When it comes to cellular IoT, customers can opt to have devices roam on regular 2/3/4 and 5G networks or opt for technologies specifically designed for IoT, such as LTE-M (Long-Term Evolution for Machines) and NB-IoT (Narrowband Internet of Things). Both are Low Power Wide Area Network (LPWAN) technologies based on the 4G LTE standard, sharing core technologies and access to network infrastructure, whilst also gearing toward low costs, energy saving and high range/high penetration rate.
What are the key differences?
LTE-M is designed for IoT applications with higher data rates, lower latency, mobility, and voice support, while NB-IoT is optimized for low-power, low-data-rate IoT applications that prioritize long battery life and deep indoor coverage. View the table below to see some of the key differences to consider when designing your IoT connectivity solution.
| NB-IoT | LTE-M | |
|---|---|---|
| Downlink | Low. 26 kbit/s (Cat-NB1) 127 kbit/s (Cat-NB2) |
High. 1 Mbit/s (Cat-M1) 4 Mbit/s (Cat-M2) |
| Uplink | Low. 66 kbit/s (Cat-NB1) 159 kbit/s (Cat-NB2) |
High. 1 Mbit/s (Cat-M1) 7 Mbit/s (Cat-M2) |
| Coverage/Penetration | Great coverage and penetration. | Great coverage and penetration. |
| Roaming capability | Less roaming possibility | Roaming available |
| Module costs | Low cost, cheaper than LTE-M. | Low cost, but more expensive than NB-IoT. |
| Energy saving | PSM and eDRX | PSM and eDRX |
| Mobility | No handover possible | Handover possible |
| Typical use cases | Lighting, parking management, smart meters | Asset tracking, video surveillance |
| Voice & SMS | No voice, SMS sometimes supported | Voice and SMS supported |
| eSIM | Technically suitable for eSIM, but without SMS profiles can’t be changed | Suitable for eSIM |
How are LTE-M and NB-IoT reducing energy consumption?
To reduce the impact on the battery life of IoT devices, LTE-M and NB-IoT use features, such as, Power Saving Mode (PSM), where the device alternates standby and active phases, and Extended Discontinous Reception (eDRX), which has longer standby phases than PSM. During the standby phase, the device will save battery by not registering to a network for a fixed amount of time, before checking for new incoming messages.
What is the best fit if I have a device that moves across countries?
It’s important to consider if your device is static or non-static. For NB-IoT, handover is not possible, so mobility is limited, whereas LTE-M is suitable for both static and non-static devices.
Which is the technology with lower latency?
LTE-M is better suited to higher data rates and real-time data transmission. Whilst, NB-IoT has higher energy-saving capabilities, it also has higher latency.
Ultimately, which technology is the best fit depends on your use case. Would you like to learn more? Contact us at hello@theiotguide.com or through our contact form.
