LTE-M vs NB-IoT: which network for which connected device?
Updated on 14 October 2026
If your device moves, pick LTE-M: it hands over from one cell to the next without dropping the connection and carries more data. If it stays in one place and sends little data, NB-IoT uses less power and reaches further indoors. For a GPS tracker that also has to work abroad, LTE Cat 1 has wider roaming and is often the simpler choice.
Two 4G technologies built for connected devices
LTE-M and NB-IoT are LPWA (low power wide area) cellular technologies. 3GPP, the body that writes mobile standards, standardised both in Release 13 in 2016. They run on 4G LTE and are designed for devices that draw little power and last a long time on a battery.
Both support two power-saving modes. With PSM (Power Saving Mode) the device sleeps between transmissions while staying registered on the network. eDRX stretches the intervals at which it listens to the network. Where they differ is bandwidth, data rate and how they handle movement.
LTE-M for devices that move
LTE-M, also called LTE Cat-M1, uses 1.4 MHz of bandwidth and reaches about 1 Mbps. It handles mobility the way a phone does, with handover from cell to cell while the connection stays up. Latency is lower than on NB-IoT, and voice over LTE (VoLTE) is possible.
That makes it the usual option for things that travel or need to respond quickly: trackers, smartwatches and other wearables, fleet telematics, alarms.
NB-IoT for fixed sensors
NB-IoT (Cat-NB1 and Cat-NB2) uses only 200 kHz. Its data rate is in the tens of kbps, and NB2 goes up to roughly 100 to 150 kbps. Mobility support is limited or absent, with no seamless handover between cells.
In return, the signal gets deeper into buildings and underground, and power draw is very low. It suits devices that stay put and send small amounts of data: water and electricity meters, sensors, smart parking bays. A meter in a basement is the typical case.
Where LTE Cat 1 fits
LTE Cat 1, along with its Cat 1 bis variant, is a standard 4G category with up to 10 Mbps down and 5 Mbps up and full mobility. It was not designed around ultra-low power the way LTE-M and NB-IoT were.
Its advantage is availability. Cat 1 runs on ordinary 4G networks and is widely available in roaming, which is why many GPS trackers built to replace 2G models use it. For a tracker wired to a vehicle battery, coverage matters more than power draw.
LTE-M, NB-IoT and LTE Cat 1 compared
Data rates are peak figures.
- LTE-M: about 1 Mbps, mobility with handover, low latency, very low power (PSM, eDRX). Typical uses: trackers, wearables, fleet telematics, alarms.
- NB-IoT: tens of kbps (100 to 150 kbps on NB2), little or no mobility, best indoor and underground penetration, lowest power. Typical uses: meters, sensors, smart parking.
- LTE Cat 1: up to 10 Mbps down and 5 Mbps up, full mobility, standard 4G coverage with wide roaming, higher power draw. Typical uses: GPS trackers, telematics units, replacing 2G devices.
Check coverage before you choose
LTE-M and NB-IoT are not deployed in every country or by every operator, and roaming on them is less common than on 2G or 4G. An NB-IoT device that connects at home may find no network across the border. Check coverage country by country before you settle on a module, especially if the device travels.
In France, the 2G shutdown adds a deadline. Orange is switching off 2G region by region during 2026, and SFR and Bouygues Telecom turn theirs off between mid-November and mid-December 2026. Devices that only support 2G will stop connecting there. Replace them with LTE Cat 1, LTE-M or NB-IoT hardware depending on the use, once you have checked coverage.
Which SIM for these devices
Atlas M2M SIMs are multi-network and work on 4G, which covers LTE Cat 1 and Cat 4 devices. For an LTE-M or NB-IoT device, ask us about coverage in your country before ordering.
Plans start at €2 per SIM per month with 50 MB of data, with no commitment and no platform fee. To test on your own hardware, the free trial gives you 3 SIMs for 30 days with 50 MB in total.