Which protocol is suitable for communication of IoT devices with restricted power and low data rates over a range of a few kilometres?

• A. Bluetooth
• B. Zigbee
• C. 4G
• D. LoRaWAN

Answer: (D)

When you need a communication method for IoT devices that run on limited power and only send small amounts of data, you want something designed to maximize battery life while covering a few kilometers. LoRaWAN fits this need because it’s built for ultra-low power, low data rate transmissions over longer distances. Devices can stay asleep most of the time and wake up to send small packets through gateways, which then forward the data to a network server. This makes it ideal for sensors spread out over several kilometers, such as environmental monitors or smart agriculture nodes.

Bluetooth and Zigbee are great for short-range links, typically tens of meters to a few hundred, and they don’t scale well for wide-area IoT without many repeaters. They also tend to consume more power per bit for similar data rates. 4G offers broad coverage and higher data rates, but it’s not optimized for tiny, battery-powered sensors that transmit infrequently; it requires more power and ongoing data costs, which isn’t ideal for low-power, low-rate IoT deployments.