What is NB-IoT?
NB-IoT (Narrowband Internet of Things) is a cellular LPWA technology standardised by 3GPP in Release 13 (June 2016) that sends small amounts of data over a narrow 180 kHz channel inside a mobile operator’s network, with very low energy consumption, deep indoor coverage and room for tens of thousands of devices per cell. Together with LTE-M it is one of the two cellular low-power technologies, and the ITU recognises it as part of 5G for massive machine-type communication (mMTC). Within the Industrial Internet of Things and OT convergence, NB-IoT is above all the choice for stationary, battery-powered sensors and meters that send a reading a few times a day: water meters, tank levels, cathodic protection and condition monitoring on dispersed assets.
🧠 How does NB-IoT work technically?
NB-IoT is derived from LTE but heavily simplified. The device uses a single 180 kHz resource block (a 200 kHz channel including margin), operates half-duplex and needs only one antenna. The downlink uses OFDM, the uplink SC-FDMA with single-tone or multi-tone transmission. This makes an NB-IoT modem cheaper and more frugal than a regular 4G modem, but also slower.
An operator can place NB-IoT in its spectrum in three ways:
| Mode | Where the channel sits | Typical use |
|---|---|---|
| In-band | Inside an existing LTE carrier | Fast rollout via a software update on the base station |
| Guard-band | In the unused margin next to an LTE carrier | No LTE capacity sacrificed |
| Standalone | Dedicated channel, for example freed-up GSM spectrum | Operators phasing out 2G |
The main 3GPP design targets were a coverage (maximum coupling loss) of 164 dB, about 20 dB better than GPRS, a battery life of ten years or more, and around 50,000 devices per cell. The extra coverage comes from Coverage Enhancement: device and base station repeat messages, up to 2048 times in the downlink. That makes NB-IoT suitable for basements, meter pits and underground installations, but every repetition costs time and energy.
After the first release, the standard kept evolving:
| Release | Category | Key additions |
|---|---|---|
| 13 (2016) | Cat-NB1 | Baseline: approx. 26 kbps downlink, approx. 66 kbps uplink (multi-tone) |
| 14 (2017) | Cat-NB2 | Approx. 127 kbps downlink and 159 kbps uplink, positioning (OTDOA), multicast for firmware updates, 14 dBm power class |
| 15 | Cat-NB2 | TDD support, Early Data Transmission, wake-up signal for more efficient paging |
| 16 and 17 | Cat-NB2 | Connection to the 5G Core, NB-IoT over satellites (non-terrestrial networks) |
The effective bandwidth per device is far below those peak values in practice. NB-IoT is built for messages of tens to hundreds of bytes, not for files or streams.
🔋 How does NB-IoT achieve a ten-year battery life?
The low consumption comes from two sleep mechanisms that LTE-M also uses:
- Power Saving Mode (PSM) - the device switches its radio off but stays registered with the network. With the extended periodic update timer (T3412) this sleep can last up to about 413 days, so the device does not have to attach again each time.
- extended Discontinuous Reception (eDRX) - the device only listens periodically for a pending message. Without eDRX a device listens every few seconds; with eDRX the cycle for NB-IoT can stretch to about 2.9 hours, against about 43 minutes for LTE-M.
The network decides which values the device actually gets, and roaming SIMs are sometimes not granted PSM or eDRX at all. Field measurements show that network settings such as the inactivity timer after a connection often matter more than the choice between NB-IoT and LTE-M. In good coverage, LTE-M can even use less energy per message thanks to its higher speed; NB-IoT wins at the cell edge and deep indoors.
🔄 What is the difference between NB-IoT, LTE-M and LoRaWAN?
