The radio you choose shapes battery life, coverage and what your device can do. It is the most expensive decision to reverse, because it is baked into the modem. Pick deliberately.
Rule of thumb
- NB-IoT for fixed, low-data, deep-indoor sensors that must last years on a battery: meters, parking, agriculture.
- LTE-M for things that move, need firmware updates or low latency and still want long battery life: trackers, wearables, alarms.
- 4G/5G for high-throughput or video: gateways, routers, cameras, kiosks.
Things people get wrong
NB-IoT does not support mobility well, so do not use it for trackers. LTE-M coverage is excellent in some countries and patchy in others, so check the map for your markets. A multi-IMSI subscriber helps here too: it can fall back across radio types where a network supports more than one.
Heads up
Coverage for NB-IoT and LTE-M varies hugely by country. Always validate against your target markets on trial subscribers before committing hardware.