining, data inquiry, and data storage \\ \hline
[168]/2017 & Liquid level sensor/water pump & Wired connection & Ethernet shield & User-defined \\ \hline
[169]/2017 & Temperature and light & IEEE 802.15.4 & IEEE 802.11g, W02.11a, and RFS 6000 & User applications and server applications \\ \hline
[170]/2017 & Temperature, pH value, and Oxygen & ZigBee & GSM, WiFi, and cloud computing & Web services, desktop application, and mobile applications \\ \hline
[171]/2017 & Relative humidity & LoRa/LoRaWAN & GPRS/3G/4G and cloud computing & Liquid crystal display (LCD) \\ \hline
[172]/2017 & Relative humidity, temperature, air pressure, and luminosity & WiFi & IBM Watson IoT, IBM Bluemk cloud service, and cloud computing & data storage, and data graphs and visualized \\ \hline
[173]/2017 & Soil moisture, salinity, and temperature & WiFi/ ZigBee/ Bluetooth & WiFi, cloud & HTTP protocol and smartphone applications \\ \hline
[174]/2017 & Soil moisture, soil pH, and camera & WiFi and drone & FarmBeats (based Ethernet or WiFi) and cloud computing & Web interface (data access, cross-form analytics, and long term applications) \\ \hline \hline \end{tabular}
\end{table} 
Table 8: _Cont._The major requirements of PA domain such as sensors, microcontrollers, and wireless technologies are highlighted and classified in Table 9. For better clarification, the sensors are classified into three main categories leaf wetness/plant, soil moisture, and environment sensors [5; 132]. These sensors can be utilized in several potential agriculture applications. In Table 9, the microcontroller/processor and wireless protocols are also highlighted. Among the microcontrollers, the majority of agriculture sensor nodes adopting ATmega128L because this microcontroller supports data aggregation, decision making, storage capability, flash memory, low complexity, and energy management through multi-levels of power down modes [132]. ZigBee and LoRa wireless protocols/technologies are widely used in several agricultural applications, as discussed previously in Section 2. In precision agriculture, to obtain high-quality products, the environmental parameters should be controlled to provide optimal values.