The choice between these LPWA technologies shapes much of the architecture of an IoT solution.
| Property | NB-IoT | LTE-M | LoRaWAN |
|---|---|---|---|
| Spectrum | Licensed (operator) | Licensed (operator) | Unlicensed (868 MHz in Europe) |
| Channel width | 180 kHz | 1.4 MHz | 125 kHz typical |
| Data rate | approx. 26 kbps (NB1) to 127 kbps (NB2) | approx. 1 Mbps | 0.3 to 50 kbps |
| Latency | approx. 1.5 to 10 seconds | 10-15 ms | Seconds, depending on class |
| Coverage (MCL) | 164 dB | 155.7 dB | Comparable, depending on spreading factor |
| Mobility | Limited, no handover during a connection (Release 13) | Handover during a connection | Limited |
| Voice | No | Yes (VoLTE) | No |
| Infrastructure | Operator, SIM subscription | Operator, SIM subscription | Own or public gateways |
The rule of thumb: NB-IoT for stationary devices with very little data in hard-to-reach places, LTE-M for moving or interactive devices, and LoRaWAN when you want to run the infrastructure yourself without per-SIM costs. The QoS of an operator network is more predictable than that of an unlicensed network, but it offers no guarantees for control.
🏭 Where is NB-IoT used in industry and infrastructure?
- Water and energy - water meters, gas meters, heat meters in district heating, tank level measurement, cathodic protection of pipelines, pressure in distribution networks and telemetry from small pumping stations without their own mains supply.
- Condition Monitoring and Predictive Maintenance - vibration and temperature sensors on pumps, transformers and fans that send feature values rather than raw waveforms.
- Building Automation - HVAC monitoring, energy metering, smoke detectors and occupancy sensors in buildings without Wi-Fi.
- Manufacturing and logistics - status messages from dispersed automation assets, silos and containers at a fixed location.
NB-IoT is not suitable for motion control, safety functions or closed-loop control: delays run into seconds and the network is outside your control. Video, large firmware files and high-rate real-time data do not fit either.
🔧 How do you connect NB-IoT data to OT systems?
An NB-IoT device sends small messages, often via CoAP or MQTT (MQTT-SN), secured with DTLS or TLS. Operators also offer Non-IP Data Delivery, where the message travels over the mobile network’s signalling instead of IP; this saves energy and shrinks the device’s attack surface. The chain to OT usually looks like this:
- Reception - a private APN or VPN carries the traffic to an IoT platform or broker in the cloud or in a DMZ.
- Translation - a gateway at the edge or in the data centre converts the data to OPC UA or to the historian data model.
- Use - SCADA, maintenance systems and analytics tools use the values for monitoring, reporting and maintenance planning.
Never let the NB-IoT path end directly in the control network. Reception belongs in a separate zone behind an industrial firewall, in line with network segmentation and the zones and conduits model of IEC 62443.
🔐 How secure is NB-IoT and which measures are needed?
NB-IoT inherits the security of LTE: mutual authentication between SIM and network, and 128-bit encryption and integrity protection. That is a stronger baseline than many unlicensed LPWAN technologies provide. The protection does end in the operator’s network, however; after that your own chain is responsible.
| Risk | Consequence | Measure |
|---|---|---|
| Stolen or misused SIM | Costs, unauthorised access | Bind the SIM to the device, private APN, usage alerts |
| Compromised or cloned device | False telemetry, stepping stone to the backend | Device certificates, secure boot, signed firmware |
| Fake base stations and jamming | Outage or manipulated connection | End-to-end encryption, detection of missing messages |
| Vulnerable cloud or broker | Data breach, manipulated commands | hardening, logging, security monitoring |
| Dependence on the operator | Outage outside your control | Local buffering, SLA agreements, multi-mode modules |
Include NB-IoT devices in your asset inventory and configuration management, manage certificates centrally and plan patch management for modem firmware. Because updates over a narrow channel are slow, the update strategy belongs in the device selection. NIST SP 800-82 describes similar requirements for wireless access to industrial systems, and the entire chain falls under your governance for cybersecurity.
🧭 How do you select and deploy NB-IoT in the Netherlands?
