While MQTT is widely used, it isn’t always the best fit for constrained devices on NB-IoT. That’s where MQTT-SN (Sensor Networks) comes in — a protocol designed to bring MQTT’s benefits to ultra-lightweight, low-power environments.
What is MQTT-SN?, MQTT vs MQTT-SN, Benefits for NB-IoT.
MQTT-SN is a variant of MQTT optimized for constrained devices and networks. It modifies the original protocol to reduce overhead:
- Runs on UDP instead of TCP.
- Uses short topic IDs (tokenized names) instead of long strings.
- Eliminates constant TCP keep-alives.
- Maintains the familiar publish/subscribe model.
Relevance to NB-IoT
MQTT-SN addresses many of the issues that make MQTT inefficient on NB-IoT:
- Lower overhead due to UDP.
- Battery savings from reduced keep-alive traffic.
- More efficient payload management.
The drawback: the ecosystem for MQTT-SN is smaller, meaning fewer off-the-shelf tools, libraries, and cloud integrations compared to MQTT.
Common Use Cases
- Battery-powered sensors in agriculture or logistics.
- Smart environment monitoring (air, water, soil).
- Industrial IoT sensors that require lightweight communication.
Key Takeaways
MQTT-SN offers a middle ground: the simplicity and familiarity of MQTT with the efficiency of UDP. It’s not as widely adopted as CoAP or LwM2M, but for specific NB-IoT sensor deployments, it’s a strong choice.