LTE-M vs NB-IoT: An Overview

Ever since IoT first hit the scene, everyone has been trying to predict the future: How many billions of devices will we have, when will we all be connected, and what sort of technology will we need? The short answer is that we will eventually have billions and billions of devices connecting pretty much everything, but when it comes to business, many will need technology designed specifically for IoT – in other words, businesses are going to need low power wide area (LPWA) technology. But what are the choices when it comes to LPWA – and what are the differences between them?

Low Power Wide Area (LPWA) technology is not a technology standard, but rather a class of wireless technologies particularly suited to the specific needs of IoT. The majority of IoT devices, such as those in smart city and industrial sectors, don’t require the same bandwidth and speed as consumer cellular devices.  

LPWA Network (LPWAN) technologies offer cost and power-efficient options that leverage existing networks while also having strong built-in security and a global reach, enabling low power consumption and long-range wireless connectivity.  LPWAN technologies also support data transfer of small intermittent data packets ranging from 10 to 1000 bytes. And because they operate with better power and bandwidth efficiency over a larger area, less infrastructure and hardware are required, leading to greater cost efficiency.  

LPWAN technologies also allow IoT devices to reliably operate for up to 10 years on a single battery charge, which is ideal for remote solutions that lack a reliable power source. These include:  

• Smart city applications 
• Track & trace
• Smart agriculture
• Smart buildings
• Smart meters 

While both LTE-M and NB-IoT are good connectivity options for industries in need of LPWA technology, and there are many similarities between the two, there are also some key differences.  

LTE-M 

LTE-M (also called eMTC and Cat-M1) leverages existing LTE networks to allow for highly efficient connectivity with extended coverage indoors and underground. It consumes less battery power and allows for cheaper modem costs thanks to design simplification. It supports downlink and uplink speeds of up to 1 Mbps with a latency of 50-100 ms, which makes it very flexible and ideal for real-time communication.  

• Efficient battery usage
• Real-time communication
• High data transfer rates
• Full mobility: Ideal for both fixed & mobile applications 
• Supports VoLTE (Voice over Long-term Evolution) 

NB-IoT 

Narrow band IoT features up to 10 years of battery life and the widest possible network coverage and can support a large number of new connections using only a portion of the available spectrum. While it also offers potentially less expensive modules, this comes at a price: latency is 1.5 to 10 seconds – it does not allow real-time or voice communication.  

• 10+ years battery life
• High latency
• Low data transfer rates
• Ideal for stationary/static devices (no connected mobility)
• Does not support VoLTE 

Ultimately, the technology you choose will depend on your use case and the challenges you want to address. For asset tracking, data throughput is small, but mobility is needed as objects move. When it comes to smart meters, on the other hand, use-cases typically require data transfer once or twice a day. Understanding the specific requirements and nuances of your use case will help you understand which connectivity option is best for you.