In the Netherlands, T-Mobile (now Odido) launched NB-IoT at the end of October 2016 in Amsterdam, Rotterdam, The Hague, Eindhoven and around Schiphol, and announced nationwide coverage for 2017. Vodafone tested NB-IoT on 800 MHz and rolled it out from May 2017. KPN chose LoRaWAN and LTE-M instead. Coverage and offerings therefore differ per operator, and they are not guaranteed to last: in the United States, AT&T announced in 2024 that it would shut down its NB-IoT network in early 2025 and move customers to LTE-M. At the same time 2G is disappearing: Odido switched it off in 2023 and KPN stops on 1 December 2027, so many GPRS modems in RTUs, metering cabinets and alarm systems need a successor. For the water sector this is a concrete point of attention within OT security in the water sector.
A practical step-by-step plan:
- Define the profile per application: message size, frequency, required response time, mobility and power supply.
- Test coverage at the real location, including meter pits and metal cabinets, and measure consumption with the actual network settings.
- Ask the operator about the supported release, PSM and eDRX values, roaming and the roadmap of the NB-IoT network over a lifecycle of ten years or more.
- Choose multi-mode modules (NB-IoT and LTE-M) so you can switch if coverage or offerings change.
- Design the chain securely according to IEC 62443 and record who manages devices, SIMs and certificates.
Regulation matters too. For organisations covered by NIS2 and the Dutch Cybersecurity Act (Cyberbeveiligingswet, in force since 15 August 2026), wireless telemetry links fall within the duty of care. Manufacturers of NB-IoT devices face the Cyber Resilience Act, with reporting obligations from 11 September 2026 and full application from 11 December 2027. Readings from household smart meters can also be personal data, which brings the AVG (the Dutch name for the GDPR) into play.
❓ Frequently asked questions
Is NB-IoT part of 5G?
NB-IoT was standardised as an LTE technology in 3GPP Release 13, but the ITU recognises NB-IoT and LTE-M as 5G technologies for massive machine-type communication (mMTC). Later releases allow connection to the 5G Core. NB-IoT equipment therefore remains usable in 5G networks.
How long does a battery last in an NB-IoT device?
An NB-IoT device that uses PSM and eDRX and sends a small message a few times a day can run for ten years or more on a single battery. Poor coverage, many repetitions and frequent firmware updates shorten that considerably. Always measure consumption at the real location with the actual network settings.
What is the difference between NB-IoT and LTE-M?
NB-IoT uses a 180 kHz channel, reaches tens to just over a hundred kbps and penetrates deeper into buildings, but has delays of seconds and no handover during a connection. LTE-M uses 1.4 MHz, reaches about 1 Mbps with 10-15 ms latency and supports movement and voice. Rule of thumb: NB-IoT for stationary meters, LTE-M for mobile and interactive devices.
Is NB-IoT suitable for process control?
NB-IoT is suitable for monitoring, alarms and meter reading, but not for control or safety functions. Latency runs into seconds and the network is managed by an operator. The control loop should stay local in a PLC or RTU.
What does NB-IoT cost and who provides it?
NB-IoT runs on a SIM subscription from a mobile operator, usually with a low monthly fee per device and a limited data bundle. In the Netherlands, T-Mobile (now Odido) and Vodafone offered NB-IoT, while KPN chose LoRa and LTE-M. Besides price, compare coverage, supported power-saving features and the expected lifetime of the network.
Does NB-IoT work abroad?
NB-IoT roaming is less widely available than regular mobile roaming, and power-saving features are sometimes not granted when roaming. Not every country has an NB-IoT network, and some only offer LTE-M. For international deployments, a multi-mode module with NB-IoT and LTE-M is therefore the safest choice.
📌 In summary
NB-IoT is the 3GPP-standardised cellular LPWA technology that uses a 180 kHz channel, 164 dB coverage and sleep modes such as PSM and eDRX to send small readings from the most difficult locations for ten years on a single battery. It is the natural choice for stationary meters and sensors, provided the connection ends in a separate zone, devices are managed centrally and control stays local.
Within industrial automation and OT convergence, NB-IoT fills the gaps where cables, Wi-Fi and 5G are not cost-effective, and together with LTE-M and LoRaWAN it forms the wireless foundation for large-scale IoT.