Choosing the right IoT connectivity: NB-IoT, LTE-M, or LTE Cat-1 bis?

A few years ago, NB-IoT and LTE-M were tipped as the future of low-power IoT connectivity.

Analysts hailed them as the backbone for billions of devices, operators promised nationwide rollouts, and hardware vendors rushed to support them.

The reality has been more nuanced.

Rollouts vary widely by country, coverage doesn’t always match the maps, and roaming support is still maturing.

Depending on who you ask, one operator will say NB-IoT is ready, another will back LTE-M, and a third will point to a different roadmap altogether.

That variation doesn’t make NB-IoT or LTE-M less valuable — both remain excellent fits for the right use cases. But it does mean that for anyone building or deploying IoT solutions, uncertainty is part of the picture.

Meanwhile, another technology has been quietly building momentum: LTE Cat-1 bis.

LTE Cat-1 bis: the practical alternative

LTE Cat-1 bis doesn’t get the same hype from operators because it isn’t “new.”

To understand it, start with its predecessor LTE Cat-1.

Cat-1 is a 4G LTE device class designed for simpler IoT deployments: it supports moderate data rates (around 10 Mb/s downlink and 5 Mb/s uplink), full mobility and roaming, and even voice — but it originally required two antennas, adding cost and complexity.

Cat-1 bis streamlines that design. It keeps the same speeds and LTE features, and runs on the same networks already in place, but only needs a single antenna, making devices smaller, cheaper, and easier to build.

Fun fact: bis is latin for “twice” or “again”.

But precisely because it’s boring, Cat-1 bis is proving to be one of the most deployable and versatile options available for IoT connectivity. It works now, in more places, with fewer deployment headaches.

This isn’t to write off NB-IoT and LTE-M. As with all IoT connectivity choices, it’s about deciding the best fit for the solution.

Why the choice matters

Connectivity isn’t just a technical detail — it defines the lifetime cost and viability of an IoT solution. The wrong decision can quietly drain margins and customer trust:

• Devices that draw too much power mean higher maintenance and replacements.
• Limited bandwidth can cap what your solution can actually deliver.
• Patchy coverage leads to tickets, complaints, and lost contracts.
• Poor future-proofing forces upgrades years earlier than planned.

With thousands of devices deployed over long lifecycles, these mistakes can compound quickly.

NB-IoT, LTE-M, and LTE Cat-1 bis: how they compare

Bandwidth & data rates

• NB-IoT: Built for tiny, infrequent data packets. Ideal for sensors that send a daily update.
• LTE-M: More bandwidth, supports firmware updates and, most importantly, mobility.
• LTE Cat-1 bis: Higher throughput than both, supporting richer telemetry and even light multimedia.

If you need more than basic sensor data, LTE Cat-1 bis gives you headroom without jumping to full LTE or 5G.

Power consumption

• NB-IoT: Extremely low, enabling multi-year battery life.
• LTE-M: Still efficient, but mobility and bandwidth can use more power.
• LTE Cat-1 bis: Higher draw than NB-IoT, though efficient for its capabilities.

For ultra-low power, NB-IoT wins. For more demanding apps, LTE Cat-1 bis remains practical.

Mobility and coverage

• NB-IoT: Best for static devices, with strong indoor penetration.
• LTE-M: Optimised for moving assets — trackers, wearables, mobile equipment.
• LTE Cat-1 bis: Supports mobility, and crucially, leverages existing LTE coverage.

For mobile or cross-location projects, LTE-M or LTE Cat-1 bis outperform NB-IoT.

Network infrastructure

• NB-IoT & LTE-M: Require specific network configurations and dedicated spectrum. Rollouts vary widely by country and operator.
• LTE Cat-1 bis: Operates on today’s LTE networks, often deployable faster.

For international or time-sensitive projects, LTE Cat-1 bis is often the least risky path.

Real-world use cases

• NB-IoT: Smart meters, streetlights, environmental sensors.
• LTE-M: Asset tracking, healthcare wearables, mobile equipment.
• LTE Cat-1 bis: Vending machines, retail kiosks, video-enabled IoT with moderate data needs.

Looking ahead

LTE Cat-1 bis isn’t the final stop. 5G RedCap will eventually serve many of the same mid-tier applications.

But today, LTE Cat-1 bis is gaining traction: it’s not flashy, but it works right now.

It gives anyone deploying IoT solutions a practical bridge between the more constrained LPWAN (NB-IoT, LTE-M) and the complexity of higher LTE categories or 5G.

Final guidance

When you’re helping customers choose cellular IoT connectivity:

• If the solution is stationary and ultra-low power, NB-IoT fits.
• If it’s on the move and power budget allows, LTE-M is strong.
• If it needs higher data throughput and wide availability today, LTE Cat-1 bis is the pragmatic choice.

Operators will keep pushing their preferred technology — NB-IoT here, LTE-M there, RedCap on the horizon. But for partners, it’s about making the right decision, right now for the solution you're connecting.

Getting that decision right will protect your margins, reduce support headaches, and ensure devices stay connected for years — not just until the next network sunset.