## 5 Connectivity Limitations of Smart Farming in Remote Areas  
The aim of IoT is to connect beyond restrictions of geographical boundaries; therefore, network connectivity in remote areas is an important silo for wider acceptance of the technology. The remote connectivity is also more important to get full advantage of smart agriculture as agricultural lands are extremely large and located in remote areas. For most of the cases, the remote agricultural lands are not fully covered with mobile networks and other forms of internet connectivity. Therefore, in remote areas, the IoT gateway must support longer communication capability to extend coverage to the nearest internet, not be power hungry and offer multiple powering options. One of the core component of IoT technology is openness; therefore, we are considering an open standard of LPWA named LoRaWAN for evaluating connectivity limitations in remote areas. To date, the LoRaWAN protocol can cover 10 km [75] in a laboratory testing environment and 5-7 km in remote areas [75]. The connectivity of LoRaWAN in rural areas is limited to 2-3 km only [75]. In remote smart farming scenarios, connectivity of 5-7 km is not enough to reach a connection to the internet nearby. Therefore, it creates a connectivity problem to extend the remote farm's IoT network to rest of the world. Furthermore, maintaining IoT connectivity devices/equipment in remote locations is a challenging task, which limits the options of deploying IoT devices. Furthermore, the remote deployment of IoT devices must \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **NB-IoT** & **SigFox** & **LoRa** \\ \hline Modulation & QPSK & BPSK & CSS \\ \hline Interference immunity & Low & Very High & Very High \\ \hline Localization & Yes (TDOA) & Yes (RSSI) & Not supported \\ \hline Standardization & 3 GPP & SigFox company with ETSI & LoRa-Alliance \\ \hline Maximum data rate & 200 kbps & 100 kbps & 50 kbps \\ \hline Bidirectional & Yes/Half-duplex & Limited/Half-duplex & Yes/Half-duplex \\ \hline Maximum message/day & Unlimited & 140 (UL), 4 (DL) & Unlimited \\ \hline Maximum payload length & 1600 bytes & \begin{tabular}{c} 12 bytes (UL) \\ 8 bytes (DL) \\ \end{tabular} & 243 bytes \\ \hline Coverage & 164 dB & 160 dB & 157 dB \\ \hline Power Consumption & Very low & Low & Low \\ \hline Security & Very High & Low & Low \\ \hline Bandwidth & 200 kHz & 100 kHz & 250 kHz and 125 kHz \\ \hline Frequency & Licensed & ISM Band 433, & ISM Band 433, \\  & LTE Frequency & 868, 915 MHz & 868, 915 MHz \\ \hline Technology & OpenLTE & Proprietary & Proprietary \\ \hline Spectrum & Licensed & Unlicensed & Unlicensed \\ \hline Topology & Star & Star & Star \\ \hline Downlink Data Rate & 0.5–200 kbps & 0.1 kbps & 0.3–50 kbps \\ \hline Uplink Data Rate & 0.2–180 kbps & 0.1 kbps & 0.3–50 kbps \\ \hline Range & \begin{tabular}{c} 1 km (urban) \\ 10 km (rural) \\ \end{tabular} & \
\begin{tabular}{c} 10 km (urban) \\ 40 km (rural) \\ \end{tabular} &
\begin{tabular}{c} 5 km (urban) \\ 20 km (rural) \\ \end{tabular} \\ \hline Duty Cycle Restriction & No & Yes & Yes \\ \hline Output Power & 23 dBm & 14 dBm & 14d Bm \\ \hline Battery Lifespan & 15 years & 10 years & 10 years \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Overview of Long range connectivity technologies [61]. support long life span and multi mode power source [76]. Below is a list of the connectivity limitations for remote smart farming:  
* **Longer range connectivity with redundant connections:** In remote areas, the IoT devices need to be spread out over a larger area to cover an entire farm. These devices often fail to get connected to nearby internet sources due to their limited communication range. Therefore, existing connectivity range of IoT gateways need to be improved to reduce dependency on backhaul systems. * **Self sustained power source:** current IoT system must reduce dependency on traditional main grid power source to make it usable in remote setting. A sensor system could use renewable energy with adaptive energy sharing and management.