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The cellular carriers are now deploying two variations of the Internet of Things (IoT) technology. The first to launch was the NB-IoT offering which went live in August 2019 with Bell Canada. Shortly afterwards and into 2020, several carriers started to offer the LTE-M (LTE CAT-M1) offering.

Neither uses much bandwidth, so they can run on less powerful hardware with lower-cost data plans while still improving range and extending battery life. How are the two protocols different from each other? In a nutshell, NB-IoT offers low bandwidth data connections at low cost and is currently Europe-focused, while LTE-M is optimized for higher bandwidth and mobile connections, including voice. It will start rolling out in North America. Let’s take a look at the details.

LTE-M has higher throughput with lower latency and battery use is optimized accordingly. It works on-the-go, so it’s appropriate for applications in transportation and supply-chain tracking. It can also carry voice for applications such as residential security systems. NB-IoT is designed for lower data rates, where small delays are fine.

For example, a smart meter sending infrequent updates from a fixed location. Its battery use is optimized for that type of situation.

Both operate using a single antenna, simplifying your designs. Since NB-IoT was debut first in European markets, while LTE-M will roll out starting here in North America, system location could be your deciding factor between these two related protocols. While LTE-M and NB-IoT networks are still being built, you can get started today with Digi XBee Cellular on LTE Cat 1, a higher bandwidth protocol. Then, seamlessly switch over to an XBee cellular LTE-M or NB-IoT device as those networks roll out.


Cat-M (officially known as LTE Cat-M1) is often viewed as the second generation of LTE chips built for IoT applications. It completes the cost and power consumption reduction for which Cat-0 originally set the stage. By capping the maximum system bandwidth at 1.4 MHz (as opposed to the full cellular carrier bandwidth of 20 MHz), Cat-M has specific use cases for LPWAN applications like smart metering, in which only small amount of data transfer is required.

But the real advantage of Cat-M over other options lies in this: Cat-M is compatible with the existing LTE network. For carriers such as Verizon, AT&T, Telus, Rogers, and Bell, this is great news as they don’t have to spend money to build new antennas, although meshing Cat-M into LTE networks requires a software patch. The existing customer bases of these carriers will most likely conclude that Cat-M is by far the superior option. Lastly, it’s almost certain that 5G and LTE technologies will coexist well into the 2020s, so the backward-compatibility of Cat-M is a bonus.

LTE-M operates inside the existing 4G and 5G spectrum so it is said to operate ‘in-band’.


NB-IoT (also called Cat-M2) has a goal similar to that of Cat-M; however, it uses DSSS modulation instead of LTE radios. Therefore, NB-IoT doesn’t operate in the LTE band, which means that providers have a higher upfront cost to deploy NB-IoT.

Nonetheless, NB-IoT is being touted as the potentially less expensive option, because it eliminates the need for a gateway. Other infrastructures typically have gateways that aggregate sensor data, which then communicates with the primary server. With NB-IoT, however, sensor data is sent directly to the primary server. For that reason, Huawei, Ericsson, Qualcomm, and Vodafone are actively investing in commercial applications of NB-IoT. Sierra Wireless predicts that by the end of 2018, NB-IoT and LTE-M will be available in many global regions.

NB-IoT operates outside the existing 4G and 5G spectrum so it is said to operate ‘out-of-band’.

5G Cellular and IoT

5G is almost here, and like 2G, 3G, and 4G before it, it will change the way we send and receive information.

What’s even more exciting is that 5G will enable countless automated wireless applications for the rapidly growing Internet of Things (IoT) market.  By 2025, more than 75 billion devices will be connected to the Internet of Things, from disposable tracking devices used in shipping pharmaceuticals and perishables to smart city lighting and utilities.

With so much bandwidth needed for such a large-scale deployment of connections, low-power wide-area (LPWA) solutions will clear the path for smooth, uninterrupted operations in a speedy, 5G-centered technoverse.

Mobile IoT technologies, such as Long-Term Evolution machine-type communications (LTE-M) and Narrowband IoT (NB-IoT), deliver secure and cost-effective LPWA capability today and are catalysts in the future of 5G integration and growth worldwide.

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Dyaks, B. (2019). NB-IoT and LTE-M: Cellular IoT for a 5G World. Telit. Retrieve on April 13, 2020 from,

Faludi, R. (2017). What are the Differences Between LTE-M and NB-IoT Cellular Protocols? Digi. Retrieve on April 13, 2020 from,

Hwang, Y. (2020). Cellular IoT Explained – NB-IoT vs. LTE-M vs. 5G and More. IoT for All. Retrieve on April 13, 2020 from,

————————–MJM ————————–

About the Author:

Michael Martin has more than 35 years of experience in systems design for applications that use broadband networks, optical fibre, wireless, and digital communications technologies.

He is a business and technology consultant. A recent contract was with Wirepas from Tampere, Finland as the Director of Business Development. Over the past 15 years with IBM, he has worked in the GBS Global Center of Competency for Energy and Utilities and the GTS Global Center of Excellence for Energy and Utilities. He is a founding partner and President of MICAN Communications and before that was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation (CYN: TSX).

Martin currently serves on the Board of Directors for TeraGo Inc (TGO: TSX) and previously served on the Board of Directors for Avante Logixx Inc. (XX: TSX.V). 

He has served as a Member, SCC ISO-IEC JTC 1/SC-41 – Internet of Things and related technologies, ISO – International Organization for Standardization, and as a member of the NIST SP 500-325 Fog Computing Conceptual Model, National Institute of Standards and Technology.

He served on the Board of Governors of the University of Ontario Institute of Technology (UOIT) [now OntarioTech University] and on the Board of Advisers of five different Colleges in Ontario.  For 16 years he served on the Board of the Society of Motion Picture and Television Engineers (SMPTE), Toronto Section. 

He holds three master’s degrees, in business (MBA), communication (MA), and education (MEd). As well, he has three undergraduate diplomas and five certifications in business, computer programming, internetworking, project management, media, photography, and communication technology. He has earned 15 badges in next generation MOOC continuous education in IoT, Cloud, AI and Cognitive systems, Blockchain, Agile, Big Data, Design Thinking, Security, and more.