LTE-M vs NB-IoT: the differences that matter for devices on the move

What are LTE-M and NB-IoT?

LTE-M and NB-IoT are two cellular standards built for devices that send small amounts of data and run on batteries, such as meters, trackers and worn badges. Both came out of 3GPP Release 13, and 3GPP announced NB-IoT complete in June 2016 (3GPP). Both run on mobile operators' licensed spectrum, so they use the carrier's towers instead of equipment you install.

They were designed with different priorities. A 3GPP overview describes LTE-M as able to offer lower latency and higher throughput than NB-IoT and to support voice over IP, while NB-IoT targets ultra-low device complexity and can run in a system bandwidth as low as 200 kHz (3GPP). The GSMA Mobile IoT Deployment Guide (February 2026) calls them complementary and says they are often deployed side by side in the same network.

LTE-M

Also called LTE Cat-M1 or eMTC. A trimmed-down LTE that rides the carrier's existing LTE network, keeps LTE's handover between cells, and carries more data.

NB-IoT

Narrowband IoT, Cat-NB1 and NB2. A much narrower radio that can sit inside an LTE carrier, in its guard band or on its own, built for small, infrequent messages and deep coverage.

How do LTE-M and NB-IoT compare side by side?

LTE-M gives up a little coverage depth in exchange for more speed and proper mobility. NB-IoT gives up speed and mobility in exchange for reach and simplicity. The table uses the GSMA's published figures.

How much data can each one move, and does it matter?

LTE-M moves several times more data than NB-IoT, and that matters for large transfers and quick replies, not for small periodic reports. The GSMA puts LTE-M at around 300 kbps down and 380 kbps up in half-duplex mode, with 100 to 150 kbps on average in the field, and NB1 at a peak of 26 kbps down and 66 kbps up, with latency around 1 second in normal coverage (GSMA).

A location report is small, so either standard carries it easily. Where the gap shows is a firmware update pushed to a fleet of devices.

What happens when a device moves from one cell to the next?

On LTE-M, the network hands a connected device over to the next cell as it moves. On NB-IoT, a device mostly reselects a new cell while idle, and keeping a connection alive across cells depends on a later feature that the GSMA says is yet to see wide adoption.

The GSMA guide explains the two modes. In idle mode, the device decides when to reselect a cell. In connected mode, the network decides when the device moves and to which cell, and triggers the handover. The guide recommends LTE-M networks support intra-frequency handover (since Release 13) and inter-frequency handover (since Release 14) for all data traffic, and it notes LTE-M performance requirements defined for speeds around 240 km/h at 1 GHz.

NB-IoT went the other way. One of its power-saving features, relaxed monitoring, lets a device that is not moving check neighbouring cells as seldom as every 24 hours. That suits a gas meter in a basement. It does nothing for a badge that rides in a pickup from the shop to a jobsite to a supply house.

How do PSM and eDRX save power, and what do they cost?

Both standards save power by letting the radio stop listening, and the cost is that the network cannot reach the device while it sleeps. Power Saving Mode (PSM) is a deep sleep. Extended discontinuous reception (eDRX) is a series of short naps. Both are available on LTE-M and NB-IoT, and the GSMA recommends both as baseline features.

PSM

After sending, the device listens for a short active time (timer T3324), then sleeps until its next periodic update (timer T3412) while staying registered, so it does not have to re-attach. The GSMA gives about 413 days as the longest possible sleep and 186 minutes as the longest active time. The device can still send at any moment.

eDRX

The device wakes on a regular cycle to check for messages, then switches its receiver off again. The GSMA describes it as suited to cases where being unreachable for several seconds to a few hours is acceptable, and as a compromise between reachability and power.

The device asks for timer values, but the network decides what to grant, and the GSMA notes networks may override requests or enable neither feature. It also recommends operators buffer at least the last 100-byte downlink packet while a device sleeps, so a short command is held rather than lost.

How far does each one reach into basements and pits?

NB-IoT reaches deeper than LTE-M in the networks actually deployed today. Both use coverage enhancement, which repeats transmissions so a weak signal can still be decoded, but the GSMA's figures put the deepest commonly available level well apart.

• NB-IoT: coverage enhancement takes maximum coupling loss from 144 dB up to 164 dB, with up to 128 repetitions at the deepest level in normal use. The GSMA recommends all three levels be supported.
• LTE-M: CE Mode A, which every LTE-M device must support, adds about 5 dB with up to 32 repetitions. Mode B adds about 15 dB with up to 2,048 repetitions, but the GSMA reports no operator known to have implemented it, and no device known to support it, as of 2025.

Deep coverage only helps if the data can wait. A device that stores its readings in a dead spot and uploads them on reconnect, with the original timestamps, loses nothing even when neither standard can get a signal out. Coverage checks for real sites are covered in cellular badge trackers.

Do carriers support both LTE-M and NB-IoT?

Some carriers support both, some support one, and support differs by country and changes over time. The GSMA counted more than 140 NB-IoT networks and 129 LTE-M networks worldwide as of October 2025, and keeps a deployment map by country and operator.

Features vary even when the radio is supported. The GSMA notes that many operators enable SMS on LTE-M but not on NB-IoT, that VoLTE on LTE-M is not widely deployed, and that different PSM and eDRX settings between networks change how a device behaves and how long its battery lasts, especially when roaming.

• Ask each carrier, in writing, whether it supports LTE-M, NB-IoT or both in every market where you work.
• Ask whether either network has an announced retirement date. Carriers have retired networks before.
• Ask which PSM and eDRX timer values the network grants, since it can override what the device requests.
• Ask whether the device can switch between LTE-M and NB-IoT if one is unavailable.
• For devices that cross borders, ask about roaming support for the specific technology, not just the carrier.

On lifespan, the GSMA guide says both technologies form part of the global 5G standard and are expected to remain in service well into the 2030s.

Which one suits a worn badge that moves between jobsites?

LTE-M, in most cases, because a worker's badge moves all day and handover is part of LTE-M's baseline. NB-IoT earns its place where devices sit still in deep coverage and send very little. Score your own use against the requirements below.

How ZeroBadge handles this

The ZeroBadge badge has its own cellular connection. It never uses the worker's phone, data plan or the site's Wi-Fi password, and nothing is installed on any jobsite. It reports about every 5 minutes, and if signal drops, reports are stored on the badge and uploaded on reconnect with their original timestamps. Badges are powered off between shifts.

For location, it uses GPS outdoors, Wi-Fi positioning indoors and cellular continuity in between, labelled low confidence, and every reading stores its method and confidence. Ask for the badge specification sheet with your quote for the radio technology and supported carriers. More on the hardware: the ZeroBadge badge.