Understanding 4G/5G Cat M1 / NB-IoT GPS

The (5G) 5th Generation cellular network technology boasts super-fast speeds, improved responsiveness, and extremely low latency.

However. With the emergence of 5G, you might think, “What about those amazing 4G GPS tracking devices I just bought?”

4G / 5G – Gee, this is confusing

The GPS tracking devices or sensors you attach to your assets are useless without a way to communicate the data they collect – location, temperature, on/off status, etc.

Cellular IoT connects devices using existing mobile networks, which makes sense considering 95% of the global population lives in an area covered by at least a primary 2G network.

Most IoT and GPS devices, especially those installed on assets that don’t move very often, do not require the same speed or bandwidth as consumer cellular devices, which transmit huge, rich data packets. Cellular IoT networks, then, send small packets of simple data periodically, for example, the GPS coordinates of an asset once a day.

So, when we talk about our 4G GPS Tracking device range, we refer to Cellular IoT networks, specifically LTE-M and NB-IoT, which were initially introduced as part of the 4G-LTE specification 2016. Cellular IoT networks are low-power, wide-area networks (LPWANs) that enable incredibly long battery life, better coverage and range, and low-cost hardware and connectivity options.

The latest news is that both 4G LTE-M and NB-IoT networks are now formally recognized as 5G technologies, which means the networks and our LTE-M / NB-IoT devices will be supported long after 4G network shutdowns (which aren’t anticipated for quite a while).

Mobile Connectivity Evolution of Industrial Value

Image: From 2G to 5G: The history of mobile connectivity

We suggest you check out GSMA’s article on Mobile IoT in the 5G Future for a more in-depth look at evolving LTE specifications.

What’s the difference between LTE-M and NB-IoT?

So now that we know LTE-M and NB-IoT networks are here to stay for the foreseeable future, what are the differences between the two?

Both LTE-M (often also referred to as Cat-M1) and Narrowband IoT (NB-IoT) are Cellular IoT networks explicitly used for Internet of Things and Machine to Machine (M2M) applications.

Bandwidth – NB-IoT uses a narrow bandwidth (200kHz) compared to LTE-M, which uses 1.4GHz (7000x larger)! Bandwidth is the width or capacity of the channel in which data can be transferred. Think lanes on a freeway – more streets mean more cars can get along the highway in a given period. Bandwidth is the width of the road here.

Data Transfer Rate – Due to NB-IoT’s narrow bandwidth, the maximum data transfer rate is around 250kb per second. The data rate on LTE-M is about four times faster – up to 1Mbps.

Cellular Tower Handover – LTE-M supports cell tower handover, which refers to transferring a connection from one cellular tower to another. NB-IoT does not support cell tower handover, and the link will be dropped if a device moves out of range.

Range – Both networks provide excellent coverage and penetration, particularly when compared to 2G or 3G networks.

Power – An NB-IoT modem uses less energy to transfer data than an LTE-M modem. But because of NB-IoT’s slower data transfer rates, uploads take longer than LTE-M. So, power consumption on either network is similar and very low.

Firmware Over-The-Air – Device firmware can be updated remotely on both networks. However, more extensive OTA updates on NB-IoT may result in substantial power use, given the network’s slow transfer rate.

Cellular IoT in Tracking Applications

In tracking, NB-IoT is well suited for sensor monitoring and data logging applications, where a very high volume (hundreds to thousands) of generally stationary assets report infrequently.

* Is the fire alarm powered – Yes

* Is the emergency exit sign powered – Yes

* Soil moisture – 22%

Because NB-IoT devices operate on a smaller bandwidth, they are also less complex and often more affordable to produce: Simpler antennas and less complicated firmware cater to the ability to affordably install and operate hundreds, if not thousands, of devices.

LTE-M is better suited for tracking vehicles, trailers, equipment, cold chain monitoring, or other tracking applications where assets are frequently moving and more significant volumes of monitoring data are required.

NB-IoT vs Cat-M1

Image: LTE-M vs. NB-IoT: What are the Differences?

Global Deployments 

As of August 2020, GSMA reports 43 LTE-M Networks and 96 NB-IoT Networks worldwide. You can check NB-IoT and LTE-M Cellular IoT deployments in The USA.

Our experience as of August 2020 with both networks can be summarized as follows:

LTE-M on the SIM’s home network: Highly confident and very well-proven.

LTE-M with a roaming SIM: With the correct Access Point Name (APN) settings, secure and well-proven.

NB-IoT on the SIM’s home network: Experience varies greatly between networks and regions. Significant testing should be completed before deployment.

NB-IoT with a roaming SIM: We have yet to see this work but hope to have an update soon as network roaming agreements progress.

In deploying thousands of LTE-M and NB-IoT devices, we have found LTE-M to be more mature and better supported globally. In the US, US Mobile coverage has been reliable and extensive. In Australia, Telstra coverage has also been reliable and comprehensive. In both the US and Australia, LTE-M has proven to be a suitable replacement for 3G, and we confidently supply devices for use on both networks.

We have had varied success with NB-IoT, specifically facing challenges around standards as operators continue deploying their networks. In fact, we recently released new firmware and a Wired Provisioning Tool to simplify NB-IoT deployments. Europe is the primary driver for this technology, and each territory has different challenges. Global roaming SIM cards are more prevalent in these regions, and these also pose a variety of technical challenges.

NB-IoT roaming has also not proven successful, so using a ‘non-home network’ SIM is risky. Roaming triggers NB-IoT network scans, which are very battery-intensive and costly in applications with essential battery life.

As a US Mobile GSM network, our business is looking to deploy Cellular IoT asset-tracking solutions. It’s a good idea to familiarize yourself with the strengths and weaknesses of LTE-M and NB-IoT and their availability in your region. For more information on cellular connectivity or our LTE-M / NB-IoT GPS asset tracking device range, please contact us here.