IoT Communication Technologies
What the exam tests
IoT Communication Technologies tests your ability to compare short-range, low-power wide-area (LPWA) and cellular options and to choose one from stated requirements: range, data rate, power, mobility, cost and spectrum.
Technology families
- Short range: ZigBee (IEEE 802.15.4, 2.4 GHz, mesh, low power), Bluetooth Low Energy, Wi-Fi, and wired buses such as RS-485/Modbus.
- LPWA: NB-IoT (3GPP, licensed LTE spectrum, 180 kHz, about 66 kbps uplink in early releases and higher later), eMTC/LTE Cat-M1 (1.4 MHz, about 1 Mbps), LoRa (unlicensed ISM, chirp spread spectrum) and Sigfox.
- Cellular: 2G/3G/4G and 5G, where mMTC targets massive machine connections, uRLLC targets low latency and eMBB targets high throughput.
LoRa is the physical layer; LoRaWAN is the MAC and network protocol built on it. NB-IoT is an LTE-based 3GPP technology, not a separate 5G radio.
Worked example
A farm needs soil-moisture readings every 30 minutes from fields 10 km from the farmhouse, on battery power for five years. Data volume is tiny. ZigBee and Wi-Fi fail on range; high-throughput cellular is unnecessary. If operator NB-IoT coverage exists, NB-IoT gives licensed-spectrum reliability and managed SIMs. If not, a private LoRa gateway with a 10 km link is the fallback. Coverage drives the decision, then power and cost.
Traps
Do not label ZigBee long-range; do not confuse LoRa with LoRaWAN; do not claim NB-IoT is high-bandwidth; and remember MQTT and CoAP are application-layer protocols, not radio technologies.