The promise of low-power IoT connectivity is compelling: deploy battery-powered devices that run for 10+ years without battery changes, connecting to cellular networks optimized for small data packets and infrequent updates. LTE-M and NB-IoT deliver on this promise, but they are fundamentally different technologies suited to different use cases.
Choose incorrectly and you will either waste battery life with unnecessary capability and cost, or discover your devices cannot do what you need. This guide explains the technical differences between LTE-M and NB-IoT, when to use each, and how to make the right choice for your deployment.
What are LTE-M and NB-IoT?
Both are Low Power Wide Area cellular technologies standardised by 3GPP for IoT applications. Both operate on licensed cellular spectrum, unlike LoRaWAN or Sigfox which use unlicensed spectrum. Both are designed to offer 10+ year battery life for IoT devices.
The key difference is that LTE-M is a simplified version of LTE optimised for IoT, while NB-IoT is a fundamentally different technology designed for very simple, static devices.
LTE-M (LTE Cat-M1)
Full name: LTE Category M1
3GPP release: Release 13 (2016)
Bandwidth: 1.4 MHz
Peak speed: 1 Mbps (downlink and uplink)
Latency: 10 to 15 ms
Mobility support: Yes, up to 160 km/h
Voice support: Yes, via VoLTE
Power saving: PSM and eDRX
LTE-M is a simplified version of standard LTE. It uses narrower bandwidth compared to standard LTE, which reduces device complexity and power consumption while maintaining key features such as mobility and voice.
NB-IoT (LTE Cat-NB1)
Full name: Narrowband IoT, also called LTE Cat-NB1 or Cat-NB2
3GPP release: Release 13 (2016), enhanced in Releases 14 to 16
Bandwidth: 200 kHz
Peak speed: 20 to 250 kbps depending on category and conditions
Latency: 1.6 to 10 seconds
Mobility support: Limited
Voice support: No
Power saving: PSM and eDRX
NB-IoT is designed for very simple devices sending small amounts of data infrequently. It trades throughput and latency for improved power efficiency and coverage.
Technical comparison
Data throughput
LTE-M supports up to 1 Mbps and is suitable for moderate data applications such as GPS tracking with frequent updates, firmware downloads, and low resolution image transmission.
NB-IoT supports 20 to 250 kbps depending on configuration and is suited to low data applications such as smart meter readings and sensor data with infrequent updates and small payloads.
Practical impact: If your device needs to send more than a few kilobytes per hour or requires firmware updates, LTE-M is the better choice. For simple periodic sensor readings, NB-IoT is sufficient.
Latency
LTE-M offers latency of 10 to 15 milliseconds, enabling near real-time communication, alerts, and interactive applications including voice.
NB-IoT latency ranges from 1.6 to 10 seconds, which is acceptable for periodic reporting and delay tolerant applications.
Practical impact: If your application requires sub second responsiveness, use LTE-M. If delays of seconds are acceptable, NB-IoT is suitable.
Coverage and penetration
Both technologies improve coverage compared to standard LTE, but NB-IoT has an advantage.
LTE-M offers around 11 km rural range with a link budget of approximately 156 dB.
NB-IoT offers around 15 km rural range with a link budget of approximately 164 dB.
NB-IoT performs better in deep indoor environments such as basements and building cores.
Practical impact: For challenging environments or deep indoor deployments, NB-IoT provides stronger coverage. For outdoor or typical indoor use, both perform well.
Mobility support
LTE-M supports full mobility, allowing devices to move while connected and hand off between cell towers.
NB-IoT is designed for stationary or slow moving devices and may experience disruption during movement.
Practical impact: For moving assets or vehicles, LTE-M is required. For fixed devices, NB-IoT is appropriate.
Voice support
LTE-M supports voice via VoLTE, enabling voice communication and emergency services access.
NB-IoT does not support voice.
Practical impact: If voice capability is required, LTE-M is the only option.
Power consumption
Both technologies support long battery life using PSM and eDRX. NB-IoT has a slight advantage.
Typical battery life assuming low data usage:
LTE-M: 10 to 15 years
NB-IoT: 10 to 20 years
Practical impact: For very long lifecycle deployments where battery replacement is difficult, NB-IoT may offer benefits. For most use cases, both meet long life requirements.
Cost comparison
Module cost:
LTE-M: approximately £5 to £15
NB-IoT: approximately £3 to £10
Network cost: typically £2 to £8 per device per month, with similar pricing across both technologies.
Practical impact: The difference in module cost becomes meaningful at large scale, but network costs are broadly similar.
Network availability
LTE-M is widely deployed in North America, Europe, and Australia, with growing adoption elsewhere.
NB-IoT has broader global deployment, particularly in Europe, Asia-Pacific, and the Middle East.
Practical impact: Availability varies by market. Always confirm which technologies are supported in your deployment regions.
Use case decision matrix
Use LTE-M when
Mobility is required
Moderate data volumes are needed
Low latency is important
Voice capability is required
Typical examples include fleet telematics, asset tracking, wearable devices, and connected vehicles.
Use NB-IoT when
Devices are stationary
Data volumes are very low
Deep indoor or remote coverage is critical
Ultra long battery life is a priority
Typical examples include smart meters, environmental sensors, and infrastructure monitoring.
Hybrid approach: multi mode devices
Some modules support both LTE-M and NB-IoT.
Advantages include broader coverage, flexibility across use cases, and future proofing.
Disadvantages include higher cost, increased complexity, and slightly higher power usage.
Use multi mode where deployments span multiple regions or requirements may change over time.
Migration from 2G and 3G
As legacy networks are retired, IoT deployments must migrate.
If devices move while transmitting, migrate to LTE-M or LTE Cat-1.
If devices are stationary with low data needs, migrate to NB-IoT.
If higher throughput is required, consider LTE Cat-1.
Start migration at least 12 months before network shutdowns and consider eSIM for flexibility.
Making your decision
Start with your core requirements:
Mobility
Data volume
Latency
Coverage conditions
Voice requirements
Battery life
Network availability
Decision logic:
If mobility is required, use LTE-M
If voice is required, use LTE-M
If higher data or low latency is needed, use LTE-M
If deep indoor coverage is critical, use NB-IoT
Otherwise, either may be suitable depending on availability and cost
OV support for LTE-M and NB-IoT
OV provides both LTE-M and NB-IoT connectivity, enabling builders to choose the right technology for their deployment.
With coverage across 180+ countries and access to 600+ networks, devices can connect globally through a single partner.
Flexible SIM options support both technologies, allowing devices to select the most appropriate network based on availability and configuration.
The OV ONE platform gives teams control over their connectivity estate, with real time visibility, API integration, and SIM lifecycle management from a single interface.
If you are evaluating LTE-M versus NB-IoT, the most practical next step is to test both in your real deployment environment.
Contact OV to discuss your use case or request a trial SIM to validate performance in the field.
